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 SkQuadClipper_DEFINED
11#define SkQuadClipper_DEFINED
12
13#include "SkPath.h"
14
15/** This class is initialized with a clip rectangle, and then can be fed quads,
16    which must already be monotonic in Y.
17
18    In the future, it might return a series of segments, allowing it to clip
19    also in X, to ensure that all segments fit in a finite coordinate system.
20 */
21class SkQuadClipper {
22public:
23    SkQuadClipper();
24
25    void setClip(const SkIRect& clip);
26
27    bool clipQuad(const SkPoint src[3], SkPoint dst[3]);
28
29private:
30    SkRect      fClip;
31};
32
33/** Iterator that returns the clipped segements of a quad clipped to a rect.
34    The segments will be either lines or quads (based on SkPath::Verb), and
35    will all be monotonic in Y
36 */
37class SkQuadClipper2 {
38public:
39    bool clipQuad(const SkPoint pts[3], const SkRect& clip);
40    bool clipCubic(const SkPoint pts[4], const SkRect& clip);
41
42    SkPath::Verb next(SkPoint pts[]);
43
44private:
45    SkPoint*        fCurrPoint;
46    SkPath::Verb*   fCurrVerb;
47
48    enum {
49        kMaxVerbs = 13,
50        kMaxPoints = 32
51    };
52    SkPoint         fPoints[kMaxPoints];
53    SkPath::Verb    fVerbs[kMaxVerbs];
54
55    void clipMonoQuad(const SkPoint srcPts[3], const SkRect& clip);
56    void clipMonoCubic(const SkPoint srcPts[4], const SkRect& clip);
57    void appendVLine(SkScalar x, SkScalar y0, SkScalar y1, bool reverse);
58    void appendQuad(const SkPoint pts[3], bool reverse);
59    void appendCubic(const SkPoint pts[4], bool reverse);
60};
61
62#ifdef SK_DEBUG
63    void sk_assert_monotonic_x(const SkPoint pts[], int count);
64    void sk_assert_monotonic_y(const SkPoint pts[], int count);
65#else
66    #define sk_assert_monotonic_x(pts, count)
67    #define sk_assert_monotonic_y(pts, count)
68#endif
69
70#endif
71