SkPoint Reference === # Vector # Point # Struct SkPoint # Overview ## Subtopics | topics | description | | --- | --- | ## Operators | description | function | | --- | --- | | SkPoint operator*(SkScalar scale) const | Returns Point multiplied by scale. | | SkPoint operator-() const | Reverses sign of Point. | | SkPoint& operator*=(SkScalar scale) | Multiplies Point by scale factor. | | SkPoint operator+(const SkPoint& a, const SkVector& b) | Returns Point offset by Vector. | | SkVector operator-(const SkPoint& a, const SkPoint& b) | Returns Vector between Points. | | bool operator!=(const SkPoint& a, const SkPoint& b) | Returns true if Point are unequal. | | bool operator==(const SkPoint& a, const SkPoint& b) | Returns true if Point are equal. | | void operator+=(const SkVector& v) | Adds Vector to Point. | | void operator-=(const SkVector& v) | Subtracts Vector from Point. | ## Member Functions | description | function | | --- | --- | | CrossProduct | Returns cross product. | | Distance | Returns straight-line distance between points. | | DotProduct | Returns dot product. | | Length | Returns straight-line distance to origin. | | Make | Constructs from SkScalar inputs. | | Normalize | Sets length to one, and returns prior length. | | Offset | Translates Point array. | | cross | Returns cross product. | | distanceToOrigin | Returns straight-line distance to origin. | | dot | Returns dot product. | | equals | Returns true if Points are equal. | | isFinite | Returns true if no member is infinite or NaN. | | isZero | Returns true if both members equal zero. | | iset | Sets to integer input. | | length | Returns straight-line distance to origin. | | negate | Reverses the sign of both members. | | normalize | Sets length to one, preserving direction. | | offset | Translates Point. | | scale | Multiplies Point by scale factor. | | set | Sets to SkScalar input. | | setAbs | Sets sign of both members to positive. | | setLength | Sets straight-line distance to origin. | | setNormalize | Sets length to one, in direction of (x, y). | | x | Returns fX. | | y | Returns fY. | SkScalar fX x-axis value used by both Point and Vector. May contain any value, including infinities and NaN. SkScalar fY y-axis value used by both Point and Vector. May contain any value, including infinities and NaN. ## Make

static constexpr SkPoint Make(SkScalar x, SkScalar y)

Sets fX to x, fY to y. Used both to set Point and Vector. ### Parameters

`x`	SkScalar x-axis value of constructed Point or Vector
`y`	SkScalar y-axis value of constructed Point or Vector

### Return Value Point (x, y) ### Example

#### Example Output ~~~~ all equal ~~~~

### See Also set iset SkIPoint::Make --- ## x

SkScalar x() const

Returns x-axis value of Point or Vector. ### Return Value fX ### Example

#### Example Output ~~~~ pt1.fX == pt1.x() ~~~~

### See Also y SkIPoint::x() --- ## y

SkScalar y() const

Returns y-axis value of Point or Vector. ### Return Value fY ### Example

#### Example Output ~~~~ pt1.fY == pt1.y() ~~~~

### See Also x SkIPoint::y() --- ## isZero

bool isZero() const

Returns true if fX and fY are both zero. ### Return Value true if fX is zero and fY is zero ### Example

#### Example Output ~~~~ pt.fX=+0 pt.fY=-0 pt.isZero() == true ~~~~

### See Also isFinite SkIPoint::isZero --- ## set

void set(SkScalar x, SkScalar y)

Sets fX to x and fY to y. ### Parameters

`x`	new value for fX
`y`	new value for fY

### Example

#### Example Output ~~~~ pt1 == pt2 ~~~~

### See Also iset Make --- ## iset

void iset(int32_t x, int32_t y)

Sets fX to x and fY to y, promoting integers to SkScalar values. Assigning a large integer value directly to fX or fY may cause a compiler error, triggered by narrowing conversion of int to SkScalar. This safely casts x and y to avoid the error. ### Parameters

`x`	new value for fX
`y`	new value for fY

### Example

### See Also set Make SkIPoint::set ---

void iset(const SkIPoint& p)

Sets fX to p.fX and fY to p.fY, promoting integers to SkScalar values. Assigning an IPoint containing a large integer value directly to fX or fY may cause a compiler error, triggered by narrowing conversion of int to SkScalar. This safely casts p.fX and p.fY to avoid the error. ### Parameters

`p`	IPoint members promoted to SkScalar

### Example

#### Example Output ~~~~ iPt: -2147483647, 2147483647 fPt: -2.14748e+09, 2.14748e+09 ~~~~

### See Also set Make SkIPoint::set --- ## setAbs

void setAbs(const SkPoint& pt)

Sets fX to absolute value of pt.fX; and fY to absolute value of pt.fY. ### Parameters

`pt`	members providing magnitude for fX and fY

### Example

#### Example Output ~~~~ pt: 0, -0 abs: 0, 0 pt: -1, -2 abs: 1, 2 pt: inf, -inf abs: inf, inf pt: nan, -nan abs: nan, nan ~~~~

### See Also set Make negate --- ## Offset

static void Offset(SkPoint points[], int count, const SkVector& offset)

Adds offset to each Point in points array with count entries. ### Parameters

`points`	Point array
`count`	entries in array
`offset`	Vector added to points

### Example

### See Also offset operator+=(const SkVector& v) ---

static void Offset(SkPoint points[], int count, SkScalar dx, SkScalar dy)

Adds offset (dx, dy) to each Point in points array of length count. ### Parameters

`points`	Point array
`count`	entries in array
`dx`	added to fX in points
`dy`	added to fY in points

### Example

### See Also offset operator+=(const SkVector& v) --- ## offset

void offset(SkScalar dx, SkScalar dy)

Adds offset (dx, dy) to Point. ### Parameters

`dx`	added to fX
`dy`	added to fY

### Example

### See Also Offset operator+=(const SkVector& v) --- ## length

SkScalar length() const

Returns the Euclidean Distance from origin, computed as:

sqrt(fX * fX + fY * fY)

. ### Return Value straight-line distance to origin ### Example

### See Also distanceToOrigin Length setLength Distance --- ## distanceToOrigin

SkScalar distanceToOrigin() const

Returns the Euclidean Distance from origin, computed as:

sqrt(fX * fX + fY * fY)

. ### Return Value straight-line distance to origin ### Example

### See Also length Length setLength Distance --- ## normalize

bool normalize()

Scales (fX, fY) so that length returns one, while preserving ratio of fX to fY, if possible. If prior length is nearly zero, sets Vector to (0, 0) and returns false; otherwise returns true. ### Return Value true if former length is not zero or nearly zero ### Example

### See Also Normalize setLength length Length --- ## setNormalize

bool setNormalize(SkScalar x, SkScalar y)

Sets Vector to (x, y) scaled so length returns one, and so that (fX, fY) is proportional to (x, y). If (x, y) length is nearly zero, sets Vector to (0, 0) and returns false; otherwise returns true. ### Parameters

`x`	proportional value for fX
`y`	proportional value for fY

### Return Value true if (x, y) length is not zero or nearly zero ### Example

### See Also normalize setLength --- ## setLength

bool setLength(SkScalar length)

Scales Vector so that distanceToOrigin returns length, if possible. If former length is nearly zero, sets Vector to (0, 0) and return false; otherwise returns true. ### Parameters

length straight-line distance to origin

### Return Value true if former length is not zero or nearly zero ### Example

### See Also length Length setNormalize setAbs ---

bool setLength(SkScalar x, SkScalar y, SkScalar length)

Sets Vector to (x, y) scaled to length, if possible. If former length is nearly zero, sets Vector to (0, 0) and return false; otherwise returns true. ### Parameters

`x`	proportional value for fX
`y`	proportional value for fY
`length`	straight-line distance to origin

### Return Value true if (x, y) length is not zero or nearly zero ### Example

### See Also length Length setNormalize setAbs --- ## scale

void scale(SkScalar scale, SkPoint* dst) const

Sets dst to Point times scale. dst may be Point to modify Point in place. ### Parameters

`scale`	factor to multiply Point by
`dst`	storage for scaled Point

### Example

void scale(SkScalar value)

Scales Point in place by scale. ### Parameters

value factor to multiply Point by

### Example

### See Also operator*(SkScalar scale) const operator*=(SkScalar scale) setLength --- ## negate

void negate()

Changes the sign of fX and fY. ### Example

#### Example Output ~~~~ pt: 0, -0 negate: -0, 0 pt: -1, -2 negate: 1, 2 pt: inf, -inf negate: -inf, inf pt: nan, -nan negate: -nan, nan ~~~~

### See Also operator-() const setAbs --- ## operator-

SkPoint operator-() _const

Returns Point changing the signs of fX and fY. ### Return Value Point as (-fX, -fY) ### Example

#### Example Output ~~~~ pt: 0, -0 negate: -0, 0 pt: -1, -2 negate: 1, 2 pt: inf, -inf negate: -inf, inf pt: nan, -nan negate: -nan, nan ~~~~

void operator+=(const SkVector& v)

Adds Vector v to Point. Sets Point to: (fX + v.fX, fY + v.fY). ### Parameters

`v`	Vector to add

### Example

### See Also offset operator+(const SkPoint& a, const SkVector& b) SkIPoint::operator+=(const SkIVector& v) --- ## operator-=

void operator-=(const SkVector& v)

Subtracts Vector v from Point. Sets Point to: (fX - v.fX, fY - v.fY). ### Parameters

`v`	Vector to subtract

### Example

### See Also offset operator-(const SkPoint& a, const SkPoint& b) SkIPoint::operator-=(const SkIVector& v) --- ## operator*

SkPoint operator*(SkScalar scale) _const

Returns Point multiplied by scale. ### Parameters

scale Scalar to multiply by

### Return Value Point as (fX * scale, fY * scale) ### Example

### See Also operator*=(SkScalar scale) scale setLength setNormalize --- ## operator*=

SkPoint& operator*=(SkScalar scale)

Multiplies Point by scale. Sets Point to: (fX * scale, fY * scale) ### Parameters

scale Scalar to multiply by

### Return Value reference to Point ### Example

### See Also operator*(SkScalar scale) const scale setLength setNormalize --- ## isFinite

bool isFinite() const

Returns true if both fX and fY are measurable values. ### Return Value true for values other than infinities and NaN ### Example

#### Example Output ~~~~ pt: 0, -0 finite: true pt: -1, -2 finite: true pt: inf, 1 finite: false pt: nan, -1 finite: false ~~~~

### See Also SkRect::isFinite SkPath::isFinite --- ## equals

bool equals(SkScalar x, SkScalar y) const

Returns true if Point is equivalent to Point constructed from (x, y). ### Parameters

`x`	value compared with fX
`y`	value compared with fY

### Return Value true if Point equals (x, y) ### Example

#### Example Output ~~~~ pt: 0, -0 == pt pt: -1, -2 == pt pt: inf, 1 == pt pt: nan, -1 != pt ~~~~

### See Also operator==(const SkPoint& a, const SkPoint& b) --- ## operator==

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

Returns true if a is equivalent to b. ### Parameters

`a`	Point to compare
`b`	Point to compare

### Return Value true if a.fX == b.fX and a.fY == b.fY ### Example

#### Example Output ~~~~ pt: 0, -0 == pt pt: -1, -2 == pt pt: inf, 1 == pt pt: nan, -1 != pt ~~~~

### See Also equals operator!=(const SkPoint& a, const SkPoint& b) --- ## operator!=

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

Returns true if a is not equivalent to b. ### Parameters

`a`	Point to compare
`b`	Point to compare

### Return Value true if a.fX != b.fX or a.fY != b.fY ### Example

#### Example Output ~~~~ pt: 0, -0 == pt pt: -1, -2 == pt pt: inf, 1 == pt pt: nan, -1 != pt ~~~~

### See Also operator==(const SkPoint& a, const SkPoint& b) equals --- ## operator-

SkVector operator-(const SkPoint& a, const SkPoint& b)

Returns Vector from b to a, computed as(a.fX - b.fX, a.fY - b.fY). Can also be used to subtract Vector from Point, returning Point. Can also be used to subtract Vector from Vector, returning Vector. ### Parameters

`a`	Point to subtract from
`b`	Point to subtract

### Return Value Vector from b to a ### Example

### See Also operator-=(const SkVector& v) offset --- ## operator+

SkPoint operator+(const SkPoint& a, const SkVector& b)

Returns Point resulting from Point a offset by Vector b, computed as: (a.fX + b.fX, a.fY + b.fY). Can also be used to offset Point b by Vector a, returning Point. Can also be used to add Vector to Vector, returning Vector. ### Parameters

`a`	Point or Vector to add to
`b`	Point or Vector to add

### Return Value Point equal to a offset by b ### Example

### See Also operator+=(const SkVector& v) offset --- ## Length

static SkScalar Length(SkScalar x, SkScalar y)

Returns the Euclidean Distance from origin, computed as:

sqrt(x * x + y * y)

. ### Parameters

`x`	component of length
`y`	component of length

### Return Value straight-line distance to origin ### Example

### See Also length Distance setLength --- ## Normalize

static SkScalar Normalize(SkVector* vec)

Scales (vec->fX, vec->fY) so that length returns one, while preserving ratio of vec->fX to vec->fY, if possible. If original length is nearly zero, sets vec to (0, 0) and returns zero; otherwise, returns length of vec before vec is scaled. Returned prior length may be SK ScalarInfinity if it can not be represented by SkScalar. Note that normalize is faster if prior length is not required. ### Parameters

vec normalized to unit length

### Return Value original vec length ### Example

### See Also normalize setLength Length --- ## Distance

static SkScalar Distance(const SkPoint& a, const SkPoint& b)

Returns the Euclidean Distance between a and b. ### Parameters

`a`	line end point
`b`	line end point

### Return Value straight-line distance from a to b ### Example

### See Also length setLength --- ## DotProduct

static SkScalar DotProduct(const SkVector& a, const SkVector& b)

Returns the dot product of Vector a and Vector b. ### Parameters

`a`	left side of dot product
`b`	right side of dot product

### Return Value product of input magnitudes and cosine of the angle between them ### Example

### See Also dot CrossProduct --- ## CrossProduct

static SkScalar CrossProduct(const SkVector& a, const SkVector& b)

Returns the cross product of Vector a and Vector b. a and b form three-dimensional vectors with z equal to zero. The cross product is a three-dimensional vector with x and y equal to zero. The cross product z term equals the returned value. ### Parameters

`a`	left side of cross product
`b`	right side of cross product

### Return Value area spanned by Vectors signed by angle direction ### Example

### See Also cross DotProduct --- ## cross

SkScalar cross(const SkVector& vec) const

Returns the cross product of Vector and vec. Vector and vec form three-dimensional vectors with z equal to zero. The cross product is a three-dimensional vector with x and y equal to zero. The cross product z term equals the returned value. ### Parameters

vec right side of cross product

### Return Value area spanned by Vectors signed by angle direction ### Example

### See Also CrossProduct dot --- ## dot

SkScalar dot(const SkVector& vec) const

Returns the dot product of Vector and Vector vec. ### Parameters

vec right side of dot product

### Return Value product of input magnitudes and cosine of the angle between them ### Example

### See Also DotProduct cross ---