Line data    Source code

       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 "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:
      19          25 :     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             : 
      27           7 :     bool canCullToTheRight() const { return fCanCullToTheRight; }
      28             : 
      29             : private:
      30             :     SkPoint*        fCurrPoint;
      31             :     SkPath::Verb*   fCurrVerb;
      32             :     const bool      fCanCullToTheRight;
      33             : 
      34             :     enum {
      35             :         kMaxVerbs = 18,  // max curvature in X and Y split cubic into 9 pieces, * (line + cubic)
      36             :         kMaxPoints = 54  // 2 lines + 1 cubic require 6 points; times 9 pieces
      37             :     };
      38             :     SkPoint         fPoints[kMaxPoints];
      39             :     SkPath::Verb    fVerbs[kMaxVerbs];
      40             : 
      41             :     void clipMonoQuad(const SkPoint srcPts[3], const SkRect& clip);
      42             :     void clipMonoCubic(const SkPoint srcPts[4], const SkRect& clip);
      43             :     void appendLine(SkPoint p0, SkPoint p1);
      44             :     void appendVLine(SkScalar x, SkScalar y0, SkScalar y1, bool reverse);
      45             :     void appendQuad(const SkPoint pts[3], bool reverse);
      46             :     void appendCubic(const SkPoint pts[4], bool reverse);
      47             : };
      48             : 
      49             : #ifdef SK_DEBUG
      50             :     void sk_assert_monotonic_x(const SkPoint pts[], int count);
      51             :     void sk_assert_monotonic_y(const SkPoint pts[], int count);
      52             : #else
      53             :     #define sk_assert_monotonic_x(pts, count)
      54             :     #define sk_assert_monotonic_y(pts, count)
      55             : #endif
      56             : 
      57             : #endif