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Diffstat (limited to 'gfx/skia/skia/include/core/SkPath.h')
| -rw-r--r-- | gfx/skia/skia/include/core/SkPath.h | 1890 |
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diff --git a/gfx/skia/skia/include/core/SkPath.h b/gfx/skia/skia/include/core/SkPath.h new file mode 100644 index 0000000000..8858e7d3c8 --- /dev/null +++ b/gfx/skia/skia/include/core/SkPath.h @@ -0,0 +1,1890 @@ +/* + * 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. + */ + +#ifndef SkPath_DEFINED +#define SkPath_DEFINED + +#include "include/core/SkMatrix.h" +#include "include/core/SkPathTypes.h" +#include "include/core/SkPoint.h" +#include "include/core/SkRect.h" +#include "include/core/SkRefCnt.h" +#include "include/core/SkScalar.h" +#include "include/core/SkTypes.h" +#include "include/private/base/SkDebug.h" +#include "include/private/base/SkTo.h" +#include "include/private/base/SkTypeTraits.h" + +#include <atomic> +#include <cstddef> +#include <cstdint> +#include <initializer_list> +#include <tuple> +#include <type_traits> + +class SkData; +class SkPathRef; +class SkRRect; +class SkWStream; +enum class SkPathConvexity; +enum class SkPathFirstDirection; + +// 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); + + static SkPath Rect(const SkRect&, SkPathDirection = SkPathDirection::kCW, + unsigned startIndex = 0); + static SkPath Oval(const SkRect&, SkPathDirection = SkPathDirection::kCW); + static SkPath Oval(const SkRect&, SkPathDirection, unsigned startIndex); + static SkPath Circle(SkScalar center_x, SkScalar center_y, SkScalar radius, + SkPathDirection dir = SkPathDirection::kCW); + static SkPath RRect(const SkRRect&, SkPathDirection dir = SkPathDirection::kCW); + static SkPath RRect(const SkRRect&, SkPathDirection, unsigned startIndex); + static SkPath RRect(const SkRect& bounds, SkScalar rx, SkScalar ry, + SkPathDirection dir = SkPathDirection::kCW); + + static SkPath Polygon(const SkPoint pts[], int count, bool isClosed, + SkPathFillType = SkPathFillType::kWinding, + bool isVolatile = false); + + static SkPath Polygon(const std::initializer_list<SkPoint>& list, bool isClosed, + SkPathFillType fillType = SkPathFillType::kWinding, + bool isVolatile = false) { + return Polygon(list.begin(), SkToInt(list.size()), isClosed, fillType, isVolatile); + } + + static SkPath Line(const SkPoint a, const SkPoint b) { + return Polygon({a, b}, false); + } + + /** Constructs an empty SkPath. By default, SkPath has no verbs, no SkPoint, and no weights. + FillType is set to kWinding. + + @return empty SkPath + + example: https://fiddle.skia.org/c/@Path_empty_constructor + */ + SkPath(); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_copy_const_SkPath + */ + SkPath(const SkPath& path); + + /** Releases ownership of any shared data and deletes data if SkPath is sole owner. + + example: https://fiddle.skia.org/c/@Path_destructor + */ + ~SkPath(); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_copy_operator + */ + SkPath& operator=(const SkPath& path); + + /** 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 bool operator==(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 + */ + friend bool operator!=(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 + + example: https://fiddle.skia.org/c/@Path_isInterpolatable + */ + bool isInterpolatable(const SkPath& compare) const; + + /** 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 + + example: https://fiddle.skia.org/c/@Path_interpolate + */ + bool interpolate(const SkPath& ending, SkScalar weight, SkPath* out) const; + + /** Returns SkPathFillType, the rule used to fill SkPath. + + @return current SkPathFillType setting + */ + SkPathFillType getFillType() const { return (SkPathFillType)fFillType; } + + /** 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 + + example: https://fiddle.skia.org/c/@Path_isOval + */ + bool isOval(SkRect* bounds) const; + + /** Returns true if path is representable as SkRRect. + Returns false if path is representable as oval, circle, or SkRect. + + rrect receives bounds of SkRRect. + + rrect is unmodified if SkRRect is not found. + + @param rrect storage for bounding SkRect of SkRRect; may be nullptr + @return true if SkPath contains only SkRRect + + example: https://fiddle.skia.org/c/@Path_isRRect + */ + bool isRRect(SkRRect* rrect) 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. + + @return reference to SkPath + + example: https://fiddle.skia.org/c/@Path_reset + */ + SkPath& reset(); + + /** 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. + + @return reference to SkPath + + example: https://fiddle.skia.org/c/@Path_rewind + */ + SkPath& rewind(); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_isLastContourClosed + */ + bool isLastContourClosed() const; + + /** 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 + SkBaseDevice to attach a cache of data which speeds repeated drawing. + + Mark temporary paths, discarded or modified after use, as volatile + to inform SkBaseDevice 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 + + example: https://fiddle.skia.org/c/@Path_IsLineDegenerate + */ + static bool IsLineDegenerate(const SkPoint& p1, const SkPoint& p2, bool exact); + + /** 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 + */ + static bool 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 + */ + static bool 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 + + example: https://fiddle.skia.org/c/@Path_isLine + */ + bool isLine(SkPoint line[2]) const; + + /** Returns the number of points in SkPath. + SkPoint count is initially zero. + + @return SkPath SkPoint array length + + example: https://fiddle.skia.org/c/@Path_countPoints + */ + int countPoints() const; + + /** Returns SkPoint at index in SkPoint array. Valid range for index is + 0 to countPoints() - 1. + Returns (0, 0) if index is out of range. + + @param index SkPoint array element selector + @return SkPoint array value or (0, 0) + + example: https://fiddle.skia.org/c/@Path_getPoint + */ + SkPoint getPoint(int index) const; + + /** 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 + + example: https://fiddle.skia.org/c/@Path_getPoints + */ + int getPoints(SkPoint points[], int max) const; + + /** Returns the number of verbs: kMove_Verb, kLine_Verb, kQuad_Verb, kConic_Verb, + kCubic_Verb, and kClose_Verb; added to SkPath. + + @return length of verb array + + example: https://fiddle.skia.org/c/@Path_countVerbs + */ + int countVerbs() const; + + /** Returns the number of verbs in the path. Up to max verbs are copied. The + verbs are copied as one byte per verb. + + @param verbs storage for verbs, may be nullptr + @param max maximum number to copy into verbs + @return the actual number of verbs in the path + + example: https://fiddle.skia.org/c/@Path_getVerbs + */ + int getVerbs(uint8_t verbs[], int max) const; + + /** Returns the approximate byte size of the SkPath in memory. + + @return approximate size + */ + size_t approximateBytesUsed() const; + + /** 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(). + + @param other SkPath exchanged by value + + example: https://fiddle.skia.org/c/@Path_swap + */ + void swap(SkPath& other); + + /** 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. + + @return tight bounds of curves in SkPath + + example: https://fiddle.skia.org/c/@Path_computeTightBounds + */ + SkRect computeTightBounds() const; + + /** 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 + + example: https://fiddle.skia.org/c/@Path_conservativelyContainsRect + */ + bool conservativelyContainsRect(const SkRect& rect) const; + + /** Grows SkPath verb array and SkPoint array to contain extraPtCount additional SkPoint. + 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 + + example: https://fiddle.skia.org/c/@Path_incReserve + */ + void incReserve(int extraPtCount); + +#ifdef SK_HIDE_PATH_EDIT_METHODS +private: +#endif + + /** Adds beginning of contour at SkPoint (x, y). + + @param x x-axis value of contour start + @param y y-axis value of contour start + @return reference to SkPath + + example: https://fiddle.skia.org/c/@Path_moveTo + */ + SkPath& moveTo(SkScalar x, SkScalar y); + + /** Adds beginning of contour at SkPoint p. + + @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 + + example: https://fiddle.skia.org/c/@Path_rMoveTo + */ + SkPath& rMoveTo(SkScalar dx, SkScalar dy); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_lineTo + */ + SkPath& lineTo(SkScalar x, SkScalar y); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_rLineTo + example: https://fiddle.skia.org/c/@Quad_a + example: https://fiddle.skia.org/c/@Quad_b + */ + SkPath& rLineTo(SkScalar dx, SkScalar dy); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_quadTo + */ + SkPath& quadTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2); + + /** 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 + + example: https://fiddle.skia.org/c/@Conic_Weight_a + example: https://fiddle.skia.org/c/@Conic_Weight_b + example: https://fiddle.skia.org/c/@Conic_Weight_c + example: https://fiddle.skia.org/c/@Path_rQuadTo + */ + SkPath& rQuadTo(SkScalar dx1, SkScalar dy1, SkScalar dx2, SkScalar dy2); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_arcTo + */ + SkPath& arcTo(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, bool forceMoveTo); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_arcTo_2_a + example: https://fiddle.skia.org/c/@Path_arcTo_2_b + example: https://fiddle.skia.org/c/@Path_arcTo_2_c + */ + SkPath& arcTo(SkScalar x1, SkScalar y1, SkScalar x2, SkScalar y2, SkScalar radius); + + /** 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. + + @return reference to SkPath + + example: https://fiddle.skia.org/c/@Path_close + */ + SkPath& close(); + +#ifdef SK_HIDE_PATH_EDIT_METHODS +public: +#endif + + /** 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 + */ + static int 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 + + example: https://fiddle.skia.org/c/@Path_isRect + */ + bool isRect(SkRect* rect, bool* isClosed = nullptr, SkPathDirection* direction = nullptr) const; + +#ifdef SK_HIDE_PATH_EDIT_METHODS +private: +#endif + + /** 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 + + example: https://fiddle.skia.org/c/@Path_addRect_2 + */ + SkPath& addRect(const SkRect& rect, SkPathDirection dir, unsigned start); + + SkPath& addRect(const SkRect& rect, SkPathDirection dir = SkPathDirection::kCW) { + return this->addRect(rect, dir, 0); + } + + SkPath& addRect(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom, + SkPathDirection dir = SkPathDirection::kCW) { + return this->addRect({left, top, right, bottom}, dir, 0); + } + + /** 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 + + example: https://fiddle.skia.org/c/@Path_addOval + */ + SkPath& addOval(const SkRect& oval, SkPathDirection dir = SkPathDirection::kCW); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_addOval_2 + */ + SkPath& addOval(const SkRect& oval, SkPathDirection dir, unsigned start); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_addArc + */ + SkPath& addArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_addRRect + */ + SkPath& addRRect(const SkRRect& rrect, SkPathDirection dir = SkPathDirection::kCW); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_addRRect_2 + */ + SkPath& addRRect(const SkRRect& rrect, SkPathDirection dir, unsigned start); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_addPoly + */ + SkPath& addPoly(const SkPoint pts[], int count, bool close); + + /** 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 { + kAppend_AddPathMode, //!< appended to destination unaltered + kExtend_AddPathMode, //!< add line if prior contour is not closed + }; + + /** 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 + + example: https://fiddle.skia.org/c/@Path_reverseAddPath + */ + SkPath& reverseAddPath(const SkPath& src); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_offset + */ + void offset(SkScalar dx, SkScalar dy, SkPath* dst) const; + + /** Offsets SkPoint array by (dx, dy). 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 + */ + void offset(SkScalar dx, SkScalar dy) { + this->offset(dx, dy, this); + } + + /** 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 + + example: https://fiddle.skia.org/c/@Path_transform + */ + void transform(const SkMatrix& matrix, SkPath* dst, + SkApplyPerspectiveClip pc = SkApplyPerspectiveClip::kYes) const; + + /** 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 + */ + void transform(const SkMatrix& matrix, + SkApplyPerspectiveClip pc = SkApplyPerspectiveClip::kYes) { + this->transform(matrix, this, pc); + } + + SkPath makeTransform(const SkMatrix& m, + SkApplyPerspectiveClip pc = SkApplyPerspectiveClip::kYes) const { + SkPath dst; + this->transform(m, &dst, pc); + return dst; + } + + SkPath makeScale(SkScalar sx, SkScalar sy) { + return this->makeTransform(SkMatrix::Scale(sx, sy), SkApplyPerspectiveClip::kNo); + } + + /** Returns last point on SkPath in lastPt. Returns false if SkPoint array is empty, + storing (0, 0) if lastPt is not nullptr. + + @param lastPt storage for final SkPoint in SkPoint array; may be nullptr + @return true if SkPoint array contains one or more SkPoint + + example: https://fiddle.skia.org/c/@Path_getLastPt + */ + bool getLastPt(SkPoint* lastPt) const; + + /** Sets last point to (x, y). If SkPoint array is empty, append kMove_Verb to + verb array and append (x, y) to SkPoint array. + + @param x set x-axis value of last point + @param y set y-axis value of last point + + example: https://fiddle.skia.org/c/@Path_setLastPt + */ + void setLastPt(SkScalar x, SkScalar y); + + /** 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. + + @return SkPath::Iter of empty SkPath + + example: https://fiddle.skia.org/c/@Path_Iter_Iter + */ + Iter(); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_Iter_const_SkPath + */ + Iter(const SkPath& path, bool forceClose); + + /** 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 + + example: https://fiddle.skia.org/c/@Path_Iter_setPath + */ + void setPath(const SkPath& path, bool forceClose); + + /** Returns next SkPath::Verb in verb array, and advances SkPath::Iter. + When verb array is exhausted, returns kDone_Verb. + + Zero to four SkPoint are stored in pts, depending on the returned SkPath::Verb. + + @param pts storage for SkPoint data describing returned SkPath::Verb + @return next SkPath::Verb from verb array + + example: https://fiddle.skia.org/c/@Path_RawIter_next + */ + Verb next(SkPoint pts[4]); + + /** 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. + + @return true if last kLine_Verb was generated by kClose_Verb + */ + bool isCloseLine() const { return SkToBool(fCloseLine); } + + /** Returns true if subsequent calls to next() return kClose_Verb before returning + kMove_Verb. if true, contour SkPath::Iter is processing may end with kClose_Verb, or + SkPath::Iter may have been initialized with force close set to true. + + @return true if contour is closed + + example: https://fiddle.skia.org/c/@Path_Iter_isClosedContour + */ + bool isClosedContour() const; + + private: + const SkPoint* fPts; + const uint8_t* fVerbs; + const uint8_t* fVerbStop; + const SkScalar* fConicWeights; + SkPoint fMoveTo; + SkPoint fLastPt; + bool fForceClose; + bool fNeedClose; + bool fCloseLine; + + Verb autoClose(SkPoint pts[2]); + }; + +private: + /** \class SkPath::RangeIter + Iterates through a raw range of path verbs, points, and conics. All values are returned + unaltered. + + NOTE: This class will be moved into SkPathPriv once RangeIter is removed. + */ + class RangeIter { + public: + RangeIter() = default; + RangeIter(const uint8_t* verbs, const SkPoint* points, const SkScalar* weights) + : fVerb(verbs), fPoints(points), fWeights(weights) { + SkDEBUGCODE(fInitialPoints = fPoints;) + } + bool operator!=(const RangeIter& that) const { + return fVerb != that.fVerb; + } + bool operator==(const RangeIter& that) const { + return fVerb == that.fVerb; + } + RangeIter& operator++() { + auto verb = static_cast<SkPathVerb>(*fVerb++); + fPoints += pts_advance_after_verb(verb); + if (verb == SkPathVerb::kConic) { + ++fWeights; + } + return *this; + } + RangeIter operator++(int) { + RangeIter copy = *this; + this->operator++(); + return copy; + } + SkPathVerb peekVerb() const { + return static_cast<SkPathVerb>(*fVerb); + } + std::tuple<SkPathVerb, const SkPoint*, const SkScalar*> operator*() const { + SkPathVerb verb = this->peekVerb(); + // We provide the starting point for beziers by peeking backwards from the current + // point, which works fine as long as there is always a kMove before any geometry. + // (SkPath::injectMoveToIfNeeded should have guaranteed this to be the case.) + int backset = pts_backset_for_verb(verb); + SkASSERT(fPoints + backset >= fInitialPoints); + return {verb, fPoints + backset, fWeights}; + } + private: + constexpr static int pts_advance_after_verb(SkPathVerb verb) { + switch (verb) { + case SkPathVerb::kMove: return 1; + case SkPathVerb::kLine: return 1; + case SkPathVerb::kQuad: return 2; + case SkPathVerb::kConic: return 2; + case SkPathVerb::kCubic: return 3; + case SkPathVerb::kClose: return 0; + } + SkUNREACHABLE; + } + constexpr static int pts_backset_for_verb(SkPathVerb verb) { + switch (verb) { + case SkPathVerb::kMove: return 0; + case SkPathVerb::kLine: return -1; + case SkPathVerb::kQuad: return -1; + case SkPathVerb::kConic: return -1; + case SkPathVerb::kCubic: return -1; + case SkPathVerb::kClose: return -1; + } + SkUNREACHABLE; + } + const uint8_t* fVerb = nullptr; + const SkPoint* fPoints = nullptr; + const SkScalar* fWeights = nullptr; + SkDEBUGCODE(const SkPoint* fInitialPoints = nullptr;) + }; +public: + + /** \class SkPath::RawIter + Use Iter instead. This class will soon be removed and RangeIter will be made private. + */ + class SK_API RawIter { + public: + + /** Initializes RawIter with an empty SkPath. next() on RawIter returns kDone_Verb. + Call setPath to initialize SkPath::Iter at a later time. + + @return RawIter of empty SkPath + */ + RawIter() {} + + /** Sets RawIter to return elements of verb array, SkPoint array, and conic weight in path. + + @param path SkPath to iterate + @return RawIter of path + */ + RawIter(const SkPath& path) { + setPath(path); + } + + /** Sets SkPath::Iter to return elements of verb array, SkPoint array, and conic weight in + path. + + @param path SkPath to iterate + */ + void setPath(const SkPath&); + + /** Returns next SkPath::Verb in verb array, and advances RawIter. + When verb array is exhausted, returns kDone_Verb. + Zero to four SkPoint are stored in pts, depending on the returned SkPath::Verb. + + @param pts storage for SkPoint data describing returned SkPath::Verb + @return next SkPath::Verb from verb array + */ + Verb next(SkPoint[4]); + + /** Returns next SkPath::Verb, but does not advance RawIter. + + @return next SkPath::Verb from verb array + */ + Verb peek() const { + return (fIter != fEnd) ? static_cast<Verb>(std::get<0>(*fIter)) : kDone_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 fConicWeight; + } + + private: + RangeIter fIter; + RangeIter fEnd; + SkScalar fConicWeight = 0; + friend class SkPath; + + }; + + /** Returns true if the point (x, y) is contained by SkPath, taking into + account FillType. + + @param x x-axis value of containment test + @param y y-axis value of containment test + @return true if SkPoint is in SkPath + + example: https://fiddle.skia.org/c/@Path_contains + */ + bool contains(SkScalar x, SkScalar y) const; + + /** Writes text representation of SkPath to stream. If stream is nullptr, writes to + standard output. Set dumpAsHex true to generate exact binary representations + of floating point numbers used in SkPoint array and conic weights. + + @param stream writable SkWStream receiving SkPath text representation; may be nullptr + @param dumpAsHex true if SkScalar values are written as hexadecimal + + example: https://fiddle.skia.org/c/@Path_dump + */ + void dump(SkWStream* stream, bool dumpAsHex) const; + + void dump() const { this->dump(nullptr, false); } + void dumpHex() const { this->dump(nullptr, true); } + + // Like dump(), but outputs for the SkPath::Make() factory + void dumpArrays(SkWStream* stream, bool dumpAsHex) const; + void dumpArrays() const { this->dumpArrays(nullptr, false); } + + /** Writes SkPath to buffer, returning the number of bytes written. + Pass nullptr to obtain the storage size. + + Writes SkPath::FillType, verb array, SkPoint array, conic weight, and + additionally writes computed information like SkPath::Convexity and bounds. + + Use only be used in concert with readFromMemory(); + the format used for SkPath in memory is not guaranteed. + + @param buffer storage for SkPath; may be nullptr + @return size of storage required for SkPath; always a multiple of 4 + + example: https://fiddle.skia.org/c/@Path_writeToMemory + */ + size_t writeToMemory(void* buffer) const; + + /** Writes SkPath to buffer, returning the buffer written to, wrapped in SkData. + + serialize() writes SkPath::FillType, verb array, SkPoint array, conic weight, and + additionally writes computed information like SkPath::Convexity and bounds. + + serialize() should only be used in concert with readFromMemory(). + The format used for SkPath in memory is not guaranteed. + + @return SkPath data wrapped in SkData buffer + + example: https://fiddle.skia.org/c/@Path_serialize + */ + sk_sp<SkData> serialize() const; + + /** Initializes SkPath from buffer of size length. Returns zero if the buffer is + data is inconsistent, or the length is too small. + + Reads SkPath::FillType, verb array, SkPoint array, conic weight, and + additionally reads computed information like SkPath::Convexity and bounds. + + Used only in concert with writeToMemory(); + the format used for SkPath in memory is not guaranteed. + + @param buffer storage for SkPath + @param length buffer size in bytes; must be multiple of 4 + @return number of bytes read, or zero on failure + + example: https://fiddle.skia.org/c/@Path_readFromMemory + */ + size_t readFromMemory(const void* buffer, size_t length); + + /** (See Skia bug 1762.) + Returns a non-zero, globally unique value. A different value is returned + if verb array, SkPoint array, or conic weight changes. + + Setting SkPath::FillType does not change generation identifier. + + Each time the path is modified, a different generation identifier will be returned. + SkPath::FillType does affect generation identifier on Android framework. + + @return non-zero, globally unique value + + example: https://fiddle.skia.org/c/@Path_getGenerationID + */ + uint32_t getGenerationID() const; + + /** Returns if SkPath data is consistent. Corrupt SkPath data is detected if + internal values are out of range or internal storage does not match + array dimensions. + + @return true if SkPath data is consistent + */ + bool isValid() const; + + using sk_is_trivially_relocatable = std::true_type; + +private: + SkPath(sk_sp<SkPathRef>, SkPathFillType, bool isVolatile, SkPathConvexity, + SkPathFirstDirection firstDirection); + + sk_sp<SkPathRef> fPathRef; + int fLastMoveToIndex; + mutable std::atomic<uint8_t> fConvexity; // SkPathConvexity + mutable std::atomic<uint8_t> fFirstDirection; // SkPathFirstDirection + uint8_t fFillType : 2; + uint8_t fIsVolatile : 1; + + static_assert(::sk_is_trivially_relocatable<decltype(fPathRef)>::value); + + /** Resets all fields other than fPathRef to their initial 'empty' values. + * Assumes the caller has already emptied fPathRef. + * On Android increments fGenerationID without reseting it. + */ + void resetFields(); + + /** Sets all fields other than fPathRef to the values in 'that'. + * Assumes the caller has already set fPathRef. + * Doesn't change fGenerationID or fSourcePath on Android. + */ + void copyFields(const SkPath& that); + + size_t writeToMemoryAsRRect(void* buffer) const; + size_t readAsRRect(const void*, size_t); + size_t readFromMemory_EQ4Or5(const void*, size_t); + + friend class Iter; + friend class SkPathPriv; + friend class SkPathStroker; + + /* Append, in reverse order, the first contour of path, ignoring path's + last point. If no moveTo() call has been made for this contour, the + first point is automatically set to (0,0). + */ + SkPath& reversePathTo(const SkPath&); + + // called before we add points for lineTo, quadTo, cubicTo, checking to see + // if we need to inject a leading moveTo first + // + // SkPath path; path.lineTo(...); <--- need a leading moveTo(0, 0) + // SkPath path; ... path.close(); path.lineTo(...) <-- need a moveTo(previous moveTo) + // + inline void injectMoveToIfNeeded(); + + inline bool hasOnlyMoveTos() const; + + SkPathConvexity computeConvexity() const; + + bool isValidImpl() const; + /** Asserts if SkPath data is inconsistent. + Debugging check intended for internal use only. + */ +#ifdef SK_DEBUG + void validate() const; + void validateRef() const; +#endif + + // called by stroker to see if all points (in the last contour) are equal and worthy of a cap + bool isZeroLengthSincePoint(int startPtIndex) const; + + /** Returns if the path can return a bound at no cost (true) or will have to + perform some computation (false). + */ + bool hasComputedBounds() const; + + // 'rect' needs to be sorted + void setBounds(const SkRect& rect); + + void setPt(int index, SkScalar x, SkScalar y); + + SkPath& dirtyAfterEdit(); + + // Bottlenecks for working with fConvexity and fFirstDirection. + // Notice the setters are const... these are mutable atomic fields. + void setConvexity(SkPathConvexity) const; + + void setFirstDirection(SkPathFirstDirection) const; + SkPathFirstDirection getFirstDirection() const; + + /** Returns the comvexity type, computing if needed. Never returns kUnknown. + @return path's convexity type (convex or concave) + */ + SkPathConvexity getConvexity() const; + + SkPathConvexity getConvexityOrUnknown() const; + + // Compares the cached value with a freshly computed one (computeConvexity()) + bool isConvexityAccurate() const; + + /** Stores a convexity type for this path. This is what will be returned if + * getConvexityOrUnknown() is called. If you pass kUnknown, then if getContexityType() + * is called, the real convexity will be computed. + * + * example: https://fiddle.skia.org/c/@Path_setConvexity + */ + void setConvexity(SkPathConvexity convexity); + + /** Shrinks SkPath verb array and SkPoint array storage to discard unused capacity. + * May reduce the heap overhead for SkPath known to be fully constructed. + * + * NOTE: This may relocate the underlying buffers, and thus any Iterators referencing + * this path should be discarded after calling shrinkToFit(). + */ + void shrinkToFit(); + + friend class SkAutoPathBoundsUpdate; + friend class SkAutoDisableOvalCheck; + friend class SkAutoDisableDirectionCheck; + friend class SkPathBuilder; + friend class SkPathEdgeIter; + friend class SkPathWriter; + friend class SkOpBuilder; + friend class SkBench_AddPathTest; // perf test reversePathTo + friend class PathTest_Private; // unit test reversePathTo + friend class ForceIsRRect_Private; // unit test isRRect + friend class FuzzPath; // for legacy access to validateRef +}; + +#endif |