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