skia2/site/user/api/SkRRect_Reference.md

SkRRect Reference

RRect

Class SkRRect

Constant

SkRRect related constants are defined by enum, enum class, #define, const, and constexpr.

Topic	Description
Corner	corner radii order
Type	specialization of Round Rect geometry
kComplex Type	non-zero width and height with arbitrary radii
kEmpty Type	zero width or height
kLastType	largest Type value
kLowerLeft Corner	index of bottom-left corner radii
kLowerRight Corner	index of bottom-right corner radii
kNinePatch Type	non-zero width and height with axis-aligned radii
kOval Type	non-zero width and height filled with radii
kRect Type	non-zero width and height, and zeroed radii
kSimple Type	non-zero width and height with equal radii
kSizeInMemory	incomplete
kUpperLeft Corner	index of top-left corner radii
kUpperRight Corner	index of top-right corner radii

Related_Function

SkRRect global, struct, and class related member functions share a topic.

Topic	Description
Type	specialization of Round Rect geometry

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

Topic	Description
Constants	enum and enum class, and their const values
Constructors	functions that construct SkRRect
Functions	global and class member functions
Operators	operator overloading methods
Related Functions	similar member functions grouped together

Constructor

SkRRect can be constructed or initialized by these functions, including C++ class constructors.

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
SkRRect()	creates with zeroed bounds and corner radii
SkRRect(const SkRRect& rrect)	copies bounds and corner radii
makeOffset	offsets bounds and radii

Operator

SkRRect operators inline class member functions with arithmetic equivalents.

Topic	Description
operator!=(const SkRRect& a, const SkRRect& b)	returns true if members are unequal
operator=(const SkRRect& rrect)	copies bounds and corner radii
operator==(const SkRRect& a, const SkRRect& b)	returns true if members are equal

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

SkRRect::MakeRect sorts its input, so width is always zero or larger.

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

SkRRect::MakeRect sorts its input, so height is always zero or larger.

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

rect	bounds to set

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

r	bounds to copy

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

oval	bounds of Oval

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

oval	bounds of Oval

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

Const	Value	Description
SkRRect::kUpperLeft_Corner	0	index of top-left corner radii
SkRRect::kUpperRight_Corner	1	index of top-right corner radii
SkRRect::kLowerRight_Corner	2	index of bottom-right corner radii
SkRRect::kLowerLeft_Corner	3	index of bottom-left corner radii

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

corner

one of: kUpperLeft Corner, kUpperRight Corner, kLowerRight Corner, kLowerLeft Corner

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

dx	offset added to rect.fLeft and rect.fRight
dy	offset added to rect.fTop and rect.fBottom

Example

See Also

makeOffset inset^[2] outset^[2]

---

makeOffset

SkRRect SK_WARN_UNUSED_RESULT makeOffset(SkScalar dx, SkScalar dy) const

Parameters

dx	offset added to rect.fLeft and rect.fRight
dy	offset added to rect.fTop and rect.fBottom

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

Const	Value	Description
SkRRect::kSizeInMemory	48	Example incomplete

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

buffer

incomplete

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

buffer	memory to read from
length	amount of memory available in the buffer

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

matrix	SkMatrix specifying the transform
dst	SkRRect to store the result

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

asHex

true if SkScalar values are written as hexadecimal

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

---