/* * Copyright 2006 The Android Open Source Project * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file.
*/
struct SkArc; class SkData; class SkPathRef; class SkRRect; class SkWStream; enumclass SkPathConvexity; enumclass SkPathFirstDirection; struct SkPathVerbAnalysis;
// WIP -- define this locally, and fix call-sites to use SkPathBuilder (skbug.com/9000) //#define SK_HIDE_PATH_EDIT_METHODS
/** \class SkPath SkPath contain geometry. SkPath may be empty, or contain one or more verbs that outline a figure. SkPath always starts with a move verb to a Cartesian coordinate, and may be followed by additional verbs that add lines or curves. Adding a close verb makes the geometry into a continuous loop, a closed contour. SkPath may contain any number of contours, each beginning with a move verb.
SkPath contours may contain only a move verb, or may also contain lines, quadratic beziers, conics, and cubic beziers. SkPath contours may be open or closed.
When used to draw a filled area, SkPath describes whether the fill is inside or outside the geometry. SkPath also describes the winding rule used to fill overlapping contours.
Internally, SkPath lazily computes metrics likes bounds and convexity. Call SkPath::updateBoundsCache to make SkPath thread safe.
*/ class SK_API SkPath { public: /** * Create a new path with the specified segments. * * The points and weights arrays are read in order, based on the sequence of verbs. * * Move 1 point * Line 1 point * Quad 2 points * Conic 2 points and 1 weight * Cubic 3 points * Close 0 points * * If an illegal sequence of verbs is encountered, or the specified number of points * or weights is not sufficient given the verbs, an empty Path is returned. * * A legal sequence of verbs consists of any number of Contours. A contour always begins * with a Move verb, followed by 0 or more segments: Line, Quad, Conic, Cubic, followed * by an optional Close.
*/ static SkPath Make(const SkPoint[], int pointCount, const uint8_t[], int verbCount, const SkScalar[], int conicWeightCount,
SkPathFillType, bool isVolatile = false);
/** Constructs a copy of an existing path. Copy constructor makes two paths identical by value. Internally, path and the returned result share pointer values. The underlying verb array, SkPoint array and weights are copied when modified.
Creating a SkPath copy is very efficient and never allocates memory. SkPath are always copied by value from the interface; the underlying shared pointers are not exposed.
@param path SkPath to copy by value @return copy of SkPath
/** Returns a copy of this path in the current state. */
SkPath snapshot() const { return *this;
}
/** Returns a copy of this path in the current state, and resets the path to empty. */
SkPath detach() {
SkPath result = *this;
this->reset(); return result;
}
/** Constructs a copy of an existing path. SkPath assignment makes two paths identical by value. Internally, assignment shares pointer values. The underlying verb array, SkPoint array and weights are copied when modified.
Copying SkPath by assignment is very efficient and never allocates memory. SkPath are always copied by value from the interface; the underlying shared pointers are not exposed.
@param path verb array, SkPoint array, weights, and SkPath::FillType to copy @return SkPath copied by value
/** Compares a and b; returns true if SkPath::FillType, verb array, SkPoint array, and weights are equivalent.
@param a SkPath to compare @param b SkPath to compare @return true if SkPath pair are equivalent
*/ friend SK_API booloperator==(const SkPath& a, const SkPath& b);
/** Compares a and b; returns true if SkPath::FillType, verb array, SkPoint array, and weights are not equivalent.
@param a SkPath to compare @param b SkPath to compare @return true if SkPath pair are not equivalent
*/ friendbooloperator!=(const SkPath& a, const SkPath& b) { return !(a == b);
}
/** Returns true if SkPath contain equal verbs and equal weights. If SkPath contain one or more conics, the weights must match.
conicTo() may add different verbs depending on conic weight, so it is not trivial to interpolate a pair of SkPath containing conics with different conic weight values.
@param compare SkPath to compare @return true if SkPath verb array and weights are equivalent
/** Interpolates between SkPath with SkPoint array of equal size. Copy verb array and weights to out, and set out SkPoint array to a weighted average of this SkPoint array and ending SkPoint array, using the formula: (Path Point * weight) + ending Point * (1 - weight).
weight is most useful when between zero (ending SkPoint array) and one (this Point_Array); will work with values outside of this range.
interpolate() returns false and leaves out unchanged if SkPoint array is not the same size as ending SkPoint array. Call isInterpolatable() to check SkPath compatibility prior to calling interpolate().
@param ending SkPoint array averaged with this SkPoint array @param weight contribution of this SkPoint array, and one minus contribution of ending SkPoint array @param out SkPath replaced by interpolated averages @return true if SkPath contain same number of SkPoint
/** Sets FillType, the rule used to fill SkPath. While there is no check that ft is legal, values outside of FillType are not supported.
*/ void setFillType(SkPathFillType ft) {
fFillType = SkToU8(ft);
}
/** Returns if FillType describes area outside SkPath geometry. The inverse fill area extends indefinitely.
@return true if FillType is kInverseWinding or kInverseEvenOdd
*/ bool isInverseFillType() const { return SkPathFillType_IsInverse(this->getFillType()); }
/** Replaces FillType with its inverse. The inverse of FillType describes the area unmodified by the original FillType.
*/ void toggleInverseFillType() {
fFillType ^= 2;
}
/** Returns true if the path is convex. If necessary, it will first compute the convexity.
*/ bool isConvex() const;
/** Returns true if this path is recognized as an oval or circle.
bounds receives bounds of oval.
bounds is unmodified if oval is not found.
@param bounds storage for bounding SkRect of oval; may be nullptr @return true if SkPath is recognized as an oval or circle
/** Returns true if path is representable as an oval arc. In other words, could this path be drawn using SkCanvas::drawArc.
arc receives parameters of arc
@param arc storage for arc; may be nullptr @return true if SkPath contains only a single arc from an oval
*/ bool isArc(SkArc* arc) const;
/** Sets SkPath to its initial state. Removes verb array, SkPoint array, and weights, and sets FillType to kWinding. Internal storage associated with SkPath is released.
/** Sets SkPath to its initial state, preserving internal storage. Removes verb array, SkPoint array, and weights, and sets FillType to kWinding. Internal storage associated with SkPath is retained.
Use rewind() instead of reset() if SkPath storage will be reused and performance is critical.
/** Returns if SkPath is empty. Empty SkPath may have FillType but has no SkPoint, SkPath::Verb, or conic weight. SkPath() constructs empty SkPath; reset() and rewind() make SkPath empty.
@return true if the path contains no SkPath::Verb array
*/ bool isEmpty() const;
/** Returns if contour is closed. Contour is closed if SkPath SkPath::Verb array was last modified by close(). When stroked, closed contour draws SkPaint::Join instead of SkPaint::Cap at first and last SkPoint.
@return true if the last contour ends with a kClose_Verb
/** Returns true for finite SkPoint array values between negative SK_ScalarMax and positive SK_ScalarMax. Returns false for any SkPoint array value of SK_ScalarInfinity, SK_ScalarNegativeInfinity, or SK_ScalarNaN.
@return true if all SkPoint values are finite
*/ bool isFinite() const;
/** Returns true if the path is volatile; it will not be altered or discarded by the caller after it is drawn. SkPath by default have volatile set false, allowing SkSurface to attach a cache of data which speeds repeated drawing. If true, SkSurface may not speed repeated drawing.
@return true if caller will alter SkPath after drawing
*/ bool isVolatile() const { return SkToBool(fIsVolatile);
}
/** Specifies whether SkPath is volatile; whether it will be altered or discarded by the caller after it is drawn. SkPath by default have volatile set false, allowing Skia to attach a cache of data which speeds repeated drawing.
Mark temporary paths, discarded or modified after use, as volatile to inform Skia that the path need not be cached.
Mark animating SkPath volatile to improve performance. Mark unchanging SkPath non-volatile to improve repeated rendering.
raster surface SkPath draws are affected by volatile for some shadows. GPU surface SkPath draws are affected by volatile for some shadows and concave geometries.
@param isVolatile true if caller will alter SkPath after drawing @return reference to SkPath
*/
SkPath& setIsVolatile(bool isVolatile) {
fIsVolatile = isVolatile; return *this;
}
/** Tests if line between SkPoint pair is degenerate. Line with no length or that moves a very short distance is degenerate; it is treated as a point.
exact changes the equality test. If true, returns true only if p1 equals p2. If false, returns true if p1 equals or nearly equals p2.
@param p1 line start point @param p2 line end point @param exact if false, allow nearly equals @return true if line is degenerate; its length is effectively zero
/** Tests if quad is degenerate. Quad with no length or that moves a very short distance is degenerate; it is treated as a point.
@param p1 quad start point @param p2 quad control point @param p3 quad end point @param exact if true, returns true only if p1, p2, and p3 are equal; if false, returns true if p1, p2, and p3 are equal or nearly equal @return true if quad is degenerate; its length is effectively zero
*/ staticbool IsQuadDegenerate(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3, bool exact);
/** Tests if cubic is degenerate. Cubic with no length or that moves a very short distance is degenerate; it is treated as a point.
@param p1 cubic start point @param p2 cubic control point 1 @param p3 cubic control point 2 @param p4 cubic end point @param exact if true, returns true only if p1, p2, p3, and p4 are equal; if false, returns true if p1, p2, p3, and p4 are equal or nearly equal @return true if cubic is degenerate; its length is effectively zero
*/ staticbool IsCubicDegenerate(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3, const SkPoint& p4, bool exact);
/** Returns true if SkPath contains only one line; SkPath::Verb array has two entries: kMove_Verb, kLine_Verb. If SkPath contains one line and line is not nullptr, line is set to line start point and line end point. Returns false if SkPath is not one line; line is unaltered.
@param line storage for line. May be nullptr @return true if SkPath contains exactly one line
/** Returns number of points in SkPath. Up to max points are copied. points may be nullptr; then, max must be zero. If max is greater than number of points, excess points storage is unaltered.
@param points storage for SkPath SkPoint array. May be nullptr @param max maximum to copy; must be greater than or equal to zero @return SkPath SkPoint array length
/** Exchanges the verb array, SkPoint array, weights, and SkPath::FillType with other. Cached state is also exchanged. swap() internally exchanges pointers, so it is lightweight and does not allocate memory.
swap() usage has largely been replaced by operator=(const SkPath& path). SkPath do not copy their content on assignment until they are written to, making assignment as efficient as swap().
/** Returns minimum and maximum axes values of SkPoint array. Returns (0, 0, 0, 0) if SkPath contains no points. Returned bounds width and height may be larger or smaller than area affected when SkPath is drawn.
SkRect returned includes all SkPoint added to SkPath, including SkPoint associated with kMove_Verb that define empty contours.
@return bounds of all SkPoint in SkPoint array
*/ const SkRect& getBounds() const;
/** Updates internal bounds so that subsequent calls to getBounds() are instantaneous. Unaltered copies of SkPath may also access cached bounds through getBounds().
For now, identical to calling getBounds() and ignoring the returned value.
Call to prepare SkPath subsequently drawn from multiple threads, to avoid a race condition where each draw separately computes the bounds.
*/ void updateBoundsCache() const { // for now, just calling getBounds() is sufficient
this->getBounds();
}
/** Returns minimum and maximum axes values of the lines and curves in SkPath. Returns (0, 0, 0, 0) if SkPath contains no points. Returned bounds width and height may be larger or smaller than area affected when SkPath is drawn.
Includes SkPoint associated with kMove_Verb that define empty contours.
Behaves identically to getBounds() when SkPath contains only lines. If SkPath contains curves, computed bounds includes the maximum extent of the quad, conic, or cubic; is slower than getBounds(); and unlike getBounds(), does not cache the result.
/** Returns true if rect is contained by SkPath. May return false when rect is contained by SkPath.
For now, only returns true if SkPath has one contour and is convex. rect may share points and edges with SkPath and be contained. Returns true if rect is empty, that is, it has zero width or height; and the SkPoint or line described by rect is contained by SkPath.
@param rect SkRect, line, or SkPoint checked for containment @return true if rect is contained
/** Grows SkPath verb array, SkPoint array, and conics to contain additional space. May improve performance and use less memory by reducing the number and size of allocations when creating SkPath.
@param extraPtCount number of additional SkPoint to allocate @param extraVerbCount number of additional verbs @param extraConicCount number of additional conics
@param p contour start @return reference to SkPath
*/
SkPath& moveTo(const SkPoint& p) { return this->moveTo(p.fX, p.fY);
}
/** Adds beginning of contour relative to last point. If SkPath is empty, starts contour at (dx, dy). Otherwise, start contour at last point offset by (dx, dy). Function name stands for "relative move to".
@param dx offset from last point to contour start on x-axis @param dy offset from last point to contour start on y-axis @return reference to SkPath
/** Adds line from last point to (x, y). If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding line.
lineTo() appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed. lineTo() then appends kLine_Verb to verb array and (x, y) to SkPoint array.
@param x end of added line on x-axis @param y end of added line on y-axis @return reference to SkPath
/** Adds line from last point to SkPoint p. If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding line.
lineTo() first appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed. lineTo() then appends kLine_Verb to verb array and SkPoint p to SkPoint array.
@param p end SkPoint of added line @return reference to SkPath
*/
SkPath& lineTo(const SkPoint& p) { return this->lineTo(p.fX, p.fY);
}
/** Adds line from last point to vector (dx, dy). If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding line.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed; then appends kLine_Verb to verb array and line end to SkPoint array. Line end is last point plus vector (dx, dy). Function name stands for "relative line to".
@param dx offset from last point to line end on x-axis @param dy offset from last point to line end on y-axis @return reference to SkPath
/** Adds quad from last point towards (x1, y1), to (x2, y2). If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding quad.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed; then appends kQuad_Verb to verb array; and (x1, y1), (x2, y2) to SkPoint array.
@param x1 control SkPoint of quad on x-axis @param y1 control SkPoint of quad on y-axis @param x2 end SkPoint of quad on x-axis @param y2 end SkPoint of quad on y-axis @return reference to SkPath
/** Adds quad from last point towards SkPoint p1, to SkPoint p2. If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding quad.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed; then appends kQuad_Verb to verb array; and SkPoint p1, p2 to SkPoint array.
@param p1 control SkPoint of added quad @param p2 end SkPoint of added quad @return reference to SkPath
*/
SkPath& quadTo(const SkPoint& p1, const SkPoint& p2) { return this->quadTo(p1.fX, p1.fY, p2.fX, p2.fY);
}
/** Adds quad from last point towards vector (dx1, dy1), to vector (dx2, dy2). If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding quad.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed; then appends kQuad_Verb to verb array; and appends quad control and quad end to SkPoint array. Quad control is last point plus vector (dx1, dy1). Quad end is last point plus vector (dx2, dy2). Function name stands for "relative quad to".
@param dx1 offset from last point to quad control on x-axis @param dy1 offset from last point to quad control on y-axis @param dx2 offset from last point to quad end on x-axis @param dy2 offset from last point to quad end on y-axis @return reference to SkPath
/** Adds conic from last point towards (x1, y1), to (x2, y2), weighted by w. If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding conic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed.
If w is finite and not one, appends kConic_Verb to verb array; and (x1, y1), (x2, y2) to SkPoint array; and w to conic weights.
If w is one, appends kQuad_Verb to verb array, and (x1, y1), (x2, y2) to SkPoint array.
If w is not finite, appends kLine_Verb twice to verb array, and (x1, y1), (x2, y2) to SkPoint array.
@param x1 control SkPoint of conic on x-axis @param y1 control SkPoint of conic on y-axis @param x2 end SkPoint of conic on x-axis @param y2 end SkPoint of conic on y-axis @param w weight of added conic @return reference to SkPath
*/
SkPath& conicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
SkScalar w);
/** Adds conic from last point towards SkPoint p1, to SkPoint p2, weighted by w. If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding conic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed.
If w is finite and not one, appends kConic_Verb to verb array; and SkPoint p1, p2 to SkPoint array; and w to conic weights.
If w is one, appends kQuad_Verb to verb array, and SkPoint p1, p2 to SkPoint array.
If w is not finite, appends kLine_Verb twice to verb array, and SkPoint p1, p2 to SkPoint array.
@param p1 control SkPoint of added conic @param p2 end SkPoint of added conic @param w weight of added conic @return reference to SkPath
*/
SkPath& conicTo(const SkPoint& p1, const SkPoint& p2, SkScalar w) { return this->conicTo(p1.fX, p1.fY, p2.fX, p2.fY, w);
}
/** Adds conic from last point towards vector (dx1, dy1), to vector (dx2, dy2), weighted by w. If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding conic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed.
If w is finite and not one, next appends kConic_Verb to verb array, and w is recorded as conic weight; otherwise, if w is one, appends kQuad_Verb to verb array; or if w is not finite, appends kLine_Verb twice to verb array.
In all cases appends SkPoint control and end to SkPoint array. control is last point plus vector (dx1, dy1). end is last point plus vector (dx2, dy2).
Function name stands for "relative conic to".
@param dx1 offset from last point to conic control on x-axis @param dy1 offset from last point to conic control on y-axis @param dx2 offset from last point to conic end on x-axis @param dy2 offset from last point to conic end on y-axis @param w weight of added conic @return reference to SkPath
*/
SkPath& rConicTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2,
SkScalar w);
/** Adds cubic from last point towards (x1, y1), then towards (x2, y2), ending at (x3, y3). If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding cubic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed; then appends kCubic_Verb to verb array; and (x1, y1), (x2, y2), (x3, y3) to SkPoint array.
@param x1 first control SkPoint of cubic on x-axis @param y1 first control SkPoint of cubic on y-axis @param x2 second control SkPoint of cubic on x-axis @param y2 second control SkPoint of cubic on y-axis @param x3 end SkPoint of cubic on x-axis @param y3 end SkPoint of cubic on y-axis @return reference to SkPath
*/
SkPath& cubicTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2,
SkScalar x3, SkScalar y3);
/** Adds cubic from last point towards SkPoint p1, then towards SkPoint p2, ending at SkPoint p3. If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding cubic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed; then appends kCubic_Verb to verb array; and SkPoint p1, p2, p3 to SkPoint array.
@param p1 first control SkPoint of cubic @param p2 second control SkPoint of cubic @param p3 end SkPoint of cubic @return reference to SkPath
*/
SkPath& cubicTo(const SkPoint& p1, const SkPoint& p2, const SkPoint& p3) { return this->cubicTo(p1.fX, p1.fY, p2.fX, p2.fY, p3.fX, p3.fY);
}
/** Adds cubic from last point towards vector (dx1, dy1), then towards vector (dx2, dy2), to vector (dx3, dy3). If SkPath is empty, or last SkPath::Verb is kClose_Verb, last point is set to (0, 0) before adding cubic.
Appends kMove_Verb to verb array and (0, 0) to SkPoint array, if needed; then appends kCubic_Verb to verb array; and appends cubic control and cubic end to SkPoint array. Cubic control is last point plus vector (dx1, dy1). Cubic end is last point plus vector (dx2, dy2). Function name stands for "relative cubic to".
@param dx1 offset from last point to first cubic control on x-axis @param dy1 offset from last point to first cubic control on y-axis @param dx2 offset from last point to second cubic control on x-axis @param dy2 offset from last point to second cubic control on y-axis @param dx3 offset from last point to cubic end on x-axis @param dy3 offset from last point to cubic end on y-axis @return reference to SkPath
*/
SkPath& rCubicTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2,
SkScalar dx3, SkScalar dy3);
/** Appends arc to SkPath. Arc added is part of ellipse bounded by oval, from startAngle through sweepAngle. Both startAngle and sweepAngle are measured in degrees, where zero degrees is aligned with the positive x-axis, and positive sweeps extends arc clockwise.
arcTo() adds line connecting SkPath last SkPoint to initial arc SkPoint if forceMoveTo is false and SkPath is not empty. Otherwise, added contour begins with first point of arc. Angles greater than -360 and less than 360 are treated modulo 360.
@param oval bounds of ellipse containing arc @param startAngle starting angle of arc in degrees @param sweepAngle sweep, in degrees. Positive is clockwise; treated modulo 360 @param forceMoveTo true to start a new contour with arc @return reference to SkPath
/** Appends arc to SkPath, after appending line if needed. Arc is implemented by conic weighted to describe part of circle. Arc is contained by tangent from last SkPath point to (x1, y1), and tangent from (x1, y1) to (x2, y2). Arc is part of circle sized to radius, positioned so it touches both tangent lines.
If last Path Point does not start Arc, arcTo appends connecting Line to Path. The length of Vector from (x1, y1) to (x2, y2) does not affect Arc.
Arc sweep is always less than 180 degrees. If radius is zero, or if tangents are nearly parallel, arcTo appends Line from last Path Point to (x1, y1).
arcTo appends at most one Line and one conic. arcTo implements the functionality of PostScript arct and HTML Canvas arcTo.
@param x1 x-axis value common to pair of tangents @param y1 y-axis value common to pair of tangents @param x2 x-axis value end of second tangent @param y2 y-axis value end of second tangent @param radius distance from arc to circle center @return reference to SkPath
/** Appends arc to SkPath, after appending line if needed. Arc is implemented by conic weighted to describe part of circle. Arc is contained by tangent from last SkPath point to p1, and tangent from p1 to p2. Arc is part of circle sized to radius, positioned so it touches both tangent lines.
If last SkPath SkPoint does not start arc, arcTo() appends connecting line to SkPath. The length of vector from p1 to p2 does not affect arc.
Arc sweep is always less than 180 degrees. If radius is zero, or if tangents are nearly parallel, arcTo() appends line from last SkPath SkPoint to p1.
arcTo() appends at most one line and one conic. arcTo() implements the functionality of PostScript arct and HTML Canvas arcTo.
@param p1 SkPoint common to pair of tangents @param p2 end of second tangent @param radius distance from arc to circle center @return reference to SkPath
*/
SkPath& arcTo(const SkPoint p1, const SkPoint p2, SkScalar radius) { return this->arcTo(p1.fX, p1.fY, p2.fX, p2.fY, radius);
}
/** \enum SkPath::ArcSize Four oval parts with radii (rx, ry) start at last SkPath SkPoint and ends at (x, y). ArcSize and Direction select one of the four oval parts.
*/ enum ArcSize {
kSmall_ArcSize, //!< smaller of arc pair
kLarge_ArcSize, //!< larger of arc pair
};
/** Appends arc to SkPath. Arc is implemented by one or more conics weighted to describe part of oval with radii (rx, ry) rotated by xAxisRotate degrees. Arc curves from last SkPath SkPoint to (x, y), choosing one of four possible routes: clockwise or counterclockwise, and smaller or larger.
Arc sweep is always less than 360 degrees. arcTo() appends line to (x, y) if either radii are zero, or if last SkPath SkPoint equals (x, y). arcTo() scales radii (rx, ry) to fit last SkPath SkPoint and (x, y) if both are greater than zero but too small.
arcTo() appends up to four conic curves. arcTo() implements the functionality of SVG arc, although SVG sweep-flag value is opposite the integer value of sweep; SVG sweep-flag uses 1 for clockwise, while kCW_Direction cast to int is zero.
@param rx radius on x-axis before x-axis rotation @param ry radius on y-axis before x-axis rotation @param xAxisRotate x-axis rotation in degrees; positive values are clockwise @param largeArc chooses smaller or larger arc @param sweep chooses clockwise or counterclockwise arc @param x end of arc @param y end of arc @return reference to SkPath
*/
SkPath& arcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
SkPathDirection sweep, SkScalar x, SkScalar y);
/** Appends arc to SkPath. Arc is implemented by one or more conic weighted to describe part of oval with radii (r.fX, r.fY) rotated by xAxisRotate degrees. Arc curves from last SkPath SkPoint to (xy.fX, xy.fY), choosing one of four possible routes: clockwise or counterclockwise, and smaller or larger.
Arc sweep is always less than 360 degrees. arcTo() appends line to xy if either radii are zero, or if last SkPath SkPoint equals (xy.fX, xy.fY). arcTo() scales radii r to fit last SkPath SkPoint and xy if both are greater than zero but too small to describe an arc.
arcTo() appends up to four conic curves. arcTo() implements the functionality of SVG arc, although SVG sweep-flag value is opposite the integer value of sweep; SVG sweep-flag uses 1 for clockwise, while kCW_Direction cast to int is zero.
@param r radii on axes before x-axis rotation @param xAxisRotate x-axis rotation in degrees; positive values are clockwise @param largeArc chooses smaller or larger arc @param sweep chooses clockwise or counterclockwise arc @param xy end of arc @return reference to SkPath
*/
SkPath& arcTo(const SkPoint r, SkScalar xAxisRotate, ArcSize largeArc, SkPathDirection sweep, const SkPoint xy) { return this->arcTo(r.fX, r.fY, xAxisRotate, largeArc, sweep, xy.fX, xy.fY);
}
/** Appends arc to SkPath, relative to last SkPath SkPoint. Arc is implemented by one or more conic, weighted to describe part of oval with radii (rx, ry) rotated by xAxisRotate degrees. Arc curves from last SkPath SkPoint to relative end SkPoint: (dx, dy), choosing one of four possible routes: clockwise or counterclockwise, and smaller or larger. If SkPath is empty, the start arc SkPoint is (0, 0).
Arc sweep is always less than 360 degrees. arcTo() appends line to end SkPoint if either radii are zero, or if last SkPath SkPoint equals end SkPoint. arcTo() scales radii (rx, ry) to fit last SkPath SkPoint and end SkPoint if both are greater than zero but too small to describe an arc.
arcTo() appends up to four conic curves. arcTo() implements the functionality of svg arc, although SVG "sweep-flag" value is opposite the integer value of sweep; SVG "sweep-flag" uses 1 for clockwise, while kCW_Direction cast to int is zero.
@param rx radius before x-axis rotation @param ry radius before x-axis rotation @param xAxisRotate x-axis rotation in degrees; positive values are clockwise @param largeArc chooses smaller or larger arc @param sweep chooses clockwise or counterclockwise arc @param dx x-axis offset end of arc from last SkPath SkPoint @param dy y-axis offset end of arc from last SkPath SkPoint @return reference to SkPath
*/
SkPath& rArcTo(SkScalar rx, SkScalar ry, SkScalar xAxisRotate, ArcSize largeArc,
SkPathDirection sweep, SkScalar dx, SkScalar dy);
/** Appends kClose_Verb to SkPath. A closed contour connects the first and last SkPoint with line, forming a continuous loop. Open and closed contour draw the same with SkPaint::kFill_Style. With SkPaint::kStroke_Style, open contour draws SkPaint::Cap at contour start and end; closed contour draws SkPaint::Join at contour start and end.
close() has no effect if SkPath is empty or last SkPath SkPath::Verb is kClose_Verb.
/** Approximates conic with quad array. Conic is constructed from start SkPoint p0, control SkPoint p1, end SkPoint p2, and weight w. Quad array is stored in pts; this storage is supplied by caller. Maximum quad count is 2 to the pow2. Every third point in array shares last SkPoint of previous quad and first SkPoint of next quad. Maximum pts storage size is given by: (1 + 2 * (1 << pow2)) * sizeof(SkPoint).
Returns quad count used the approximation, which may be smaller than the number requested.
conic weight determines the amount of influence conic control point has on the curve. w less than one represents an elliptical section. w greater than one represents a hyperbolic section. w equal to one represents a parabolic section.
Two quad curves are sufficient to approximate an elliptical conic with a sweep of up to 90 degrees; in this case, set pow2 to one.
@param p0 conic start SkPoint @param p1 conic control SkPoint @param p2 conic end SkPoint @param w conic weight @param pts storage for quad array @param pow2 quad count, as power of two, normally 0 to 5 (1 to 32 quad curves) @return number of quad curves written to pts
*/ staticint ConvertConicToQuads(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2,
SkScalar w, SkPoint pts[], int pow2);
/** Returns true if SkPath is equivalent to SkRect when filled. If false: rect, isClosed, and direction are unchanged. If true: rect, isClosed, and direction are written to if not nullptr.
rect may be smaller than the SkPath bounds. SkPath bounds may include kMove_Verb points that do not alter the area drawn by the returned rect.
@param rect storage for bounds of SkRect; may be nullptr @param isClosed storage set to true if SkPath is closed; may be nullptr @param direction storage set to SkRect direction; may be nullptr @return true if SkPath contains SkRect
/** Adds a new contour to the path, defined by the rect, and wound in the specified direction. The verbs added to the path will be:
kMove, kLine, kLine, kLine, kClose
start specifies which corner to begin the contour: 0: upper-left corner 1: upper-right corner 2: lower-right corner 3: lower-left corner
This start point also acts as the implied beginning of the subsequent, contour, if it does not have an explicit moveTo(). e.g.
path.addRect(...) // if we don't say moveTo() here, we will use the rect's start point path.lineTo(...)
@param rect SkRect to add as a closed contour @param dir SkPath::Direction to orient the new contour @param start initial corner of SkRect to add @return reference to SkPath
/** Adds oval to path, appending kMove_Verb, four kConic_Verb, and kClose_Verb. Oval is upright ellipse bounded by SkRect oval with radii equal to half oval width and half oval height. Oval begins at (oval.fRight, oval.centerY()) and continues clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction.
@param oval bounds of ellipse added @param dir SkPath::Direction to wind ellipse @return reference to SkPath
/** Adds oval to SkPath, appending kMove_Verb, four kConic_Verb, and kClose_Verb. Oval is upright ellipse bounded by SkRect oval with radii equal to half oval width and half oval height. Oval begins at start and continues clockwise if dir is kCW_Direction, counterclockwise if dir is kCCW_Direction.
@param oval bounds of ellipse added @param dir SkPath::Direction to wind ellipse @param start index of initial point of ellipse @return reference to SkPath
/** Adds circle centered at (x, y) of size radius to SkPath, appending kMove_Verb, four kConic_Verb, and kClose_Verb. Circle begins at: (x + radius, y), continuing clockwise if dir is kCW_Direction, and counterclockwise if dir is kCCW_Direction.
Has no effect if radius is zero or negative.
@param x center of circle @param y center of circle @param radius distance from center to edge @param dir SkPath::Direction to wind circle @return reference to SkPath
*/
SkPath& addCircle(SkScalar x, SkScalar y, SkScalar radius,
SkPathDirection dir = SkPathDirection::kCW);
/** Appends arc to SkPath, as the start of new contour. Arc added is part of ellipse bounded by oval, from startAngle through sweepAngle. Both startAngle and sweepAngle are measured in degrees, where zero degrees is aligned with the positive x-axis, and positive sweeps extends arc clockwise.
If sweepAngle <= -360, or sweepAngle >= 360; and startAngle modulo 90 is nearly zero, append oval instead of arc. Otherwise, sweepAngle values are treated modulo 360, and arc may or may not draw depending on numeric rounding.
@param oval bounds of ellipse containing arc @param startAngle starting angle of arc in degrees @param sweepAngle sweep, in degrees. Positive is clockwise; treated modulo 360 @return reference to SkPath
/** Appends SkRRect to SkPath, creating a new closed contour. SkRRect has bounds equal to rect; each corner is 90 degrees of an ellipse with radii (rx, ry). If dir is kCW_Direction, SkRRect starts at top-left of the lower-left corner and winds clockwise. If dir is kCCW_Direction, SkRRect starts at the bottom-left of the upper-left corner and winds counterclockwise.
If either rx or ry is too large, rx and ry are scaled uniformly until the corners fit. If rx or ry is less than or equal to zero, addRoundRect() appends SkRect rect to SkPath.
After appending, SkPath may be empty, or may contain: SkRect, oval, or SkRRect.
@param rect bounds of SkRRect @param rx x-axis radius of rounded corners on the SkRRect @param ry y-axis radius of rounded corners on the SkRRect @param dir SkPath::Direction to wind SkRRect @return reference to SkPath
*/
SkPath& addRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry,
SkPathDirection dir = SkPathDirection::kCW);
/** Appends SkRRect to SkPath, creating a new closed contour. SkRRect has bounds equal to rect; each corner is 90 degrees of an ellipse with radii from the array.
@param rect bounds of SkRRect @param radii array of 8 SkScalar values, a radius pair for each corner @param dir SkPath::Direction to wind SkRRect @return reference to SkPath
*/
SkPath& addRoundRect(const SkRect& rect, const SkScalar radii[],
SkPathDirection dir = SkPathDirection::kCW);
/** Adds rrect to SkPath, creating a new closed contour. If dir is kCW_Direction, rrect starts at top-left of the lower-left corner and winds clockwise. If dir is kCCW_Direction, rrect starts at the bottom-left of the upper-left corner and winds counterclockwise.
After appending, SkPath may be empty, or may contain: SkRect, oval, or SkRRect.
@param rrect bounds and radii of rounded rectangle @param dir SkPath::Direction to wind SkRRect @return reference to SkPath
/** Adds rrect to SkPath, creating a new closed contour. If dir is kCW_Direction, rrect winds clockwise; if dir is kCCW_Direction, rrect winds counterclockwise. start determines the first point of rrect to add.
@param rrect bounds and radii of rounded rectangle @param dir SkPath::Direction to wind SkRRect @param start index of initial point of SkRRect @return reference to SkPath
/** Adds contour created from line array, adding (count - 1) line segments. Contour added starts at pts[0], then adds a line for every additional SkPoint in pts array. If close is true, appends kClose_Verb to SkPath, connecting pts[count - 1] and pts[0].
If count is zero, append kMove_Verb to path. Has no effect if count is less than one.
@param pts array of line sharing end and start SkPoint @param count length of SkPoint array @param close true to add line connecting contour end and start @return reference to SkPath
/** Adds contour created from list. Contour added starts at list[0], then adds a line for every additional SkPoint in list. If close is true, appends kClose_Verb to SkPath, connecting last and first SkPoint in list.
If list is empty, append kMove_Verb to path.
@param list array of SkPoint @param close true to add line connecting contour end and start @return reference to SkPath
*/
SkPath& addPoly(const std::initializer_list<SkPoint>& list, bool close) { return this->addPoly(list.begin(), SkToInt(list.size()), close);
}
#ifdef SK_HIDE_PATH_EDIT_METHODS public: #endif
/** \enum SkPath::AddPathMode AddPathMode chooses how addPath() appends. Adding one SkPath to another can extend the last contour or start a new contour.
*/ enum AddPathMode { /** Contours are appended to the destination path as new contours.
*/
kAppend_AddPathMode, /** Extends the last contour of the destination path with the first countour of the source path, connecting them with a line. If the last contour is closed, a new empty contour starting at its start point is extended instead. If the destination path is empty, the result is the source path. The last path of the result is closed only if the last path of the source is.
*/
kExtend_AddPathMode,
};
/** Appends src to SkPath, offset by (dx, dy).
If mode is kAppend_AddPathMode, src verb array, SkPoint array, and conic weights are added unaltered. If mode is kExtend_AddPathMode, add line before appending verbs, SkPoint, and conic weights.
@param src SkPath verbs, SkPoint, and conic weights to add @param dx offset added to src SkPoint array x-axis coordinates @param dy offset added to src SkPoint array y-axis coordinates @param mode kAppend_AddPathMode or kExtend_AddPathMode @return reference to SkPath
*/
SkPath& addPath(const SkPath& src, SkScalar dx, SkScalar dy,
AddPathMode mode = kAppend_AddPathMode);
/** Appends src to SkPath.
If mode is kAppend_AddPathMode, src verb array, SkPoint array, and conic weights are added unaltered. If mode is kExtend_AddPathMode, add line before appending verbs, SkPoint, and conic weights.
@param src SkPath verbs, SkPoint, and conic weights to add @param mode kAppend_AddPathMode or kExtend_AddPathMode @return reference to SkPath
*/
SkPath& addPath(const SkPath& src, AddPathMode mode = kAppend_AddPathMode) {
SkMatrix m;
m.reset(); return this->addPath(src, m, mode);
}
/** Appends src to SkPath, transformed by matrix. Transformed curves may have different verbs, SkPoint, and conic weights.
If mode is kAppend_AddPathMode, src verb array, SkPoint array, and conic weights are added unaltered. If mode is kExtend_AddPathMode, add line before appending verbs, SkPoint, and conic weights.
@param src SkPath verbs, SkPoint, and conic weights to add @param matrix transform applied to src @param mode kAppend_AddPathMode or kExtend_AddPathMode @return reference to SkPath
*/
SkPath& addPath(const SkPath& src, const SkMatrix& matrix,
AddPathMode mode = kAppend_AddPathMode);
/** Appends src to SkPath, from back to front. Reversed src always appends a new contour to SkPath.
@param src SkPath verbs, SkPoint, and conic weights to add @return reference to SkPath
/** Offsets SkPoint array by (dx, dy). Offset SkPath replaces dst. If dst is nullptr, SkPath is replaced by offset data.
@param dx offset added to SkPoint array x-axis coordinates @param dy offset added to SkPoint array y-axis coordinates @param dst overwritten, translated copy of SkPath; may be nullptr
/** Transforms verb array, SkPoint array, and weight by matrix. transform may change verbs and increase their number. Transformed SkPath replaces dst; if dst is nullptr, original data is replaced.
@param matrix SkMatrix to apply to SkPath @param dst overwritten, transformed copy of SkPath; may be nullptr @param pc whether to apply perspective clipping
/** Transforms verb array, SkPoint array, and weight by matrix. transform may change verbs and increase their number. SkPath is replaced by transformed data.
@param matrix SkMatrix to apply to SkPath @param pc whether to apply perspective clipping
*/
SkPath& transform(const SkMatrix& matrix,
SkApplyPerspectiveClip pc = SkApplyPerspectiveClip::kYes) {
this->transform(matrix, this, pc); return *this;
}
SkPath makeTransform(const SkMatrix& m,
SkApplyPerspectiveClip pc = SkApplyPerspectiveClip::kYes) const {
SkPath dst;
this->transform(m, &dst, pc); return dst;
}
/** Sets the last point on the path. If SkPoint array is empty, append kMove_Verb to verb array and append p to SkPoint array.
@param p set value of last point
*/ void setLastPt(const SkPoint& p) {
this->setLastPt(p.fX, p.fY);
}
/** \enum SkPath::SegmentMask SegmentMask constants correspond to each drawing Verb type in SkPath; for instance, if SkPath only contains lines, only the kLine_SegmentMask bit is set.
*/ enum SegmentMask {
kLine_SegmentMask = kLine_SkPathSegmentMask,
kQuad_SegmentMask = kQuad_SkPathSegmentMask,
kConic_SegmentMask = kConic_SkPathSegmentMask,
kCubic_SegmentMask = kCubic_SkPathSegmentMask,
};
/** Returns a mask, where each set bit corresponds to a SegmentMask constant if SkPath contains one or more verbs of that type. Returns zero if SkPath contains no lines, or curves: quads, conics, or cubics.
getSegmentMasks() returns a cached result; it is very fast.
@return SegmentMask bits or zero
*/
uint32_t getSegmentMasks() const;
/** \enum SkPath::Verb Verb instructs SkPath how to interpret one or more SkPoint and optional conic weight; manage contour, and terminate SkPath.
*/ enum Verb {
kMove_Verb = static_cast<int>(SkPathVerb::kMove),
kLine_Verb = static_cast<int>(SkPathVerb::kLine),
kQuad_Verb = static_cast<int>(SkPathVerb::kQuad),
kConic_Verb = static_cast<int>(SkPathVerb::kConic),
kCubic_Verb = static_cast<int>(SkPathVerb::kCubic),
kClose_Verb = static_cast<int>(SkPathVerb::kClose),
kDone_Verb = kClose_Verb + 1
};
/** \class SkPath::Iter Iterates through verb array, and associated SkPoint array and conic weight. Provides options to treat open contours as closed, and to ignore degenerate data.
*/ class SK_API Iter { public:
/** Initializes SkPath::Iter with an empty SkPath. next() on SkPath::Iter returns kDone_Verb. Call setPath to initialize SkPath::Iter at a later time.
/** Sets SkPath::Iter to return elements of verb array, SkPoint array, and conic weight in path. If forceClose is true, SkPath::Iter will add kLine_Verb and kClose_Verb after each open contour. path is not altered.
@param path SkPath to iterate @param forceClose true if open contours generate kClose_Verb @return SkPath::Iter of path
/** Sets SkPath::Iter to return elements of verb array, SkPoint array, and conic weight in path. If forceClose is true, SkPath::Iter will add kLine_Verb and kClose_Verb after each open contour. path is not altered.
@param path SkPath to iterate @param forceClose true if open contours generate kClose_Verb
/** Returns conic weight if next() returned kConic_Verb.
If next() has not been called, or next() did not return kConic_Verb, result is undefined.
@return conic weight for conic SkPoint returned by next()
*/
SkScalar conicWeight() const { return *fConicWeights; }
/** Returns true if last kLine_Verb returned by next() was generated by kClose_Verb. When true, the end point returned by next() is also the start point of contour.
If next() has not been called, or next() did not return kLine_Verb, result is undefined.
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