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skia2/site/user/api/SkMatrix_Reference.md
Cary Clark 2be81cf973 Condense embedded formulas. 
Bookmaker delimits formulas and equations to allow
representing variables and symbols without tripping
up reference lookup, spell checking, and comment
generation.

Before, formulas were represented with:
some text
#Formula
(x + y, 0)
##
, and more text

This made it difficult to know when spacing should
be preserved before and after the formula. Now,
formulas are represented with:
some text #Formula # (x + y, 0) ##, and more text

The presence or absence of a space between ## and ,
is now significant (before it was not).

Also, formulas are bracketed by <code> in markdown
generation, so that variables stand out better.
See:
https://skia.org/user/api/SkBlendMode_Reference?cl=152781#Dst_Out
for an example.

Also fixed 100 column offenders and added a code
check to identify them. For the moment, 100 column
offenders are outed with SkDebugf but their presence
does not cause bookmaker to fail.

TBR=caryclark@google.com

Docs-Preview: https://skia.org/?cl=152781
Bug: skia:6898
Change-Id: If92a65a234f5d616bf4485984a8d219a6f04821a
Reviewed-on: https://skia-review.googlesource.com/152781
Commit-Queue: Cary Clark <caryclark@skia.org>
Auto-Submit: Cary Clark <caryclark@skia.org>
Reviewed-by: Cary Clark <caryclark@skia.org>
2018-09-13 16:50:25 +00:00

5772 lines
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SkMatrix Reference
===
# <a name='Matrix'>Matrix</a>
# <a name='SkMatrix'>Class SkMatrix</a>
## <a name='Constant'>Constant</a>
SkMatrix related constants are defined by <code>enum</code>, <code>enum class</code>, <code>#define</code>, <code>const</code>, and <code>constexpr</code>.
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_ScaleToFit'>ScaleToFit</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>options to map <a href='SkRect_Reference#Rect'>Rects</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_TypeMask'>TypeMask</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>bit field for <a href='#Matrix'>Matrix</a> complexity</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kAScaleX'>kAScaleX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kAScaleY'>kAScaleY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical scale factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kASkewX'>kASkewX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal skew factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kASkewY'>kASkewY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kATransX'>kATransX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kATransY'>kATransY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical translation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kAffine_Mask'>kAffine Mask</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>skew or rotate <a href='#Matrix'>Matrix</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kCenter_ScaleToFit'>kCenter ScaleToFit</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>scales and aligns to center</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kEnd_ScaleToFit'>kEnd ScaleToFit</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>scales and aligns to right and bottom</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kFill_ScaleToFit'>kFill ScaleToFit</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>scales in x and y to fill destination <a href='SkRect_Reference#Rect'>Rect</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kIdentity_Mask'>kIdentity Mask</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>identity <a href='#Matrix'>Matrix</a>; all bits clear</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMPersp0'>kMPersp0</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>input x perspective factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMPersp1'>kMPersp1</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>input y perspective factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMPersp2'>kMPersp2</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>perspective bias</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMScaleX'>kMScaleX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMScaleY'>kMScaleY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical scale factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMSkewX'>kMSkewX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal skew factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMSkewY'>kMSkewY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMTransX'>kMTransX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMTransY'>kMTransY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical translation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kPerspective_Mask'>kPerspective Mask</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>perspective <a href='#Matrix'>Matrix</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kScale_Mask'>kScale Mask</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>scale <a href='#Matrix'>Matrix</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kStart_ScaleToFit'>kStart ScaleToFit</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>scales and aligns to left and top</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kTranslate_Mask'>kTranslate Mask</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>translation <a href='#Matrix'>Matrix</a></td>
</tr>
</table>
<a href='#Matrix'>Matrix</a> holds a 3x3 matrix for transforming coordinates. This allows mapping
<a href='SkPoint_Reference#Point'>Points</a> and <a href='SkPoint_Reference#Vector'>Vectors</a> with translation, scaling, skewing, rotation, and
perspective.
<a href='#Matrix'>Matrix</a> elements are in row major order. <a href='#Matrix'>Matrix</a> does not have a constructor,
so it must be explicitly initialized. <a href='#SkMatrix_setIdentity'>setIdentity</a> initializes <a href='#Matrix'>Matrix</a>
so it has no effect. <a href='#SkMatrix_setTranslate'>setTranslate</a>, <a href='#SkMatrix_setScale'>setScale</a>, <a href='#SkMatrix_setSkew'>setSkew</a>, <a href='#SkMatrix_setRotate'>setRotate</a>, <a href='#SkMatrix_set9'>set9</a> and <a href='#SkMatrix_setAll'>setAll</a>
initializes all <a href='#Matrix'>Matrix</a> elements with the corresponding mapping.
<a href='#Matrix'>Matrix</a> includes a hidden variable that classifies the type of matrix to
improve performance. <a href='#Matrix'>Matrix</a> is not thread safe unless <a href='#SkMatrix_getType'>getType</a> is called first.
## Overview
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Constant'>Constants</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>enum and enum class, and their const values</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Constructor'>Constructors</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>functions that construct <a href='#SkMatrix'>SkMatrix</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Member_Function'>Functions</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>global and class member functions</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Operator'>Operators</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>operator overloading methods</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Related_Function'>Related Functions</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>similar member functions grouped together</td>
</tr>
</table>
## <a name='Member_Function'>Member Function</a>
SkMatrix member functions read and modify the structure properties.
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_Concat'>Concat</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns the concatenation of <a href='#Matrix'>Matrix</a> pair</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>I</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns a reference to a const identity <a href='#Matrix'>Matrix</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_InvalidMatrix'>InvalidMatrix</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns a reference to a const invalid <a href='#Matrix'>Matrix</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_MakeAll'>MakeAll</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>constructs all nine values</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>constructs from source <a href='SkRect_Reference#Rect'>Rect</a> to destination <a href='SkRect_Reference#Rect'>Rect</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_MakeScale'>MakeScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>constructs from scale in x and y</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_MakeTrans'>MakeTrans</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>constructs from translate in x and y</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets 3x2 array to identity</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_asAffine'>asAffine</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>copies to 3x2 array</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_cheapEqualTo'>cheapEqualTo</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>compares <a href='#Matrix'>Matrix</a> pair using memcmp()</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_decomposeScale'>decomposeScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>separates scale if possible</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_dirtyMatrixTypeCache'>dirtyMatrixTypeCache</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets internal cache to unknown state</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_dump'>dump</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sends text representation using floats to standard output</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_fixedStepInX'>fixedStepInX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns step in x for a position in y</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_get'>get</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns one of nine <a href='#Matrix'>Matrix</a> values</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_get9'>get9</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns all nine <a href='#Matrix'>Matrix</a> values</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getMaxScale'>getMaxScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns maximum scaling, if possible</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getMinMaxScales'>getMinMaxScales</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns minimum and maximum scaling, if possible</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getMinScale'>getMinScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns minimum scaling, if possible</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getPerspX'>getPerspX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns input x perspective factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getPerspY'>getPerspY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns input y perspective factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getScaleX'>getScaleX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns horizontal scale factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getScaleY'>getScaleY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns vertical scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getSkewX'>getSkewX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns horizontal skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getSkewY'>getSkewY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns vertical skew factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getTranslateX'>getTranslateX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns horizontal translation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getTranslateY'>getTranslateY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns vertical translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getType'>getType</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns transform complexity</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_hasPerspective'>hasPerspective</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if transform includes perspective</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_invert'>invert</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns inverse, if possible</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isFinite'>isFinite</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if all <a href='#Matrix'>Matrix</a> values are not infinity, NaN</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if transformation supports fixed step in x</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isIdentity'>isIdentity</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if matrix equals the identity <a href='#Matrix'>Matrix</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if transform is limited to scale and translate</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isSimilarity'>isSimilarity</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if transform is limited to square scale and rotation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isTranslate'>isTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if transform is limited to translate</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapHomogeneousPoints'>mapHomogeneousPoints</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='undocumented#Point3'>Point3</a> array</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapPoints'>mapPoints</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='SkPoint_Reference#Point'>Point</a> array</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRadius'>mapRadius</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns mean radius of mapped <a href='undocumented#Circle'>Circle</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRect'>mapRect</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns bounds of mapped <a href='SkRect_Reference#Rect'>Rect</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns bounds of mapped <a href='SkRect_Reference#Rect'>Rect</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRectToQuad'>mapRectToQuad</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='SkRect_Reference#Rect'>Rect</a> to <a href='SkPoint_Reference#Point'>Point</a> array</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapVector'>mapVector</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='SkPoint_Reference#Vector'>Vector</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapVectors'>mapVectors</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='SkPoint_Reference#Vector'>Vector</a> array</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapXY'>mapXY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='SkPoint_Reference#Point'>Point</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postConcat'>postConcat</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by <a href='#Matrix'>Matrix</a> parameter</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postIDiv'>postIDiv</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by inverse scale</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postRotate'>postRotate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by rotation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postScale'>postScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by scale</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postSkew'>postSkew</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by skew</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postTranslate'>postTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preConcat'>preConcat</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pre-multiplies <a href='#Matrix'>Matrix</a> by <a href='#Matrix'>Matrix</a> parameter</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preRotate'>preRotate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pre-multiplies <a href='#Matrix'>Matrix</a> by rotation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preScale'>preScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pre-multiplies <a href='#Matrix'>Matrix</a> by scale</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preSkew'>preSkew</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pre-multiplies <a href='#Matrix'>Matrix</a> by skew</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preTranslate'>preTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pre-multiplies <a href='#Matrix'>Matrix</a> by translation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preservesAxisAlignment'>preservesAxisAlignment</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if mapping restricts to 90 degree multiples and mirroring</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if mapped 90 angle remains 90 degrees</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_rectStaysRect'>rectStaysRect</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if mapped <a href='SkRect_Reference#Rect'>Rect</a> can be represented by another <a href='SkRect_Reference#Rect'>Rect</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_reset'>reset</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets <a href='#Matrix'>Matrix</a> to identity</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_set'>set</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets one value</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_set9'>set9</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets all values from <a href='undocumented#Scalar'>Scalar</a> array</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setAffine'>setAffine</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets left two columns</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setAll'>setAll</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets all values from parameters</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setConcat'>setConcat</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to <a href='#Matrix'>Matrix</a> parameter multiplied by <a href='#Matrix'>Matrix</a> parameter</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setIdentity'>setIdentity</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets <a href='#Matrix'>Matrix</a> to identity</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setPerspX'>setPerspX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets input x perspective factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setPerspY'>setPerspY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets input y perspective factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to map one to four points to an equal array of points</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setRSXform'>setRSXform</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to rotate, scale, and translate</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setRectToRect'>setRectToRect</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to map one <a href='SkRect_Reference#Rect'>Rect</a> to another</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setRotate'>setRotate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to rotate about a point</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setScale'>setScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to scale about a point</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setScaleTranslate'>setScaleTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to scale and translate</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setScaleX'>setScaleX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets horizontal scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setScaleY'>setScaleY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets vertical scale factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSinCos'>setSinCos</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to rotate and scale about a point</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSkew'>setSkew</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to skew about a point</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSkewX'>setSkewX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets horizontal skew factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSkewY'>setSkewY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets vertical skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setTranslate'>setTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to translate in x and y</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setTranslateX'>setTranslateX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets horizontal translation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setTranslateY'>setTranslateY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets vertical translation</td>
</tr>
</table>
## <a name='Related_Function'>Related Function</a>
SkMatrix global, <code>struct</code>, and <code>class</code> related member functions share a topic.
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#AffineIndex'>AffineIndex</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>affine member indices</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#MemberIndex'>MemberIndex</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>member indices</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Property'>Property</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>values and attributes</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Set'>Set</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets one or more matrix values</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Transform'>Transform</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>map points with <a href='#Matrix'>Matrix</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Utility'>Utility</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>rarely called management functions</td>
</tr>
</table>
## <a name='Constructor'>Constructor</a>
SkMatrix can be constructed or initialized by these functions, including C++ class constructors.
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>I</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns a reference to a const identity <a href='#Matrix'>Matrix</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_InvalidMatrix'>InvalidMatrix</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns a reference to a const invalid <a href='#Matrix'>Matrix</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_MakeAll'>MakeAll</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>constructs all nine values</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>constructs from source <a href='SkRect_Reference#Rect'>Rect</a> to destination <a href='SkRect_Reference#Rect'>Rect</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_MakeScale'>MakeScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>constructs from scale in x and y</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_MakeScale'>MakeScale(SkScalar sx, SkScalar sy)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_MakeScale_2'>MakeScale(SkScalar scale)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_MakeTrans'>MakeTrans</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>constructs from translate in x and y</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets 3x2 array to identity</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_asAffine'>asAffine</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>copies to 3x2 array</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_reset'>reset</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets <a href='#Matrix'>Matrix</a> to identity</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setAffine'>setAffine</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets left two columns</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setConcat'>setConcat</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to <a href='#Matrix'>Matrix</a> parameter multiplied by <a href='#Matrix'>Matrix</a> parameter</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setIdentity'>setIdentity</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets <a href='#Matrix'>Matrix</a> to identity</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setRSXform'>setRSXform</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to rotate, scale, and translate</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setRotate'>setRotate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to rotate about a point</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setRotate'>setRotate(SkScalar degrees, SkScalar px, SkScalar py)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setRotate_2'>setRotate(SkScalar degrees)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setScale'>setScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to scale about a point</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setScale'>setScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setScale_2'>setScale(SkScalar sx, SkScalar sy)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setScaleTranslate'>setScaleTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to scale and translate</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSinCos'>setSinCos</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to rotate and scale about a point</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSinCos'>setSinCos(SkScalar sinValue, SkScalar cosValue, SkScalar px, SkScalar py)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSinCos_2'>setSinCos(SkScalar sinValue, SkScalar cosValue)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSkew'>setSkew</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to skew about a point</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSkew'>setSkew(SkScalar kx, SkScalar ky, SkScalar px, SkScalar py)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSkew_2'>setSkew(SkScalar kx, SkScalar ky)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setTranslate'>setTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to translate in x and y</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setTranslate'>setTranslate(SkScalar dx, SkScalar dy)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setTranslate_2'>setTranslate(const SkVector& v)</a></td>
</tr>
</table>
<a name='SkMatrix_MakeScale'></a>
## MakeScale
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
static <a href='#SkMatrix'>SkMatrix</a> SK_WARN_UNUSED_RESULT <a href='#SkMatrix_MakeScale'>MakeScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy)
</pre>
Sets <a href='#Matrix'>Matrix</a> to scale by (<a href='#SkMatrix_MakeScale_sx'>sx</a>, <a href='#SkMatrix_MakeScale_sy'>sy</a>). Returned matrix is:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| sx 0 0 |
| 0 sy 0 |
| 0 0 1 |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_MakeScale_sx'><code><strong>sx</strong></code></a></td>
<td>horizontal scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_MakeScale_sy'><code><strong>sy</strong></code></a></td>
<td>vertical scale factor</td>
</tr>
</table>
### Return Value
<a href='#Matrix'>Matrix</a> with scale
### Example
<div><fiddle-embed name="7ff17718111df6d6f95381d8a8f1b389"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_postScale'>postScale</a><sup><a href='#SkMatrix_postScale_2'>[2]</a></sup> <a href='#SkMatrix_preScale'>preScale</a><sup><a href='#SkMatrix_preScale_2'>[2]</a></sup>
---
<a name='SkMatrix_MakeScale_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
static <a href='#SkMatrix'>SkMatrix</a> SK_WARN_UNUSED_RESULT <a href='#SkMatrix_MakeScale'>MakeScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> scale)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#SkMatrix_MakeScale_2_scale'>scale</a> by (<a href='#SkMatrix_MakeScale_2_scale'>scale</a>, <a href='#SkMatrix_MakeScale_2_scale'>scale</a>). Returned matrix is:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| scale 0 0 |
| 0 scale 0 |
| 0 0 1 |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_MakeScale_2_scale'><code><strong>scale</strong></code></a></td>
<td>horizontal and vertical <a href='#SkMatrix_MakeScale_2_scale'>scale</a> factor</td>
</tr>
</table>
### Return Value
<a href='#Matrix'>Matrix</a> with <a href='#SkMatrix_MakeScale_2_scale'>scale</a>
### Example
<div><fiddle-embed name="2956aeb50fa862cdb13995e1e56a4bc8"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_postScale'>postScale</a><sup><a href='#SkMatrix_postScale_2'>[2]</a></sup> <a href='#SkMatrix_preScale'>preScale</a><sup><a href='#SkMatrix_preScale_2'>[2]</a></sup>
---
<a name='SkMatrix_MakeTrans'></a>
## MakeTrans
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
static <a href='#SkMatrix'>SkMatrix</a> SK_WARN_UNUSED_RESULT <a href='#SkMatrix_MakeTrans'>MakeTrans</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy)
</pre>
Sets <a href='#Matrix'>Matrix</a> to translate by (<a href='#SkMatrix_MakeTrans_dx'>dx</a>, <a href='#SkMatrix_MakeTrans_dy'>dy</a>). Returned matrix is:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 1 0 dx |
| 0 1 dy |
| 0 0 1 |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_MakeTrans_dx'><code><strong>dx</strong></code></a></td>
<td>horizontal translation</td>
</tr>
<tr> <td><a name='SkMatrix_MakeTrans_dy'><code><strong>dy</strong></code></a></td>
<td>vertical translation</td>
</tr>
</table>
### Return Value
<a href='#Matrix'>Matrix</a> with translation
### Example
<div><fiddle-embed name="b2479df0d9cf296ff64ac31e36684557"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setTranslate'>setTranslate</a><sup><a href='#SkMatrix_setTranslate_2'>[2]</a></sup> <a href='#SkMatrix_postTranslate'>postTranslate</a> <a href='#SkMatrix_preTranslate'>preTranslate</a>
---
<a name='SkMatrix_MakeAll'></a>
## MakeAll
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
static <a href='#SkMatrix'>SkMatrix</a> SK_WARN_UNUSED_RESULT <a href='#SkMatrix_MakeAll'>MakeAll</a>(<a href='undocumented#SkScalar'>SkScalar</a> scaleX, <a href='undocumented#SkScalar'>SkScalar</a> skewX, <a href='undocumented#SkScalar'>SkScalar</a> transX,
<a href='undocumented#SkScalar'>SkScalar</a> skewY, <a href='undocumented#SkScalar'>SkScalar</a> scaleY, <a href='undocumented#SkScalar'>SkScalar</a> transY,
<a href='undocumented#SkScalar'>SkScalar</a> pers0, <a href='undocumented#SkScalar'>SkScalar</a> pers1, <a href='undocumented#SkScalar'>SkScalar</a> pers2)
</pre>
Sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| scaleX skewX transX |
| skewY scaleY transY |
| pers0 pers1 pers2 |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_MakeAll_scaleX'><code><strong>scaleX</strong></code></a></td>
<td>horizontal scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_MakeAll_skewX'><code><strong>skewX</strong></code></a></td>
<td>horizontal skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_MakeAll_transX'><code><strong>transX</strong></code></a></td>
<td>horizontal translation</td>
</tr>
<tr> <td><a name='SkMatrix_MakeAll_skewY'><code><strong>skewY</strong></code></a></td>
<td>vertical skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_MakeAll_scaleY'><code><strong>scaleY</strong></code></a></td>
<td>vertical scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_MakeAll_transY'><code><strong>transY</strong></code></a></td>
<td>vertical translation</td>
</tr>
<tr> <td><a name='SkMatrix_MakeAll_pers0'><code><strong>pers0</strong></code></a></td>
<td>input x-axis perspective factor</td>
</tr>
<tr> <td><a name='SkMatrix_MakeAll_pers1'><code><strong>pers1</strong></code></a></td>
<td>input y-axis perspective factor</td>
</tr>
<tr> <td><a name='SkMatrix_MakeAll_pers2'><code><strong>pers2</strong></code></a></td>
<td>perspective scale factor</td>
</tr>
</table>
### Return Value
<a href='#Matrix'>Matrix</a> constructed from parameters
### Example
<div><fiddle-embed name="6bad83b64de9266e323c29d550e04188"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setAll'>setAll</a> <a href='#SkMatrix_set9'>set9</a> <a href='#SkMatrix_postConcat'>postConcat</a> <a href='#SkMatrix_preConcat'>preConcat</a>
---
## <a name='SkMatrix_TypeMask'>Enum SkMatrix::TypeMask</a>
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
enum <a href='#SkMatrix_TypeMask'>TypeMask</a> {
<a href='#SkMatrix_kIdentity_Mask'>kIdentity Mask</a> = 0,
<a href='#SkMatrix_kTranslate_Mask'>kTranslate Mask</a> = 0x01,
<a href='#SkMatrix_kScale_Mask'>kScale Mask</a> = 0x02,
<a href='#SkMatrix_kAffine_Mask'>kAffine Mask</a> = 0x04,
<a href='#SkMatrix_kPerspective_Mask'>kPerspective Mask</a> = 0x08,
};
</pre>
Enum of bit fields for mask returned by <a href='#SkMatrix_getType'>getType</a>.
Used to identify the complexity of <a href='#Matrix'>Matrix</a>, to optimize performance.
### Constants
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Const</th>
<th style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>Value</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kIdentity_Mask'><code>SkMatrix::kIdentity_Mask</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>0</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
all bits clear if <a href='#Matrix'>Matrix</a> is identity</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kTranslate_Mask'><code>SkMatrix::kTranslate_Mask</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>1</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
set if <a href='#Matrix'>Matrix</a> has translation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kScale_Mask'><code>SkMatrix::kScale_Mask</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>2</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
set if <a href='#Matrix'>Matrix</a> has x or y scale</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kAffine_Mask'><code>SkMatrix::kAffine_Mask</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>4</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
set if <a href='#Matrix'>Matrix</a> skews or rotates</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kPerspective_Mask'><code>SkMatrix::kPerspective_Mask</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>8</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
set if <a href='#Matrix'>Matrix</a> has perspective</td>
</tr>
</table>
### Example
<div><fiddle-embed name="ba19b36df8cd78586f3dff54e2d4c093">
#### Example Output
~~~~
after reset: kIdentity_Mask
after postTranslate: kTranslate_Mask
after postScale: kTranslate_Mask kScale_Mask
after postScale: kTranslate_Mask kScale_Mask kAffine_Mask
after setPolyToPoly: kTranslate_Mask kScale_Mask kAffine_Mask kPerspective_Mask
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_getType'>getType</a>
## <a name='Property'>Property</a>
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_decomposeScale'>decomposeScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>separates scale if possible</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_fixedStepInX'>fixedStepInX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns step in x for a position in y</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_get'>get</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns one of nine <a href='#Matrix'>Matrix</a> values</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_get9'>get9</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns all nine <a href='#Matrix'>Matrix</a> values</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getMaxScale'>getMaxScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns maximum scaling, if possible</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getMinMaxScales'>getMinMaxScales</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns minimum and maximum scaling, if possible</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getMinScale'>getMinScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns minimum scaling, if possible</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getPerspX'>getPerspX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns input x perspective factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getPerspY'>getPerspY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns input y perspective factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getScaleX'>getScaleX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns horizontal scale factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getScaleY'>getScaleY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns vertical scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getSkewX'>getSkewX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns horizontal skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getSkewY'>getSkewY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns vertical skew factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getTranslateX'>getTranslateX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns horizontal translation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getTranslateY'>getTranslateY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns vertical translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_getType'>getType</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns transform complexity</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_hasPerspective'>hasPerspective</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if transform includes perspective</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isFinite'>isFinite</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if all <a href='#Matrix'>Matrix</a> values are not infinity, NaN</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if transformation supports fixed step in x</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isIdentity'>isIdentity</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if matrix equals the identity <a href='#Matrix'>Matrix</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if transform is limited to scale and translate</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isSimilarity'>isSimilarity</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if transform is limited to square scale and rotation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_isTranslate'>isTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if transform is limited to translate</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preservesAxisAlignment'>preservesAxisAlignment</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if mapping restricts to 90 degree multiples and mirroring</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if mapped 90 angle remains 90 degrees</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_rectStaysRect'>rectStaysRect</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns if mapped <a href='SkRect_Reference#Rect'>Rect</a> can be represented by another <a href='SkRect_Reference#Rect'>Rect</a></td>
</tr>
</table>
<a name='SkMatrix_getType'></a>
## getType
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='#SkMatrix_TypeMask'>TypeMask</a> <a href='#SkMatrix_getType'>getType</a>() const
</pre>
Returns a bit field describing the transformations the matrix may
perform. The bit field is computed conservatively, so it may include
false positives. For example, when <a href='#SkMatrix_kPerspective_Mask'>kPerspective Mask</a> is set, all
other bits are set.
### Return Value
<a href='#SkMatrix_kIdentity_Mask'>kIdentity Mask</a>, or combinations of: <a href='#SkMatrix_kTranslate_Mask'>kTranslate Mask</a>, <a href='#SkMatrix_kScale_Mask'>kScale Mask</a>,
<a href='#SkMatrix_kAffine_Mask'>kAffine Mask</a>, <a href='#SkMatrix_kPerspective_Mask'>kPerspective Mask</a>
### Example
<div><fiddle-embed name="8e45fe2dd52731bb2d4318686257e1d7">
#### Example Output
~~~~
identity flags hex: 0 decimal: 0
set all flags hex: f decimal: 15
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_TypeMask'>TypeMask</a>
---
<a name='SkMatrix_isIdentity'></a>
## isIdentity
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_isIdentity'>isIdentity</a>() const
</pre>
Returns true if <a href='#Matrix'>Matrix</a> is identity. Identity matrix is:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 1 0 0 |
| 0 1 0 |
| 0 0 1 |
</pre>
### Return Value
true if <a href='#Matrix'>Matrix</a> has no effect
### Example
<div><fiddle-embed name="780ab376325b3cfa889ea26c0769ec11">
#### Example Output
~~~~
is identity: true
is identity: false
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_reset'>reset</a> <a href='#SkMatrix_setIdentity'>setIdentity</a> <a href='#SkMatrix_getType'>getType</a>
---
<a name='SkMatrix_isScaleTranslate'></a>
## isScaleTranslate
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a>() const
</pre>
Returns true if <a href='#Matrix'>Matrix</a> at most scales and translates. <a href='#Matrix'>Matrix</a> may be identity,
contain only scale elements, only translate elements, or both. <a href='#Matrix'>Matrix</a> form is:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| scale-x 0 translate-x |
| 0 scale-y translate-y |
| 0 0 1 |
</pre>
### Return Value
true if <a href='#Matrix'>Matrix</a> is identity; or scales, translates, or both
### Example
<div><fiddle-embed name="6287e29674a487eb94174992d45b9a34">
#### Example Output
~~~~
is scale-translate: true
is scale-translate: true
is scale-translate: true
is scale-translate: true
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_isTranslate'>isTranslate</a> <a href='#SkMatrix_setTranslate'>setTranslate</a><sup><a href='#SkMatrix_setTranslate_2'>[2]</a></sup> <a href='#SkMatrix_getType'>getType</a>
---
<a name='SkMatrix_isTranslate'></a>
## isTranslate
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_isTranslate'>isTranslate</a>() const
</pre>
Returns true if <a href='#Matrix'>Matrix</a> is identity, or translates. <a href='#Matrix'>Matrix</a> form is:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 1 0 translate-x |
| 0 1 translate-y |
| 0 0 1 |
</pre>
### Return Value
true if <a href='#Matrix'>Matrix</a> is identity, or translates
### Example
<div><fiddle-embed name="73ac71a8a30841873577c11c6c9b38ee">
#### Example Output
~~~~
is translate: true
is translate: true
is translate: false
is translate: false
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_setTranslate'>setTranslate</a><sup><a href='#SkMatrix_setTranslate_2'>[2]</a></sup> <a href='#SkMatrix_getType'>getType</a>
---
<a name='SkMatrix_rectStaysRect'></a>
## rectStaysRect
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>() const
</pre>
Returns true <a href='#Matrix'>Matrix</a> maps <a href='SkRect_Reference#Rect'>Rect</a> to another <a href='SkRect_Reference#Rect'>Rect</a>. If true, <a href='#Matrix'>Matrix</a> is identity,
or scales, or rotates a multiple of 90 degrees, or mirrors on axes. In all
cases, <a href='#Matrix'>Matrix</a> may also have translation. <a href='#Matrix'>Matrix</a> form is either:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| scale-x 0 translate-x |
| 0 scale-y translate-y |
| 0 0 1 |
</pre>
or
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 0 rotate-x translate-x |
| rotate-y 0 translate-y |
| 0 0 1 |
</pre>
for non-zero values of scale-x, scale-y, rotate-x, and rotate-y.
Also called <a href='#SkMatrix_preservesAxisAlignment'>preservesAxisAlignment</a>; use the one that provides better inline
documentation.
### Return Value
true if <a href='#Matrix'>Matrix</a> maps one <a href='SkRect_Reference#Rect'>Rect</a> into another
### Example
<div><fiddle-embed name="ce5319c036c9b5086da8a0009fe409f8">
#### Example Output
~~~~
rectStaysRect: true
rectStaysRect: true
rectStaysRect: true
rectStaysRect: true
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_preservesAxisAlignment'>preservesAxisAlignment</a> <a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a>
---
<a name='SkMatrix_preservesAxisAlignment'></a>
## preservesAxisAlignment
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_preservesAxisAlignment'>preservesAxisAlignment</a>() const
</pre>
Returns true <a href='#Matrix'>Matrix</a> maps <a href='SkRect_Reference#Rect'>Rect</a> to another <a href='SkRect_Reference#Rect'>Rect</a>. If true, <a href='#Matrix'>Matrix</a> is identity,
or scales, or rotates a multiple of 90 degrees, or mirrors on axes. In all
cases, <a href='#Matrix'>Matrix</a> may also have translation. <a href='#Matrix'>Matrix</a> form is either:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| scale-x 0 translate-x |
| 0 scale-y translate-y |
| 0 0 1 |
</pre>
or
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 0 rotate-x translate-x |
| rotate-y 0 translate-y |
| 0 0 1 |
</pre>
for non-zero values of scale-x, scale-y, rotate-x, and rotate-y.
Also called <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>; use the one that provides better inline
documentation.
### Return Value
true if <a href='#Matrix'>Matrix</a> maps one <a href='SkRect_Reference#Rect'>Rect</a> into another
### Example
<div><fiddle-embed name="7a234c96608fb7cb8135b9940b0b15f7">
#### Example Output
~~~~
preservesAxisAlignment: true
preservesAxisAlignment: true
preservesAxisAlignment: true
preservesAxisAlignment: true
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_rectStaysRect'>rectStaysRect</a> <a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a>
---
<a name='SkMatrix_hasPerspective'></a>
## hasPerspective
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_hasPerspective'>hasPerspective</a>() const
</pre>
Returns true if the matrix contains perspective elements. <a href='#Matrix'>Matrix</a> form is:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| -- -- -- |
| -- -- -- |
| perspective-x perspective-y perspective-scale |
</pre>
where perspective-x or perspective-y is non-zero, or perspective-scale is
not one. All other elements may have any value.
### Return Value
true if <a href='#Matrix'>Matrix</a> is in most general form
### Example
<div><fiddle-embed name="688123908c733169bbbfaf11f41ecff6"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setAll'>setAll</a> <a href='#SkMatrix_set9'>set9</a> <a href='#SkMatrix_MakeAll'>MakeAll</a>
---
<a name='SkMatrix_isSimilarity'></a>
## isSimilarity
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_isSimilarity'>isSimilarity</a>(<a href='undocumented#SkScalar'>SkScalar</a> tol = <a href='undocumented#SK_ScalarNearlyZero'>SK ScalarNearlyZero</a>) const
</pre>
Returns true if <a href='#Matrix'>Matrix</a> contains only translation, rotation, reflection, and
uniform scale.
Returns false if <a href='#Matrix'>Matrix</a> contains different scales, skewing, perspective, or
degenerate forms that collapse to a line or point.
Describes that the <a href='#Matrix'>Matrix</a> makes rendering with and without the matrix are
visually alike; a transformed circle remains a circle. Mathematically, this is
referred to as similarity of a <a href='undocumented#Euclidean_Space'>Euclidean Space</a>, or a similarity transformation.
Preserves right angles, keeping the arms of the angle equal lengths.
### Parameters
<table> <tr> <td><a name='SkMatrix_isSimilarity_tol'><code><strong>tol</strong></code></a></td>
<td>to be deprecated</td>
</tr>
</table>
### Return Value
true if <a href='#Matrix'>Matrix</a> only rotates, uniformly scales, translates
### Example
<div><fiddle-embed name="8b37f4ae7fec1756433c0f984175fb14"><div><a href='undocumented#String'>String</a> is drawn four times through but only two are visible. Drawing the pair
with <a href='#SkMatrix_isSimilarity'>isSimilarity</a> false reveals the pair not visible through the matrix.
</div></fiddle-embed></div>
### See Also
<a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a> <a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a> <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a> <a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a>
---
<a name='SkMatrix_preservesRightAngles'></a>
## preservesRightAngles
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_preservesRightAngles'>preservesRightAngles</a>(<a href='undocumented#SkScalar'>SkScalar</a> tol = <a href='undocumented#SK_ScalarNearlyZero'>SK ScalarNearlyZero</a>) const
</pre>
Returns true if <a href='#Matrix'>Matrix</a> contains only translation, rotation, reflection, and
scale. Scale may differ along rotated axes.
Returns false if <a href='#Matrix'>Matrix</a> skewing, perspective, or degenerate forms that collapse
to a line or point.
Preserves right angles, but not requiring that the arms of the angle
retain equal lengths.
### Parameters
<table> <tr> <td><a name='SkMatrix_preservesRightAngles_tol'><code><strong>tol</strong></code></a></td>
<td>to be deprecated</td>
</tr>
</table>
### Return Value
true if <a href='#Matrix'>Matrix</a> only rotates, scales, translates
### Example
<div><fiddle-embed name="b9becf0dc24a9f00726e24a81fb72f16"><div>Equal scale is both similar and preserves right angles.
Unequal scale is not similar but preserves right angles.
Skews are not similar and do not preserve right angles.
</div></fiddle-embed></div>
### See Also
<a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a> <a href='#SkMatrix_isSimilarity'>isSimilarity</a> <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a> <a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a>
---
## <a name='MemberIndex'>MemberIndex</a>
### Constants
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Const</th>
<th style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>Value</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMScaleX'><code>SkMatrix::kMScaleX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>0</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMSkewX'><code>SkMatrix::kMSkewX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>1</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMTransX'><code>SkMatrix::kMTransX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>2</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMSkewY'><code>SkMatrix::kMSkewY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>3</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMScaleY'><code>SkMatrix::kMScaleY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>4</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMTransY'><code>SkMatrix::kMTransY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>5</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical translation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMPersp0'><code>SkMatrix::kMPersp0</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>6</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>input x perspective factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMPersp1'><code>SkMatrix::kMPersp1</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>7</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>input y perspective factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kMPersp2'><code>SkMatrix::kMPersp2</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>8</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>perspective bias</td>
</tr>
</table>
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
static constexpr int <a href='#SkMatrix_kMScaleX'>kMScaleX</a> = 0;
static constexpr int <a href='#SkMatrix_kMSkewX'>kMSkewX</a> = 1;
static constexpr int <a href='#SkMatrix_kMTransX'>kMTransX</a> = 2;
static constexpr int <a href='#SkMatrix_kMSkewY'>kMSkewY</a> = 3;
static constexpr int <a href='#SkMatrix_kMScaleY'>kMScaleY</a> = 4;
static constexpr int <a href='#SkMatrix_kMTransY'>kMTransY</a> = 5;
static constexpr int <a href='#SkMatrix_kMPersp0'>kMPersp0</a> = 6;
static constexpr int <a href='#SkMatrix_kMPersp1'>kMPersp1</a> = 7;
static constexpr int <a href='#SkMatrix_kMPersp2'>kMPersp2</a> = 8;
</pre>
<a href='#Matrix'>Matrix</a> organizes its values in row order. These members correspond to
each value in <a href='#Matrix'>Matrix</a>.
### Constants
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Const</th>
<th style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>Value</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMScaleX'><code>SkMatrix::kMScaleX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>0</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
horizontal scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMSkewX'><code>SkMatrix::kMSkewX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>1</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
horizontal skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMTransX'><code>SkMatrix::kMTransX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>2</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
horizontal translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMSkewY'><code>SkMatrix::kMSkewY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>3</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
vertical skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMScaleY'><code>SkMatrix::kMScaleY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>4</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
vertical scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMTransY'><code>SkMatrix::kMTransY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>5</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
vertical translation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMPersp0'><code>SkMatrix::kMPersp0</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>6</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
input x perspective factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMPersp1'><code>SkMatrix::kMPersp1</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>7</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
input y perspective factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kMPersp2'><code>SkMatrix::kMPersp2</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>8</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
perspective bias</td>
</tr>
</table>
### Example
<div><fiddle-embed name="3bbf75f4748420810aa2586e3c8548d9"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_set'>set</a>
## <a name='AffineIndex'>AffineIndex</a>
### Constants
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Const</th>
<th style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>Value</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kAScaleX'><code>SkMatrix::kAScaleX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>0</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kASkewY'><code>SkMatrix::kASkewY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>1</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kASkewX'><code>SkMatrix::kASkewX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>2</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal skew factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kAScaleY'><code>SkMatrix::kAScaleY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>3</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical scale factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kATransX'><code>SkMatrix::kATransX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>4</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>horizontal translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_kATransY'><code>SkMatrix::kATransY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>5</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>vertical translation</td>
</tr>
</table>
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
static constexpr int <a href='#SkMatrix_kAScaleX'>kAScaleX</a> = 0;
static constexpr int <a href='#SkMatrix_kASkewY'>kASkewY</a> = 1;
static constexpr int <a href='#SkMatrix_kASkewX'>kASkewX</a> = 2;
static constexpr int <a href='#SkMatrix_kAScaleY'>kAScaleY</a> = 3;
static constexpr int <a href='#SkMatrix_kATransX'>kATransX</a> = 4;
static constexpr int <a href='#SkMatrix_kATransY'>kATransY</a> = 5;
</pre>
Affine arrays are in column major order to match the matrix used by
PDF and XPS.
### Constants
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Const</th>
<th style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>Value</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kAScaleX'><code>SkMatrix::kAScaleX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>0</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
horizontal scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kASkewY'><code>SkMatrix::kASkewY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>1</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
vertical skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kASkewX'><code>SkMatrix::kASkewX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>2</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
horizontal skew factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kAScaleY'><code>SkMatrix::kAScaleY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>3</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
vertical scale factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kATransX'><code>SkMatrix::kATransX</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>4</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
horizontal translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kATransY'><code>SkMatrix::kATransY</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>5</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
vertical translation</td>
</tr>
</table>
### See Also
<a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a> <a href='#SkMatrix_asAffine'>asAffine</a> <a href='#SkMatrix_setAffine'>setAffine</a>
## <a name='Operator'>Operator</a>
SkMatrix operators inline class member functions with arithmetic equivalents.
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_Concat'>Concat</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns the concatenation of <a href='#Matrix'>Matrix</a> pair</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_cheapEqualTo'>cheapEqualTo</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>compares <a href='#Matrix'>Matrix</a> pair using memcmp()</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_invert'>invert</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns inverse, if possible</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_notequal_operator'>operator!=(const SkMatrix& a, const SkMatrix& b)</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns true if members are unequal</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_equal_operator'>operator==(const SkMatrix& a, const SkMatrix& b)</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns true if members are equal</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_array1_operator'>operator[](int index)</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns writable reference to <a href='#Matrix'>Matrix</a> value</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_array_operator'>operator[](int index) const</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns <a href='#Matrix'>Matrix</a> value</td>
</tr>
</table>
<a name='SkMatrix_array_operator'></a>
## operator[]
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_array1_operator'>operator[](int index)</a> _const
</pre>
Returns one matrix value. Asserts if <a href='#SkMatrix_array_operator_index'>index</a> is out of range and SK_DEBUG is
defined.
### Parameters
<table> <tr> <td><a name='SkMatrix_array_operator_index'><code><strong>index</strong></code></a></td>
<td>one of: <a href='#SkMatrix_kMScaleX'>kMScaleX</a>, <a href='#SkMatrix_kMSkewX'>kMSkewX</a>, <a href='#SkMatrix_kMTransX'>kMTransX</a>, <a href='#SkMatrix_kMSkewY'>kMSkewY</a>, <a href='#SkMatrix_kMScaleY'>kMScaleY</a>, <a href='#SkMatrix_kMTransY'>kMTransY</a>,
<a href='#SkMatrix_kMPersp0'>kMPersp0</a>, <a href='#SkMatrix_kMPersp1'>kMPersp1</a>, <a href='#SkMatrix_kMPersp2'>kMPersp2</a></td>
</tr>
</table>
### Return Value
value corresponding to <a href='#SkMatrix_array_operator_index'>index</a>
### Example
<div><fiddle-embed name="e8740493abdf0c6341762db9cee56b89">
#### Example Output
~~~~
matrix[SkMatrix::kMScaleX] == 42
matrix[SkMatrix::kMScaleY] == 24
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_set'>set</a>
---
<a name='SkMatrix_get'></a>
## get
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_get'>get</a>(int index) const
</pre>
Returns one matrix value. Asserts if <a href='#SkMatrix_get_index'>index</a> is out of range and SK_DEBUG is
defined.
### Parameters
<table> <tr> <td><a name='SkMatrix_get_index'><code><strong>index</strong></code></a></td>
<td>one of: <a href='#SkMatrix_kMScaleX'>kMScaleX</a>, <a href='#SkMatrix_kMSkewX'>kMSkewX</a>, <a href='#SkMatrix_kMTransX'>kMTransX</a>, <a href='#SkMatrix_kMSkewY'>kMSkewY</a>, <a href='#SkMatrix_kMScaleY'>kMScaleY</a>, <a href='#SkMatrix_kMTransY'>kMTransY</a>,
<a href='#SkMatrix_kMPersp0'>kMPersp0</a>, <a href='#SkMatrix_kMPersp1'>kMPersp1</a>, <a href='#SkMatrix_kMPersp2'>kMPersp2</a></td>
</tr>
</table>
### Return Value
value corresponding to <a href='#SkMatrix_get_index'>index</a>
### Example
<div><fiddle-embed name="f5ed382bd04fa7d50b2398cce2fca23a">
#### Example Output
~~~~
matrix.get(SkMatrix::kMSkewX) == 42
matrix.get(SkMatrix::kMSkewY) == 24
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_array1_operator'>operator[](int index)</a> <a href='#SkMatrix_set'>set</a>
---
<a name='SkMatrix_getScaleX'></a>
## getScaleX
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getScaleX'>getScaleX</a>() const
</pre>
Returns scale factor multiplied by x-axis input, contributing to x-axis output.
With <a href='#SkMatrix_mapPoints'>mapPoints</a>, scales <a href='SkPoint_Reference#Point'>Points</a> along the x-axis.
### Return Value
horizontal scale factor
### Example
<div><fiddle-embed name="ab746d9be63975041ae8e50cba84dc3d">
#### Example Output
~~~~
matrix.getScaleX() == 42
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getScaleY'>getScaleY</a> <a href='#SkMatrix_setScaleX'>setScaleX</a> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup>
---
<a name='SkMatrix_getScaleY'></a>
## getScaleY
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getScaleY'>getScaleY</a>() const
</pre>
Returns scale factor multiplied by y-axis input, contributing to y-axis output.
With <a href='#SkMatrix_mapPoints'>mapPoints</a>, scales <a href='SkPoint_Reference#Point'>Points</a> along the y-axis.
### Return Value
vertical scale factor
### Example
<div><fiddle-embed name="708b1a548a2f8661b2ab570782fbc751">
#### Example Output
~~~~
matrix.getScaleY() == 24
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getScaleX'>getScaleX</a> <a href='#SkMatrix_setScaleY'>setScaleY</a> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup>
---
<a name='SkMatrix_getSkewY'></a>
## getSkewY
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getSkewY'>getSkewY</a>() const
</pre>
Returns scale factor multiplied by x-axis input, contributing to y-axis output.
With <a href='#SkMatrix_mapPoints'>mapPoints</a>, skews <a href='SkPoint_Reference#Point'>Points</a> along the y-axis.
Skewing both axes can rotate <a href='SkPoint_Reference#Point'>Points</a>.
### Return Value
vertical skew factor
### Example
<div><fiddle-embed name="6be5704506d029ffc91ba03b1d3e674b">
#### Example Output
~~~~
matrix.getSkewY() == 24
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getSkewX'>getSkewX</a> <a href='#SkMatrix_setSkewY'>setSkewY</a> <a href='#SkMatrix_setSkew'>setSkew</a><sup><a href='#SkMatrix_setSkew_2'>[2]</a></sup>
---
<a name='SkMatrix_getSkewX'></a>
## getSkewX
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getSkewX'>getSkewX</a>() const
</pre>
Returns scale factor multiplied by y-axis input, contributing to x-axis output.
With <a href='#SkMatrix_mapPoints'>mapPoints</a>, skews <a href='SkPoint_Reference#Point'>Points</a> along the x-axis.
Skewing both axes can rotate <a href='SkPoint_Reference#Point'>Points</a>.
### Return Value
horizontal scale factor
### Example
<div><fiddle-embed name="df3a5d3c688e7597eae1e4e07bf91ae6">
#### Example Output
~~~~
matrix.getSkewX() == 42
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getSkewY'>getSkewY</a> <a href='#SkMatrix_setSkewX'>setSkewX</a> <a href='#SkMatrix_setSkew'>setSkew</a><sup><a href='#SkMatrix_setSkew_2'>[2]</a></sup>
---
<a name='SkMatrix_getTranslateX'></a>
## getTranslateX
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getTranslateX'>getTranslateX</a>() const
</pre>
Returns translation contributing to x-axis output.
With <a href='#SkMatrix_mapPoints'>mapPoints</a>, moves <a href='SkPoint_Reference#Point'>Points</a> along the x-axis.
### Return Value
horizontal translation factor
### Example
<div><fiddle-embed name="6236f7f2b91aff977a66ba2ee2558ca4">
#### Example Output
~~~~
matrix.getTranslateX() == 42
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getTranslateY'>getTranslateY</a> <a href='#SkMatrix_setTranslateX'>setTranslateX</a> <a href='#SkMatrix_setTranslate'>setTranslate</a><sup><a href='#SkMatrix_setTranslate_2'>[2]</a></sup>
---
<a name='SkMatrix_getTranslateY'></a>
## getTranslateY
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getTranslateY'>getTranslateY</a>() const
</pre>
Returns translation contributing to y-axis output.
With <a href='#SkMatrix_mapPoints'>mapPoints</a>, moves <a href='SkPoint_Reference#Point'>Points</a> along the y-axis.
### Return Value
vertical translation factor
### Example
<div><fiddle-embed name="08464e32d22421d2b254c71a84545ef5">
#### Example Output
~~~~
matrix.getTranslateY() == 24
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_getTranslateX'>getTranslateX</a> <a href='#SkMatrix_setTranslateY'>setTranslateY</a> <a href='#SkMatrix_setTranslate'>setTranslate</a><sup><a href='#SkMatrix_setTranslate_2'>[2]</a></sup>
---
<a name='SkMatrix_getPerspX'></a>
## getPerspX
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getPerspX'>getPerspX</a>() const
</pre>
Returns factor scaling input x-axis relative to input y-axis.
### Return Value
input x-axis perspective factor
### Example
<div><fiddle-embed name="a0f5bf4b55e8c33bfda29bf67e34306f"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_kMPersp0'>kMPersp0</a> <a href='#SkMatrix_getPerspY'>getPerspY</a>
---
<a name='SkMatrix_getPerspY'></a>
## getPerspY
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getPerspY'>getPerspY</a>() const
</pre>
Returns factor scaling input y-axis relative to input x-axis.
### Return Value
input y-axis perspective factor
### Example
<div><fiddle-embed name="424a00a73675dbd99ad20feb0267442b"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_kMPersp1'>kMPersp1</a> <a href='#SkMatrix_getPerspX'>getPerspX</a>
---
<a name='SkMatrix_array1_operator'></a>
## operator[]
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a>& <a href='#SkMatrix_array1_operator'>operator[](int index)</a>
</pre>
Returns writable <a href='#Matrix'>Matrix</a> value. Asserts if <a href='#SkMatrix_array1_operator_index'>index</a> is out of range and SK_DEBUG is
defined. Clears internal cache anticipating that caller will change <a href='#Matrix'>Matrix</a> value.
Next call to read <a href='#Matrix'>Matrix</a> state may recompute cache; subsequent writes to <a href='#Matrix'>Matrix</a>
value must be followed by <a href='#SkMatrix_dirtyMatrixTypeCache'>dirtyMatrixTypeCache</a>.
### Parameters
<table> <tr> <td><a name='SkMatrix_array1_operator_index'><code><strong>index</strong></code></a></td>
<td>one of: <a href='#SkMatrix_kMScaleX'>kMScaleX</a>, <a href='#SkMatrix_kMSkewX'>kMSkewX</a>, <a href='#SkMatrix_kMTransX'>kMTransX</a>, <a href='#SkMatrix_kMSkewY'>kMSkewY</a>, <a href='#SkMatrix_kMScaleY'>kMScaleY</a>, <a href='#SkMatrix_kMTransY'>kMTransY</a>,
<a href='#SkMatrix_kMPersp0'>kMPersp0</a>, <a href='#SkMatrix_kMPersp1'>kMPersp1</a>, <a href='#SkMatrix_kMPersp2'>kMPersp2</a></td>
</tr>
</table>
### Return Value
writable value corresponding to <a href='#SkMatrix_array1_operator_index'>index</a>
### Example
<div><fiddle-embed name="f4365ef332f51f7fd25040e0771ba9a2">
#### Example Output
~~~~
with identity matrix: x = 24
after skew x mod: x = 24
after 2nd skew x mod: x = 24
after dirty cache: x = 66
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_get'>get</a> <a href='#SkMatrix_dirtyMatrixTypeCache'>dirtyMatrixTypeCache</a> <a href='#SkMatrix_set'>set</a>
---
## <a name='Set'>Set</a>
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postConcat'>postConcat</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by <a href='#Matrix'>Matrix</a> parameter</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postIDiv'>postIDiv</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by inverse scale</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postRotate'>postRotate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by rotation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postRotate'>postRotate(SkScalar degrees, SkScalar px, SkScalar py)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postRotate_2'>postRotate(SkScalar degrees)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postScale'>postScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by scale</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postScale'>postScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postScale_2'>postScale(SkScalar sx, SkScalar sy)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postSkew'>postSkew</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by skew</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postSkew'>postSkew(SkScalar kx, SkScalar ky, SkScalar px, SkScalar py)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postSkew_2'>postSkew(SkScalar kx, SkScalar ky)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_postTranslate'>postTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>post-multiplies <a href='#Matrix'>Matrix</a> by translation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preConcat'>preConcat</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pre-multiplies <a href='#Matrix'>Matrix</a> by <a href='#Matrix'>Matrix</a> parameter</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preRotate'>preRotate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pre-multiplies <a href='#Matrix'>Matrix</a> by rotation</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preRotate'>preRotate(SkScalar degrees, SkScalar px, SkScalar py)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preRotate_2'>preRotate(SkScalar degrees)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preScale'>preScale</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pre-multiplies <a href='#Matrix'>Matrix</a> by scale</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preScale'>preScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preScale_2'>preScale(SkScalar sx, SkScalar sy)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preSkew'>preSkew</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pre-multiplies <a href='#Matrix'>Matrix</a> by skew</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preSkew'>preSkew(SkScalar kx, SkScalar ky, SkScalar px, SkScalar py)</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preSkew_2'>preSkew(SkScalar kx, SkScalar ky)</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_preTranslate'>preTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pre-multiplies <a href='#Matrix'>Matrix</a> by translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_set'>set</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets one value</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_set9'>set9</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets all values from <a href='undocumented#Scalar'>Scalar</a> array</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setAll'>setAll</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets all values from parameters</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setPerspX'>setPerspX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets input x perspective factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setPerspY'>setPerspY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets input y perspective factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to map one to four points to an equal array of points</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setRectToRect'>setRectToRect</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets to map one <a href='SkRect_Reference#Rect'>Rect</a> to another</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setScaleX'>setScaleX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets horizontal scale factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setScaleY'>setScaleY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets vertical scale factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSkewX'>setSkewX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets horizontal skew factor</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setSkewY'>setSkewY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets vertical skew factor</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setTranslateX'>setTranslateX</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets horizontal translation</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_setTranslateY'>setTranslateY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets vertical translation</td>
</tr>
</table>
<a name='SkMatrix_set'></a>
## set
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_set'>set</a>(int index, <a href='undocumented#SkScalar'>SkScalar</a> value)
</pre>
Sets <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_set_value'>value</a>. Asserts if <a href='#SkMatrix_set_index'>index</a> is out of range and SK_DEBUG is
defined. Safer than operator[]; internal cache is always maintained.
### Parameters
<table> <tr> <td><a name='SkMatrix_set_index'><code><strong>index</strong></code></a></td>
<td>one of: <a href='#SkMatrix_kMScaleX'>kMScaleX</a>, <a href='#SkMatrix_kMSkewX'>kMSkewX</a>, <a href='#SkMatrix_kMTransX'>kMTransX</a>, <a href='#SkMatrix_kMSkewY'>kMSkewY</a>, <a href='#SkMatrix_kMScaleY'>kMScaleY</a>, <a href='#SkMatrix_kMTransY'>kMTransY</a>,
<a href='#SkMatrix_kMPersp0'>kMPersp0</a>, <a href='#SkMatrix_kMPersp1'>kMPersp1</a>, <a href='#SkMatrix_kMPersp2'>kMPersp2</a></td>
</tr>
<tr> <td><a name='SkMatrix_set_value'><code><strong>value</strong></code></a></td>
<td><a href='undocumented#Scalar'>Scalar</a> to store in <a href='#Matrix'>Matrix</a></td>
</tr>
</table>
### Example
<div><fiddle-embed name="1d400a92ca826cc89bcb88ea051f28c8">
#### Example Output
~~~~
with identity matrix: x = 24
after skew x mod: x = 24
after 2nd skew x mod: x = 66
~~~~
</fiddle-embed></div>
### See Also
operator[] <a href='#SkMatrix_get'>get</a>
---
<a name='SkMatrix_setScaleX'></a>
## setScaleX
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setScaleX'>setScaleX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v)
</pre>
Sets horizontal scale factor.
### Parameters
<table> <tr> <td><a name='SkMatrix_setScaleX_v'><code><strong>v</strong></code></a></td>
<td>horizontal scale factor to store</td>
</tr>
</table>
### Example
<div><fiddle-embed name="a39dfed98c3c3c3a56be9ad59fe4e21e"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_setScaleY'>setScaleY</a>
---
<a name='SkMatrix_setScaleY'></a>
## setScaleY
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setScaleY'>setScaleY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v)
</pre>
Sets vertical scale factor.
### Parameters
<table> <tr> <td><a name='SkMatrix_setScaleY_v'><code><strong>v</strong></code></a></td>
<td>vertical scale factor to store</td>
</tr>
</table>
### Example
<div><fiddle-embed name="f040c6dd85a02e94eaca00d5c2832604"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_setScaleX'>setScaleX</a>
---
<a name='SkMatrix_setSkewY'></a>
## setSkewY
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setSkewY'>setSkewY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v)
</pre>
Sets vertical skew factor.
### Parameters
<table> <tr> <td><a name='SkMatrix_setSkewY_v'><code><strong>v</strong></code></a></td>
<td>vertical skew factor to store</td>
</tr>
</table>
### Example
<div><fiddle-embed name="b418d15df9829aefcc6aca93a37428bb"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setSkew'>setSkew</a><sup><a href='#SkMatrix_setSkew_2'>[2]</a></sup> <a href='#SkMatrix_setSkewX'>setSkewX</a>
---
<a name='SkMatrix_setSkewX'></a>
## setSkewX
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setSkewX'>setSkewX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v)
</pre>
Sets horizontal skew factor.
### Parameters
<table> <tr> <td><a name='SkMatrix_setSkewX_v'><code><strong>v</strong></code></a></td>
<td>horizontal skew factor to store</td>
</tr>
</table>
### Example
<div><fiddle-embed name="c7177a6fbc1545be95a5ebca87e0cd0d"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setSkew'>setSkew</a><sup><a href='#SkMatrix_setSkew_2'>[2]</a></sup> <a href='#SkMatrix_setSkewX'>setSkewX</a>
---
<a name='SkMatrix_setTranslateX'></a>
## setTranslateX
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setTranslateX'>setTranslateX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v)
</pre>
Sets horizontal translation.
### Parameters
<table> <tr> <td><a name='SkMatrix_setTranslateX_v'><code><strong>v</strong></code></a></td>
<td>horizontal translation to store</td>
</tr>
</table>
### Example
<div><fiddle-embed name="a18bc2e3607ac3a8e438bcb61fb13130"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setTranslate'>setTranslate</a><sup><a href='#SkMatrix_setTranslate_2'>[2]</a></sup> <a href='#SkMatrix_setTranslateY'>setTranslateY</a>
---
<a name='SkMatrix_setTranslateY'></a>
## setTranslateY
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setTranslateY'>setTranslateY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v)
</pre>
Sets vertical translation.
### Parameters
<table> <tr> <td><a name='SkMatrix_setTranslateY_v'><code><strong>v</strong></code></a></td>
<td>vertical translation to store</td>
</tr>
</table>
### Example
<div><fiddle-embed name="34e3c70a72b836abf7f4858d35eecc98"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setTranslate'>setTranslate</a><sup><a href='#SkMatrix_setTranslate_2'>[2]</a></sup> <a href='#SkMatrix_setTranslateX'>setTranslateX</a>
---
<a name='SkMatrix_setPerspX'></a>
## setPerspX
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setPerspX'>setPerspX</a>(<a href='undocumented#SkScalar'>SkScalar</a> v)
</pre>
Sets input x-axis perspective factor, which causes <a href='#SkMatrix_mapXY'>mapXY</a> to vary input x-axis values
inversely proportional to input y-axis values.
### Parameters
<table> <tr> <td><a name='SkMatrix_setPerspX_v'><code><strong>v</strong></code></a></td>
<td>perspective factor</td>
</tr>
</table>
### Example
<div><fiddle-embed name="830a9e4e4bb93d25afd83b2fea63929e"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_getPerspX'>getPerspX</a> <a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setAll'>setAll</a> <a href='#SkMatrix_set9'>set9</a> <a href='#SkMatrix_MakeAll'>MakeAll</a>
---
<a name='SkMatrix_setPerspY'></a>
## setPerspY
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setPerspY'>setPerspY</a>(<a href='undocumented#SkScalar'>SkScalar</a> v)
</pre>
Sets input y-axis perspective factor, which causes <a href='#SkMatrix_mapXY'>mapXY</a> to vary input y-axis values
inversely proportional to input x-axis values.
### Parameters
<table> <tr> <td><a name='SkMatrix_setPerspY_v'><code><strong>v</strong></code></a></td>
<td>perspective factor</td>
</tr>
</table>
### Example
<div><fiddle-embed name="aeb258b7922c1a11b698b00f562182ec"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_getPerspY'>getPerspY</a> <a href='#SkMatrix_set'>set</a> <a href='#SkMatrix_setAll'>setAll</a> <a href='#SkMatrix_set9'>set9</a> <a href='#SkMatrix_MakeAll'>MakeAll</a>
---
<a name='SkMatrix_setAll'></a>
## setAll
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setAll'>setAll</a>(<a href='undocumented#SkScalar'>SkScalar</a> scaleX, <a href='undocumented#SkScalar'>SkScalar</a> skewX, <a href='undocumented#SkScalar'>SkScalar</a> transX, <a href='undocumented#SkScalar'>SkScalar</a> skewY, <a href='undocumented#SkScalar'>SkScalar</a> scaleY,
<a href='undocumented#SkScalar'>SkScalar</a> transY, <a href='undocumented#SkScalar'>SkScalar</a> persp0, <a href='undocumented#SkScalar'>SkScalar</a> persp1, <a href='undocumented#SkScalar'>SkScalar</a> persp2)
</pre>
Sets all values from parameters. Sets matrix to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| scaleX skewX transX |
| skewY scaleY transY |
| persp0 persp1 persp2 |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_setAll_scaleX'><code><strong>scaleX</strong></code></a></td>
<td>horizontal scale factor to store</td>
</tr>
<tr> <td><a name='SkMatrix_setAll_skewX'><code><strong>skewX</strong></code></a></td>
<td>horizontal skew factor to store</td>
</tr>
<tr> <td><a name='SkMatrix_setAll_transX'><code><strong>transX</strong></code></a></td>
<td>horizontal translation to store</td>
</tr>
<tr> <td><a name='SkMatrix_setAll_skewY'><code><strong>skewY</strong></code></a></td>
<td>vertical skew factor to store</td>
</tr>
<tr> <td><a name='SkMatrix_setAll_scaleY'><code><strong>scaleY</strong></code></a></td>
<td>vertical scale factor to store</td>
</tr>
<tr> <td><a name='SkMatrix_setAll_transY'><code><strong>transY</strong></code></a></td>
<td>vertical translation to store</td>
</tr>
<tr> <td><a name='SkMatrix_setAll_persp0'><code><strong>persp0</strong></code></a></td>
<td>input x-axis values perspective factor to store</td>
</tr>
<tr> <td><a name='SkMatrix_setAll_persp1'><code><strong>persp1</strong></code></a></td>
<td>input y-axis values perspective factor to store</td>
</tr>
<tr> <td><a name='SkMatrix_setAll_persp2'><code><strong>persp2</strong></code></a></td>
<td>perspective scale factor to store</td>
</tr>
</table>
### Example
<div><fiddle-embed name="95ccfc2a89ce593e6b7a9f992a844bc0"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_set9'>set9</a> <a href='#SkMatrix_MakeAll'>MakeAll</a>
---
<a name='SkMatrix_get9'></a>
## get9
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_get9'>get9</a>(<a href='undocumented#SkScalar'>SkScalar</a> buffer[9]) const
</pre>
Copies nine <a href='undocumented#Scalar'>Scalar</a> values contained by <a href='#Matrix'>Matrix</a> into <a href='#SkMatrix_get9_buffer'>buffer</a>, in member value
ascending order: <a href='#SkMatrix_kMScaleX'>kMScaleX</a>, <a href='#SkMatrix_kMSkewX'>kMSkewX</a>, <a href='#SkMatrix_kMTransX'>kMTransX</a>, <a href='#SkMatrix_kMSkewY'>kMSkewY</a>, <a href='#SkMatrix_kMScaleY'>kMScaleY</a>, <a href='#SkMatrix_kMTransY'>kMTransY</a>,
<a href='#SkMatrix_kMPersp0'>kMPersp0</a>, <a href='#SkMatrix_kMPersp1'>kMPersp1</a>, <a href='#SkMatrix_kMPersp2'>kMPersp2</a>.
### Parameters
<table> <tr> <td><a name='SkMatrix_get9_buffer'><code><strong>buffer</strong></code></a></td>
<td>storage for nine <a href='undocumented#Scalar'>Scalar</a> values</td>
</tr>
</table>
### Example
<div><fiddle-embed name="379fc375e011050b54ed9df83c0996a7">
#### Example Output
~~~~
{4, 0, 3},
{0, 5, 4},
{0, 0, 1}
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_set9'>set9</a>
---
<a name='SkMatrix_set9'></a>
## set9
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_set9'>set9</a>(const <a href='undocumented#SkScalar'>SkScalar</a> buffer[9])
</pre>
Sets <a href='#Matrix'>Matrix</a> to nine <a href='undocumented#Scalar'>Scalar</a> values in <a href='#SkMatrix_set9_buffer'>buffer</a>, in member value ascending order:
<a href='#SkMatrix_kMScaleX'>kMScaleX</a>, <a href='#SkMatrix_kMSkewX'>kMSkewX</a>, <a href='#SkMatrix_kMTransX'>kMTransX</a>, <a href='#SkMatrix_kMSkewY'>kMSkewY</a>, <a href='#SkMatrix_kMScaleY'>kMScaleY</a>, <a href='#SkMatrix_kMTransY'>kMTransY</a>, <a href='#SkMatrix_kMPersp0'>kMPersp0</a>, <a href='#SkMatrix_kMPersp1'>kMPersp1</a>,
<a href='#SkMatrix_kMPersp2'>kMPersp2</a>.
Sets matrix to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| buffer[0] buffer[1] buffer[2] |
| buffer[3] buffer[4] buffer[5] |
| buffer[6] buffer[7] buffer[8] |
</pre>
In the future, <a href='#SkMatrix_set9'>set9</a> followed by <a href='#SkMatrix_get9'>get9</a> may not return the same values. Since <a href='#Matrix'>Matrix</a>
maps non-homogeneous coordinates, scaling all nine values produces an equivalent
transformation, possibly improving precision.
### Parameters
<table> <tr> <td><a name='SkMatrix_set9_buffer'><code><strong>buffer</strong></code></a></td>
<td>nine <a href='undocumented#Scalar'>Scalar</a> values</td>
</tr>
</table>
### Example
<div><fiddle-embed name="ec5de0d23e5fe28ba7628625d1402e85"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setAll'>setAll</a> <a href='#SkMatrix_get9'>get9</a> <a href='#SkMatrix_MakeAll'>MakeAll</a>
---
<a name='SkMatrix_reset'></a>
## reset
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_reset'>reset</a>()
</pre>
Sets <a href='#Matrix'>Matrix</a> to identity; which has no effect on mapped <a href='SkPoint_Reference#Point'>Points</a>. Sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 1 0 0 |
| 0 1 0 |
| 0 0 1 |
</pre>
Also called <a href='#SkMatrix_setIdentity'>setIdentity</a>; use the one that provides better inline
documentation.
### Example
<div><fiddle-embed name="ca94f7922bc37ef03bbc51ad70536fcf">
#### Example Output
~~~~
m.isIdentity(): true
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_isIdentity'>isIdentity</a> <a href='#SkMatrix_setIdentity'>setIdentity</a>
---
<a name='SkMatrix_setIdentity'></a>
## setIdentity
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setIdentity'>setIdentity</a>()
</pre>
Sets <a href='#Matrix'>Matrix</a> to identity; which has no effect on mapped <a href='SkPoint_Reference#Point'>Points</a>. Sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 1 0 0 |
| 0 1 0 |
| 0 0 1 |
</pre>
Also called <a href='#SkMatrix_reset'>reset</a>; use the one that provides better inline
documentation.
### Example
<div><fiddle-embed name="3979c865bb482e6ef1fafc71e56bbb91">
#### Example Output
~~~~
m.isIdentity(): true
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_isIdentity'>isIdentity</a> <a href='#SkMatrix_reset'>reset</a>
---
<a name='SkMatrix_setTranslate'></a>
## setTranslate
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setTranslate'>setTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy)
</pre>
Sets <a href='#Matrix'>Matrix</a> to translate by (<a href='#SkMatrix_setTranslate_dx'>dx</a>, <a href='#SkMatrix_setTranslate_dy'>dy</a>).
### Parameters
<table> <tr> <td><a name='SkMatrix_setTranslate_dx'><code><strong>dx</strong></code></a></td>
<td>horizontal translation</td>
</tr>
<tr> <td><a name='SkMatrix_setTranslate_dy'><code><strong>dy</strong></code></a></td>
<td>vertical translation</td>
</tr>
</table>
### Example
<div><fiddle-embed name="63ca62985741b1bccb5e8b9cf734874e"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setTranslateX'>setTranslateX</a> <a href='#SkMatrix_setTranslateY'>setTranslateY</a>
---
<a name='SkMatrix_setTranslate_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setTranslate'>setTranslate</a>(const <a href='SkPoint_Reference#SkVector'>SkVector</a>& v)
</pre>
Sets <a href='#Matrix'>Matrix</a> to translate by (<a href='#SkMatrix_setTranslate_2_v'>v</a>.fX, <a href='#SkMatrix_setTranslate_2_v'>v</a>.fY).
### Parameters
<table> <tr> <td><a name='SkMatrix_setTranslate_2_v'><code><strong>v</strong></code></a></td>
<td><a href='SkPoint_Reference#Vector'>Vector</a> containing horizontal and vertical translation</td>
</tr>
</table>
### Example
<div><fiddle-embed name="ccfc734aff2ddea0b097c83f5621de5e"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setTranslateX'>setTranslateX</a> <a href='#SkMatrix_setTranslateY'>setTranslateY</a> <a href='#SkMatrix_MakeTrans'>MakeTrans</a>
---
<a name='SkMatrix_setScale'></a>
## setScale
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setScale'>setScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py)
</pre>
Sets <a href='#Matrix'>Matrix</a> to scale by <a href='#SkMatrix_setScale_sx'>sx</a> and <a href='#SkMatrix_setScale_sy'>sy</a>, about a pivot point at (<a href='#SkMatrix_setScale_px'>px</a>, <a href='#SkMatrix_setScale_py'>py</a>).
The pivot point is unchanged when mapped with <a href='#Matrix'>Matrix</a>.
### Parameters
<table> <tr> <td><a name='SkMatrix_setScale_sx'><code><strong>sx</strong></code></a></td>
<td>horizontal scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_setScale_sy'><code><strong>sy</strong></code></a></td>
<td>vertical scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_setScale_px'><code><strong>px</strong></code></a></td>
<td>pivot x</td>
</tr>
<tr> <td><a name='SkMatrix_setScale_py'><code><strong>py</strong></code></a></td>
<td>pivot y</td>
</tr>
</table>
### Example
<div><fiddle-embed name="4565a0792058178c88e0a129a87272d6"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setScaleX'>setScaleX</a> <a href='#SkMatrix_setScaleY'>setScaleY</a> <a href='#SkMatrix_MakeScale'>MakeScale</a><sup><a href='#SkMatrix_MakeScale_2'>[2]</a></sup> <a href='#SkMatrix_preScale'>preScale</a><sup><a href='#SkMatrix_preScale_2'>[2]</a></sup> <a href='#SkMatrix_postScale'>postScale</a><sup><a href='#SkMatrix_postScale_2'>[2]</a></sup>
---
<a name='SkMatrix_setScale_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setScale'>setScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy)
</pre>
Sets <a href='#Matrix'>Matrix</a> to scale by <a href='#SkMatrix_setScale_2_sx'>sx</a> and <a href='#SkMatrix_setScale_2_sy'>sy</a> about at pivot point at (0, 0).
### Parameters
<table> <tr> <td><a name='SkMatrix_setScale_2_sx'><code><strong>sx</strong></code></a></td>
<td>horizontal scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_setScale_2_sy'><code><strong>sy</strong></code></a></td>
<td>vertical scale factor</td>
</tr>
</table>
### Example
<div><fiddle-embed name="1579d0cc109c26e69f66f73abd35fb0e"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setScaleX'>setScaleX</a> <a href='#SkMatrix_setScaleY'>setScaleY</a> <a href='#SkMatrix_MakeScale'>MakeScale</a><sup><a href='#SkMatrix_MakeScale_2'>[2]</a></sup> <a href='#SkMatrix_preScale'>preScale</a><sup><a href='#SkMatrix_preScale_2'>[2]</a></sup> <a href='#SkMatrix_postScale'>postScale</a><sup><a href='#SkMatrix_postScale_2'>[2]</a></sup>
---
<a name='SkMatrix_setRotate'></a>
## setRotate
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setRotate'>setRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py)
</pre>
Sets <a href='#Matrix'>Matrix</a> to rotate by <a href='#SkMatrix_setRotate_degrees'>degrees</a> about a pivot point at (<a href='#SkMatrix_setRotate_px'>px</a>, <a href='#SkMatrix_setRotate_py'>py</a>).
The pivot point is unchanged when mapped with <a href='#Matrix'>Matrix</a>.
Positive <a href='#SkMatrix_setRotate_degrees'>degrees</a> rotates clockwise.
### Parameters
<table> <tr> <td><a name='SkMatrix_setRotate_degrees'><code><strong>degrees</strong></code></a></td>
<td>angle of axes relative to upright axes</td>
</tr>
<tr> <td><a name='SkMatrix_setRotate_px'><code><strong>px</strong></code></a></td>
<td>pivot x</td>
</tr>
<tr> <td><a name='SkMatrix_setRotate_py'><code><strong>py</strong></code></a></td>
<td>pivot y</td>
</tr>
</table>
### Example
<div><fiddle-embed name="8c28db3add9cd0177225088f6df6bbb5"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setSinCos'>setSinCos</a><sup><a href='#SkMatrix_setSinCos_2'>[2]</a></sup> <a href='#SkMatrix_preRotate'>preRotate</a><sup><a href='#SkMatrix_preRotate_2'>[2]</a></sup> <a href='#SkMatrix_postRotate'>postRotate</a><sup><a href='#SkMatrix_postRotate_2'>[2]</a></sup>
---
<a name='SkMatrix_setRotate_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setRotate'>setRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees)
</pre>
Sets <a href='#Matrix'>Matrix</a> to rotate by <a href='#SkMatrix_setRotate_2_degrees'>degrees</a> about a pivot point at (0, 0).
Positive <a href='#SkMatrix_setRotate_2_degrees'>degrees</a> rotates clockwise.
### Parameters
<table> <tr> <td><a name='SkMatrix_setRotate_2_degrees'><code><strong>degrees</strong></code></a></td>
<td>angle of axes relative to upright axes</td>
</tr>
</table>
### Example
<div><fiddle-embed name="93efb9d191bf1b9710c173513e014d6c"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setSinCos'>setSinCos</a><sup><a href='#SkMatrix_setSinCos_2'>[2]</a></sup> <a href='#SkMatrix_preRotate'>preRotate</a><sup><a href='#SkMatrix_preRotate_2'>[2]</a></sup> <a href='#SkMatrix_postRotate'>postRotate</a><sup><a href='#SkMatrix_postRotate_2'>[2]</a></sup>
---
<a name='SkMatrix_setSinCos'></a>
## setSinCos
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setSinCos'>setSinCos</a>(<a href='undocumented#SkScalar'>SkScalar</a> sinValue, <a href='undocumented#SkScalar'>SkScalar</a> cosValue, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py)
</pre>
Sets <a href='#Matrix'>Matrix</a> to rotate by <a href='#SkMatrix_setSinCos_sinValue'>sinValue</a> and <a href='#SkMatrix_setSinCos_cosValue'>cosValue</a>, about a pivot point at (<a href='#SkMatrix_setSinCos_px'>px</a>, <a href='#SkMatrix_setSinCos_py'>py</a>).
The pivot point is unchanged when mapped with <a href='#Matrix'>Matrix</a>.
<a href='SkPoint_Reference#Vector'>Vector</a> (<a href='#SkMatrix_setSinCos_sinValue'>sinValue</a>, <a href='#SkMatrix_setSinCos_cosValue'>cosValue</a>) describes the angle of rotation relative to (0, 1).
<a href='SkPoint_Reference#Vector'>Vector</a> length specifies scale.
### Parameters
<table> <tr> <td><a name='SkMatrix_setSinCos_sinValue'><code><strong>sinValue</strong></code></a></td>
<td>rotation vector x-axis component</td>
</tr>
<tr> <td><a name='SkMatrix_setSinCos_cosValue'><code><strong>cosValue</strong></code></a></td>
<td>rotation vector y-axis component</td>
</tr>
<tr> <td><a name='SkMatrix_setSinCos_px'><code><strong>px</strong></code></a></td>
<td>pivot x-axis</td>
</tr>
<tr> <td><a name='SkMatrix_setSinCos_py'><code><strong>py</strong></code></a></td>
<td>pivot y-axis</td>
</tr>
</table>
### Example
<div><fiddle-embed name="187e1d9228e2e4341ef820bd77b6fda9"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setRotate'>setRotate</a><sup><a href='#SkMatrix_setRotate_2'>[2]</a></sup> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_setRSXform'>setRSXform</a>
---
<a name='SkMatrix_setSinCos_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setSinCos'>setSinCos</a>(<a href='undocumented#SkScalar'>SkScalar</a> sinValue, <a href='undocumented#SkScalar'>SkScalar</a> cosValue)
</pre>
Sets <a href='#Matrix'>Matrix</a> to rotate by <a href='#SkMatrix_setSinCos_2_sinValue'>sinValue</a> and <a href='#SkMatrix_setSinCos_2_cosValue'>cosValue</a>, about a pivot point at (0, 0).
<a href='SkPoint_Reference#Vector'>Vector</a> (<a href='#SkMatrix_setSinCos_2_sinValue'>sinValue</a>, <a href='#SkMatrix_setSinCos_2_cosValue'>cosValue</a>) describes the angle of rotation relative to (0, 1).
<a href='SkPoint_Reference#Vector'>Vector</a> length specifies scale.
### Parameters
<table> <tr> <td><a name='SkMatrix_setSinCos_2_sinValue'><code><strong>sinValue</strong></code></a></td>
<td>rotation vector x-axis component</td>
</tr>
<tr> <td><a name='SkMatrix_setSinCos_2_cosValue'><code><strong>cosValue</strong></code></a></td>
<td>rotation vector y-axis component</td>
</tr>
</table>
### Example
<div><fiddle-embed name="e37a94a53c959951b059fcd624639ef6"><div><a href='SkCanvas_Reference#Canvas'>Canvas</a> needs offset after applying <a href='#Matrix'>Matrix</a> to pivot about <a href='SkRect_Reference#Rect'>Rect</a> center.
</div></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setRotate'>setRotate</a><sup><a href='#SkMatrix_setRotate_2'>[2]</a></sup> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_setRSXform'>setRSXform</a>
---
<a name='SkMatrix_setRSXform'></a>
## setRSXform
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_setRSXform'>setRSXform</a>(const <a href='undocumented#SkRSXform'>SkRSXform</a>& rsxForm)
</pre>
Sets <a href='#Matrix'>Matrix</a> to rotate, scale, and translate using a compressed matrix form.
<a href='SkPoint_Reference#Vector'>Vector</a> (<a href='#SkMatrix_setRSXform_rsxForm'>rsxForm</a>.fSSin, <a href='#SkMatrix_setRSXform_rsxForm'>rsxForm</a>.fSCos) describes the angle of rotation relative
to (0, 1). <a href='SkPoint_Reference#Vector'>Vector</a> length specifies scale. Mapped point is rotated and scaled
by <a href='SkPoint_Reference#Vector'>Vector</a>, then translated by (<a href='#SkMatrix_setRSXform_rsxForm'>rsxForm</a>.fTx, <a href='#SkMatrix_setRSXform_rsxForm'>rsxForm</a>.fTy).
### Parameters
<table> <tr> <td><a name='SkMatrix_setRSXform_rsxForm'><code><strong>rsxForm</strong></code></a></td>
<td>compressed <a href='undocumented#RSXform'>RSXform</a> matrix</td>
</tr>
</table>
### Return Value
reference to <a href='#Matrix'>Matrix</a>
### Example
<div><fiddle-embed name="c3f5faddca466f78278b32b88fd5f5eb"><div><a href='SkCanvas_Reference#Canvas'>Canvas</a> needs offset after applying <a href='#Matrix'>Matrix</a> to pivot about <a href='SkRect_Reference#Rect'>Rect</a> center.
</div></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setSinCos'>setSinCos</a><sup><a href='#SkMatrix_setSinCos_2'>[2]</a></sup> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_setTranslate'>setTranslate</a><sup><a href='#SkMatrix_setTranslate_2'>[2]</a></sup>
---
<a name='SkMatrix_setSkew'></a>
## setSkew
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setSkew'>setSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py)
</pre>
Sets <a href='#Matrix'>Matrix</a> to skew by <a href='#SkMatrix_setSkew_kx'>kx</a> and <a href='#SkMatrix_setSkew_ky'>ky</a>, about a pivot point at (<a href='#SkMatrix_setSkew_px'>px</a>, <a href='#SkMatrix_setSkew_py'>py</a>).
The pivot point is unchanged when mapped with <a href='#Matrix'>Matrix</a>.
### Parameters
<table> <tr> <td><a name='SkMatrix_setSkew_kx'><code><strong>kx</strong></code></a></td>
<td>horizontal skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_setSkew_ky'><code><strong>ky</strong></code></a></td>
<td>vertical skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_setSkew_px'><code><strong>px</strong></code></a></td>
<td>pivot x</td>
</tr>
<tr> <td><a name='SkMatrix_setSkew_py'><code><strong>py</strong></code></a></td>
<td>pivot y</td>
</tr>
</table>
### Example
<div><fiddle-embed name="55e0431adc6c5b1987ebb8123cc10342"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setSkewX'>setSkewX</a> <a href='#SkMatrix_setSkewY'>setSkewY</a> <a href='#SkMatrix_preSkew'>preSkew</a><sup><a href='#SkMatrix_preSkew_2'>[2]</a></sup> <a href='#SkMatrix_postSkew'>postSkew</a><sup><a href='#SkMatrix_postSkew_2'>[2]</a></sup>
---
<a name='SkMatrix_setSkew_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setSkew'>setSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky)
</pre>
Sets <a href='#Matrix'>Matrix</a> to skew by <a href='#SkMatrix_setSkew_2_kx'>kx</a> and <a href='#SkMatrix_setSkew_2_ky'>ky</a>, about a pivot point at (0, 0).
### Parameters
<table> <tr> <td><a name='SkMatrix_setSkew_2_kx'><code><strong>kx</strong></code></a></td>
<td>horizontal skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_setSkew_2_ky'><code><strong>ky</strong></code></a></td>
<td>vertical skew factor</td>
</tr>
</table>
### Example
<div><fiddle-embed name="05be7844e9afdd7b9bfc31c5423a70a2"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setSkewX'>setSkewX</a> <a href='#SkMatrix_setSkewY'>setSkewY</a> <a href='#SkMatrix_preSkew'>preSkew</a><sup><a href='#SkMatrix_preSkew_2'>[2]</a></sup> <a href='#SkMatrix_postSkew'>postSkew</a><sup><a href='#SkMatrix_postSkew_2'>[2]</a></sup>
---
<a name='SkMatrix_setConcat'></a>
## setConcat
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setConcat'>setConcat</a>(const <a href='#SkMatrix'>SkMatrix</a>& a, const <a href='#SkMatrix'>SkMatrix</a>& b)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_setConcat_a'>a</a> multiplied by <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_setConcat_b'>b</a>. Either <a href='#SkMatrix_setConcat_a'>a</a> or <a href='#SkMatrix_setConcat_b'>b</a> may be this.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | J K L |
a = | D E F |, b = | M N O |
| G H I | | P Q R |
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | J K L | | AJ+BM+CP AK+BN+CQ AL+BO+CR |
a * b = | D E F | * | M N O | = | DJ+EM+FP DK+EN+FQ DL+EO+FR |
| G H I | | P Q R | | GJ+HM+IP GK+HN+IQ GL+HO+IR |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_setConcat_a'><code><strong>a</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> on left side of multiply expression</td>
</tr>
<tr> <td><a name='SkMatrix_setConcat_b'><code><strong>b</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> on right side of multiply expression</td>
</tr>
</table>
### Example
<div><fiddle-embed name="0381a10ac69bdefdf9d15b47cbb9fefe"><div><a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> creates perspective matrices, one the inverse of the other.
Multiplying the matrix by its inverse turns into an identity matrix.
</div></fiddle-embed></div>
### See Also
<a href='#SkMatrix_Concat'>Concat</a> <a href='#SkMatrix_preConcat'>preConcat</a> <a href='#SkMatrix_postConcat'>postConcat</a> <a href='SkCanvas_Reference#SkCanvas_concat'>SkCanvas::concat</a>
---
<a name='SkMatrix_preTranslate'></a>
## preTranslate
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_preTranslate'>preTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> multiplied by <a href='#Matrix'>Matrix</a> constructed from translation (<a href='#SkMatrix_preTranslate_dx'>dx</a>, <a href='#SkMatrix_preTranslate_dy'>dy</a>).
This can be thought of as moving the point to be mapped before applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | 1 0 dx |
Matrix = | D E F |, T(dx, dy) = | 0 1 dy |
| G H I | | 0 0 1 |
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | 1 0 dx | | A B A*dx+B*dy+C |
Matrix * T(dx, dy) = | D E F | | 0 1 dy | = | D E D*dx+E*dy+F |
| G H I | | 0 0 1 | | G H G*dx+H*dy+I |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_preTranslate_dx'><code><strong>dx</strong></code></a></td>
<td>x-axis translation before applying <a href='#Matrix'>Matrix</a></td>
</tr>
<tr> <td><a name='SkMatrix_preTranslate_dy'><code><strong>dy</strong></code></a></td>
<td>y-axis translation before applying <a href='#Matrix'>Matrix</a></td>
</tr>
</table>
### Example
<div><fiddle-embed name="f75a9b629aa6c51ed888f8799b5ba5f7"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_postTranslate'>postTranslate</a> <a href='#SkMatrix_setTranslate'>setTranslate</a><sup><a href='#SkMatrix_setTranslate_2'>[2]</a></sup> <a href='#SkMatrix_MakeTrans'>MakeTrans</a>
---
<a name='SkMatrix_preScale'></a>
## preScale
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_preScale'>preScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> multiplied by <a href='#Matrix'>Matrix</a> constructed from scaling by (<a href='#SkMatrix_preScale_sx'>sx</a>, <a href='#SkMatrix_preScale_sy'>sy</a>)
about pivot point (<a href='#SkMatrix_preScale_px'>px</a>, <a href='#SkMatrix_preScale_py'>py</a>).
This can be thought of as scaling about a pivot point before applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | sx 0 dx |
Matrix = | D E F |, S(sx, sy, px, py) = | 0 sy dy |
| G H I | | 0 0 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
dx = px - sx * px
dy = py - sy * py
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | sx 0 dx | | A*sx B*sy A*dx+B*dy+C |
Matrix * S(sx, sy, px, py) = | D E F | | 0 sy dy | = | D*sx E*sy D*dx+E*dy+F |
| G H I | | 0 0 1 | | G*sx H*sy G*dx+H*dy+I |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_preScale_sx'><code><strong>sx</strong></code></a></td>
<td>horizontal scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_preScale_sy'><code><strong>sy</strong></code></a></td>
<td>vertical scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_preScale_px'><code><strong>px</strong></code></a></td>
<td>pivot x</td>
</tr>
<tr> <td><a name='SkMatrix_preScale_py'><code><strong>py</strong></code></a></td>
<td>pivot y</td>
</tr>
</table>
### Example
<div><fiddle-embed name="2531f8d1e05d7b6dc22f3efcd2fb84e4"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_postScale'>postScale</a><sup><a href='#SkMatrix_postScale_2'>[2]</a></sup> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_MakeScale'>MakeScale</a><sup><a href='#SkMatrix_MakeScale_2'>[2]</a></sup>
---
<a name='SkMatrix_preScale_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_preScale'>preScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> multiplied by <a href='#Matrix'>Matrix</a> constructed from scaling by (<a href='#SkMatrix_preScale_2_sx'>sx</a>, <a href='#SkMatrix_preScale_2_sy'>sy</a>)
about pivot point (0, 0).
This can be thought of as scaling about the origin before applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | sx 0 0 |
Matrix = | D E F |, S(sx, sy) = | 0 sy 0 |
| G H I | | 0 0 1 |
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | sx 0 0 | | A*sx B*sy C |
Matrix * S(sx, sy) = | D E F | | 0 sy 0 | = | D*sx E*sy F |
| G H I | | 0 0 1 | | G*sx H*sy I |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_preScale_2_sx'><code><strong>sx</strong></code></a></td>
<td>horizontal scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_preScale_2_sy'><code><strong>sy</strong></code></a></td>
<td>vertical scale factor</td>
</tr>
</table>
### Example
<div><fiddle-embed name="3edbdea8e43d06086abf33ec4a9b415b"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_postScale'>postScale</a><sup><a href='#SkMatrix_postScale_2'>[2]</a></sup> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_MakeScale'>MakeScale</a><sup><a href='#SkMatrix_MakeScale_2'>[2]</a></sup>
---
<a name='SkMatrix_preRotate'></a>
## preRotate
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_preRotate'>preRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> multiplied by <a href='#Matrix'>Matrix</a> constructed from rotating by <a href='#SkMatrix_preRotate_degrees'>degrees</a>
about pivot point (<a href='#SkMatrix_preRotate_px'>px</a>, <a href='#SkMatrix_preRotate_py'>py</a>).
This can be thought of as rotating about a pivot point before applying <a href='#Matrix'>Matrix</a>.
Positive <a href='#SkMatrix_preRotate_degrees'>degrees</a> rotates clockwise.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | c -s dx |
Matrix = | D E F |, R(degrees, px, py) = | s c dy |
| G H I | | 0 0 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
c = cos(degrees)
s = sin(degrees)
dx = s * py + (1 - c) * px
dy = -s * px + (1 - c) * py
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | c -s dx | | Ac+Bs -As+Bc A*dx+B*dy+C |
Matrix * R(degrees, px, py) = | D E F | | s c dy | = | Dc+Es -Ds+Ec D*dx+E*dy+F |
| G H I | | 0 0 1 | | Gc+Hs -Gs+Hc G*dx+H*dy+I |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_preRotate_degrees'><code><strong>degrees</strong></code></a></td>
<td>angle of axes relative to upright axes</td>
</tr>
<tr> <td><a name='SkMatrix_preRotate_px'><code><strong>px</strong></code></a></td>
<td>pivot x</td>
</tr>
<tr> <td><a name='SkMatrix_preRotate_py'><code><strong>py</strong></code></a></td>
<td>pivot y</td>
</tr>
</table>
### Example
<div><fiddle-embed name="a70bb18d67c06a20ab514e7a47924e5a"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_postRotate'>postRotate</a><sup><a href='#SkMatrix_postRotate_2'>[2]</a></sup> <a href='#SkMatrix_setRotate'>setRotate</a><sup><a href='#SkMatrix_setRotate_2'>[2]</a></sup>
---
<a name='SkMatrix_preRotate_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_preRotate'>preRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> multiplied by <a href='#Matrix'>Matrix</a> constructed from rotating by <a href='#SkMatrix_preRotate_2_degrees'>degrees</a>
about pivot point (0, 0).
This can be thought of as rotating about the origin before applying <a href='#Matrix'>Matrix</a>.
Positive <a href='#SkMatrix_preRotate_2_degrees'>degrees</a> rotates clockwise.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | c -s 0 |
Matrix = | D E F |, R(degrees, px, py) = | s c 0 |
| G H I | | 0 0 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
c = cos(degrees)
s = sin(degrees)
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | c -s 0 | | Ac+Bs -As+Bc C |
Matrix * R(degrees, px, py) = | D E F | | s c 0 | = | Dc+Es -Ds+Ec F |
| G H I | | 0 0 1 | | Gc+Hs -Gs+Hc I |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_preRotate_2_degrees'><code><strong>degrees</strong></code></a></td>
<td>angle of axes relative to upright axes</td>
</tr>
</table>
### Example
<div><fiddle-embed name="5acd49bd931c79a808dd6c7cc0e92f72"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_postRotate'>postRotate</a><sup><a href='#SkMatrix_postRotate_2'>[2]</a></sup> <a href='#SkMatrix_setRotate'>setRotate</a><sup><a href='#SkMatrix_setRotate_2'>[2]</a></sup>
---
<a name='SkMatrix_preSkew'></a>
## preSkew
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_preSkew'>preSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> multiplied by <a href='#Matrix'>Matrix</a> constructed from skewing by (<a href='#SkMatrix_preSkew_kx'>kx</a>, <a href='#SkMatrix_preSkew_ky'>ky</a>)
about pivot point (<a href='#SkMatrix_preSkew_px'>px</a>, <a href='#SkMatrix_preSkew_py'>py</a>).
This can be thought of as skewing about a pivot point before applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | 1 kx dx |
Matrix = | D E F |, K(kx, ky, px, py) = | ky 1 dy |
| G H I | | 0 0 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
dx = -kx * py
dy = -ky * px
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | 1 kx dx | | A+B*ky A*kx+B A*dx+B*dy+C |
Matrix * K(kx, ky, px, py) = | D E F | | ky 1 dy | = | D+E*ky D*kx+E D*dx+E*dy+F |
| G H I | | 0 0 1 | | G+H*ky G*kx+H G*dx+H*dy+I |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_preSkew_kx'><code><strong>kx</strong></code></a></td>
<td>horizontal skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_preSkew_ky'><code><strong>ky</strong></code></a></td>
<td>vertical skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_preSkew_px'><code><strong>px</strong></code></a></td>
<td>pivot x</td>
</tr>
<tr> <td><a name='SkMatrix_preSkew_py'><code><strong>py</strong></code></a></td>
<td>pivot y</td>
</tr>
</table>
### Example
<div><fiddle-embed name="199a18ad61d702664ce6df1d7037aa48"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_postSkew'>postSkew</a><sup><a href='#SkMatrix_postSkew_2'>[2]</a></sup> <a href='#SkMatrix_setSkew'>setSkew</a><sup><a href='#SkMatrix_setSkew_2'>[2]</a></sup>
---
<a name='SkMatrix_preSkew_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_preSkew'>preSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> multiplied by <a href='#Matrix'>Matrix</a> constructed from skewing by (<a href='#SkMatrix_preSkew_2_kx'>kx</a>, <a href='#SkMatrix_preSkew_2_ky'>ky</a>)
about pivot point (0, 0).
This can be thought of as skewing about the origin before applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | 1 kx 0 |
Matrix = | D E F |, K(kx, ky) = | ky 1 0 |
| G H I | | 0 0 1 |
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | 1 kx 0 | | A+B*ky A*kx+B C |
Matrix * K(kx, ky) = | D E F | | ky 1 0 | = | D+E*ky D*kx+E F |
| G H I | | 0 0 1 | | G+H*ky G*kx+H I |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_preSkew_2_kx'><code><strong>kx</strong></code></a></td>
<td>horizontal skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_preSkew_2_ky'><code><strong>ky</strong></code></a></td>
<td>vertical skew factor</td>
</tr>
</table>
### Example
<div><fiddle-embed name="e100c543869fe8fd516ba69de79444ba"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_postSkew'>postSkew</a><sup><a href='#SkMatrix_postSkew_2'>[2]</a></sup> <a href='#SkMatrix_setSkew'>setSkew</a><sup><a href='#SkMatrix_setSkew_2'>[2]</a></sup>
---
<a name='SkMatrix_preConcat'></a>
## preConcat
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_preConcat'>preConcat</a>(const <a href='#SkMatrix'>SkMatrix</a>& other)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> multiplied by <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_preConcat_other'>other</a>.
This can be thought of mapping by <a href='#SkMatrix_preConcat_other'>other</a> before applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | J K L |
Matrix = | D E F |, other = | M N O |
| G H I | | P Q R |
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | J K L | | AJ+BM+CP AK+BN+CQ AL+BO+CR |
Matrix * other = | D E F | * | M N O | = | DJ+EM+FP DK+EN+FQ DL+EO+FR |
| G H I | | P Q R | | GJ+HM+IP GK+HN+IQ GL+HO+IR |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_preConcat_other'><code><strong>other</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> on right side of multiply expression</td>
</tr>
</table>
### Example
<div><fiddle-embed name="b07e62298e7b0ab5683db199faffceb2"><div><a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> creates perspective matrices, one the inverse of the <a href='#SkMatrix_preConcat_other'>other</a>.
Multiplying the matrix by its inverse turns into an identity matrix.
</div></fiddle-embed></div>
### See Also
<a href='#SkMatrix_postConcat'>postConcat</a> <a href='#SkMatrix_setConcat'>setConcat</a> <a href='#SkMatrix_Concat'>Concat</a>
---
<a name='SkMatrix_postTranslate'></a>
## postTranslate
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_postTranslate'>postTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> constructed from translation (<a href='#SkMatrix_postTranslate_dx'>dx</a>, <a href='#SkMatrix_postTranslate_dy'>dy</a>) multiplied by <a href='#Matrix'>Matrix</a>.
This can be thought of as moving the point to be mapped after applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| J K L | | 1 0 dx |
Matrix = | M N O |, T(dx, dy) = | 0 1 dy |
| P Q R | | 0 0 1 |
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 1 0 dx | | J K L | | J+dx*P K+dx*Q L+dx*R |
T(dx, dy) * Matrix = | 0 1 dy | | M N O | = | M+dy*P N+dy*Q O+dy*R |
| 0 0 1 | | P Q R | | P Q R |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_postTranslate_dx'><code><strong>dx</strong></code></a></td>
<td>x-axis translation after applying <a href='#Matrix'>Matrix</a></td>
</tr>
<tr> <td><a name='SkMatrix_postTranslate_dy'><code><strong>dy</strong></code></a></td>
<td>y-axis translation after applying <a href='#Matrix'>Matrix</a></td>
</tr>
</table>
### Example
<div><fiddle-embed name="f5144ef4bd7cea294fad2f756ed335af"><div>Compare with <a href='#SkMatrix_preTranslate'>preTranslate</a> example.
</div></fiddle-embed></div>
### See Also
<a href='#SkMatrix_preTranslate'>preTranslate</a> <a href='#SkMatrix_setTranslate'>setTranslate</a><sup><a href='#SkMatrix_setTranslate_2'>[2]</a></sup> <a href='#SkMatrix_MakeTrans'>MakeTrans</a>
---
<a name='SkMatrix_postScale'></a>
## postScale
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_postScale'>postScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> constructed from scaling by (<a href='#SkMatrix_postScale_sx'>sx</a>, <a href='#SkMatrix_postScale_sy'>sy</a>) about pivot point
(<a href='#SkMatrix_postScale_px'>px</a>, <a href='#SkMatrix_postScale_py'>py</a>), multiplied by <a href='#Matrix'>Matrix</a>.
This can be thought of as scaling about a pivot point after applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| J K L | | sx 0 dx |
Matrix = | M N O |, S(sx, sy, px, py) = | 0 sy dy |
| P Q R | | 0 0 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
dx = px - sx * px
dy = py - sy * py
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| sx 0 dx | | J K L | | sx*J+dx*P sx*K+dx*Q sx*L+dx+R |
S(sx, sy, px, py) * Matrix = | 0 sy dy | | M N O | = | sy*M+dy*P sy*N+dy*Q sy*O+dy*R |
| 0 0 1 | | P Q R | | P Q R |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_postScale_sx'><code><strong>sx</strong></code></a></td>
<td>horizontal scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_postScale_sy'><code><strong>sy</strong></code></a></td>
<td>vertical scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_postScale_px'><code><strong>px</strong></code></a></td>
<td>pivot x</td>
</tr>
<tr> <td><a name='SkMatrix_postScale_py'><code><strong>py</strong></code></a></td>
<td>pivot y</td>
</tr>
</table>
### Example
<div><fiddle-embed name="ed3aa18ba0ea95c85cc49aa3829fe384"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_preScale'>preScale</a><sup><a href='#SkMatrix_preScale_2'>[2]</a></sup> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_MakeScale'>MakeScale</a><sup><a href='#SkMatrix_MakeScale_2'>[2]</a></sup>
---
<a name='SkMatrix_postScale_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_postScale'>postScale</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> constructed from scaling by (<a href='#SkMatrix_postScale_2_sx'>sx</a>, <a href='#SkMatrix_postScale_2_sy'>sy</a>) about pivot point
(0, 0), multiplied by <a href='#Matrix'>Matrix</a>.
This can be thought of as scaling about the origin after applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| J K L | | sx 0 0 |
Matrix = | M N O |, S(sx, sy) = | 0 sy 0 |
| P Q R | | 0 0 1 |
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| sx 0 0 | | J K L | | sx*J sx*K sx*L |
S(sx, sy) * Matrix = | 0 sy 0 | | M N O | = | sy*M sy*N sy*O |
| 0 0 1 | | P Q R | | P Q R |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_postScale_2_sx'><code><strong>sx</strong></code></a></td>
<td>horizontal scale factor</td>
</tr>
<tr> <td><a name='SkMatrix_postScale_2_sy'><code><strong>sy</strong></code></a></td>
<td>vertical scale factor</td>
</tr>
</table>
### Example
<div><fiddle-embed name="1931017698766a67d3a26423453b8095"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_preScale'>preScale</a><sup><a href='#SkMatrix_preScale_2'>[2]</a></sup> <a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_MakeScale'>MakeScale</a><sup><a href='#SkMatrix_MakeScale_2'>[2]</a></sup>
---
<a name='SkMatrix_postIDiv'></a>
## postIDiv
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_postIDiv'>postIDiv</a>(int divx, int divy)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> constructed from scaling by <code>\(1/<a href='#SkMatrix_postIDiv_divx'>divx</a>, 1/<a href='#SkMatrix_postIDiv_divy'>divy</a>\)</code>,
about pivot point (px, py), multiplied by <a href='#Matrix'>Matrix</a>.
Returns false if either <a href='#SkMatrix_postIDiv_divx'>divx</a> or <a href='#SkMatrix_postIDiv_divy'>divy</a> is zero.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| J K L | | sx 0 0 |
Matrix = | M N O |, I(divx, divy) = | 0 sy 0 |
| P Q R | | 0 0 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
sx = 1 / divx
sy = 1 / divy
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| sx 0 0 | | J K L | | sx*J sx*K sx*L |
I(divx, divy) * Matrix = | 0 sy 0 | | M N O | = | sy*M sy*N sy*O |
| 0 0 1 | | P Q R | | P Q R |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_postIDiv_divx'><code><strong>divx</strong></code></a></td>
<td>integer divisor for inverse scale in x</td>
</tr>
<tr> <td><a name='SkMatrix_postIDiv_divy'><code><strong>divy</strong></code></a></td>
<td>integer divisor for inverse scale in y</td>
</tr>
</table>
### Return Value
true on successful scale
### Example
<div><fiddle-embed name="e6ad0bd2999613d9e4758b661d45070c"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_postScale'>postScale</a><sup><a href='#SkMatrix_postScale_2'>[2]</a></sup> <a href='#SkMatrix_MakeScale'>MakeScale</a><sup><a href='#SkMatrix_MakeScale_2'>[2]</a></sup>
---
<a name='SkMatrix_postRotate'></a>
## postRotate
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_postRotate'>postRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> constructed from rotating by <a href='#SkMatrix_postRotate_degrees'>degrees</a> about pivot point
(<a href='#SkMatrix_postRotate_px'>px</a>, <a href='#SkMatrix_postRotate_py'>py</a>), multiplied by <a href='#Matrix'>Matrix</a>.
This can be thought of as rotating about a pivot point after applying <a href='#Matrix'>Matrix</a>.
Positive <a href='#SkMatrix_postRotate_degrees'>degrees</a> rotates clockwise.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| J K L | | c -s dx |
Matrix = | M N O |, R(degrees, px, py) = | s c dy |
| P Q R | | 0 0 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
c = cos(degrees)
s = sin(degrees)
dx = s * py + (1 - c) * px
dy = -s * px + (1 - c) * py
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|c -s dx| |J K L| |cJ-sM+dx*P cK-sN+dx*Q cL-sO+dx+R|
R(degrees, px, py) * Matrix = |s c dy| |M N O| = |sJ+cM+dy*P sK+cN+dy*Q sL+cO+dy*R|
|0 0 1| |P Q R| | P Q R|
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_postRotate_degrees'><code><strong>degrees</strong></code></a></td>
<td>angle of axes relative to upright axes</td>
</tr>
<tr> <td><a name='SkMatrix_postRotate_px'><code><strong>px</strong></code></a></td>
<td>pivot x</td>
</tr>
<tr> <td><a name='SkMatrix_postRotate_py'><code><strong>py</strong></code></a></td>
<td>pivot y</td>
</tr>
</table>
### Example
<div><fiddle-embed name="e09194ee48a81e7b375ade473d340f0d"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_preRotate'>preRotate</a><sup><a href='#SkMatrix_preRotate_2'>[2]</a></sup> <a href='#SkMatrix_setRotate'>setRotate</a><sup><a href='#SkMatrix_setRotate_2'>[2]</a></sup>
---
<a name='SkMatrix_postRotate_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_postRotate'>postRotate</a>(<a href='undocumented#SkScalar'>SkScalar</a> degrees)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> constructed from rotating by <a href='#SkMatrix_postRotate_2_degrees'>degrees</a> about pivot point
(0, 0), multiplied by <a href='#Matrix'>Matrix</a>.
This can be thought of as rotating about the origin after applying <a href='#Matrix'>Matrix</a>.
Positive <a href='#SkMatrix_postRotate_2_degrees'>degrees</a> rotates clockwise.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| J K L | | c -s 0 |
Matrix = | M N O |, R(degrees, px, py) = | s c 0 |
| P Q R | | 0 0 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
c = cos(degrees)
s = sin(degrees)
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| c -s dx | | J K L | | cJ-sM cK-sN cL-sO |
R(degrees, px, py) * Matrix = | s c dy | | M N O | = | sJ+cM sK+cN sL+cO |
| 0 0 1 | | P Q R | | P Q R |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_postRotate_2_degrees'><code><strong>degrees</strong></code></a></td>
<td>angle of axes relative to upright axes</td>
</tr>
</table>
### Example
<div><fiddle-embed name="52e4c53e26971af5576b30de60fa70c2"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_preRotate'>preRotate</a><sup><a href='#SkMatrix_preRotate_2'>[2]</a></sup> <a href='#SkMatrix_setRotate'>setRotate</a><sup><a href='#SkMatrix_setRotate_2'>[2]</a></sup>
---
<a name='SkMatrix_postSkew'></a>
## postSkew
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_postSkew'>postSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky, <a href='undocumented#SkScalar'>SkScalar</a> px, <a href='undocumented#SkScalar'>SkScalar</a> py)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> constructed from skewing by (<a href='#SkMatrix_postSkew_kx'>kx</a>, <a href='#SkMatrix_postSkew_ky'>ky</a>) about pivot point
(<a href='#SkMatrix_postSkew_px'>px</a>, <a href='#SkMatrix_postSkew_py'>py</a>), multiplied by <a href='#Matrix'>Matrix</a>.
This can be thought of as skewing about a pivot point after applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| J K L | | 1 kx dx |
Matrix = | M N O |, K(kx, ky, px, py) = | ky 1 dy |
| P Q R | | 0 0 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
dx = -kx * py
dy = -ky * px
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 1 kx dx| |J K L| |J+kx*M+dx*P K+kx*N+dx*Q L+kx*O+dx+R|
K(kx, ky, px, py) * Matrix = |ky 1 dy| |M N O| = |ky*J+M+dy*P ky*K+N+dy*Q ky*L+O+dy*R|
| 0 0 1| |P Q R| | P Q R|
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_postSkew_kx'><code><strong>kx</strong></code></a></td>
<td>horizontal skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_postSkew_ky'><code><strong>ky</strong></code></a></td>
<td>vertical skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_postSkew_px'><code><strong>px</strong></code></a></td>
<td>pivot x</td>
</tr>
<tr> <td><a name='SkMatrix_postSkew_py'><code><strong>py</strong></code></a></td>
<td>pivot y</td>
</tr>
</table>
### Example
<div><fiddle-embed name="8c34ae3a2b7e2742bb969819737365ec"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_preSkew'>preSkew</a><sup><a href='#SkMatrix_preSkew_2'>[2]</a></sup> <a href='#SkMatrix_setSkew'>setSkew</a><sup><a href='#SkMatrix_setSkew_2'>[2]</a></sup>
---
<a name='SkMatrix_postSkew_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_postSkew'>postSkew</a>(<a href='undocumented#SkScalar'>SkScalar</a> kx, <a href='undocumented#SkScalar'>SkScalar</a> ky)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> constructed from skewing by (<a href='#SkMatrix_postSkew_2_kx'>kx</a>, <a href='#SkMatrix_postSkew_2_ky'>ky</a>) about pivot point
(0, 0), multiplied by <a href='#Matrix'>Matrix</a>.
This can be thought of as skewing about the origin after applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| J K L | | 1 kx 0 |
Matrix = | M N O |, K(kx, ky) = | ky 1 0 |
| P Q R | | 0 0 1 |
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 1 kx 0 | | J K L | | J+kx*M K+kx*N L+kx*O |
K(kx, ky) * Matrix = | ky 1 0 | | M N O | = | ky*J+M ky*K+N ky*L+O |
| 0 0 1 | | P Q R | | P Q R |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_postSkew_2_kx'><code><strong>kx</strong></code></a></td>
<td>horizontal skew factor</td>
</tr>
<tr> <td><a name='SkMatrix_postSkew_2_ky'><code><strong>ky</strong></code></a></td>
<td>vertical skew factor</td>
</tr>
</table>
### Example
<div><fiddle-embed name="3aa2603225dff72ac53dd359f897f494"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_preSkew'>preSkew</a><sup><a href='#SkMatrix_preSkew_2'>[2]</a></sup> <a href='#SkMatrix_setSkew'>setSkew</a><sup><a href='#SkMatrix_setSkew_2'>[2]</a></sup>
---
<a name='SkMatrix_postConcat'></a>
## postConcat
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_postConcat'>postConcat</a>(const <a href='#SkMatrix'>SkMatrix</a>& other)
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_postConcat_other'>other</a> multiplied by <a href='#Matrix'>Matrix</a>.
This can be thought of mapping by <a href='#SkMatrix_postConcat_other'>other</a> after applying <a href='#Matrix'>Matrix</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| J K L | | A B C |
Matrix = | M N O |, other = | D E F |
| P Q R | | G H I |
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | J K L | | AJ+BM+CP AK+BN+CQ AL+BO+CR |
other * Matrix = | D E F | * | M N O | = | DJ+EM+FP DK+EN+FQ DL+EO+FR |
| G H I | | P Q R | | GJ+HM+IP GK+HN+IQ GL+HO+IR |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_postConcat_other'><code><strong>other</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> on left side of multiply expression</td>
</tr>
</table>
### Example
<div><fiddle-embed name="e4226c55d9bdbc119264bd372b2b9835"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_preConcat'>preConcat</a> <a href='#SkMatrix_setConcat'>setConcat</a> <a href='#SkMatrix_Concat'>Concat</a>
---
## <a name='SkMatrix_ScaleToFit'>Enum SkMatrix::ScaleToFit</a>
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
enum <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> {
<a href='#SkMatrix_kFill_ScaleToFit'>kFill ScaleToFit</a>,
<a href='#SkMatrix_kStart_ScaleToFit'>kStart ScaleToFit</a>,
<a href='#SkMatrix_kCenter_ScaleToFit'>kCenter ScaleToFit</a>,
<a href='#SkMatrix_kEnd_ScaleToFit'>kEnd ScaleToFit</a>,
};
</pre>
<a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> describes how <a href='#Matrix'>Matrix</a> is constructed to map one <a href='SkRect_Reference#Rect'>Rect</a> to another.
<a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> may allow <a href='#Matrix'>Matrix</a> to have unequal horizontal and vertical scaling,
or may restrict <a href='#Matrix'>Matrix</a> to square scaling. If restricted, <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> specifies
how <a href='#Matrix'>Matrix</a> maps to the side or center of the destination <a href='SkRect_Reference#Rect'>Rect</a>.
### Constants
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Const</th>
<th style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>Value</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kFill_ScaleToFit'><code>SkMatrix::kFill_ScaleToFit</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>0</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
Computes <a href='#Matrix'>Matrix</a> that scales in x and y independently, so that source <a href='SkRect_Reference#Rect'>Rect</a> is
mapped to completely fill destination <a href='SkRect_Reference#Rect'>Rect</a>. The aspect ratio of source <a href='SkRect_Reference#Rect'>Rect</a>
may change.
</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kStart_ScaleToFit'><code>SkMatrix::kStart_ScaleToFit</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>1</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
Computes <a href='#Matrix'>Matrix</a> that maintains source <a href='SkRect_Reference#Rect'>Rect</a> aspect ratio, mapping source <a href='SkRect_Reference#Rect'>Rect</a>
width or height to destination <a href='SkRect_Reference#Rect'>Rect</a>. Aligns mapping to left and top edges
of destination <a href='SkRect_Reference#Rect'>Rect</a>.
</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kCenter_ScaleToFit'><code>SkMatrix::kCenter_ScaleToFit</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>2</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
Computes <a href='#Matrix'>Matrix</a> that maintains source <a href='SkRect_Reference#Rect'>Rect</a> aspect ratio, mapping source <a href='SkRect_Reference#Rect'>Rect</a>
width or height to destination <a href='SkRect_Reference#Rect'>Rect</a>. Aligns mapping to center of destination
<a href='SkRect_Reference#Rect'>Rect</a>.
</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='SkMatrix_kEnd_ScaleToFit'><code>SkMatrix::kEnd_ScaleToFit</code></a></td>
<td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>3</td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>
Computes <a href='#Matrix'>Matrix</a> that maintains source <a href='SkRect_Reference#Rect'>Rect</a> aspect ratio, mapping source <a href='SkRect_Reference#Rect'>Rect</a>
width or height to destination <a href='SkRect_Reference#Rect'>Rect</a>. Aligns mapping to right and bottom
edges of destination <a href='SkRect_Reference#Rect'>Rect</a>.
</td>
</tr>
</table>
### Example
<div><fiddle-embed name="17c3070b31b700ea8f52e48af9a66b6e"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setRectToRect'>setRectToRect</a> <a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a> <a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a>
<a name='SkMatrix_setRectToRect'></a>
## setRectToRect
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_setRectToRect'>setRectToRect</a>(const <a href='SkRect_Reference#SkRect'>SkRect</a>& src, const <a href='SkRect_Reference#SkRect'>SkRect</a>& dst, <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> stf)
</pre>
Sets <a href='#Matrix'>Matrix</a> to scale and translate <a href='#SkMatrix_setRectToRect_src'>src</a> <a href='SkRect_Reference#Rect'>Rect</a> to <a href='#SkMatrix_setRectToRect_dst'>dst</a> <a href='SkRect_Reference#Rect'>Rect</a>. <a href='#SkMatrix_setRectToRect_stf'>stf</a> selects whether
mapping completely fills <a href='#SkMatrix_setRectToRect_dst'>dst</a> or preserves the aspect ratio, and how to align
<a href='#SkMatrix_setRectToRect_src'>src</a> within <a href='#SkMatrix_setRectToRect_dst'>dst</a>. Returns false if <a href='#SkMatrix_setRectToRect_src'>src</a> is empty, and sets <a href='#Matrix'>Matrix</a> to identity.
Returns true if <a href='#SkMatrix_setRectToRect_dst'>dst</a> is empty, and sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 0 0 0 |
| 0 0 0 |
| 0 0 1 |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_setRectToRect_src'><code><strong>src</strong></code></a></td>
<td><a href='SkRect_Reference#Rect'>Rect</a> to map from</td>
</tr>
<tr> <td><a name='SkMatrix_setRectToRect_dst'><code><strong>dst</strong></code></a></td>
<td><a href='SkRect_Reference#Rect'>Rect</a> to map to</td>
</tr>
<tr> <td><a name='SkMatrix_setRectToRect_stf'><code><strong>stf</strong></code></a></td>
<td>one of: <a href='#SkMatrix_kFill_ScaleToFit'>kFill ScaleToFit</a>, <a href='#SkMatrix_kStart_ScaleToFit'>kStart ScaleToFit</a>,
<a href='#SkMatrix_kCenter_ScaleToFit'>kCenter ScaleToFit</a>, <a href='#SkMatrix_kEnd_ScaleToFit'>kEnd ScaleToFit</a></td>
</tr>
</table>
### Return Value
true if <a href='#Matrix'>Matrix</a> can represent <a href='SkRect_Reference#Rect'>Rect</a> mapping
### Example
<div><fiddle-embed name="69cdea599dcaaec35efcb24403f4287b">
#### Example Output
~~~~
src: 0, 0, 0, 0 dst: 0, 0, 0, 0 success: false
[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000]
src: 0, 0, 0, 0 dst: 5, 6, 8, 9 success: false
[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000]
src: 1, 2, 3, 4 dst: 0, 0, 0, 0 success: true
[ 0.0000 0.0000 0.0000][ 0.0000 0.0000 0.0000][ 0.0000 0.0000 1.0000]
src: 1, 2, 3, 4 dst: 5, 6, 8, 9 success: true
[ 1.5000 0.0000 3.5000][ 0.0000 1.5000 3.0000][ 0.0000 0.0000 1.0000]
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a> <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> <a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> <a href='SkRect_Reference#SkRect_isEmpty'>SkRect::isEmpty</a>
---
<a name='SkMatrix_MakeRectToRect'></a>
## MakeRectToRect
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
static <a href='#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a>(const <a href='SkRect_Reference#SkRect'>SkRect</a>& src, const <a href='SkRect_Reference#SkRect'>SkRect</a>& dst, <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> stf)
</pre>
Returns <a href='#Matrix'>Matrix</a> set to scale and translate <a href='#SkMatrix_MakeRectToRect_src'>src</a> <a href='SkRect_Reference#Rect'>Rect</a> to <a href='#SkMatrix_MakeRectToRect_dst'>dst</a> <a href='SkRect_Reference#Rect'>Rect</a>. <a href='#SkMatrix_MakeRectToRect_stf'>stf</a> selects
whether mapping completely fills <a href='#SkMatrix_MakeRectToRect_dst'>dst</a> or preserves the aspect ratio, and how to
align <a href='#SkMatrix_MakeRectToRect_src'>src</a> within <a href='#SkMatrix_MakeRectToRect_dst'>dst</a>. Returns the identity <a href='#Matrix'>Matrix</a> if <a href='#SkMatrix_MakeRectToRect_src'>src</a> is empty. If <a href='#SkMatrix_MakeRectToRect_dst'>dst</a> is
empty, returns <a href='#Matrix'>Matrix</a> set to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 0 0 0 |
| 0 0 0 |
| 0 0 1 |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_MakeRectToRect_src'><code><strong>src</strong></code></a></td>
<td><a href='SkRect_Reference#Rect'>Rect</a> to map from</td>
</tr>
<tr> <td><a name='SkMatrix_MakeRectToRect_dst'><code><strong>dst</strong></code></a></td>
<td><a href='SkRect_Reference#Rect'>Rect</a> to map to</td>
</tr>
<tr> <td><a name='SkMatrix_MakeRectToRect_stf'><code><strong>stf</strong></code></a></td>
<td>one of: <a href='#SkMatrix_kFill_ScaleToFit'>kFill ScaleToFit</a>, <a href='#SkMatrix_kStart_ScaleToFit'>kStart ScaleToFit</a>,
<a href='#SkMatrix_kCenter_ScaleToFit'>kCenter ScaleToFit</a>, <a href='#SkMatrix_kEnd_ScaleToFit'>kEnd ScaleToFit</a></td>
</tr>
</table>
### Return Value
<a href='#Matrix'>Matrix</a> mapping <a href='#SkMatrix_MakeRectToRect_src'>src</a> to <a href='#SkMatrix_MakeRectToRect_dst'>dst</a>
### Example
<div><fiddle-embed name="a1d6a6721b39350f81021f71a1b93208">
#### Example Output
~~~~
src: 0, 0, 0, 0 dst: 0, 0, 0, 0
[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000]
src: 0, 0, 0, 0 dst: 5, 6, 8, 9
[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000]
src: 1, 2, 3, 4 dst: 0, 0, 0, 0
[ 0.0000 0.0000 0.0000][ 0.0000 0.0000 0.0000][ 0.0000 0.0000 1.0000]
src: 1, 2, 3, 4 dst: 5, 6, 8, 9
[ 1.5000 0.0000 3.5000][ 0.0000 1.5000 3.0000][ 0.0000 0.0000 1.0000]
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_setRectToRect'>setRectToRect</a> <a href='#SkMatrix_ScaleToFit'>ScaleToFit</a> <a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> <a href='SkRect_Reference#SkRect_isEmpty'>SkRect::isEmpty</a>
---
<a name='SkMatrix_setPolyToPoly'></a>
## setPolyToPoly
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a>(const <a href='SkPoint_Reference#SkPoint'>SkPoint</a> src[], const <a href='SkPoint_Reference#SkPoint'>SkPoint</a> dst[], int count)
</pre>
Sets <a href='#Matrix'>Matrix</a> to map <a href='#SkMatrix_setPolyToPoly_src'>src</a> to <a href='#SkMatrix_setPolyToPoly_dst'>dst</a>. <a href='#SkMatrix_setPolyToPoly_count'>count</a> must be zero or greater, and four or less.
If <a href='#SkMatrix_setPolyToPoly_count'>count</a> is zero, sets <a href='#Matrix'>Matrix</a> to identity and returns true.
If <a href='#SkMatrix_setPolyToPoly_count'>count</a> is one, sets <a href='#Matrix'>Matrix</a> to translate and returns true.
If <a href='#SkMatrix_setPolyToPoly_count'>count</a> is two or more, sets <a href='#Matrix'>Matrix</a> to map <a href='SkPoint_Reference#Point'>Points</a> if possible; returns false
if <a href='#Matrix'>Matrix</a> cannot be constructed. If <a href='#SkMatrix_setPolyToPoly_count'>count</a> is four, <a href='#Matrix'>Matrix</a> may include
perspective.
### Parameters
<table> <tr> <td><a name='SkMatrix_setPolyToPoly_src'><code><strong>src</strong></code></a></td>
<td><a href='SkPoint_Reference#Point'>Points</a> to map from</td>
</tr>
<tr> <td><a name='SkMatrix_setPolyToPoly_dst'><code><strong>dst</strong></code></a></td>
<td><a href='SkPoint_Reference#Point'>Points</a> to map to</td>
</tr>
<tr> <td><a name='SkMatrix_setPolyToPoly_count'><code><strong>count</strong></code></a></td>
<td>number of <a href='SkPoint_Reference#Point'>Points</a> in <a href='#SkMatrix_setPolyToPoly_src'>src</a> and <a href='#SkMatrix_setPolyToPoly_dst'>dst</a></td>
</tr>
</table>
### Return Value
true if <a href='#Matrix'>Matrix</a> was constructed successfully
### Example
<div><fiddle-embed name="c851d1313e8909aaea4f0591699fdb7b"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_setRectToRect'>setRectToRect</a> <a href='#SkMatrix_MakeRectToRect'>MakeRectToRect</a>
---
<a name='SkMatrix_invert'></a>
## invert
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool SK_WARN_UNUSED_RESULT <a href='#SkMatrix_invert'>invert</a>(<a href='#SkMatrix'>SkMatrix</a>* inverse) const
</pre>
Sets <a href='#SkMatrix_invert_inverse'>inverse</a> to reciprocal matrix, returning true if <a href='#Matrix'>Matrix</a> can be inverted.
Geometrically, if <a href='#Matrix'>Matrix</a> maps from source to destination, <a href='#SkMatrix_invert_inverse'>inverse</a> <a href='#Matrix'>Matrix</a>
maps from destination to source. If <a href='#Matrix'>Matrix</a> can not be inverted, <a href='#SkMatrix_invert_inverse'>inverse</a> is
unchanged.
### Parameters
<table> <tr> <td><a name='SkMatrix_invert_inverse'><code><strong>inverse</strong></code></a></td>
<td>storage for inverted <a href='#Matrix'>Matrix</a>; may be nullptr</td>
</tr>
</table>
### Return Value
true if <a href='#Matrix'>Matrix</a> can be inverted
### Example
<div><fiddle-embed name="0e03cd9f154603ed4b21ca56d69dae44"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_Concat'>Concat</a>
---
<a name='SkMatrix_SetAffineIdentity'></a>
## SetAffineIdentity
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
static void <a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a>(<a href='undocumented#SkScalar'>SkScalar</a> affine[6])
</pre>
Fills <a href='#SkMatrix_SetAffineIdentity_affine'>affine</a> with identity values in column major order.
Sets <a href='#SkMatrix_SetAffineIdentity_affine'>affine</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 1 0 0 |
| 0 1 0 |
</pre>
Affine 3x2 matrices in column major order are used by OpenGL and XPS.
### Parameters
<table> <tr> <td><a name='SkMatrix_SetAffineIdentity_affine'><code><strong>affine</strong></code></a></td>
<td>storage for 3x2 <a href='#SkMatrix_SetAffineIdentity_affine'>affine</a> matrix</td>
</tr>
</table>
### Example
<div><fiddle-embed name="e10adbd0bcc940c5d4d872db0e78e892">
#### Example Output
~~~~
ScaleX: 1 SkewY: 0 SkewX: 0 ScaleY: 1 TransX: 0 TransY: 0
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_setAffine'>setAffine</a> <a href='#SkMatrix_asAffine'>asAffine</a>
---
<a name='SkMatrix_asAffine'></a>
## asAffine
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool SK_WARN_UNUSED_RESULT <a href='#SkMatrix_asAffine'>asAffine</a>(<a href='undocumented#SkScalar'>SkScalar</a> affine[6]) const
</pre>
Fills <a href='#SkMatrix_asAffine_affine'>affine</a> in column major order. Sets <a href='#SkMatrix_asAffine_affine'>affine</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| scale-x skew-x translate-x |
| skew-y scale-y translate-y |
</pre>
If <a href='#Matrix'>Matrix</a> contains perspective, returns false and leaves <a href='#SkMatrix_asAffine_affine'>affine</a> unchanged.
### Parameters
<table> <tr> <td><a name='SkMatrix_asAffine_affine'><code><strong>affine</strong></code></a></td>
<td>storage for 3x2 <a href='#SkMatrix_asAffine_affine'>affine</a> matrix; may be nullptr</td>
</tr>
</table>
### Return Value
true if <a href='#Matrix'>Matrix</a> does not contain perspective
### Example
<div><fiddle-embed name="3325bdf82bd86d9fbc4199f248afa82c">
#### Example Output
~~~~
ScaleX: 2 SkewY: 5 SkewX: 3 ScaleY: 6 TransX: 4 TransY: 7
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_setAffine'>setAffine</a> <a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a>
---
<a name='SkMatrix_setAffine'></a>
## setAffine
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setAffine'>setAffine</a>(const <a href='undocumented#SkScalar'>SkScalar</a> affine[6])
</pre>
Sets <a href='#Matrix'>Matrix</a> to <a href='#SkMatrix_setAffine_affine'>affine</a> values, passed in column major order. Given <a href='#SkMatrix_setAffine_affine'>affine</a>,
column, then row, as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| scale-x skew-x translate-x |
| skew-y scale-y translate-y |
</pre>
<a href='#Matrix'>Matrix</a> is set, row, then column, to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| scale-x skew-x translate-x |
| skew-y scale-y translate-y |
| 0 0 1 |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_setAffine_affine'><code><strong>affine</strong></code></a></td>
<td>3x2 <a href='#SkMatrix_setAffine_affine'>affine</a> matrix</td>
</tr>
</table>
### Example
<div><fiddle-embed name="f5b6d371c4d65e5b5ac6eebdd4b237d8">
#### Example Output
~~~~
ScaleX: 2 SkewY: 5 SkewX: 3 ScaleY: 6 TransX: 4 TransY: 7
[ 2.0000 3.0000 4.0000][ 5.0000 6.0000 7.0000][ 0.0000 0.0000 1.0000]
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_asAffine'>asAffine</a> <a href='#SkMatrix_SetAffineIdentity'>SetAffineIdentity</a>
---
## <a name='Transform'>Transform</a>
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapHomogeneousPoints'>mapHomogeneousPoints</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='undocumented#Point3'>Point3</a> array</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapPoints'>mapPoints</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='SkPoint_Reference#Point'>Point</a> array</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapPoints'>mapPoints(SkPoint dst[], const SkPoint src[], int count)</a> const</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapPoints_2'>mapPoints(SkPoint pts[], int count)</a> const</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRadius'>mapRadius</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns mean radius of mapped <a href='undocumented#Circle'>Circle</a></td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRect'>mapRect</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns bounds of mapped <a href='SkRect_Reference#Rect'>Rect</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRect'>mapRect(SkRect* dst, const SkRect& src)</a> const</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRect_2'>mapRect(SkRect* rect)</a> const</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRect_3'>mapRect(const SkRect& src)</a> const</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>returns bounds of mapped <a href='SkRect_Reference#Rect'>Rect</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapRectToQuad'>mapRectToQuad</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='SkRect_Reference#Rect'>Rect</a> to <a href='SkPoint_Reference#Point'>Point</a> array</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapVector'>mapVector</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='SkPoint_Reference#Vector'>Vector</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapVector'>mapVector(SkScalar dx, SkScalar dy, SkVector* result)</a> const</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapVector_2'>mapVector(SkScalar dx, SkScalar dy)</a> const</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapVectors'>mapVectors</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='SkPoint_Reference#Vector'>Vector</a> array</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapVectors'>mapVectors(SkVector dst[], const SkVector src[], int count)</a> const</td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapVectors_2'>mapVectors(SkVector vecs[], int count)</a> const</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapXY'>mapXY</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>maps <a href='SkPoint_Reference#Point'>Point</a></td>
</tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapXY'>mapXY(SkScalar x, SkScalar y, SkPoint* result)</a> const</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_mapXY_2'>mapXY(SkScalar x, SkScalar y)</a> const</td>
</tr>
</table>
<a name='SkMatrix_mapPoints'></a>
## mapPoints
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_mapPoints'>mapPoints</a>(<a href='SkPoint_Reference#SkPoint'>SkPoint</a> dst[], const <a href='SkPoint_Reference#SkPoint'>SkPoint</a> src[], int count) const
</pre>
Maps <a href='#SkMatrix_mapPoints_src'>src</a> <a href='SkPoint_Reference#Point'>Point</a> array of length <a href='#SkMatrix_mapPoints_count'>count</a> to <a href='#SkMatrix_mapPoints_dst'>dst</a> <a href='SkPoint_Reference#Point'>Point</a> array of equal or greater
length. <a href='SkPoint_Reference#Point'>Points</a> are mapped by multiplying each <a href='SkPoint_Reference#Point'>Point</a> by <a href='#Matrix'>Matrix</a>. Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | x |
Matrix = | D E F |, pt = | y |
| G H I | | 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
for (i = 0; i < count; ++i) {
x = src[i].fX
y = src[i].fY
}
</pre>
each <a href='#SkMatrix_mapPoints_dst'>dst</a> <a href='SkPoint_Reference#Point'>Point</a> is computed as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|A B C| |x| Ax+By+C Dx+Ey+F
Matrix * pt = |D E F| |y| = |Ax+By+C Dx+Ey+F Gx+Hy+I| = ------- , -------
|G H I| |1| Gx+Hy+I Gx+Hy+I
</pre>
<a href='#SkMatrix_mapPoints_src'>src</a> and <a href='#SkMatrix_mapPoints_dst'>dst</a> may point to the same storage.
### Parameters
<table> <tr> <td><a name='SkMatrix_mapPoints_dst'><code><strong>dst</strong></code></a></td>
<td>storage for mapped <a href='SkPoint_Reference#Point'>Points</a></td>
</tr>
<tr> <td><a name='SkMatrix_mapPoints_src'><code><strong>src</strong></code></a></td>
<td><a href='SkPoint_Reference#Point'>Points</a> to transform</td>
</tr>
<tr> <td><a name='SkMatrix_mapPoints_count'><code><strong>count</strong></code></a></td>
<td>number of <a href='SkPoint_Reference#Point'>Points</a> to transform</td>
</tr>
</table>
### Example
<div><fiddle-embed name="f99dcb00296d0c56b6c0e178e94b3534"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapXY'>mapXY</a><sup><a href='#SkMatrix_mapXY_2'>[2]</a></sup> <a href='#SkMatrix_mapHomogeneousPoints'>mapHomogeneousPoints</a> <a href='#SkMatrix_mapVectors'>mapVectors</a><sup><a href='#SkMatrix_mapVectors_2'>[2]</a></sup>
---
<a name='SkMatrix_mapPoints_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_mapPoints'>mapPoints</a>(<a href='SkPoint_Reference#SkPoint'>SkPoint</a> pts[], int count) const
</pre>
Maps <a href='#SkMatrix_mapPoints_2_pts'>pts</a> <a href='SkPoint_Reference#Point'>Point</a> array of length <a href='#SkMatrix_mapPoints_2_count'>count</a> in place. <a href='SkPoint_Reference#Point'>Points</a> are mapped by multiplying
each <a href='SkPoint_Reference#Point'>Point</a> by <a href='#Matrix'>Matrix</a>. Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | x |
Matrix = | D E F |, pt = | y |
| G H I | | 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
for (i = 0; i < count; ++i) {
x = pts[i].fX
y = pts[i].fY
}
</pre>
each resulting <a href='#SkMatrix_mapPoints_2_pts'>pts</a> <a href='SkPoint_Reference#Point'>Point</a> is computed as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|A B C| |x| Ax+By+C Dx+Ey+F
Matrix * pt = |D E F| |y| = |Ax+By+C Dx+Ey+F Gx+Hy+I| = ------- , -------
|G H I| |1| Gx+Hy+I Gx+Hy+I
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_mapPoints_2_pts'><code><strong>pts</strong></code></a></td>
<td>storage for mapped <a href='SkPoint_Reference#Point'>Points</a></td>
</tr>
<tr> <td><a name='SkMatrix_mapPoints_2_count'><code><strong>count</strong></code></a></td>
<td>number of <a href='SkPoint_Reference#Point'>Points</a> to transform</td>
</tr>
</table>
### Example
<div><fiddle-embed name="428ca171ae3bd0d3f992458ac598b97b"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapXY'>mapXY</a><sup><a href='#SkMatrix_mapXY_2'>[2]</a></sup> <a href='#SkMatrix_mapHomogeneousPoints'>mapHomogeneousPoints</a> <a href='#SkMatrix_mapVectors'>mapVectors</a><sup><a href='#SkMatrix_mapVectors_2'>[2]</a></sup>
---
<a name='SkMatrix_mapHomogeneousPoints'></a>
## mapHomogeneousPoints
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_mapHomogeneousPoints'>mapHomogeneousPoints</a>(<a href='undocumented#SkPoint3'>SkPoint3</a> dst[], const <a href='undocumented#SkPoint3'>SkPoint3</a> src[], int count) const
</pre>
Maps <a href='#SkMatrix_mapHomogeneousPoints_src'>src</a> <a href='undocumented#Point3'>Point3</a> array of length <a href='#SkMatrix_mapHomogeneousPoints_count'>count</a> to <a href='#SkMatrix_mapHomogeneousPoints_dst'>dst</a> <a href='undocumented#Point3'>Point3</a> array, which must of length <a href='#SkMatrix_mapHomogeneousPoints_count'>count</a> or
greater. <a href='undocumented#Point3'>Point3</a> array is mapped by multiplying each <a href='undocumented#Point3'>Point3</a> by <a href='#Matrix'>Matrix</a>. Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | x |
Matrix = | D E F |, src = | y |
| G H I | | z |
</pre>
each resulting <a href='#SkMatrix_mapHomogeneousPoints_dst'>dst</a> <a href='SkPoint_Reference#Point'>Point</a> is computed as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|A B C| |x|
Matrix * src = |D E F| |y| = |Ax+By+Cz Dx+Ey+Fz Gx+Hy+Iz|
|G H I| |z|
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_mapHomogeneousPoints_dst'><code><strong>dst</strong></code></a></td>
<td>storage for mapped <a href='undocumented#Point3'>Point3</a> array</td>
</tr>
<tr> <td><a name='SkMatrix_mapHomogeneousPoints_src'><code><strong>src</strong></code></a></td>
<td><a href='undocumented#Point3'>Point3</a> array to transform</td>
</tr>
<tr> <td><a name='SkMatrix_mapHomogeneousPoints_count'><code><strong>count</strong></code></a></td>
<td>items in <a href='undocumented#Point3'>Point3</a> array to transform</td>
</tr>
</table>
### Example
<div><fiddle-embed name="d56f93e4bc763c7ba4914321ed07a8b5"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapPoints'>mapPoints</a><sup><a href='#SkMatrix_mapPoints_2'>[2]</a></sup> <a href='#SkMatrix_mapXY'>mapXY</a><sup><a href='#SkMatrix_mapXY_2'>[2]</a></sup> <a href='#SkMatrix_mapVectors'>mapVectors</a><sup><a href='#SkMatrix_mapVectors_2'>[2]</a></sup>
---
<a name='SkMatrix_mapXY'></a>
## mapXY
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_mapXY'>mapXY</a>(<a href='undocumented#SkScalar'>SkScalar</a> x, <a href='undocumented#SkScalar'>SkScalar</a> y, <a href='SkPoint_Reference#SkPoint'>SkPoint</a>* result) const
</pre>
Maps <a href='SkPoint_Reference#Point'>Point</a> (<a href='#SkMatrix_mapXY_x'>x</a>, <a href='#SkMatrix_mapXY_y'>y</a>) to <a href='#SkMatrix_mapXY_result'>result</a>. <a href='SkPoint_Reference#Point'>Point</a> is mapped by multiplying by <a href='#Matrix'>Matrix</a>. Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | x |
Matrix = | D E F |, pt = | y |
| G H I | | 1 |
</pre>
<a href='#SkMatrix_mapXY_result'>result</a> is computed as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|A B C| |x| Ax+By+C Dx+Ey+F
Matrix * pt = |D E F| |y| = |Ax+By+C Dx+Ey+F Gx+Hy+I| = ------- , -------
|G H I| |1| Gx+Hy+I Gx+Hy+I
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_mapXY_x'><code><strong>x</strong></code></a></td>
<td><a href='#SkMatrix_mapXY_x'>x</a>-axis value of <a href='SkPoint_Reference#Point'>Point</a> to map</td>
</tr>
<tr> <td><a name='SkMatrix_mapXY_y'><code><strong>y</strong></code></a></td>
<td><a href='#SkMatrix_mapXY_y'>y</a>-axis value of <a href='SkPoint_Reference#Point'>Point</a> to map</td>
</tr>
<tr> <td><a name='SkMatrix_mapXY_result'><code><strong>result</strong></code></a></td>
<td>storage for mapped <a href='SkPoint_Reference#Point'>Point</a></td>
</tr>
</table>
### Example
<div><fiddle-embed name="9e50185d502dc6903783679a84106089"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapPoints'>mapPoints</a><sup><a href='#SkMatrix_mapPoints_2'>[2]</a></sup> <a href='#SkMatrix_mapVectors'>mapVectors</a><sup><a href='#SkMatrix_mapVectors_2'>[2]</a></sup>
---
<a name='SkMatrix_mapXY_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='SkPoint_Reference#SkPoint'>SkPoint</a> <a href='#SkMatrix_mapXY'>mapXY</a>(<a href='undocumented#SkScalar'>SkScalar</a> x, <a href='undocumented#SkScalar'>SkScalar</a> y) const
</pre>
Returns <a href='SkPoint_Reference#Point'>Point</a> (<a href='#SkMatrix_mapXY_2_x'>x</a>, <a href='#SkMatrix_mapXY_2_y'>y</a>) multiplied by <a href='#Matrix'>Matrix</a>. Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | x |
Matrix = | D E F |, pt = | y |
| G H I | | 1 |
</pre>
result is computed as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|A B C| |x| Ax+By+C Dx+Ey+F
Matrix * pt = |D E F| |y| = |Ax+By+C Dx+Ey+F Gx+Hy+I| = ------- , -------
|G H I| |1| Gx+Hy+I Gx+Hy+I
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_mapXY_2_x'><code><strong>x</strong></code></a></td>
<td><a href='#SkMatrix_mapXY_2_x'>x</a>-axis value of <a href='SkPoint_Reference#Point'>Point</a> to map</td>
</tr>
<tr> <td><a name='SkMatrix_mapXY_2_y'><code><strong>y</strong></code></a></td>
<td><a href='#SkMatrix_mapXY_2_y'>y</a>-axis value of <a href='SkPoint_Reference#Point'>Point</a> to map</td>
</tr>
</table>
### Return Value
mapped <a href='SkPoint_Reference#Point'>Point</a>
### Example
<div><fiddle-embed name="b1ead09c67a177ab8eace12b061610a7"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapPoints'>mapPoints</a><sup><a href='#SkMatrix_mapPoints_2'>[2]</a></sup> <a href='#SkMatrix_mapVectors'>mapVectors</a><sup><a href='#SkMatrix_mapVectors_2'>[2]</a></sup>
---
<a name='SkMatrix_mapVectors'></a>
## mapVectors
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_mapVectors'>mapVectors</a>(<a href='SkPoint_Reference#SkVector'>SkVector</a> dst[], const <a href='SkPoint_Reference#SkVector'>SkVector</a> src[], int count) const
</pre>
Maps <a href='#SkMatrix_mapVectors_src'>src</a> <a href='SkPoint_Reference#Vector'>Vector</a> array of length <a href='#SkMatrix_mapVectors_count'>count</a> to <a href='SkPoint_Reference#Vector'>Vector</a> <a href='SkPoint_Reference#Point'>Point</a> array of equal or greater
length. <a href='SkPoint_Reference#Vector'>Vectors</a> are mapped by multiplying each <a href='SkPoint_Reference#Vector'>Vector</a> by <a href='#Matrix'>Matrix</a>, treating
<a href='#Matrix'>Matrix</a> translation as zero. Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B 0 | | x |
Matrix = | D E 0 |, src = | y |
| G H I | | 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
for (i = 0; i < count; ++i) {
x = src[i].fX
y = src[i].fY
}
</pre>
each <a href='#SkMatrix_mapVectors_dst'>dst</a> <a href='SkPoint_Reference#Vector'>Vector</a> is computed as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|A B 0| |x| Ax+By Dx+Ey
Matrix * src = |D E 0| |y| = |Ax+By Dx+Ey Gx+Hy+I| = ------- , -------
|G H I| |1| Gx+Hy+I Gx+Hy+I
</pre>
<a href='#SkMatrix_mapVectors_src'>src</a> and <a href='#SkMatrix_mapVectors_dst'>dst</a> may point to the same storage.
### Parameters
<table> <tr> <td><a name='SkMatrix_mapVectors_dst'><code><strong>dst</strong></code></a></td>
<td>storage for mapped <a href='SkPoint_Reference#Vector'>Vectors</a></td>
</tr>
<tr> <td><a name='SkMatrix_mapVectors_src'><code><strong>src</strong></code></a></td>
<td><a href='SkPoint_Reference#Vector'>Vectors</a> to transform</td>
</tr>
<tr> <td><a name='SkMatrix_mapVectors_count'><code><strong>count</strong></code></a></td>
<td>number of <a href='SkPoint_Reference#Vector'>Vectors</a> to transform</td>
</tr>
</table>
### Example
<div><fiddle-embed name="918a9778c3d7d5cb306692784399f6dc"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapVector'>mapVector</a><sup><a href='#SkMatrix_mapVector_2'>[2]</a></sup> <a href='#SkMatrix_mapPoints'>mapPoints</a><sup><a href='#SkMatrix_mapPoints_2'>[2]</a></sup> <a href='#SkMatrix_mapXY'>mapXY</a><sup><a href='#SkMatrix_mapXY_2'>[2]</a></sup>
---
<a name='SkMatrix_mapVectors_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_mapVectors'>mapVectors</a>(<a href='SkPoint_Reference#SkVector'>SkVector</a> vecs[], int count) const
</pre>
Maps <a href='#SkMatrix_mapVectors_2_vecs'>vecs</a> <a href='SkPoint_Reference#Vector'>Vector</a> array of length <a href='#SkMatrix_mapVectors_2_count'>count</a> in place, multiplying each <a href='SkPoint_Reference#Vector'>Vector</a> by
<a href='#Matrix'>Matrix</a>, treating <a href='#Matrix'>Matrix</a> translation as zero. Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B 0 | | x |
Matrix = | D E 0 |, vec = | y |
| G H I | | 1 |
</pre>
where
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
for (i = 0; i < count; ++i) {
x = vecs[i].fX
y = vecs[i].fY
}
</pre>
each result <a href='SkPoint_Reference#Vector'>Vector</a> is computed as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|A B 0| |x| Ax+By Dx+Ey
Matrix * vec = |D E 0| |y| = |Ax+By Dx+Ey Gx+Hy+I| = ------- , -------
|G H I| |1| Gx+Hy+I Gx+Hy+I
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_mapVectors_2_vecs'><code><strong>vecs</strong></code></a></td>
<td><a href='SkPoint_Reference#Vector'>Vectors</a> to transform, and storage for mapped <a href='SkPoint_Reference#Vector'>Vectors</a></td>
</tr>
<tr> <td><a name='SkMatrix_mapVectors_2_count'><code><strong>count</strong></code></a></td>
<td>number of <a href='SkPoint_Reference#Vector'>Vectors</a> to transform</td>
</tr>
</table>
### Example
<div><fiddle-embed name="5754501a00a1323e76353fb53153e939"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapVector'>mapVector</a><sup><a href='#SkMatrix_mapVector_2'>[2]</a></sup> <a href='#SkMatrix_mapPoints'>mapPoints</a><sup><a href='#SkMatrix_mapPoints_2'>[2]</a></sup> <a href='#SkMatrix_mapXY'>mapXY</a><sup><a href='#SkMatrix_mapXY_2'>[2]</a></sup>
---
<a name='SkMatrix_mapVector'></a>
## mapVector
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_mapVector'>mapVector</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy, <a href='SkPoint_Reference#SkVector'>SkVector</a>* result) const
</pre>
Maps <a href='SkPoint_Reference#Vector'>Vector</a> (x, y) to <a href='#SkMatrix_mapVector_result'>result</a>. <a href='SkPoint_Reference#Vector'>Vector</a> is mapped by multiplying by <a href='#Matrix'>Matrix</a>,
treating <a href='#Matrix'>Matrix</a> translation as zero. Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B 0 | | dx |
Matrix = | D E 0 |, vec = | dy |
| G H I | | 1 |
</pre>
each <a href='#SkMatrix_mapVector_result'>result</a> <a href='SkPoint_Reference#Vector'>Vector</a> is computed as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|A B 0| |dx| A*dx+B*dy D*dx+E*dy
Matrix * vec = |D E 0| |dy| = |A*dx+B*dy D*dx+E*dy G*dx+H*dy+I| = ----------- , -----------
|G H I| | 1| G*dx+H*dy+I G*dx+*dHy+I
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_mapVector_dx'><code><strong>dx</strong></code></a></td>
<td>x-axis value of <a href='SkPoint_Reference#Vector'>Vector</a> to map</td>
</tr>
<tr> <td><a name='SkMatrix_mapVector_dy'><code><strong>dy</strong></code></a></td>
<td>y-axis value of <a href='SkPoint_Reference#Vector'>Vector</a> to map</td>
</tr>
<tr> <td><a name='SkMatrix_mapVector_result'><code><strong>result</strong></code></a></td>
<td>storage for mapped <a href='SkPoint_Reference#Vector'>Vector</a></td>
</tr>
</table>
### Example
<div><fiddle-embed name="aed143fc6cd0bce4ed029b98d1e61f2d"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapVectors'>mapVectors</a><sup><a href='#SkMatrix_mapVectors_2'>[2]</a></sup> <a href='#SkMatrix_mapPoints'>mapPoints</a><sup><a href='#SkMatrix_mapPoints_2'>[2]</a></sup> <a href='#SkMatrix_mapXY'>mapXY</a><sup><a href='#SkMatrix_mapXY_2'>[2]</a></sup>
---
<a name='SkMatrix_mapVector_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='SkPoint_Reference#SkVector'>SkVector</a> <a href='#SkMatrix_mapVector'>mapVector</a>(<a href='undocumented#SkScalar'>SkScalar</a> dx, <a href='undocumented#SkScalar'>SkScalar</a> dy) const
</pre>
Returns <a href='SkPoint_Reference#Vector'>Vector</a> (x, y) multiplied by <a href='#Matrix'>Matrix</a>, treating <a href='#Matrix'>Matrix</a> translation as zero.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B 0 | | dx |
Matrix = | D E 0 |, vec = | dy |
| G H I | | 1 |
</pre>
each result <a href='SkPoint_Reference#Vector'>Vector</a> is computed as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|A B 0| |dx| A*dx+B*dy D*dx+E*dy
Matrix * vec = |D E 0| |dy| = |A*dx+B*dy D*dx+E*dy G*dx+H*dy+I| = ----------- , -----------
|G H I| | 1| G*dx+H*dy+I G*dx+*dHy+I
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_mapVector_2_dx'><code><strong>dx</strong></code></a></td>
<td>x-axis value of <a href='SkPoint_Reference#Vector'>Vector</a> to map</td>
</tr>
<tr> <td><a name='SkMatrix_mapVector_2_dy'><code><strong>dy</strong></code></a></td>
<td>y-axis value of <a href='SkPoint_Reference#Vector'>Vector</a> to map</td>
</tr>
</table>
### Return Value
mapped <a href='SkPoint_Reference#Vector'>Vector</a>
### Example
<div><fiddle-embed name="8bf1518db3f369696cd3065b541a8bd7"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapVectors'>mapVectors</a><sup><a href='#SkMatrix_mapVectors_2'>[2]</a></sup> <a href='#SkMatrix_mapPoints'>mapPoints</a><sup><a href='#SkMatrix_mapPoints_2'>[2]</a></sup> <a href='#SkMatrix_mapXY'>mapXY</a><sup><a href='#SkMatrix_mapXY_2'>[2]</a></sup>
---
<a name='SkMatrix_mapRect'></a>
## mapRect
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_mapRect'>mapRect</a>(<a href='SkRect_Reference#SkRect'>SkRect</a>* dst, const <a href='SkRect_Reference#SkRect'>SkRect</a>& src) const
</pre>
Sets <a href='#SkMatrix_mapRect_dst'>dst</a> to bounds of <a href='#SkMatrix_mapRect_src'>src</a> corners mapped by <a href='#Matrix'>Matrix</a>.
Returns true if mapped corners are <a href='#SkMatrix_mapRect_dst'>dst</a> corners.
Returned value is the same as calling <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>.
### Parameters
<table> <tr> <td><a name='SkMatrix_mapRect_dst'><code><strong>dst</strong></code></a></td>
<td>storage for bounds of mapped <a href='SkPoint_Reference#Point'>Points</a></td>
</tr>
<tr> <td><a name='SkMatrix_mapRect_src'><code><strong>src</strong></code></a></td>
<td><a href='SkRect_Reference#Rect'>Rect</a> to map</td>
</tr>
</table>
### Return Value
true if <a href='#SkMatrix_mapRect_dst'>dst</a> is equivalent to mapped <a href='#SkMatrix_mapRect_src'>src</a>
### Example
<div><fiddle-embed name="dbcf928b035a31ca69c99392e2e2cca9"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapPoints'>mapPoints</a><sup><a href='#SkMatrix_mapPoints_2'>[2]</a></sup> <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>
---
<a name='SkMatrix_mapRect_2'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_mapRect'>mapRect</a>(<a href='SkRect_Reference#SkRect'>SkRect</a>* rect) const
</pre>
Sets <a href='#SkMatrix_mapRect_2_rect'>rect</a> to bounds of <a href='#SkMatrix_mapRect_2_rect'>rect</a> corners mapped by <a href='#Matrix'>Matrix</a>.
Returns true if mapped corners are computed <a href='#SkMatrix_mapRect_2_rect'>rect</a> corners.
Returned value is the same as calling <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>.
### Parameters
<table> <tr> <td><a name='SkMatrix_mapRect_2_rect'><code><strong>rect</strong></code></a></td>
<td>rectangle to map, and storage for bounds of mapped corners</td>
</tr>
</table>
### Return Value
true if result is equivalent to mapped src
### Example
<div><fiddle-embed name="5fafd0bd23d1ed37425b970b4a3c6cc9"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a> <a href='#SkMatrix_mapPoints'>mapPoints</a><sup><a href='#SkMatrix_mapPoints_2'>[2]</a></sup> <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>
---
<a name='SkMatrix_mapRect_3'></a>
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='SkRect_Reference#SkRect'>SkRect</a> <a href='#SkMatrix_mapRect'>mapRect</a>(const <a href='SkRect_Reference#SkRect'>SkRect</a>& src) const
</pre>
Returns bounds of <a href='#SkMatrix_mapRect_3_src'>src</a> corners mapped by <a href='#Matrix'>Matrix</a>.
### Parameters
<table> <tr> <td><a name='SkMatrix_mapRect_3_src'><code><strong>src</strong></code></a></td>
<td>rectangle to map</td>
</tr>
</table>
### Return Value
mapped bounds
### Example
<div><fiddle-embed name="3b7b1f884437ab450f986234e4aec27f"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapRectToQuad'>mapRectToQuad</a> <a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a>
---
<a name='SkMatrix_mapRectToQuad'></a>
## mapRectToQuad
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_mapRectToQuad'>mapRectToQuad</a>(<a href='SkPoint_Reference#SkPoint'>SkPoint</a> dst[4], const <a href='SkRect_Reference#SkRect'>SkRect</a>& rect) const
</pre>
Maps four corners of <a href='#SkMatrix_mapRectToQuad_rect'>rect</a> to <a href='#SkMatrix_mapRectToQuad_dst'>dst</a>. <a href='SkPoint_Reference#Point'>Points</a> are mapped by multiplying each
<a href='#SkMatrix_mapRectToQuad_rect'>rect</a> corner by <a href='#Matrix'>Matrix</a>. <a href='#SkMatrix_mapRectToQuad_rect'>rect</a> corner is processed in this order:
(<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fLeft, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fTop), (<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fRight, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fTop), (<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fRight, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fBottom),
(<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fLeft, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fBottom).
<a href='#SkMatrix_mapRectToQuad_rect'>rect</a> may be empty: <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fLeft may be greater than or equal to <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fRight;
<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fTop may be greater than or equal to <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fBottom.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | x |
Matrix = | D E F |, pt = | y |
| G H I | | 1 |
</pre>
where pt is initialized from each of (<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fLeft, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fTop),
(<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fRight, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fTop), (<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fRight, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fBottom), (<a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fLeft, <a href='#SkMatrix_mapRectToQuad_rect'>rect</a>.fBottom),
each <a href='#SkMatrix_mapRectToQuad_dst'>dst</a> <a href='SkPoint_Reference#Point'>Point</a> is computed as:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
|A B C| |x| Ax+By+C Dx+Ey+F
Matrix * pt = |D E F| |y| = |Ax+By+C Dx+Ey+F Gx+Hy+I| = ------- , -------
|G H I| |1| Gx+Hy+I Gx+Hy+I
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_mapRectToQuad_dst'><code><strong>dst</strong></code></a></td>
<td>storage for mapped corner <a href='SkPoint_Reference#Point'>Points</a></td>
</tr>
<tr> <td><a name='SkMatrix_mapRectToQuad_rect'><code><strong>rect</strong></code></a></td>
<td><a href='SkRect_Reference#Rect'>Rect</a> to map</td>
</tr>
</table>
### Example
<div><fiddle-embed name="c69cd2a590b5733c3cbc92cb9ceed3f5"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapRect'>mapRect</a><sup><a href='#SkMatrix_mapRect_2'>[2]</a></sup><sup><a href='#SkMatrix_mapRect_3'>[3]</a></sup> <a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a>
---
<a name='SkMatrix_mapRectScaleTranslate'></a>
## mapRectScaleTranslate
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_mapRectScaleTranslate'>mapRectScaleTranslate</a>(<a href='SkRect_Reference#SkRect'>SkRect</a>* dst, const <a href='SkRect_Reference#SkRect'>SkRect</a>& src) const
</pre>
Sets <a href='#SkMatrix_mapRectScaleTranslate_dst'>dst</a> to bounds of <a href='#SkMatrix_mapRectScaleTranslate_src'>src</a> corners mapped by <a href='#Matrix'>Matrix</a>. If matrix contains
elements other than scale or translate: asserts if SK_DEBUG is defined;
otherwise, results are undefined.
### Parameters
<table> <tr> <td><a name='SkMatrix_mapRectScaleTranslate_dst'><code><strong>dst</strong></code></a></td>
<td>storage for bounds of mapped <a href='SkPoint_Reference#Point'>Points</a></td>
</tr>
<tr> <td><a name='SkMatrix_mapRectScaleTranslate_src'><code><strong>src</strong></code></a></td>
<td><a href='SkRect_Reference#Rect'>Rect</a> to map</td>
</tr>
</table>
### Example
<div><fiddle-embed name="62bc26989c2b4c2a54d516596a71dd97"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapRect'>mapRect</a><sup><a href='#SkMatrix_mapRect_2'>[2]</a></sup><sup><a href='#SkMatrix_mapRect_3'>[3]</a></sup> <a href='#SkMatrix_mapRectToQuad'>mapRectToQuad</a> <a href='#SkMatrix_isScaleTranslate'>isScaleTranslate</a> <a href='#SkMatrix_rectStaysRect'>rectStaysRect</a>
---
<a name='SkMatrix_mapRadius'></a>
## mapRadius
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_mapRadius'>mapRadius</a>(<a href='undocumented#SkScalar'>SkScalar</a> radius) const
</pre>
Returns geometric mean <a href='#SkMatrix_mapRadius_radius'>radius</a> of ellipse formed by constructing <a href='undocumented#Circle'>Circle</a> of
size <a href='#SkMatrix_mapRadius_radius'>radius</a>, and mapping constructed <a href='undocumented#Circle'>Circle</a> with <a href='#Matrix'>Matrix</a>. The result squared is
equal to the major axis length times the minor axis length.
Result is not meaningful if <a href='#Matrix'>Matrix</a> contains perspective elements.
### Parameters
<table> <tr> <td><a name='SkMatrix_mapRadius_radius'><code><strong>radius</strong></code></a></td>
<td><a href='undocumented#Circle'>Circle</a> size to map</td>
</tr>
</table>
### Return Value
average mapped <a href='#SkMatrix_mapRadius_radius'>radius</a>
### Example
<div><fiddle-embed name="6d6f2082fcf59d9f02bfb1758b87db69"><div>The area enclosed by a square with sides equal to mappedRadius is the same as
the area enclosed by the ellipse major and minor axes.
</div></fiddle-embed></div>
### See Also
<a href='#SkMatrix_mapVector'>mapVector</a><sup><a href='#SkMatrix_mapVector_2'>[2]</a></sup>
---
<a name='SkMatrix_isFixedStepInX'></a>
## isFixedStepInX
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a>() const
</pre>
Returns true if a unit step on x-axis at some y-axis value mapped through <a href='#Matrix'>Matrix</a>
can be represented by a constant <a href='SkPoint_Reference#Vector'>Vector</a>. Returns true if <a href='#SkMatrix_getType'>getType</a> returns
<a href='#SkMatrix_kIdentity_Mask'>kIdentity Mask</a>, or combinations of: <a href='#SkMatrix_kTranslate_Mask'>kTranslate Mask</a>, <a href='#SkMatrix_kScale_Mask'>kScale Mask</a>, and <a href='#SkMatrix_kAffine_Mask'>kAffine Mask</a>.
May return true if <a href='#SkMatrix_getType'>getType</a> returns <a href='#SkMatrix_kPerspective_Mask'>kPerspective Mask</a>, but only when <a href='#Matrix'>Matrix</a>
does not include rotation or skewing along the y-axis.
### Return Value
true if <a href='#Matrix'>Matrix</a> does not have complex perspective
### Example
<div><fiddle-embed name="ab57b232acef69f26de9cb23d23c8a1a">
#### Example Output
~~~~
[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000]
isFixedStepInX: true
[ 1.0000 0.0000 0.0000][ 0.0000 2.0000 0.0000][ 0.0000 0.0000 1.0000]
isFixedStepInX: true
[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.0000 0.1000 1.0000]
isFixedStepInX: true
[ 1.0000 0.0000 0.0000][ 0.0000 2.0000 0.0000][ 0.0000 0.1000 1.0000]
isFixedStepInX: true
[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.1000 0.0000 1.0000]
isFixedStepInX: false
[ 1.0000 0.0000 0.0000][ 0.0000 2.0000 0.0000][ 0.1000 0.0000 1.0000]
isFixedStepInX: false
[ 1.0000 0.0000 0.0000][ 0.0000 1.0000 0.0000][ 0.1000 0.1000 1.0000]
isFixedStepInX: false
[ 1.0000 0.0000 0.0000][ 0.0000 2.0000 0.0000][ 0.1000 0.1000 1.0000]
isFixedStepInX: false
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_fixedStepInX'>fixedStepInX</a> <a href='#SkMatrix_getType'>getType</a>
---
<a name='SkMatrix_fixedStepInX'></a>
## fixedStepInX
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='SkPoint_Reference#SkVector'>SkVector</a> <a href='#SkMatrix_fixedStepInX'>fixedStepInX</a>(<a href='undocumented#SkScalar'>SkScalar</a> y) const
</pre>
Returns <a href='SkPoint_Reference#Vector'>Vector</a> representing a unit step on x-axis at <a href='#SkMatrix_fixedStepInX_y'>y</a> mapped through <a href='#Matrix'>Matrix</a>.
If <a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a> is false, returned value is undefined.
### Parameters
<table> <tr> <td><a name='SkMatrix_fixedStepInX_y'><code><strong>y</strong></code></a></td>
<td>position of line parallel to x-axis</td>
</tr>
</table>
### Return Value
<a href='SkPoint_Reference#Vector'>Vector</a> advance of mapped unit step on x-axis
### Example
<div><fiddle-embed name="fad6b92b21b1e1deeae61978cec2d232"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_isFixedStepInX'>isFixedStepInX</a> <a href='#SkMatrix_getType'>getType</a>
---
<a name='SkMatrix_cheapEqualTo'></a>
## cheapEqualTo
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_cheapEqualTo'>cheapEqualTo</a>(const <a href='#SkMatrix'>SkMatrix</a>& m) const
</pre>
Returns true if <a href='#Matrix'>Matrix</a> equals <a href='#SkMatrix_cheapEqualTo_m'>m</a>, using an efficient comparison.
Returns false when the sign of zero values is the different; when one
matrix has positive zero value and the other has negative zero value.
Returns true even when both <a href='#Matrix'>Matrices</a> contain NaN.
NaN never equals any value, including itself. To improve performance, NaN values
are treated as bit patterns that are equal if their bit patterns are equal.
### Parameters
<table> <tr> <td><a name='SkMatrix_cheapEqualTo_m'><code><strong>m</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> to compare</td>
</tr>
</table>
### Return Value
true if <a href='#SkMatrix_cheapEqualTo_m'>m</a> and <a href='#Matrix'>Matrix</a> are represented by identical bit patterns
### Example
<div><fiddle-embed name="39016b3cfc6bbabb09348a53822ce508">
#### Example Output
~~~~
identity: a == b a.cheapEqualTo(b): true
neg zero: a == b a.cheapEqualTo(b): false
one NaN: a != b a.cheapEqualTo(b): false
both NaN: a != b a.cheapEqualTo(b): true
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_equal_operator'>operator==(const SkMatrix& a, const SkMatrix& b)</a>
---
<a name='SkMatrix_equal_operator'></a>
## operator==
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_equal_operator'>operator==(const SkMatrix& a, const SkMatrix& b)</a>
</pre>
Compares <a href='#SkMatrix_equal_operator_a'>a</a> and <a href='#SkMatrix_equal_operator_b'>b</a>; returns true if <a href='#SkMatrix_equal_operator_a'>a</a> and <a href='#SkMatrix_equal_operator_b'>b</a> are numerically equal. Returns true
even if sign of zero values are different. Returns false if either <a href='#Matrix'>Matrix</a>
contains NaN, even if the other <a href='#Matrix'>Matrix</a> also contains NaN.
### Parameters
<table> <tr> <td><a name='SkMatrix_equal_operator_a'><code><strong>a</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> to compare</td>
</tr>
<tr> <td><a name='SkMatrix_equal_operator_b'><code><strong>b</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> to compare</td>
</tr>
</table>
### Return Value
true if <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_equal_operator_a'>a</a> and <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_equal_operator_b'>b</a> are numerically equal
### Example
<div><fiddle-embed name="3902859150b0f0c4aeb1f25d00434baa">
#### Example Output
~~~~
identity: a == b a.cheapEqualTo(b): true
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_cheapEqualTo'>cheapEqualTo</a> <a href='#SkMatrix_notequal_operator'>operator!=(const SkMatrix& a, const SkMatrix& b)</a>
---
<a name='SkMatrix_notequal_operator'></a>
## operator!=
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_notequal_operator'>operator!=(const SkMatrix& a, const SkMatrix& b)</a>
</pre>
Compares <a href='#SkMatrix_notequal_operator_a'>a</a> and <a href='#SkMatrix_notequal_operator_b'>b</a>; returns true if <a href='#SkMatrix_notequal_operator_a'>a</a> and <a href='#SkMatrix_notequal_operator_b'>b</a> are not numerically equal. Returns false
even if sign of zero values are different. Returns true if either <a href='#Matrix'>Matrix</a>
contains NaN, even if the other <a href='#Matrix'>Matrix</a> also contains NaN.
### Parameters
<table> <tr> <td><a name='SkMatrix_notequal_operator_a'><code><strong>a</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> to compare</td>
</tr>
<tr> <td><a name='SkMatrix_notequal_operator_b'><code><strong>b</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> to compare</td>
</tr>
</table>
### Return Value
true if <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_notequal_operator_a'>a</a> and <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_notequal_operator_b'>b</a> are numerically not equal
### Example
<div><fiddle-embed name="088ab41f877599f980a99523749b0afd"></fiddle-embed></div>
### See Also
<a href='#SkMatrix_cheapEqualTo'>cheapEqualTo</a> <a href='#SkMatrix_equal_operator'>operator==(const SkMatrix& a, const SkMatrix& b)</a>
---
## <a name='Utility'>Utility</a>
<table style='border-collapse: collapse; width: 62.5em'>
<tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th>
<th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr>
<tr style='background-color: #f0f0f0; '>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_dirtyMatrixTypeCache'>dirtyMatrixTypeCache</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sets internal cache to unknown state</td>
</tr>
<tr>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#SkMatrix_dump'>dump</a></td>
<td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>sends text representation using floats to standard output</td>
</tr>
</table>
<a name='SkMatrix_dump'></a>
## dump
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_dump'>dump</a>() const
</pre>
Writes text representation of <a href='#Matrix'>Matrix</a> to standard output. Floating point values
are written with limited precision; it may not be possible to reconstruct
original <a href='#Matrix'>Matrix</a> from output.
### Example
<div><fiddle-embed name="8d72a4818e5a9188348f6c08ab5d8a40">
#### Example Output
~~~~
[ 0.7071 -0.7071 0.0000][ 0.7071 0.7071 0.0000][ 0.0000 0.0000 1.0000]
[ 0.7071 -0.7071 0.0000][ 0.7071 0.7071 0.0000][ 0.0000 0.0000 1.0000]
matrix != nearlyEqual
~~~~
</fiddle-embed></div>
### See Also
<a href='SkPath_Reference#SkPath_dump'>SkPath::dump</a><sup><a href='SkPath_Reference#SkPath_dump_2'>[2]</a></sup>
---
<a name='SkMatrix_getMinScale'></a>
## getMinScale
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getMinScale'>getMinScale</a>() const
</pre>
Returns the minimum scaling factor of <a href='#Matrix'>Matrix</a> by decomposing the scaling and
skewing elements.
Returns -1 if scale factor overflows or <a href='#Matrix'>Matrix</a> contains perspective.
### Return Value
minimum scale factor
### Example
<div><fiddle-embed name="1d6f67904c88a806c3731879e9af4ae5">
#### Example Output
~~~~
matrix.getMinScale() 24
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_getMaxScale'>getMaxScale</a> <a href='#SkMatrix_getMinMaxScales'>getMinMaxScales</a>
---
<a name='SkMatrix_getMaxScale'></a>
## getMaxScale
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
<a href='undocumented#SkScalar'>SkScalar</a> <a href='#SkMatrix_getMaxScale'>getMaxScale</a>() const
</pre>
Returns the maximum scaling factor of <a href='#Matrix'>Matrix</a> by decomposing the scaling and
skewing elements.
Returns -1 if scale factor overflows or <a href='#Matrix'>Matrix</a> contains perspective.
### Return Value
maximum scale factor
### Example
<div><fiddle-embed name="3fee4364929899649cf9efc37897e964">
#### Example Output
~~~~
matrix.getMaxScale() 42
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_getMinScale'>getMinScale</a> <a href='#SkMatrix_getMinMaxScales'>getMinMaxScales</a>
---
<a name='SkMatrix_getMinMaxScales'></a>
## getMinMaxScales
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool SK_WARN_UNUSED_RESULT <a href='#SkMatrix_getMinMaxScales'>getMinMaxScales</a>(<a href='undocumented#SkScalar'>SkScalar</a> scaleFactors[2]) const
</pre>
Sets <a href='#SkMatrix_getMinMaxScales_scaleFactors'>scaleFactors</a>[0] to the minimum scaling factor, and <a href='#SkMatrix_getMinMaxScales_scaleFactors'>scaleFactors</a>[1] to the
maximum scaling factor. Scaling factors are computed by decomposing
the <a href='#Matrix'>Matrix</a> scaling and skewing elements.
Returns true if <a href='#SkMatrix_getMinMaxScales_scaleFactors'>scaleFactors</a> are found; otherwise, returns false and sets
<a href='#SkMatrix_getMinMaxScales_scaleFactors'>scaleFactors</a> to undefined values.
### Parameters
<table> <tr> <td><a name='SkMatrix_getMinMaxScales_scaleFactors'><code><strong>scaleFactors</strong></code></a></td>
<td>storage for minimum and maximum scale factors</td>
</tr>
</table>
### Return Value
true if scale factors were computed correctly
### Example
<div><fiddle-embed name="13adba0ecf5f82247cf051b4fa4d8a9c">
#### Example Output
~~~~
matrix.getMinMaxScales() false 2 2
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_getMinScale'>getMinScale</a> <a href='#SkMatrix_getMaxScale'>getMaxScale</a>
---
<a name='SkMatrix_decomposeScale'></a>
## decomposeScale
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_decomposeScale'>decomposeScale</a>(<a href='undocumented#SkSize'>SkSize</a>* scale, <a href='#SkMatrix'>SkMatrix</a>* remaining = nullptr) const
</pre>
Decomposes <a href='#Matrix'>Matrix</a> into <a href='#SkMatrix_decomposeScale_scale'>scale</a> components and whatever remains. Returns false if
<a href='#Matrix'>Matrix</a> could not be decomposed.
Sets <a href='#SkMatrix_decomposeScale_scale'>scale</a> to portion of <a href='#Matrix'>Matrix</a> that <a href='#SkMatrix_decomposeScale_scale'>scale</a> axes. Sets <a href='#SkMatrix_decomposeScale_remaining'>remaining</a> to <a href='#Matrix'>Matrix</a>
with scaling factored out. <a href='#SkMatrix_decomposeScale_remaining'>remaining</a> may be passed as nullptr
to determine if <a href='#Matrix'>Matrix</a> can be decomposed without computing remainder.
Returns true if <a href='#SkMatrix_decomposeScale_scale'>scale</a> components are found. <a href='#SkMatrix_decomposeScale_scale'>scale</a> and <a href='#SkMatrix_decomposeScale_remaining'>remaining</a> are
unchanged if <a href='#Matrix'>Matrix</a> contains perspective; <a href='#SkMatrix_decomposeScale_scale'>scale</a> factors are not finite, or
are nearly zero.
On success: <code><a href='#Matrix'>Matrix</a>&nbsp;=&nbsp;<a href='#SkMatrix_decomposeScale_scale'>scale</a>&nbsp;\*&nbsp;Remaining</code>.
### Parameters
<table> <tr> <td><a name='SkMatrix_decomposeScale_scale'><code><strong>scale</strong></code></a></td>
<td>axes scaling factors; may be nullptr</td>
</tr>
<tr> <td><a name='SkMatrix_decomposeScale_remaining'><code><strong>remaining</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> without scaling; may be nullptr</td>
</tr>
</table>
### Return Value
true if <a href='#SkMatrix_decomposeScale_scale'>scale</a> can be computed
### Example
<div><fiddle-embed name="139b874da0a3ede1f3df88119085c0aa">
#### Example Output
~~~~
[ 0.0000 -0.2500 0.0000][ 0.5000 0.0000 0.0000][ 0.0000 0.0000 1.0000]
success: true scale: 0.5, 0.25
[ 0.0000 -0.5000 0.0000][ 2.0000 0.0000 0.0000][ 0.0000 0.0000 1.0000]
[ 0.0000 -0.2500 0.0000][ 0.5000 0.0000 0.0000][ 0.0000 0.0000 1.0000]
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_MakeScale'>MakeScale</a><sup><a href='#SkMatrix_MakeScale_2'>[2]</a></sup>
---
<a name='SkMatrix_I'></a>
## I
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
static const <a href='#SkMatrix'>SkMatrix</a>& I()
</pre>
Returns reference to const identity <a href='#Matrix'>Matrix</a>. Returned <a href='#Matrix'>Matrix</a> is set to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| 1 0 0 |
| 0 1 0 |
| 0 0 1 |
</pre>
### Return Value
const identity <a href='#Matrix'>Matrix</a>
### Example
<div><fiddle-embed name="d961d91020f19037204a8c3fd8cb1060">
#### Example Output
~~~~
m1 == m2
m2 == m3
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_reset'>reset</a> <a href='#SkMatrix_setIdentity'>setIdentity</a>
---
<a name='SkMatrix_InvalidMatrix'></a>
## InvalidMatrix
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
static const <a href='#SkMatrix'>SkMatrix</a>& <a href='#SkMatrix_InvalidMatrix'>InvalidMatrix</a>()
</pre>
Returns reference to a const <a href='#Matrix'>Matrix</a> with invalid values. Returned <a href='#Matrix'>Matrix</a> is set
to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| SK_ScalarMax SK_ScalarMax SK_ScalarMax |
| SK_ScalarMax SK_ScalarMax SK_ScalarMax |
| SK_ScalarMax SK_ScalarMax SK_ScalarMax |
</pre>
### Return Value
const invalid <a href='#Matrix'>Matrix</a>
### Example
<div><fiddle-embed name="af0b72360c1c7a25b4754bfa47011dd5">
#### Example Output
~~~~
scaleX 3.40282e+38
~~~~
</fiddle-embed></div>
### See Also
SeeAlso <a href='#SkMatrix_getType'>getType</a>
---
<a name='SkMatrix_Concat'></a>
## Concat
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
static <a href='#SkMatrix'>SkMatrix</a> <a href='#SkMatrix_Concat'>Concat</a>(const <a href='#SkMatrix'>SkMatrix</a>& a, const <a href='#SkMatrix'>SkMatrix</a>& b)
</pre>
Returns <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_Concat_a'>a</a> multiplied by <a href='#Matrix'>Matrix</a> <a href='#SkMatrix_Concat_b'>b</a>.
Given:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | J K L |
a = | D E F |, b = | M N O |
| G H I | | P Q R |
</pre>
sets <a href='#Matrix'>Matrix</a> to:
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| A B C | | J K L | | AJ+BM+CP AK+BN+CQ AL+BO+CR |
a * b = | D E F | * | M N O | = | DJ+EM+FP DK+EN+FQ DL+EO+FR |
| G H I | | P Q R | | GJ+HM+IP GK+HN+IQ GL+HO+IR |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_Concat_a'><code><strong>a</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> on left side of multiply expression</td>
</tr>
<tr> <td><a name='SkMatrix_Concat_b'><code><strong>b</strong></code></a></td>
<td><a href='#Matrix'>Matrix</a> on right side of multiply expression</td>
</tr>
</table>
### Return Value
<a href='#Matrix'>Matrix</a> computed from <a href='#SkMatrix_Concat_a'>a</a> times <a href='#SkMatrix_Concat_b'>b</a>
### Example
<div><fiddle-embed name="6b4562c7052da94f3d5b2412dca41946"><div><a href='#SkMatrix_setPolyToPoly'>setPolyToPoly</a> creates perspective matrices, one the inverse of the other.
Multiplying the matrix by its inverse turns into an identity matrix.
</div></fiddle-embed></div>
### See Also
<a href='#SkMatrix_preConcat'>preConcat</a> <a href='#SkMatrix_postConcat'>postConcat</a>
---
<a name='SkMatrix_dirtyMatrixTypeCache'></a>
## dirtyMatrixTypeCache
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_dirtyMatrixTypeCache'>dirtyMatrixTypeCache</a>()
</pre>
Sets internal cache to unknown state. Use to force update after repeated
modifications to <a href='#Matrix'>Matrix</a> element reference returned by <a href='#SkMatrix_array1_operator'>operator[](int index)</a>.
### Example
<div><fiddle-embed name="f4365ef332f51f7fd25040e0771ba9a2">
#### Example Output
~~~~
with identity matrix: x = 24
after skew x mod: x = 24
after 2nd skew x mod: x = 24
after dirty cache: x = 66
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_array1_operator'>operator[](int index)</a> <a href='#SkMatrix_getType'>getType</a>
---
<a name='SkMatrix_setScaleTranslate'></a>
## setScaleTranslate
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
void <a href='#SkMatrix_setScaleTranslate'>setScaleTranslate</a>(<a href='undocumented#SkScalar'>SkScalar</a> sx, <a href='undocumented#SkScalar'>SkScalar</a> sy, <a href='undocumented#SkScalar'>SkScalar</a> tx, <a href='undocumented#SkScalar'>SkScalar</a> ty)
</pre>
Initializes <a href='#Matrix'>Matrix</a> with scale and translate elements.
<pre style="padding: 1em 1em 1em 1em;width: 62.5em; background-color: #f0f0f0">
| sx 0 tx |
| 0 sy ty |
| 0 0 1 |
</pre>
### Parameters
<table> <tr> <td><a name='SkMatrix_setScaleTranslate_sx'><code><strong>sx</strong></code></a></td>
<td>horizontal scale factor to store</td>
</tr>
<tr> <td><a name='SkMatrix_setScaleTranslate_sy'><code><strong>sy</strong></code></a></td>
<td>vertical scale factor to store</td>
</tr>
<tr> <td><a name='SkMatrix_setScaleTranslate_tx'><code><strong>tx</strong></code></a></td>
<td>horizontal translation to store</td>
</tr>
<tr> <td><a name='SkMatrix_setScaleTranslate_ty'><code><strong>ty</strong></code></a></td>
<td>vertical translation to store</td>
</tr>
</table>
### Example
<div><fiddle-embed name="fed43797f13796529cb6731385d6f8f3">
#### Example Output
~~~~
[ 1.0000 0.0000 3.0000][ 0.0000 2.0000 4.0000][ 0.0000 0.0000 1.0000]
~~~~
</fiddle-embed></div>
### See Also
<a href='#SkMatrix_setScale'>setScale</a><sup><a href='#SkMatrix_setScale_2'>[2]</a></sup> <a href='#SkMatrix_preTranslate'>preTranslate</a> <a href='#SkMatrix_postTranslate'>postTranslate</a>
---
<a name='SkMatrix_isFinite'></a>
## isFinite
<pre style="padding: 1em 1em 1em 1em; width: 62.5em;background-color: #f0f0f0">
bool <a href='#SkMatrix_isFinite'>isFinite</a>() const
</pre>
Returns true if all elements of the matrix are finite. Returns false if any
element is infinity, or NaN.
### Return Value
true if matrix has only finite elements
### Example
<div><fiddle-embed name="bc6c6f6a5df770287120d87f81b922eb">
#### Example Output
~~~~
[ 1.0000 0.0000 nan][ 0.0000 1.0000 0.0000][ 0.0000 0.0000 1.0000]
matrix is finite: false
matrix != matrix
~~~~
</fiddle-embed></div>
### See Also
operator==
---
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