| /* |
| * Copyright 2018 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef SkContourMeasure_DEFINED |
| #define SkContourMeasure_DEFINED |
| |
| #include "include/core/SkPath.h" |
| #include "include/core/SkRefCnt.h" |
| #include "include/private/base/SkTDArray.h" |
| |
| struct SkConic; |
| |
| class SK_API SkContourMeasure : public SkRefCnt { |
| public: |
| /** Return the length of the contour. |
| */ |
| SkScalar length() const { return fLength; } |
| |
| /** Pins distance to 0 <= distance <= length(), and then computes the corresponding |
| * position and tangent. |
| */ |
| bool SK_WARN_UNUSED_RESULT getPosTan(SkScalar distance, SkPoint* position, |
| SkVector* tangent) const; |
| |
| enum MatrixFlags { |
| kGetPosition_MatrixFlag = 0x01, |
| kGetTangent_MatrixFlag = 0x02, |
| kGetPosAndTan_MatrixFlag = kGetPosition_MatrixFlag | kGetTangent_MatrixFlag |
| }; |
| |
| /** Pins distance to 0 <= distance <= getLength(), and then computes |
| the corresponding matrix (by calling getPosTan). |
| Returns false if there is no path, or a zero-length path was specified, in which case |
| matrix is unchanged. |
| */ |
| bool SK_WARN_UNUSED_RESULT getMatrix(SkScalar distance, SkMatrix* matrix, |
| MatrixFlags flags = kGetPosAndTan_MatrixFlag) const; |
| |
| /** Given a start and stop distance, return in dst the intervening segment(s). |
| If the segment is zero-length, return false, else return true. |
| startD and stopD are pinned to legal values (0..getLength()). If startD > stopD |
| then return false (and leave dst untouched). |
| Begin the segment with a moveTo if startWithMoveTo is true |
| */ |
| bool SK_WARN_UNUSED_RESULT getSegment(SkScalar startD, SkScalar stopD, SkPath* dst, |
| bool startWithMoveTo) const; |
| |
| /** Return true if the contour is closed() |
| */ |
| bool isClosed() const { return fIsClosed; } |
| |
| private: |
| struct Segment { |
| SkScalar fDistance; // total distance up to this point |
| unsigned fPtIndex; // index into the fPts array |
| unsigned fTValue : 30; |
| unsigned fType : 2; // actually the enum SkSegType |
| // See SkPathMeasurePriv.h |
| |
| SkScalar getScalarT() const; |
| |
| static const Segment* Next(const Segment* seg) { |
| unsigned ptIndex = seg->fPtIndex; |
| do { |
| ++seg; |
| } while (seg->fPtIndex == ptIndex); |
| return seg; |
| } |
| |
| }; |
| |
| const SkTDArray<Segment> fSegments; |
| const SkTDArray<SkPoint> fPts; // Points used to define the segments |
| |
| const SkScalar fLength; |
| const bool fIsClosed; |
| |
| SkContourMeasure(SkTDArray<Segment>&& segs, SkTDArray<SkPoint>&& pts, |
| SkScalar length, bool isClosed); |
| ~SkContourMeasure() override {} |
| |
| const Segment* distanceToSegment(SkScalar distance, SkScalar* t) const; |
| |
| friend class SkContourMeasureIter; |
| }; |
| |
| class SK_API SkContourMeasureIter { |
| public: |
| SkContourMeasureIter(); |
| /** |
| * Initialize the Iter with a path. |
| * The parts of the path that are needed are copied, so the client is free to modify/delete |
| * the path after this call. |
| * |
| * resScale controls the precision of the measure. values > 1 increase the |
| * precision (and possibly slow down the computation). |
| */ |
| SkContourMeasureIter(const SkPath& path, bool forceClosed, SkScalar resScale = 1); |
| ~SkContourMeasureIter(); |
| |
| /** |
| * Reset the Iter with a path. |
| * The parts of the path that are needed are copied, so the client is free to modify/delete |
| * the path after this call. |
| */ |
| void reset(const SkPath& path, bool forceClosed, SkScalar resScale = 1); |
| |
| /** |
| * Iterates through contours in path, returning a contour-measure object for each contour |
| * in the path. Returns null when it is done. |
| * |
| * This only returns non-zero length contours, where a contour is the segments between |
| * a kMove_Verb and either ... |
| * - the next kMove_Verb |
| * - kClose_Verb (1 or more) |
| * - kDone_Verb |
| * If it encounters a zero-length contour, it is skipped. |
| */ |
| sk_sp<SkContourMeasure> next(); |
| |
| private: |
| class Impl; |
| |
| std::unique_ptr<Impl> fImpl; |
| }; |
| |
| #endif |