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 #include "include/core/SkPoint.h" 14 #include "include/core/SkScalar.h" 15 #include "include/private/base/SkDebug.h" 16 17 struct SkRect; 18 19 /** This is basically an iterator. It is initialized with an edge and a clip, 20 and then next() is called until it returns kDone_Verb. 21 */ 22 class SkEdgeClipper { 23 public: SkEdgeClipper(bool canCullToTheRight)24 SkEdgeClipper(bool canCullToTheRight) : fCanCullToTheRight(canCullToTheRight) {} 25 26 bool clipLine(SkPoint p0, SkPoint p1, const SkRect& clip); 27 bool clipQuad(const SkPoint pts[3], const SkRect& clip); 28 bool clipCubic(const SkPoint pts[4], const SkRect& clip); 29 30 SkPath::Verb next(SkPoint pts[]); 31 canCullToTheRight()32 bool canCullToTheRight() const { return fCanCullToTheRight; } 33 34 /** 35 * Clips each segment from the path, and passes the result (in a clipper) to the 36 * consume proc. 37 */ 38 static void ClipPath(const SkPath& path, const SkRect& clip, bool canCullToTheRight, 39 void (*consume)(SkEdgeClipper*, bool newCtr, void* ctx), void* ctx); 40 41 private: 42 SkPoint* fCurrPoint; 43 SkPath::Verb* fCurrVerb; 44 const bool fCanCullToTheRight; 45 46 enum { 47 kMaxVerbs = 18, // max curvature in X and Y split cubic into 9 pieces, * (line + cubic) 48 kMaxPoints = 54 // 2 lines + 1 cubic require 6 points; times 9 pieces 49 }; 50 SkPoint fPoints[kMaxPoints]; 51 SkPath::Verb fVerbs[kMaxVerbs]; 52 53 void clipMonoQuad(const SkPoint srcPts[3], const SkRect& clip); 54 void clipMonoCubic(const SkPoint srcPts[4], const SkRect& clip); 55 void appendLine(SkPoint p0, SkPoint p1); 56 void appendVLine(SkScalar x, SkScalar y0, SkScalar y1, bool reverse); 57 void appendQuad(const SkPoint pts[3], bool reverse); 58 void appendCubic(const SkPoint pts[4], bool reverse); 59 }; 60 61 #ifdef SK_DEBUG 62 void sk_assert_monotonic_x(const SkPoint pts[], int count); 63 void sk_assert_monotonic_y(const SkPoint pts[], int count); 64 #else 65 #define sk_assert_monotonic_x(pts, count) 66 #define sk_assert_monotonic_y(pts, count) 67 #endif 68 69 #endif 70