1 
2 /*
3  * Copyright 2009 The Android Open Source Project
4  *
5  * Use of this source code is governed by a BSD-style license that can be
6  * found in the LICENSE file.
7  */
8 
9 
10 #ifndef SkEdgeClipper_DEFINED
11 #define SkEdgeClipper_DEFINED
12 
13 #include "SkPath.h"
14 
15 /** This is basically an iterator. It is initialized with an edge and a clip,
16     and then next() is called until it returns kDone_Verb.
17  */
18 class SkEdgeClipper {
19 public:
SkEdgeClipper(bool canCullToTheRight)20     SkEdgeClipper(bool canCullToTheRight) : fCanCullToTheRight(canCullToTheRight) {}
21 
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 private:
30     SkPoint*        fCurrPoint;
31     SkPath::Verb*   fCurrVerb;
32     const bool      fCanCullToTheRight;
33 
34     enum {
35         kMaxVerbs = 13,
36         kMaxPoints = 32
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 appendVLine(SkScalar x, SkScalar y0, SkScalar y1, bool reverse);
44     void appendQuad(const SkPoint pts[3], bool reverse);
45     void appendCubic(const SkPoint pts[4], bool reverse);
46 };
47 
48 #ifdef SK_DEBUG
49     void sk_assert_monotonic_x(const SkPoint pts[], int count);
50     void sk_assert_monotonic_y(const SkPoint pts[], int count);
51 #else
52     #define sk_assert_monotonic_x(pts, count)
53     #define sk_assert_monotonic_y(pts, count)
54 #endif
55 
56 #endif
57