SkRRect Reference
===
# RRect
# Class SkRRect
## Constant
SkRRect related constants are defined by enum
, enum class
, #define
, const
, and constexpr
.
## Related_Function
SkRRect global, struct
, and class
related member functions share a topic.
The SkRRect class represents a rounded rect with a potentially different
radii for each corner. It does not have a constructor so must be
initialized with one of the initialization functions (e.g., setEmpty,
setRectRadii, etc.)
This class allows implementing CSS properties that describe rounded corners.
A rectangle may have up to eight radii, one for each axis on each of its four
corners.
If either corner's radii are zero, the corner is square.
Negative radii are treated as zero.
If corner curves overlap, they are proportionally reduced to fit.
## Overview
## Constructor
SkRRect can be constructed or initialized by these functions, including C++ class constructors.
## Operator
SkRRect operators inline class member functions with arithmetic equivalents.
## Member Function
SkRRect member functions read and modify the structure properties.
Topic |
Description |
MakeEmpty |
creates with zeroed bounds and corner radii |
MakeOval |
creates Oval to fit bounds |
MakeRect |
copies bounds and zeroes corner radii |
MakeRectXY |
creates rounded rectangle |
contains |
returns true if Rect is inside |
dump |
sends text representation to standard output |
dumpHex |
sends text representation using hexadecimal to standard output |
getBounds |
returns bounds |
getSimpleRadii |
returns corner radii for simple types |
getType |
returns Type |
height |
returns span in y |
inset |
insets bounds and radii |
isComplex |
returns true if not empty, rect, oval, simple, or nine-patch |
isEmpty |
returns true if width or height are zero |
isNinePatch |
returns true if not empty, rect, oval or simple; and radii are axis-aligned |
isOval |
returns true if not empty, axes radii are equal, radii fill bounds |
isRect |
returns true if not empty, and one radius at each corner is zero |
isSimple |
returns true if not empty, rect or oval; and axes radii are equal |
isValid |
incomplete |
makeOffset |
offsets bounds and radii |
offset |
offsets bounds and radii |
outset |
outsets bounds and radii |
radii |
returns x-axis and y-axis radii for one corner |
readFromMemory |
incomplete |
rect |
returns bounds |
setEmpty |
zeroes width, height, and corner radii |
setNinePatch |
replaces with rounded rectangle |
setOval |
replaces with Oval to fit bounds |
setRect |
sets rect bounds with zeroed corners |
setRectRadii |
replaces with rounded rectangle |
setRectXY |
replaces with rounded rectangle |
transform |
scales and offsets into copy |
type |
returns Type |
width |
returns span in x |
writeToMemory |
incomplete |
## SkRRect
SkRRect()
Initializes bounds at (0, 0), the origin, with zero width and height.
Initializes corner radii to (0, 0), and sets type of kEmpty Type.
### Return Value
empty Round Rect
### Example
### See Also
setEmpty isEmpty
---
## SkRRect
SkRRect(const SkRRect& rrect)
Initializes to copy of rrect bounds and corner radii.
### Parameters
rrect |
bounds and corner to copy |
### Return Value
copy of rrect
### Example
### See Also
operator=(const SkRRect& rrect) MakeRect
---
## operator=
SkRRect& operator=(const SkRRect& rrect)
Copies rrect bounds and corner radii.
### Parameters
rrect |
bounds and corner to copy |
### Return Value
copy of rrect
### Example
### See Also
SkRRect(const SkRRect& rrect) MakeRect
---
## Type
## Enum SkRRect::Type
enum Type {
kEmpty Type,
kRect Type,
kOval Type,
kSimple Type,
kNinePatch Type,
kComplex Type,
kLastType = kComplex Type,
};
Type describes possible specializations of Round Rect. Each Type is
exclusive; a Round Rect may only have one type.
The enum members become progressively less restrictive; larger values of
Type have more degrees of freedom than smaller values.
### Constants
Const |
Value |
Description |
SkRRect::kEmpty_Type |
#Line # zero width or height ## |
Round Rect has zero width or height. All radii are zero.
|
SkRRect::kRect_Type |
#Line # non-zero width and height, and zeroed radii ## |
Round Rect has width and height. All radii are zero.
|
SkRRect::kOval_Type |
#Line # non-zero width and height filled with radii ## |
Round Rect has width and height. All four x-radii are equal,
and at least half the width. All four y-radii are equal,
and at least half the height.
|
SkRRect::kSimple_Type |
#Line # non-zero width and height with equal radii ## |
Round Rect has width and height. All four x-radii are equal and
greater than zero, and all four y-radii are equal and greater than
zero. Either x-radii are less than half the width, or y-radii is
less than half the height, or both.
|
SkRRect::kNinePatch_Type |
#Line # non-zero width and height with axis-aligned radii ## |
Round Rect has width and height. Left x-radii are equal, top
y-radii are equal, right x-radii are equal, and bottom y-radii
are equal. The radii do not describe a rect, oval, or simple type.
The centers of the corner ellipses form an axis-aligned rectangle
that divides the Round Rect into nine rectangular patches; an
interior rectangle, four edges, and four corners.
|
SkRRect::kComplex_Type |
#Line # non-zero width and height with arbitrary radii ## |
both radii are non-zero.
|
SkRRect::kLastType |
= kComplex_Type |
largest Type value |
### Example
### See Also
Rect Path
## getType
Type getType() const
Returns Type, one of: kEmpty Type, kRect Type, kOval Type, kSimple Type, kNinePatch Type,
kComplex Type.
### Return Value
Type
### Example
rrect2 is not a
Rect;
inset has made it empty.
### See Also
Type type
---
## type
Type type() const
Returns Type, one of: kEmpty Type, kRect Type, kOval Type, kSimple Type, kNinePatch Type,
kComplex Type.
### Return Value
Type
### Example
inset has made rrect2 empty.
### See Also
Type getType
---
## isEmpty
inline bool isEmpty() const
Returns true if rect.fLeft is equal to rect.fRight, or if rect.fTop is equal
to rect.fBottom.
### Return Value
true if width or height are zero
### Example
### See Also
SkRect::isEmpty height width
---
## isRect
inline bool isRect() const
Returns true if not empty, and if either x or y radius at each corner is zero.
### Return Value
true if not empty, and one radius at each corner is zero
### Example
### See Also
isEmpty radii
---
## isOval
inline bool isOval() const
Returns true if not empty, if all x-axis radii are equal, if all y-axis radii
are equal, x-axis radii are at least half the width, and y-axis radii are at
least half the height.
### Return Value
true if has identical geometry to Oval
### Example
The first radii are scaled down proportionately until both x-axis and y-axis fit
within the bounds. After scaling, x-axis radius is smaller than half the width;
left round rect is not an oval. The second radii are equal to half the
dimensions; right round rect is an oval.
### See Also
isEmpty isSimple SkCanvas::drawOval
---
## isSimple
inline bool isSimple() const
Returns true if not empty, if all x-axis radii are equal but not zero,
if all y-axis radii are equal but not zero; and x-axis radius is less than half
width, or y-axis radius is less than half height.
### Return Value
true if not empty, rect or oval; and axes radii are equal
### Example
### See Also
isEmpty isRect isOval isNinePatch
---
## isNinePatch
inline bool isNinePatch() const
Returns true if isEmpty, isRect, isOval, and isSimple return false; and if
left x-axis radii are equal, right x-axis radii are equal, top y-axis radii are
equal, and bottom y-axis radii are equal.
### Return Value
true if not empty, rect, oval or simple; and radii are axis-aligned
### Example
### See Also
isEmpty isRect isOval isSimple isComplex
---
## isComplex
inline bool isComplex() const
Returns true if isEmpty, isRect, isOval, isSimple, and isNinePatch return false.
If true: width and height are greater than zero, at least one corner radii are
both greater than zero; left x-axis radii are not equal, or right x-axis radii
are not equal, or top y-axis radii are not equal, or bottom y-axis radii are not
equal.
### Return Value
true if not empty, rect, oval, simple, or nine-patch
### Example
### See Also
isEmpty isRect isOval isSimple isNinePatch
---
## width
SkScalar width() const
Returns span on the x-axis. This does not check if result fits in 32-bit float;
result may be infinity.
### Return Value
bounds().fRight minus bounds().fLeft
### Example
#### Example Output
~~~~
unsorted width: 5
large width: inf
~~~~
### See Also
SkRect::width height getBounds
---
## height
SkScalar height() const
Returns span on the y-axis. This does not check if result fits in 32-bit float;
result may be infinity.
### Return Value
bounds().fBottom minus bounds().fTop
### Example
#### Example Output
~~~~
unsorted height: 5
large height: inf
~~~~
### See Also
SkRect.height width getBounds
---
## getSimpleRadii
SkVector getSimpleRadii() const
Returns top-left corner x-radii. If type returns kEmpty Type, kRect Type,
kOval Type, or kSimple Type, returns a value representative of all corner radii.
If type returns kNinePatch Type or kComplex Type, at least one of the
remaining three corners has a different value.
### Return Value
corner radii for simple types
### Example
### See Also
radii getBounds getType isSimple
---
## setEmpty
void setEmpty()
Sets bounds to zero width and height at (0, 0), the origin. Sets
corner radii to zero and sets type to kEmpty Type.
### Example
Nothing blue is drawn because rrect is set to empty.
### See Also
MakeEmpty setRect
---
## setRect
void setRect(const SkRect& rect)
Sets bounds to sorted rect, and sets corner radii to zero.
If set bounds has width and height, and sets type to kRect Type;
otherwise, sets type to kEmpty Type.
### Parameters
### Example
### See Also
MakeRect setRectXY
---
## MakeEmpty
static SkRRect MakeEmpty()
Initializes bounds at (0, 0), the origin, with zero width and height.
Initializes corner radii to (0, 0), and sets type of kEmpty Type.
### Return Value
empty Round Rect
### Example
### See Also
SkRRect() SkRect::MakeEmpty
---
## MakeRect
static SkRRect MakeRect(const SkRect& r)
Initializes to copy of r bounds and zeroes corner radii.
### Parameters
### Return Value
copy of r
### Example
### See Also
setRect MakeOval MakeRectXY
---
## MakeOval
static SkRRect MakeOval(const SkRect& oval)
Sets bounds to oval, x-axis radii to half oval.width, and all y-axis radii
to half oval.height. If rect is empty, sets to kEmpty Type.
Otherwise, sets to kOval Type.
### Parameters
### Return Value
Oval
### Example
### See Also
setOval MakeRect MakeRectXY
---
## MakeRectXY
static SkRRect MakeRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad)
Sets to rounded rectangle with the same radii for all four corners.
If rect is empty, sets to kEmpty Type.
Otherwise, if xRad and yRad are zero, sets to kRect Type.
Otherwise, if xRad is at least half rect.width and yRad is at least half
rect.height, sets to kOval Type.
Otherwise, sets to kSimple Type.
### Parameters
rect |
bounds of rounded rectangle |
xRad |
x-axis radius of corners |
yRad |
y-axis radius of corners |
### Return Value
rounded rectangle
### Example
### See Also
setRectXY
---
## setOval
void setOval(const SkRect& oval)
Sets bounds to oval, x-axis radii to half oval.width, and all y-axis radii
to half oval.height. If rect is empty, sets to kEmpty Type.
Otherwise, sets to kOval Type.
### Parameters
### Example
### See Also
MakeOval
---
## setRectXY
void setRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad)
Sets to rounded rectangle with the same radii for all four corners.
If rect is empty, sets to kEmpty Type.
Otherwise, if xRad or yRad is zero, sets to kRect Type.
Otherwise, if xRad is at least half rect.width and yRad is at least half
rect.height, sets to kOval Type.
Otherwise, sets to kSimple Type.
### Parameters
rect |
bounds of rounded rectangle |
xRad |
x-axis radius of corners |
yRad |
y-axis radius of corners |
### Example
### See Also
MakeRectXY SkPath::addRoundRect[2]
---
## setNinePatch
void setNinePatch(const SkRect& rect, SkScalar leftRad, SkScalar topRad, SkScalar rightRad,
SkScalar bottomRad)
Sets bounds to rect. Sets radii to (leftRad, topRad), (rightRad, topRad),
(rightRad, bottomRad), (leftRad, bottomRad).
If rect is empty, sets to kEmpty Type.
Otherwise, if leftRad and rightRad are zero, sets to kRect Type.
Otherwise, if topRad and bottomRad are zero, sets to kRect Type.
Otherwise, if leftRad and rightRad are equal and at least half rect.width, and
topRad and bottomRad are equal at least half rect.height, sets to kOval Type.
Otherwise, if leftRad and rightRad are equal, and topRad and bottomRad are equal,
sets to kSimple Type. Otherwise, sets to kNinePatch Type.
Nine patch refers to the nine parts defined by the radii: one center rectangle,
four edge patches, and four corner patches.
### Parameters
rect |
bounds of rounded rectangle |
leftRad |
left-top and left-bottom x-axis radius |
topRad |
left-top and right-top y-axis radius |
rightRad |
right-top and right-bottom x-axis radius |
bottomRad |
left-bottom and right-bottom y-axis radius |
### Example
### See Also
setRectRadii
---
## setRectRadii
void setRectRadii(const SkRect& rect, const SkVector radii[4])
Sets bounds to rect. Sets radii array for individual control of all for corners.
If rect is empty, sets to kEmpty Type.
Otherwise, if one of each corner radii are zero, sets to kRect Type.
Otherwise, if all x-axis radii are equal and at least half rect.width, and
all y-axis radii are equal at least half rect.height, sets to kOval Type.
Otherwise, if all x-axis radii are equal, and all y-axis radii are equal,
sets to kSimple Type. Otherwise, sets to kNinePatch Type.
### Parameters
rect |
bounds of rounded rectangle |
radii |
corner x-axis and y-axis radii |
### Example
### See Also
setNinePatch SkPath::addRoundRect[2]
---
## Enum SkRRect::Corner
enum Corner {
kUpperLeft Corner,
kUpperRight Corner,
kLowerRight Corner,
kLowerLeft Corner,
};
The radii are stored: top-left, top-right, bottom-right, bottom-left.
### Constants
### Example
### See Also
radii
## rect
const SkRect& rect() const
Returns bounds. Bounds may have zero width or zero height. Bounds right is
greater than or equal to left; bounds bottom is greater than or equal to top.
Result is identical to getBounds.
### Return Value
bounding box
### Example
#### Example Output
~~~~
left bounds: (nan) 0
left bounds: (inf) 0
left bounds: (100) 60
left bounds: (50) 50
left bounds: (25) 25
~~~~
### See Also
getBounds
---
## radii
SkVector radii(Corner corner) const
Returns Scalar pair for radius of curve on x-axis and y-axis for one corner.
Both radii may be zero. If not zero, both are positive and finite.
### Parameters
### Return Value
x-axis and y-axis radii for one corner
### Example
Finite values are scaled proportionately to fit; other values are set to zero.
Scaled values cannot be larger than 25, half the bounding rect width.
Small scaled values are halved to scale in proportion to the y-axis
corner
radius, which is twice the bounds height.
#### Example Output
~~~~
left corner: (nan) 0
left corner: (inf) 0
left corner: (100) 25
left corner: (50) 25
left corner: (25) 12.5
~~~~
### See Also
Corner
---
## getBounds
const SkRect& getBounds() const
Returns bounds. Bounds may have zero width or zero height. Bounds right is
greater than or equal to left; bounds bottom is greater than or equal to top.
Result is identical to rect.
### Return Value
bounding box
### Example
### See Also
rect
---
## operator==
bool operator==(const SkRRect& a, const SkRRect& b)
Returns true if bounds and radii in a are equal to bounds and radii in b.
a and b are not equal if either contain NaN. a and b are equal if members
contain zeroes width different signs.
### Parameters
a |
Rect bounds and radii to compare |
b |
Rect bounds and radii to compare |
### Return Value
true if members are equal
### Example
### See Also
operator!=(const SkRRect& a, const SkRRect& b)
---
## operator!=
bool operator!=(const SkRRect& a, const SkRRect& b)
Returns true if bounds and radii in a are not equal to bounds and radii in b.
a and b are not equal if either contain NaN. a and b are equal if members
contain zeroes width different signs.
### Parameters
a |
Rect bounds and radii to compare |
b |
Rect bounds and radii to compare |
### Return Value
true if members are not equal
### Example
### See Also
operator==(const SkRRect& a, const SkRRect& b)
---
## inset
void inset(SkScalar dx, SkScalar dy, SkRRect* dst) const
Calls inset on the bounds, and adjust the radii to reflect what happens.
If the corner is sharp (no curvature), leave it alone,
otherwise we grow/shrink the radii by the amount of the inset. If a
given radius becomes negative, it is pinned to 0.
If the inset amount is larger than the width/height then the rrect collapses to
a degenerate line or point.
If the inset is sufficiently negative to cause the bounds to become infinite then
the result is a default initialized rrect.
It is valid for dst == this.
### Parameters
dx |
added to rect.fLeft, and subtracted from rect.fRight |
dy |
added to rect.fTop, and subtracted from rect.fBottom |
dst |
insets bounds and radii |
### Example
### See Also
outset[2] offset makeOffset
---
void inset(SkScalar dx, SkScalar dy)
### Parameters
dx |
added to rect.fLeft, and subtracted from rect.fRight |
dy |
added to rect.fTop, and subtracted from rect.fBottom |
### Example
### See Also
outset[2] offset makeOffset
---
## outset
void outset(SkScalar dx, SkScalar dy, SkRRect* dst) const
Call outset on the bounds, and adjust the radii to reflect what happens
in stroking. If the corner is sharp (no curvature), leave it alone,
otherwise we grow/shrink the radii by the amount of the inset. If a
given radius becomes negative, it is pinned to 0.
It is valid for dst == this.
### Parameters
dx |
subtracted from rect.fLeft, and added to rect.fRight |
dy |
subtracted from rect.fTop, and added to rect.fBottom |
dst |
outset bounds and radii |
### Example
### See Also
inset[2] offset makeOffset
---
void outset(SkScalar dx, SkScalar dy)
### Parameters
dx |
subtracted from rect.fLeft, and added to rect.fRight |
dy |
subtracted from rect.fTop, and added to rect.fBottom |
### Example
### See Also
inset[2] offset makeOffset
---
## offset
void offset(SkScalar dx, SkScalar dy)
Translates the rrect by (dx, dy).
### Parameters
### Example
### See Also
makeOffset inset[2] outset[2]
---
## makeOffset
SkRRect SK_WARN_UNUSED_RESULT makeOffset(SkScalar dx, SkScalar dy) const
### Parameters
### Return Value
Round Rect bounds offset by (dx, dy), with unchanged corner radii
### Example
### See Also
offset inset[2] outset[2]
---
## contains
bool contains(const SkRect& rect) const
Returns true if rect is inside the bounds and corner radii, and if
Round Rect and rect are not empty.
### Parameters
rect |
area tested for containment |
### Return Value
true if Round Rect contains rect
### Example
### See Also
SkRect::contains[2][3]
---
## isValid
bool isValid() const
### Return Value
incomplete
### Example
### See Also
incomplete
---
### Constants
## writeToMemory
size_t writeToMemory(void* buffer) const
Write the rrect into the specified buffer. This is guaranteed to always
write kSizeInMemory bytes, and that value is guaranteed to always be
a multiple of 4. Return kSizeInMemory.
### Parameters
### Return Value
incomplete
### Example
### See Also
incomplete
---
## readFromMemory
size_t readFromMemory(const void* buffer, size_t length)
Reads the rrect from the specified buffer.
If the specified buffer is large enough, this will read kSizeInMemory bytes,
and that value is guaranteed to always be a multiple of 4.
### Parameters
### Return Value
number of bytes read (must be a multiple of 4) or
0 if there was not enough memory available
### Example
### See Also
incomplete
---
## transform
bool transform(const SkMatrix& matrix, SkRRect* dst) const
Transforms by Round Rect by matrix, storing result in dst.
Returns true if Round Rect transformed can be represented by another Round Rect.
Returns false if matrix contains transformations other than scale and translate.
Asserts in debug builds if Round Rect equals dst.
### Parameters
### Return Value
true if transformation succeeded.
### Example
### See Also
incomplete
---
## dump
void dump(bool asHex) const
Writes text representation of Round Rect to standard output.
Set asHex true to generate exact binary representations
of floating point numbers.
### Parameters
### Example
#### Example Output
~~~~
SkRect::MakeLTRB(0.857143f, 0.666667f, 0.857143f, 0.666667f);
const SkPoint corners[] = {
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
};
SkRect::MakeLTRB(SkBits2Float(0x3f5b6db7), /* 0.857143 */
SkBits2Float(0x3f2aaaab), /* 0.666667 */
SkBits2Float(0x3f5b6db7), /* 0.857143 */
SkBits2Float(0x3f2aaaab) /* 0.666667 */);
const SkPoint corners[] = {
{ SkBits2Float(0x00000000), SkBits2Float(0x00000000) }, /* 0.000000 0.000000 */
{ SkBits2Float(0x00000000), SkBits2Float(0x00000000) }, /* 0.000000 0.000000 */
{ SkBits2Float(0x00000000), SkBits2Float(0x00000000) }, /* 0.000000 0.000000 */
{ SkBits2Float(0x00000000), SkBits2Float(0x00000000) }, /* 0.000000 0.000000 */
};
~~~~
### See Also
dumpHex SkRect::dump[2] SkPath::dump[2] SkPathMeasure::dump
---
void dump() const
Writes text representation of Round Rect to standard output. The representation
may be directly compiled as C++ code. Floating point values are written
with limited precision; it may not be possible to reconstruct original
Round Rect from output.
### Example
#### Example Output
~~~~
SkRect::MakeLTRB(0.857143f, 0.666667f, 0.857143f, 0.666667f);
const SkPoint corners[] = {
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
};
rrect is not equal to copy
~~~~
### See Also
dumpHex SkRect::dump[2] SkPath::dump[2] SkPathMeasure::dump
---
## dumpHex
void dumpHex() const
Writes text representation of Round Rect to standard output. The representation
may be directly compiled as C++ code. Floating point values are written
in hexadecimal to preserve their exact bit pattern. The output reconstructs the
original Round Rect.
### Example
#### Example Output
~~~~
SkRect::MakeLTRB(SkBits2Float(0x3f5b6db7), /* 0.857143 */
SkBits2Float(0x3f2aaaab), /* 0.666667 */
SkBits2Float(0x3f5b6db7), /* 0.857143 */
SkBits2Float(0x3f2aaaab) /* 0.666667 */);
const SkPoint corners[] = {
{ SkBits2Float(0x00000000), SkBits2Float(0x00000000) }, /* 0.000000 0.000000 */
{ SkBits2Float(0x00000000), SkBits2Float(0x00000000) }, /* 0.000000 0.000000 */
{ SkBits2Float(0x00000000), SkBits2Float(0x00000000) }, /* 0.000000 0.000000 */
{ SkBits2Float(0x00000000), SkBits2Float(0x00000000) }, /* 0.000000 0.000000 */
};
rrect is equal to copy
~~~~
### See Also
dump[2] SkRect::dumpHex SkPath::dumpHex
---