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Skia
2DGraphicsLibrary
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Skia
2DGraphicsLibrary
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Public Types | |
| enum | Side { kLeft_Side = -1, kOn_Side = 0, kRight_Side = 1 } |
| The side of a point relative to a line. More... | |
Public Member Functions | |
| SkScalar | x () const |
| SkScalar | y () const |
| bool | isZero () const |
| Returns true iff fX and fY are both zero. | |
| void | set (SkScalar x, SkScalar y) |
| Set the point's X and Y coordinates. | |
| void | iset (int32_t x, int32_t y) |
| Set the point's X and Y coordinates by automatically promoting (x,y) to SkScalar values. | |
| void | iset (const SkIPoint &p) |
| Set the point's X and Y coordinates by automatically promoting p's coordinates to SkScalar values. | |
| void | setAbs (const SkPoint &pt) |
| void | setIRectFan (int l, int t, int r, int b) |
| void | setIRectFan (int l, int t, int r, int b, size_t stride) |
| void | setRectFan (SkScalar l, SkScalar t, SkScalar r, SkScalar b) |
| void | setRectFan (SkScalar l, SkScalar t, SkScalar r, SkScalar b, size_t stride) |
| void | offset (SkScalar dx, SkScalar dy) |
| SkScalar | length () const |
| Return the euclidian distance from (0,0) to the point. | |
| SkScalar | distanceToOrigin () const |
| bool | canNormalize () const |
| bool | normalize () |
| Set the point (vector) to be unit-length in the same direction as it already points. More... | |
| bool | setNormalize (SkScalar x, SkScalar y) |
| Set the point (vector) to be unit-length in the same direction as the x,y params. More... | |
| bool | setLength (SkScalar length) |
| Scale the point (vector) to have the specified length, and return that length. More... | |
| bool | setLength (SkScalar x, SkScalar y, SkScalar length) |
| Set the point (vector) to have the specified length in the same direction as (x,y). More... | |
| bool | setLengthFast (SkScalar length) |
| Same as setLength, but favoring speed over accuracy. | |
| bool | setLengthFast (SkScalar x, SkScalar y, SkScalar length) |
| Same as setLength, but favoring speed over accuracy. | |
| void | scale (SkScalar scale, SkPoint *dst) const |
| Scale the point's coordinates by scale, writing the answer into dst. More... | |
| void | scale (SkScalar value) |
| Scale the point's coordinates by scale, writing the answer back into the point. | |
| void | rotateCW (SkPoint *dst) const |
| Rotate the point clockwise by 90 degrees, writing the answer into dst. More... | |
| void | rotateCW () |
| Rotate the point clockwise by 90 degrees, writing the answer back into the point. | |
| void | rotateCCW (SkPoint *dst) const |
| Rotate the point counter-clockwise by 90 degrees, writing the answer into dst. More... | |
| void | rotateCCW () |
| Rotate the point counter-clockwise by 90 degrees, writing the answer back into the point. | |
| void | negate () |
| Negate the point's coordinates. | |
| SkPoint | operator- () const |
| Returns a new point whose coordinates are the negative of the point's. | |
| void | operator+= (const SkPoint &v) |
| Add v's coordinates to the point's. | |
| void | operator-= (const SkPoint &v) |
| Subtract v's coordinates from the point's. | |
| SkPoint | operator* (SkScalar scale) const |
| SkPoint & | operator*= (SkScalar scale) |
| bool | isFinite () const |
| Returns true if both X and Y are finite (not infinity or NaN) | |
| bool | equals (SkScalar x, SkScalar y) const |
| Returns true if the point's coordinates equal (x,y) | |
| bool | equalsWithinTolerance (const SkPoint &p) const |
| Return true if this point and the given point are far enough apart such that a vector between them would be non-degenerate. More... | |
| bool | equalsWithinTolerance (const SkPoint &p, SkScalar tol) const |
| WARNING: There is no guarantee that the result will reflect judgments elsewhere regarding degeneracy ("points A and B are so close that the
vector between them is essentially zero"). | |
| SkScalar | cross (const SkPoint &vec) const |
| SkScalar | dot (const SkPoint &vec) const |
| SkScalar | lengthSqd () const |
| SkScalar | distanceToSqd (const SkPoint &pt) const |
| SkScalar | distanceToLineBetweenSqd (const SkPoint &a, const SkPoint &b, Side *side=NULL) const |
| Returns the squared distance to the infinite line between two pts. More... | |
| SkScalar | distanceToLineBetween (const SkPoint &a, const SkPoint &b, Side *side=NULL) const |
| Returns the distance to the infinite line between two pts. More... | |
| SkScalar | distanceToLineSegmentBetweenSqd (const SkPoint &a, const SkPoint &b) const |
| Returns the squared distance to the line segment between pts a and b. | |
| SkScalar | distanceToLineSegmentBetween (const SkPoint &a, const SkPoint &b) const |
| Returns the distance to the line segment between pts a and b. | |
| void | setOrthog (const SkPoint &vec, Side side=kLeft_Side) |
| Make this vector be orthogonal to vec. More... | |
| const SkScalar * | asScalars () const |
| cast-safe way to treat the point as an array of (2) SkScalars. | |
Static Public Member Functions | |
| static SkPoint | Make (SkScalar x, SkScalar y) |
| static void | Offset (SkPoint points[], int count, const SkPoint &offset) |
| static void | Offset (SkPoint points[], int count, SkScalar dx, SkScalar dy) |
| static bool | CanNormalize (SkScalar dx, SkScalar dy) |
| Return true if the computed length of the vector is >= the internal tolerance (used to avoid dividing by tiny values). | |
| static SkScalar | Length (SkScalar x, SkScalar y) |
| Returns the euclidian distance from (0,0) to (x,y) | |
| static SkScalar | Normalize (SkPoint *pt) |
| Normalize pt, returning its previous length. More... | |
| static SkScalar | Distance (const SkPoint &a, const SkPoint &b) |
| Returns the euclidian distance between a and b. | |
| static SkScalar | DotProduct (const SkPoint &a, const SkPoint &b) |
| Returns the dot product of a and b, treating them as 2D vectors. | |
| static SkScalar | CrossProduct (const SkPoint &a, const SkPoint &b) |
| Returns the cross product of a and b, treating them as 2D vectors. | |
Public Attributes | |
| SkScalar | fX |
| SkScalar | fY |
Friends | |
| bool | operator== (const SkPoint &a, const SkPoint &b) |
| bool | operator!= (const SkPoint &a, const SkPoint &b) |
| SkPoint | operator- (const SkPoint &a, const SkPoint &b) |
| Returns a new point whose coordinates are the difference between a's and b's (a - b) | |
| SkPoint | operator+ (const SkPoint &a, const SkPoint &b) |
| Returns a new point whose coordinates are the sum of a's and b's (a + b) | |
| enum SkPoint::Side |
The side of a point relative to a line.
If the line is from a to b then the values are consistent with the sign of (b-a) cross (pt-a)
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inline |
Returns the distance to the infinite line between two pts.
Also optionally returns the side of the line that the pt falls on (looking along the line from a to b)
| SkScalar SkPoint::distanceToLineBetweenSqd | ( | const SkPoint & | a, |
| const SkPoint & | b, | ||
| Side * | side = NULL |
||
| ) | const |
Returns the squared distance to the infinite line between two pts.
Also optionally returns the side of the line that the pt falls on (looking along line from a to b)
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inline |
Return true if this point and the given point are far enough apart such that a vector between them would be non-degenerate.
WARNING: Unlike the explicit tolerance version, this method does not use componentwise comparison. Instead, it uses a comparison designed to match judgments elsewhere regarding degeneracy ("points A and B are so close that the vector between them is essentially zero").
| bool SkPoint::normalize | ( | ) |
Set the point (vector) to be unit-length in the same direction as it already points.
If the point has a degenerate length (i.e. nearly 0) then set it to (0,0) and return false; otherwise return true.
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static |
Normalize pt, returning its previous length.
If the prev length is too small (degenerate), set pt to (0,0) and return 0. This uses the same tolerance as CanNormalize.
Note that this method may be significantly more expensive than the non-static normalize(), because it has to return the previous length of the point. If you don't need the previous length, call the non-static normalize() method instead.
| void SkPoint::rotateCCW | ( | SkPoint * | dst | ) | const |
Rotate the point counter-clockwise by 90 degrees, writing the answer into dst.
It is legal for dst == this.
| void SkPoint::rotateCW | ( | SkPoint * | dst | ) | const |
Rotate the point clockwise by 90 degrees, writing the answer into dst.
It is legal for dst == this.
| void SkPoint::scale | ( | SkScalar | scale, |
| SkPoint * | dst | ||
| ) | const |
Scale the point's coordinates by scale, writing the answer into dst.
It is legal for dst == this.
| bool SkPoint::setLength | ( | SkScalar | length | ) |
Scale the point (vector) to have the specified length, and return that length.
If the original length is degenerately small (nearly zero), set it to (0,0) and return false, otherwise return true.
| bool SkPoint::setLength | ( | SkScalar | x, |
| SkScalar | y, | ||
| SkScalar | length | ||
| ) |
Set the point (vector) to have the specified length in the same direction as (x,y).
If the vector (x,y) has a degenerate length (i.e. nearly 0) then set it to (0,0) and return false, otherwise return true.
| bool SkPoint::setNormalize | ( | SkScalar | x, |
| SkScalar | y | ||
| ) |
Set the point (vector) to be unit-length in the same direction as the x,y params.
If the vector (x,y) has a degenerate length (i.e. nearly 0) then set it to (0,0) and return false, otherwise return true.
Make this vector be orthogonal to vec.
Looking down vec the new vector will point in direction indicated by side (which must be kLeft_Side or kRight_Side).
