skia2/site/user/api/SkRect_Reference.md

SkRect Reference

Rect

Struct SkRect

SkRect holds four SkScalar coordinates describing the upper and lower bounds of a rectangle. SkRect may be created from outer bounds or from position, width, and height. SkRect describes an area; if its right is less than or equal to its left, or if its bottom is less than or equal to its top, it is considered empty.

SkRect can be constructed from int values to avoid compiler warnings that integer input cannot convert to SkScalar without loss of precision.

Overview

Topic	Description
Constructors	functions that construct SkRect
Functions	global and class member functions
Members	member values
Operators	operator overloading methods
Related Functions	similar member functions grouped together

Related Function

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

Topic	Description
As Points	conversion to and from Points
From Integers	sets Scalar values from integer input
Inset Outset Offset	moves sides
Intersection	sets to shared bounds
Join	sets to union of bounds
Property	member values, center, validity
Rounding	adjust to integer bounds
Set	replaces all values
Sorting	orders sides

Member Function

SkRect member functions read and modify the structure properties.

Topic	Description
Intersects	returns true if areas overlap
Make	constructs from ISize returning (0, 0, width, height)
MakeEmpty	constructs from bounds of (0, 0, 0, 0)
MakeIWH	constructs from int input returning (0, 0, width, height)
MakeLTRB	constructs from SkScalar left, top, right, bottom
MakeSize	constructs from Size returning (0, 0, width, height)
MakeWH	constructs from SkScalar input returning (0, 0, width, height)
MakeXYWH	constructs from SkScalar input returning (x, y, width, height)
asScalars	returns pointer to members as array
bottom	returns larger bounds in y, if sorted
centerX	returns midpoint in x
centerY	returns midpoint in y
contains	returns true if points are equal or inside
dump	sends text representation to standard output using floats
dumpHex	sends text representation to standard output using hexadecimal
height	returns span in y
inset	moves the sides symmetrically about the center
intersect	sets to shared area; returns true if not empty
intersects	returns true if areas overlap
isEmpty	returns true if width or height are zero or negative
isFinite	returns true if no member is infinite or NaN
isSorted	returns true if width or height are zero or positive
iset	sets to int input (left, top, right, bottom)
isetWH	sets to int input (0, 0, width, height)
join	sets to union of bounds
joinNonEmptyArg	sets to union of bounds, asserting that argument is not empty
joinPossiblyEmptyRect	sets to union of bounds; skips empty check for both
left	returns smaller bounds in x, if sorted
makeInset	constructs from sides moved symmetrically about the center
makeOffset	constructs from translated sides
makeOutset	constructs from sides moved symmetrically about the center
makeSorted	constructs Rect, ordering sides from smaller to larger
offset	translates sides without changing width and height
offsetTo	translates to (x, y) without changing width and height
outset	moves the sides symmetrically about the center
right	returns larger bounds in x, if sorted
round	sets members to nearest integer value
roundIn	sets members to nearest integer value towards opposite
roundOut	sets members to nearest integer value away from opposite
set	sets to SkScalar input (left, top, right, bottom) and others
setBounds	sets to upper and lower limits of Point array
setBoundsCheck	sets to upper and lower limits of Point array
setBoundsNoCheck	sets to upper and lower limits of Point array
setEmpty	sets to (0, 0, 0, 0)
setLTRB	sets to SkScalar input (left, top, right, bottom)
setWH	sets to SkScalar input (0, 0, width, height)
setXYWH	sets to SkScalar input (x, y, width, height)
sort	orders sides from smaller to larger
toQuad	returns four corners as Point
top	returns smaller bounds in y, if sorted
width	returns span in x
x	returns bounds left
y	returns bounds top

Member

Members

Type	Name	Description
SkScalar	fLeft	smaller x-axis bounds
SkScalar	fTop	smaller y-axis bounds
SkScalar	fRight	larger x-axis bounds
SkScalar	fBottom	larger y-axis bounds

SkRect members may be read and written directly without using a member function.

Topic	Description
fBottom	larger y-axis bounds
fLeft	smaller x-axis bounds
fRight	larger x-axis bounds
fTop	smaller y-axis bounds

Members

Constructor

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

Type	Name	Description
SkScalar	fLeft	May contain any value, including infinities and NaN. The smaller of the horizontal values when sorted. When equal to or greater than fRight, Rect is empty.
SkScalar	fTop	May contain any value, including infinities and NaN. The smaller of the vertical values when sorted. When equal to or greater than fBottom, Rect is empty.
SkScalar	fRight	May contain any value, including infinities and NaN. The larger of the horizontal values when sorted. When equal to or less than fLeft, Rect is empty.
SkScalar	fBottom	May contain any value, including infinities and NaN. The larger of the vertical values when sorted. When equal to or less than fTop, Rect is empty.

Topic	Description
Make	constructs from ISize returning (0, 0, width, height)
MakeEmpty	constructs from bounds of (0, 0, 0, 0)
MakeIWH	constructs from int input returning (0, 0, width, height)
MakeLTRB	constructs from SkScalar left, top, right, bottom
MakeSize	constructs from Size returning (0, 0, width, height)
MakeWH	constructs from SkScalar input returning (0, 0, width, height)
MakeXYWH	constructs from SkScalar input returning (x, y, width, height)
makeInset	constructs from sides moved symmetrically about the center
makeOffset	constructs from translated sides
makeOutset	constructs from sides moved symmetrically about the center
makeSorted	constructs Rect, ordering sides from smaller to larger

MakeEmpty

static constexpr SkRect SK_WARN_UNUSED_RESULT MakeEmpty()

Returns constructed Rect set to (0, 0, 0, 0). Many other rectangles are empty; if left is equal to or greater than right, or if top is equal to or greater than bottom. Setting all members to zero is a convenience, but does not designate a special empty rectangle.

Return Value

bounds (0, 0, 0, 0)

Example

Example Output

MakeEmpty isEmpty: true
offset rect isEmpty: true
inset rect isEmpty: true
outset rect isEmpty: false

See Also

isEmpty setEmpty SkIRect::MakeEmpty

---

MakeWH

static constexpr SkRect SK_WARN_UNUSED_RESULT MakeWH(SkScalar w, SkScalar h)

Returns constructed Rect set to SkScalar values (0, 0, w, h). Does not validate input; w or h may be negative.

Passing integer values may generate a compiler warning since Rect cannot represent 32-bit integers exactly. Use SkIRect for an exact integer rectangle.

Parameters

w	SkScalar width of constructed Rect
h	SkScalar height of constructed Rect

Return Value

bounds (0, 0, w, h)

Example

Example Output

all equal

See Also

MakeSize MakeXYWH MakeIWH setWH SkIRect::MakeWH

---

MakeIWH

static SkRect SK_WARN_UNUSED_RESULT MakeIWH(int w, int h)

Returns constructed Rect set to integer values (0, 0, w, h). Does not validate input; w or h may be negative.

Use to avoid a compiler warning that input may lose precision when stored. Use SkIRect for an exact integer rectangle.

Parameters

w	integer width of constructed Rect
h	integer height of constructed Rect

Return Value

bounds (0, 0, w, h)

Example

Example Output

i_rect width: 25 f_rect width:25
i_rect width: 125000111 f_rect width:125000112

See Also

MakeXYWH MakeWH isetWH SkIRect::MakeWH

---

MakeSize

static constexpr SkRect SK_WARN_UNUSED_RESULT MakeSize(const SkSize& size)

Returns constructed Rect set to (0, 0, size.width, size.height). Does not validate input; size.width or size.height may be negative.

Parameters

size	SkScalar values for Rect width and height

Return Value

bounds (0, 0, size.width, size.height)

Example

Example Output

rect width: 25.5  height: 35.5
floor width: 25  height: 35

See Also

MakeWH MakeXYWH MakeIWH setWH SkIRect::MakeWH

---

MakeLTRB

static constexpr SkRect SK_WARN_UNUSED_RESULT MakeLTRB(SkScalar l, SkScalar t, SkScalar r, SkScalar b)

Returns constructed Rect set to (l, t, r, b). Does not sort input; Rect may result in fLeft greater than fRight, or fTop greater than fBottom.

Parameters

l	SkScalar stored in fLeft
t	SkScalar stored in fTop
r	SkScalar stored in fRight
b	SkScalar stored in fBottom

Return Value

bounds (l, t, r, b)

Example

Example Output

rect: 5, 35, 15, 25  isEmpty: true
rect: 5, 25, 15, 35  isEmpty: false

See Also

MakeXYWH SkIRect::MakeLTRB

---

MakeXYWH

static constexpr SkRect SK_WARN_UNUSED_RESULT MakeXYWH(SkScalar x, SkScalar y, SkScalar w, SkScalar h)

Returns constructed Rect set to(x, y, x + w, y + h) . Does not validate input; w or h may be negative.

Parameters

x	stored in fLeft
y	stored in fTop
w	added to x and stored in fRight
h	added to y and stored in fBottom

Return Value

bounds at (x, y) with width w and height h

Example

Example Output

rect: 5, 35, -10, 60  isEmpty: true
rect: -10, 35, 5, 60  isEmpty: false

See Also

MakeLTRB SkIRect::MakeXYWH

---

MakeFromIRect

static SkRect SK_WARN_UNUSED_RESULT MakeFromIRect(const SkIRect& irect)

Deprecated.

---

Make

static SkRect Make(const SkISize& size)

Returns constructed IRect set to (0, 0, size.width, size.height). Does not validate input; size.width or size.height may be negative.

Parameters

size	integer values for Rect width and height

Return Value

bounds (0, 0, size.width, size.height)

Example

Example Output

rect1 == rect2

See Also

MakeWH MakeXYWH SkRect::MakeIWH SkIRect::MakeSize

---

static SkRect SK_WARN_UNUSED_RESULT Make(const SkIRect& irect)

Returns constructed IRect set to irect, promoting integers to Scalar. Does not validate input; fLeft may be greater than fRight, fTop may be greater than fBottom.

Parameters

irect

integer unsorted bounds

Return Value

irect members converted to SkScalar

Example

See Also

MakeLTRB

---

Property

Topic	Description
asScalars	returns pointer to members as array
bottom	returns larger bounds in y, if sorted
centerX	returns midpoint in x
centerY	returns midpoint in y
dump	sends text representation to standard output using floats
	dump(bool asHex) const
	dump const
dumpHex	sends text representation to standard output using hexadecimal
height	returns span in y
isEmpty	returns true if width or height are zero or negative
isFinite	returns true if no member is infinite or NaN
isSorted	returns true if width or height are zero or positive
left	returns smaller bounds in x, if sorted
right	returns larger bounds in x, if sorted
top	returns smaller bounds in y, if sorted
width	returns span in x
x	returns bounds left
y	returns bounds top

isEmpty

bool isEmpty() const

Returns true if fLeft is equal to or greater than fRight, or if fTop is equal to or greater than fBottom. Call sort to reverse rectangles with negative width or height.

Return Value

true if width or height are zero or negative

Example

Example Output

rect: {20, 40, 10, 50} is empty
sorted: {10, 40, 20, 50} is not empty
rect: {20, 40, 20, 50} is empty
sorted: {20, 40, 20, 50} is empty

See Also

MakeEmpty sort SkIRect::isEmpty

---

isSorted

bool isSorted() const

Returns true if fLeft is equal to or less than fRight, or if fTop is equal to or less than fBottom. Call sort to reverse rectangles with negative width or height.

Return Value

true if width or height are zero or positive

Example

Example Output

rect: {20, 40, 10, 50} is not sorted
sorted: {10, 40, 20, 50} is sorted
rect: {20, 40, 20, 50} is sorted
sorted: {20, 40, 20, 50} is sorted

See Also

sort makeSorted isEmpty

---

isFinite

bool isFinite() const

Returns true if all values in the rectangle are finite: SK ScalarMin or larger, and SK ScalarMax or smaller.

Return Value

true if no member is infinite or NaN

Example

Example Output

largest is finite: true
large width inf
widest is finite: false

See Also

SkScalarIsFinite SkScalarIsNaN

---

x

SkScalar    x() const

Returns left edge of Rect, if sorted. Call isSorted to see if Rect is valid. Call sort to reverse fLeft and fRight if needed.

Return Value

fLeft

Example

Example Output

unsorted.fLeft: 15 unsorted.x(): 15
sorted.fLeft: 10 sorted.x(): 10

See Also

fLeft left y SkIRect::x()

---

y

SkScalar    y() const

Returns top edge of Rect, if sorted. Call isEmpty to see if Rect may be invalid, and sort to reverse fTop and fBottom if needed.

Return Value

fTop

Example

Example Output

unsorted.fTop: 25 unsorted.y(): 25
sorted.fTop: 5 sorted.y(): 5

See Also

fTop top x SkIRect::y()

---

left

SkScalar    left() const

Returns left edge of Rect, if sorted. Call isSorted to see if Rect is valid. Call sort to reverse fLeft and fRight if needed.

Return Value

fLeft

Example

Example Output

unsorted.fLeft: 15 unsorted.left(): 15
sorted.fLeft: 10 sorted.left(): 10

See Also

fLeft x SkIRect::left()

---

top

SkScalar    top() const

Returns top edge of Rect, if sorted. Call isEmpty to see if Rect may be invalid, and sort to reverse fTop and fBottom if needed.

Return Value

fTop

Example

Example Output

unsorted.fTop: 25 unsorted.top(): 25
sorted.fTop: 5 sorted.top(): 5

See Also

fTop y SkIRect::top()

---

right

SkScalar    right() const

Returns right edge of Rect, if sorted. Call isSorted to see if Rect is valid. Call sort to reverse fLeft and fRight if needed.

Return Value

fRight

Example

Example Output

unsorted.fRight: 10 unsorted.right(): 10
sorted.fRight: 15 sorted.right(): 15

See Also

fRight SkIRect::right()

---

bottom

SkScalar    bottom() const

Returns bottom edge of Rect, if sorted. Call isEmpty to see if Rect may be invalid, and sort to reverse fTop and fBottom if needed.

Return Value

fBottom

Example

Example Output

unsorted.fBottom: 5 unsorted.bottom(): 5
sorted.fBottom: 25 sorted.bottom(): 25

See Also

fBottom SkIRect::bottom()

---

width

SkScalar    width() const

Returns span on the x-axis. This does not check if Rect is sorted, or if result fits in 32-bit float; result may be negative or infinity.

Return Value

fRight minus fLeft

Example

Compare with SkIRect::width() example.

Example Output

unsorted width: -5
large width: 4294967296

See Also

height SkIRect::width()

---

height

SkScalar    height() const

Returns span on the y-axis. This does not check if Rect is sorted, or if result fits in 32-bit float; result may be negative or infinity.

Return Value

fBottom minus fTop

Example

Compare with SkIRect::height() example.

Example Output

unsorted height: -5
large height: 4294967296

See Also

width SkIRect::height()

---

centerX

SkScalar    centerX() const

Returns average of left edge and right edge. Result does not change if Rect is sorted. Result may overflow to infinity if Rect is far from the origin.

Return Value

midpoint in x

Example

Example Output

left:  20 right:  41 centerX: 30.5
left:  20 right:  41 centerX: 30.5
left: -20 right: -41 centerX: -30.5
left: -41 right: -20 centerX: -30.5

See Also

centerY

---

centerY

SkScalar    centerY() const

Returns average of top edge and bottom edge. Result does not change if Rect is sorted.

Return Value

midpoint in y

Example

Example Output

left: 2e+38 right: 3e+38 centerX: 2.5e+38 safe mid x: 2.5e+38

See Also

centerX

---

Operator

SkRect operators inline class member functions with arithmetic equivalents.

Topic	Description
operator!=(const SkRect& a, const SkRect& b)	returns true if members are unequal
operator==(const SkRect& a, const SkRect& b)	returns true if members are equal

operator==

bool operator==(const SkRect& a, const SkRect& b)

Returns true if all members in a: fLeft, fTop, fRight, and fBottom; are equal to the corresponding members 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 to compare
b	Rect to compare

Return Value

true if members are equal

Example

Example Output

tests are equal
{0, 0, 2, 2} == {-0, -0, 2, 2} and are numerically equal
{0, 0, 2, 2} == {-0, -0, 2, 2} and are numerically equal
{0, 0, 2, 2} == {-0, -0, 2, 2} and are numerically equal

See Also

operator!=(const SkRect& a, const SkRect& b)

---

operator!=

bool operator!=(const SkRect& a, const SkRect& b)

Returns true if any in a: fLeft, fTop, fRight, and fBottom; does not equal the corresponding members 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 to compare
b	Rect to compare

Return Value

true if members are not equal

Example

Example Output

test with NaN is not equal to itself

See Also

operator==(const SkRect& a, const SkRect& b)

---

As Points

Topic	Description
setBounds	sets to upper and lower limits of Point array
setBoundsCheck	sets to upper and lower limits of Point array
toQuad	returns four corners as Point

toQuad

void toQuad(SkPoint quad[4]) const

Returns four points in quad that enclose Rect ordered as: top-left, top-right, bottom-right, bottom-left.

Parameters

quad	storage for corners of Rect

Example

Example Output

rect: {1, 2, 3, 4}
corners: {1, 2} {3, 2} {3, 4} {1, 4}

See Also

SkPath::addRect^[2][3]

---

setBounds

void setBounds(const SkPoint pts[], int count)

Sets to bounds of Point array with count entries. If count is zero or smaller, or if Point array contains an infinity or NaN, sets to (0, 0, 0, 0).

Result is either empty or sorted: fLeft is less than or equal to fRight, and fTop is less than or equal to fBottom.

Parameters

pts	Point array
count	entries in array

Example

Example Output

count: 0 rect: 0, 0, 0, 0
added:   3, 4 count: 1 rect: 3, 4, 3, 4
added:   1, 2 count: 2 rect: 1, 2, 3, 4
added:   5, 6 count: 3 rect: 1, 2, 5, 6
added: nan, 8 count: 4 rect: 0, 0, 0, 0

See Also

set^[2][3][4] setBoundsCheck SkPath::addPoly

---

setBoundsCheck

bool setBoundsCheck(const SkPoint pts[], int count)

Sets to bounds of Point array with count entries. Returns false if count is zero or smaller, or if Point array contains an infinity or NaN; in these cases sets Rect to (0, 0, 0, 0).

Result is either empty or sorted: fLeft is less than or equal to fRight, and fTop is less than or equal to fBottom.

Parameters

pts	Point array
count	entries in array

Return Value

true if all Point values are finite

Example

Example Output

count: 0 rect: 0, 0, 0, 0 success: true
added:   3, 4 count: 1 rect: 3, 4, 3, 4 success: true
added:   1, 2 count: 2 rect: 1, 2, 3, 4 success: true
added:   5, 6 count: 3 rect: 1, 2, 5, 6 success: true
added: nan, 8 count: 4 rect: 0, 0, 0, 0 success: false

See Also

set^[2][3][4] setBounds SkPath::addPoly

---

Set

Topic	Description
set	sets to SkScalar input (left, top, right, bottom) and others
	set(const SkIRect& src)
setBoundsNoCheck	sets to upper and lower limits of Point array
setEmpty	sets to (0, 0, 0, 0)
setLTRB	sets to SkScalar input (left, top, right, bottom)
setWH	sets to SkScalar input (0, 0, width, height)
setXYWH	sets to SkScalar input (x, y, width, height)

setBoundsNoCheck

void setBoundsNoCheck(const SkPoint pts[], int count)

Sets to bounds of Point pts array with count entries. If any Point in pts contains infinity or NaN, all Rect dimensions are set to NaN.

Parameters

pts	Point array
count	entries in array

Example

See Also

setBoundsCheck

---

setEmpty

void setEmpty()

Sets Rect to (0, 0, 0, 0).

Many other rectangles are empty; if left is equal to or greater than right, or if top is equal to or greater than bottom. Setting all members to zero is a convenience, but does not designate a special empty rectangle.

Example

Example Output

rect: {3, 4, 1, 2} is empty
rect: {0, 0, 0, 0} is empty

See Also

MakeEmpty SkIRect::setEmpty

---

set

void set(const SkIRect& src)

Sets Rect to src, promoting src members from integer to Scalar. Very large values in src may lose precision.

Parameters

src	integer Rect

Example

Example Output

i_rect: {3, 4, 1, 2}
f_rect: {3, 4, 1, 2}

See Also

setLTRB SkIntToScalar

---

void set(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom)

Sets Rect to (left, top, right, bottom). left and right are not sorted; left is not necessarily less than right. top and bottom are not sorted; top is not necessarily less than bottom.

Parameters

left	stored in fLeft
top	stored in fTop
right	stored in fRight
bottom	stored in fBottom

Example

Example Output

rect1: {3, 4, 1, 2}
rect2: {3, 4, 1, 2}

See Also

setLTRB setXYWH SkIRect::set

---

setLTRB

void setLTRB(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom)

Sets Rect to (left, top, right, bottom). left and right are not sorted; left is not necessarily less than right. top and bottom are not sorted; top is not necessarily less than bottom.

Parameters

left	stored in fLeft
top	stored in fTop
right	stored in fRight
bottom	stored in fBottom

Example

Example Output

rect1: {3, 4, 1, 2}
rect2: {3, 4, 1, 2}

See Also

set^[2][3][4] setXYWH SkIRect::set

---

void set(const SkPoint pts[], int count)

Sets to bounds of Point array with count entries. If count is zero or smaller, or if Point array contains an infinity or NaN, sets Rect to (0, 0, 0, 0).

Result is either empty or sorted: fLeft is less than or equal to fRight, and fTop is less than or equal to fBottom.

Parameters

pts	Point array
count	entries in array

Example

Example Output

count: 0 rect: 0, 0, 0, 0
added:   3, 4 count: 1 rect: 3, 4, 3, 4
added:   1, 2 count: 2 rect: 1, 2, 3, 4
added:   5, 6 count: 3 rect: 1, 2, 5, 6
added: nan, 8 count: 4 rect: 0, 0, 0, 0

See Also

setBounds setBoundsCheck SkPath::addPoly

---

void set(const SkPoint& p0, const SkPoint& p1)

Sets bounds to the smallest Rect enclosing Points p0 and p1. The result is sorted and may be empty. Does not check to see if values are finite.

Parameters

p0	corner to include
p1	corner to include

Example

p0 and p1 may be swapped and have the same effect unless one contains NaN.

See Also

setBounds setBoundsCheck

---

setXYWH

void setXYWH(SkScalar x, SkScalar y, SkScalar width, SkScalar height)

Sets Rect to(x, y, x + width, y + height) . Does not validate input; width or height may be negative.

Parameters

x	stored in fLeft
y	stored in fTop
width	added to x and stored in fRight
height	added to y and stored in fBottom

Example

Example Output

rect: 5, 35, -10, 60  isEmpty: true
rect: -10, 35, 5, 60  isEmpty: false

See Also

MakeXYWH setLTRB set^[2][3][4] SkIRect::setXYWH

---

setWH

void setWH(SkScalar width, SkScalar height)

Sets Rect to (0, 0, width, height). Does not validate input; width or height may be negative.

Parameters

width	stored in fRight
height	stored in fBottom

Example

Example Output

rect: 0, 0, -15, 25  isEmpty: true
rect: -15, 0, 0, 25  isEmpty: false

See Also

MakeWH setXYWH isetWH

---

From Integers

Topic	Description
iset	sets to int input (left, top, right, bottom)
isetWH	sets to int input (0, 0, width, height)

iset

void iset(int left, int top, int right, int bottom)

Sets Rect to (left, top, right, bottom). All parameters are promoted from integer to Scalar. left and right are not sorted; left is not necessarily less than right. top and bottom are not sorted; top is not necessarily less than bottom.

Parameters

left	promoted to SkScalar and stored in fLeft
top	promoted to SkScalar and stored in fTop
right	promoted to SkScalar and stored in fRight
bottom	promoted to SkScalar and stored in fBottom

Example

Example Output

rect1: {3, 4, 1, 2}
rect2: {3, 4, 1, 2}

See Also

set^[2][3][4] setLTRB SkIRect::set SkIntToScalar

---

isetWH

void isetWH(int width, int height)

Sets Rect to (0, 0, width, height). width and height may be zero or negative. width and height are promoted from integer to SkScalar, large values may lose precision.

Parameters

width	promoted to SkScalar and stored in fRight
height	promoted to SkScalar and stored in fBottom

Example

Example Output

rect1: {0, 0, 1, 2}
rect2: {0, 0, 1, 2}

See Also

MakeWH MakeXYWH iset SkIRect:MakeWH

---

Inset Outset Offset

Topic	Description
inset	moves the sides symmetrically about the center
offset	translates sides without changing width and height
	offset(SkScalar dx, SkScalar dy)
offsetTo	translates to (x, y) without changing width and height
outset	moves the sides symmetrically about the center

makeOffset

SkRect makeOffset(SkScalar dx, SkScalar dy) const

Returns Rect offset by (dx, dy).

If dx is negative, Rect returned is moved to the left. If dx is positive, Rect returned is moved to the right. If dy is negative, Rect returned is moved upward. If dy is positive, Rect returned is moved downward.

Parameters

dx	added to fLeft and fRight
dy	added to fTop and fBottom

Return Value

Rect offset on axes, with original width and height

Example

Example Output

rect: 10, 50, 20, 60  isEmpty: false
rect: 25, 82, 35, 92  isEmpty: false

See Also

offset^[2] makeInset makeOutset SkIRect::makeOffset

---

makeInset

SkRect makeInset(SkScalar dx, SkScalar dy) const

Returns Rect, inset by (dx, dy).

If dx is negative, Rect returned is wider. If dx is positive, Rect returned is narrower. If dy is negative, Rect returned is taller. If dy is positive, Rect returned is shorter.

Parameters

dx	added to fLeft and subtracted from fRight
dy	added to fTop and subtracted from fBottom

Return Value

Rect inset symmetrically left and right, top and bottom

Example

Example Output

rect: 10, 50, 20, 60  isEmpty: false
rect: 25, 82, 5, 28  isEmpty: true

See Also

inset makeOffset makeOutset SkIRect::makeInset

---

makeOutset

SkRect makeOutset(SkScalar dx, SkScalar dy) const

Returns Rect, outset by (dx, dy).

If dx is negative, Rect returned is narrower. If dx is positive, Rect returned is wider. If dy is negative, Rect returned is shorter. If dy is positive, Rect returned is taller.

Parameters

dx	subtracted to fLeft and added from fRight
dy	subtracted to fTop and added from fBottom

Return Value

Rect outset symmetrically left and right, top and bottom

Example

Example Output

rect: 10, 50, 20, 60  isEmpty: false
rect: -5, 18, 35, 92  isEmpty: false

See Also

outset makeOffset makeInset SkIRect::makeOutset

---

offset

void offset(SkScalar dx, SkScalar dy)

Offsets Rect by adding dx to fLeft, fRight; and by adding dy to fTop, fBottom.

If dx is negative, moves Rect to the left. If dx is positive, moves Rect to the right. If dy is negative, moves Rect upward. If dy is positive, moves Rect downward.

Parameters

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

Example

Example Output

rect: 15, 27, 55, 86

See Also

offsetTo makeOffset SkIRect::offset^[2]

---

void offset(const SkPoint& delta)

Offsets Rect by adding delta.fX to fLeft, fRight; and by adding delta.fY to fTop, fBottom.

If delta.fX is negative, moves Rect to the left. If delta.fX is positive, moves Rect to the right. If delta.fY is negative, moves Rect upward. If delta.fY is positive, moves Rect downward.

Parameters

delta

added to Rect

Example

Example Output

rect: 15, 27, 55, 86

See Also

offsetTo makeOffset SkIRect::offset^[2]

---

offsetTo

void offsetTo(SkScalar newX, SkScalar newY)

Offsets Rect so that fLeft equals newX, and fTop equals newY. width and height are unchanged.

Parameters

newX	stored in fLeft, preserving width
newY	stored in fTop, preserving height

Example

Example Output

rect: 15, 27, 55, 86

See Also

offset^[2] makeOffset setXYWH SkIRect::offsetTo

---

inset

void inset(SkScalar dx, SkScalar dy)

Insets Rect by (dx, dy).

If dx is positive, makes Rect narrower. If dx is negative, makes Rect wider. If dy is positive, makes Rect shorter. If dy is negative, makes Rect taller.

Parameters

dx	added to fLeft and subtracted from fRight
dy	added to fTop and subtracted from fBottom

Example

Example Output

rect: 15, 27, 45, 60

See Also

outset makeInset SkIRect::inset

---

outset

void outset(SkScalar dx, SkScalar dy)

Outsets Rect by (dx, dy).

If dx is positive, makes Rect wider. If dx is negative, makes Rect narrower. If dy is positive, makes Rect taller. If dy is negative, makes Rect shorter.

Parameters

dx	subtracted to fLeft and added from fRight
dy	subtracted to fTop and added from fBottom

Example

Example Output

rect: 5, 1, 55, 86

See Also

inset makeOutset SkIRect::outset

---

Intersection

Rects intersect when they enclose a common area. To intersect, each of the pair must describe area; fLeft is less than fRight, and fTop is less than fBottom; empty() returns false. The intersection of Rect pair can be described by:

(max(a.fLeft, b.fLeft), max(a.fTop, b.fTop), min(a.fRight, b.fRight), min(a.fBottom, b.fBottom)) .

The intersection is only meaningful if the resulting Rect is not empty and describes an area: fLeft is less than fRight, and fTop is less than fBottom.

Topic	Description
Intersects	returns true if areas overlap
contains	returns true if points are equal or inside
	contains(SkScalar x, SkScalar y) const
intersect	sets to shared area; returns true if not empty
	intersect(const SkRect& r)
intersects	returns true if areas overlap
	intersects(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom) const

contains

bool contains(SkScalar x, SkScalar y) const

Returns true if: fLeft <= x < fRight && fTop <= y < fBottom. Returns false if SkRect is empty.

Parameters

x	test SkPoint x-coordinate
y	test SkPoint y-coordinate

Return Value

true if (x, y) is inside SkRect

Example

Example Output

rect: (30, 50, 40, 60) contains (30, 50)
rect: (30, 50, 40, 60) does not contain (39, 49)
rect: (30, 50, 40, 60) does not contain (29, 59)

See Also

SkIRect::contains^[2][3][4] SkRRect::contains

---

bool contains(const SkRect& r) const

Returns true if Rect contains r. Returns false if Rect is empty or r is empty.

Rect contains r when Rect area completely includes r area.

Parameters

r	Rect contained

Return Value

true if all sides of Rect are outside r

Example

Example Output

rect: (30, 50, 40, 60) contains (30, 50, 31, 51)
rect: (30, 50, 40, 60) does not contain (39, 49, 40, 50)
rect: (30, 50, 40, 60) does not contain (29, 59, 30, 60)

See Also

SkIRect::contains^[2][3][4]

---

bool contains(const SkIRect& r) const

Returns true if Rect contains r. Returns false if Rect is empty or r is empty.

Rect contains r when Rect area completely includes r area.

Parameters

r	IRect contained

Return Value

true if all sides of Rect are outside r

Example

Example Output

rect: (30, 50, 40, 60) contains (30, 50, 31, 51)
rect: (30, 50, 40, 60) does not contain (39, 49, 40, 50)
rect: (30, 50, 40, 60) does not contain (29, 59, 30, 60)

See Also

SkIRect::contains^[2][3][4]

---

intersect

bool intersect(const SkRect& r)

Returns true if Rect intersects r, and sets Rect to intersection. Returns false if Rect does not intersect r, and leaves Rect unchanged.

Returns false if either r or Rect is empty, leaving Rect unchanged.

Parameters

r	limit of result

Return Value

true if r and Rect have area in common

Example

Two SkDebugf calls are required. If the calls are combined, their arguments may not be evaluated in left to right order: the printed intersection may be before or after the call to intersect.

Example Output

intersection: 30, 60, 50, 80

See Also

intersects^[2] Intersects join^[2] SkIRect::intersect^[2][3]

---

bool intersect(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom)

Constructs Rect to intersect from (left, top, right, bottom). Does not sort construction.

Returns true if Rect intersects construction, and sets Rect to intersection. Returns false if Rect does not intersect construction, and leaves Rect unchanged.

Returns false if either construction or Rect is empty, leaving Rect unchanged.

Parameters

left	x-axis minimum of constructed Rect
top	y-axis minimum of constructed Rect
right	x-axis maximum of constructed Rect
bottom	y-axis maximum of constructed Rect

Return Value

true if construction and Rect have area in common

Example

Two SkDebugf calls are required. If the calls are combined, their arguments may not be evaluated in left to right order: the printed intersection may be before or after the call to intersect.

Example Output

intersection: 30, 60, 50, 80

See Also

intersects^[2] Intersects join^[2] SkIRect::intersect^[2][3]

---

bool SK_WARN_UNUSED_RESULT intersect(const SkRect& a, const SkRect& b)

Returns true if a intersects b, and sets Rect to intersection. Returns false if a does not intersect b, and leaves Rect unchanged.

Returns false if either a or b is empty, leaving Rect unchanged.

Parameters

a	Rect to intersect
b	Rect to intersect

Return Value

true if a and b have area in common

Example

Example Output

intersection: 30, 60, 50, 80

See Also

intersects^[2] Intersects join^[2] SkIRect::intersect^[2][3]

---

intersects

bool intersects(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom) const

Constructs Rect to intersect from (left, top, right, bottom). Does not sort construction.

Returns true if Rect intersects construction. Returns false if either construction or Rect is empty, or do not intersect.

Parameters

left	x-axis minimum of constructed Rect
top	y-axis minimum of constructed Rect
right	x-axis maximum of constructed Rect
bottom	y-axis maximum of constructed Rect

Return Value

true if construction and Rect have area in common

Example

Example Output

intersection

See Also

intersect^[2][3] Intersects SkIRect::Intersects

---

bool intersects(const SkRect& r) const

Returns true if Rect intersects r. Returns false if either r or Rect is empty, or do not intersect.

Parameters

r	Rect to intersect

Return Value

true if r and Rect have area in common

Example

Example Output

intersection

See Also

intersect^[2][3] Intersects SkIRect::Intersects

---

Intersects

static bool Intersects(const SkRect& a, const SkRect& b)

Returns true if a intersects b. Returns false if either a or b is empty, or do not intersect.

Parameters

a	Rect to intersect
b	Rect to intersect

Return Value

true if a and b have area in common

Example

Example Output

intersection

See Also

intersect^[2][3] intersects^[2] SkIRect::Intersects

---

Join

Topic	Description
join	sets to union of bounds
	join(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom)
joinNonEmptyArg	sets to union of bounds, asserting that argument is not empty
joinPossiblyEmptyRect	sets to union of bounds; skips empty check for both

join

void join(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom)

Constructs Rect to intersect from (left, top, right, bottom). Does not sort construction.

Sets Rect to the union of itself and the construction.

Has no effect if construction is empty. Otherwise, if Rect is empty, sets Rect to construction.

Parameters

left	x-axis minimum of constructed Rect
top	y-axis minimum of constructed Rect
right	x-axis maximum of constructed Rect
bottom	y-axis maximum of constructed Rect

Example

Example Output

join: 10, 20, 55, 65

See Also

joinNonEmptyArg joinPossiblyEmptyRect SkIRect::join^[2]

---

void join(const SkRect& r)

Sets Rect to the union of itself and r.

Has no effect if r is empty. Otherwise, if Rect is empty, sets Rect to r.

Parameters

r	expansion Rect

Example

Example Output

join: 10, 20, 55, 65

See Also

joinNonEmptyArg joinPossiblyEmptyRect SkIRect::join^[2]

---

joinNonEmptyArg

void joinNonEmptyArg(const SkRect& r)

Sets Rect to the union of itself and r.

Asserts if r is empty and SK_DEBUG is defined. If Rect is empty, sets Rect to r.

May produce incorrect results if r is empty.

Parameters

r	expansion Rect

Example

Since Rect is not sorted, first result is copy of toJoin.

Example Output

rect: 50, 60, 55, 65
sorted: 10, 0, 55, 100

See Also

join^[2] joinPossiblyEmptyRect SkIRect::join^[2]

---

joinPossiblyEmptyRect

void joinPossiblyEmptyRect(const SkRect& r)

Sets Rect to the union of itself and the construction.

May produce incorrect results if Rect or r is empty.

Parameters

r	expansion Rect

Example

Since Rect is not sorted, first result is not useful.

Example Output

rect: 10, 60, 55, 65
sorted: 10, 0, 55, 100

See Also

joinNonEmptyArg join^[2] SkIRect::join^[2]

---

Rounding

Topic	Description
round	sets members to nearest integer value
	round(SkIRect* dst) const
roundIn	sets members to nearest integer value towards opposite
roundOut	sets members to nearest integer value away from opposite
	roundOut(SkIRect* dst) const

round

void round(SkIRect* dst) const

Sets IRect by adding 0.5 and discarding the fractional portion of Rect members, using(SkScalarRoundToInt(fLeft), SkScalarRoundToInt(fTop), SkScalarRoundToInt(fRight), SkScalarRoundToInt(fBottom)) .

Parameters

dst	storage for IRect

Example

Example Output

round: 31, 51, 41, 61

See Also

roundIn roundOut^[2][3] SkScalarRoundToInt

---

roundOut

void roundOut(SkIRect* dst) const

Sets IRect by discarding the fractional portion of fLeft and fTop; and rounding up fRight and fBottom, using(SkScalarFloorToInt(fLeft), SkScalarFloorToInt(fTop), SkScalarCeilToInt(fRight), SkScalarCeilToInt(fBottom)) .

Parameters

dst	storage for IRect

Example

Example Output

round: 30, 50, 41, 61

See Also

roundIn round^[2] SkScalarRoundToInt

---

void roundOut(SkRect* dst) const

Sets Rect by discarding the fractional portion of fLeft and fTop; and rounding up fRight and fBottom, using(SkScalarFloorToInt(fLeft), SkScalarFloorToInt(fTop), SkScalarCeilToInt(fRight), SkScalarCeilToInt(fBottom)) .

Parameters

dst	storage for Rect

Example

Example Output

round: 30, 50, 41, 61

See Also

roundIn round^[2] SkScalarRoundToInt

---

roundIn

void roundIn(SkIRect* dst) const

Sets Rect by rounding up fLeft and fTop; and discarding the fractional portion of fRight and fBottom, using(SkScalarCeilToInt(fLeft), SkScalarCeilToInt(fTop), SkScalarFloorToInt(fRight), SkScalarFloorToInt(fBottom)) .

Parameters

dst	storage for IRect

Example

Example Output

round: 31, 51, 40, 60

See Also

roundOut^[2][3] round^[2] SkScalarRoundToInt

---

SkIRect round() const

Returns IRect by adding 0.5 and discarding the fractional portion of Rect members, using(SkScalarRoundToInt(fLeft), SkScalarRoundToInt(fTop), SkScalarRoundToInt(fRight), SkScalarRoundToInt(fBottom)) .

Return Value

rounded IRect

Example

Example Output

round: 31, 51, 41, 61

See Also

roundOut^[2][3] roundIn SkScalarRoundToInt

---

SkIRect roundOut() const

Sets IRect by discarding the fractional portion of fLeft and fTop; and rounding up fRight and fBottom, using(SkScalarFloorToInt(fLeft), SkScalarFloorToInt(fTop), SkScalarCeilToInt(fRight), SkScalarCeilToInt(fBottom)) .

Return Value

rounded IRect

Example

Example Output

round: 30, 50, 41, 61

See Also

round^[2] roundIn SkScalarRoundToInt

---

Sorting

Topic	Description
sort	orders sides from smaller to larger

sort

void sort()

Swaps fLeft and fRight if fLeft is greater than fRight; and swaps fTop and fBottom if fTop is greater than fBottom. Result may be empty; and width and height will be zero or positive.

Example

Example Output

rect: 30.5, 50.5, 20.5, 10.5
sorted: 20.5, 10.5, 30.5, 50.5

See Also

makeSorted SkIRect::sort isSorted

---

makeSorted

SkRect makeSorted() const

Returns Rect with fLeft and fRight swapped if fLeft is greater than fRight; and with fTop and fBottom swapped if fTop is greater than fBottom. Result may be empty; and width and height will be zero or positive.

Return Value

sorted Rect

Example

Example Output

rect: 30.5, 50.5, 20.5, 10.5
sorted: 20.5, 10.5, 30.5, 50.5

See Also

sort SkIRect::makeSorted isSorted

---

asScalars

const SkScalar* asScalars() const

Returns pointer to first Scalar in Rect, to treat it as an array with four entries.

Return Value

pointer to fLeft

Example

Example Output

rect.asScalars() == &rect.fLeft

See Also

toQuad

---

dump

void dump(bool asHex) const

Writes text representation of Rect to standard output. Set asHex to 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(20, 30, 40, 50);
SkRect::MakeLTRB(SkBits2Float(0x41a00000), /* 20.000000 */
SkBits2Float(0x41f00000), /* 30.000000 */
SkBits2Float(0x42200000), /* 40.000000 */
SkBits2Float(0x42480000)  /* 50.000000 */);

See Also

dumpHex

---

void dump() const

Writes text representation of 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 Rect from output.

Example

Example Output

SkRect::MakeLTRB(0.857143f, 0.666667f, 2.6f, 7);
rect is not equal to copy

See Also

dumpHex

---

dumpHex

void dumpHex() const

Writes text representation of 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 Rect.

Use instead of dump when submitting bug reports against Skia .

Example

Example Output

SkRect::MakeLTRB(SkBits2Float(0x3f5b6db7), /* 0.857143 */
SkBits2Float(0x3f2aaaab), /* 0.666667 */
SkBits2Float(0x40266666), /* 2.600000 */
SkBits2Float(0x40e00000)  /* 7.000000 */);
rect is equal to copy

See Also

dump^[2]

---

MakeLargest

static SkRect SK_WARN_UNUSED_RESULT MakeLargest()

Deprecated.

---