1 /* 2 * Copyright 2009 The Android Open Source Project 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 9 #ifndef SkEdgeClipper_DEFINED 10 #define SkEdgeClipper_DEFINED 11 12 #include "include/core/SkPath.h" 13 14 /** This is basically an iterator. It is initialized with an edge and a clip, 15 and then next() is called until it returns kDone_Verb. 16 */ 17 class SkEdgeClipper { 18 public: SkEdgeClipper(bool canCullToTheRight)19 SkEdgeClipper(bool canCullToTheRight) : fCanCullToTheRight(canCullToTheRight) {} 20 21 bool clipLine(SkPoint p0, SkPoint p1, const SkRect& clip); 22 bool clipQuad(const SkPoint pts[3], const SkRect& clip); 23 bool clipCubic(const SkPoint pts[4], const SkRect& clip); 24 25 SkPath::Verb next(SkPoint pts[]); 26 canCullToTheRight()27 bool canCullToTheRight() const { return fCanCullToTheRight; } 28 29 /** 30 * Clips each segment from the path, and passes the result (in a clipper) to the 31 * consume proc. 32 */ 33 static void ClipPath(const SkPath& path, const SkRect& clip, bool canCullToTheRight, 34 void (*consume)(SkEdgeClipper*, bool newCtr, void* ctx), void* ctx); 35 36 private: 37 SkPoint* fCurrPoint; 38 SkPath::Verb* fCurrVerb; 39 const bool fCanCullToTheRight; 40 41 enum { 42 kMaxVerbs = 18, // max curvature in X and Y split cubic into 9 pieces, * (line + cubic) 43 kMaxPoints = 54 // 2 lines + 1 cubic require 6 points; times 9 pieces 44 }; 45 SkPoint fPoints[kMaxPoints]; 46 SkPath::Verb fVerbs[kMaxVerbs]; 47 48 void clipMonoQuad(const SkPoint srcPts[3], const SkRect& clip); 49 void clipMonoCubic(const SkPoint srcPts[4], const SkRect& clip); 50 void appendLine(SkPoint p0, SkPoint p1); 51 void appendVLine(SkScalar x, SkScalar y0, SkScalar y1, bool reverse); 52 void appendQuad(const SkPoint pts[3], bool reverse); 53 void appendCubic(const SkPoint pts[4], bool reverse); 54 }; 55 56 #ifdef SK_DEBUG 57 void sk_assert_monotonic_x(const SkPoint pts[], int count); 58 void sk_assert_monotonic_y(const SkPoint pts[], int count); 59 #else 60 #define sk_assert_monotonic_x(pts, count) 61 #define sk_assert_monotonic_y(pts, count) 62 #endif 63 64 #endif 65