1/*
2 * Copyright 2010 Google Inc.
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#ifndef GrClip_DEFINED
9#define GrClip_DEFINED
10
11#include "SkClipStack.h"
12
13struct SkIRect;
14
15/**
16 * GrClip encapsulates the information required to construct the clip
17 * masks. 'A GrClip is either wide open, just an IRect, just a Rect, or a full clipstack.
18 * If the clip is a clipstack than the origin is used to translate the stack with
19 * respect to device coordinates. This allows us to use a clip stack that is
20 * specified for a root device with a layer device that is restricted to a subset
21 * of the original canvas. For other clip types the origin will always be (0,0).
22 *
23 * NOTE: GrClip *must* point to a const clipstack
24 */
25class GrClip : SkNoncopyable {
26public:
27    GrClip() : fClipType(kWideOpen_ClipType) {
28        fOrigin.setZero();
29    }
30
31    GrClip(const SkIRect& rect) : fClipType(kIRect_ClipType) {
32        fOrigin.setZero();
33        fClip.fIRect = rect;
34    }
35
36    GrClip(const SkRect& rect) : fClipType(kIRect_ClipType) {
37        fOrigin.setZero();
38        fClip.fIRect.fLeft   = SkScalarRoundToInt(rect.fLeft);
39        fClip.fIRect.fTop    = SkScalarRoundToInt(rect.fTop);
40        fClip.fIRect.fRight  = SkScalarRoundToInt(rect.fRight);
41        fClip.fIRect.fBottom = SkScalarRoundToInt(rect.fBottom);
42    }
43
44    ~GrClip() { this->reset(); }
45
46    const GrClip& operator=(const GrClip& other) {
47        this->reset();
48        fClipType = other.fClipType;
49        switch (other.fClipType) {
50            case kWideOpen_ClipType:
51                fOrigin.setZero();
52                break;
53            case kClipStack_ClipType:
54                fClip.fStack = SkRef(other.clipStack());
55                fOrigin = other.origin();
56                break;
57            case kIRect_ClipType:
58                fClip.fIRect = other.irect();
59                fOrigin.setZero();
60                break;
61        }
62        return *this;
63    }
64
65    bool operator==(const GrClip& other) const {
66        if (this->clipType() != other.clipType()) {
67            return false;
68        }
69
70        switch (fClipType) {
71            case kWideOpen_ClipType:
72                return true;
73            case kClipStack_ClipType:
74                if (this->origin() != other.origin()) {
75                    return false;
76                }
77
78                if (this->clipStack() && other.clipStack()) {
79                    return *this->clipStack() == *other.clipStack();
80                } else {
81                    return this->clipStack() == other.clipStack();
82                }
83                break;
84            case kIRect_ClipType:
85                return this->irect() == other.irect();
86                break;
87        }
88        SkFAIL("This should not occur\n");
89        return false;
90    }
91
92    bool operator!=(const GrClip& other) const {
93        return !(*this == other);
94    }
95
96    const SkClipStack* clipStack() const {
97        SkASSERT(kClipStack_ClipType == fClipType);
98        return fClip.fStack;
99    }
100
101    void setClipStack(const SkClipStack* clipStack, const SkIPoint* origin = NULL) {
102        this->reset();
103        if (clipStack->isWideOpen()) {
104            fClipType = kWideOpen_ClipType;
105            fOrigin.setZero();
106        } else {
107            fClipType = kClipStack_ClipType;
108            fClip.fStack = SkRef(clipStack);
109            if (origin) {
110                fOrigin = *origin;
111            } else {
112                fOrigin.setZero();
113            }
114        }
115    }
116
117    const SkIRect& irect() const {
118        SkASSERT(kIRect_ClipType == fClipType);
119        return fClip.fIRect;
120    }
121
122    void reset() {
123        if (kClipStack_ClipType == fClipType) {
124            fClip.fStack->unref();
125            fClip.fStack = NULL;
126        }
127        fClipType = kWideOpen_ClipType;
128        fOrigin.setZero();
129    }
130
131    // We support this for all cliptypes to simplify the logic a bit in clip mask manager.
132    // non clipstack clip types MUST have a (0,0) origin
133    const SkIPoint& origin() const {
134        SkASSERT(fClipType == kClipStack_ClipType || (fOrigin.fX == 0 && fOrigin.fY == 0));
135        return fOrigin;
136    }
137
138    bool isWideOpen(const SkRect& rect) const {
139        return (kWideOpen_ClipType == fClipType) ||
140               (kClipStack_ClipType == fClipType && this->clipStack()->isWideOpen()) ||
141               (kIRect_ClipType == fClipType && this->irect().contains(rect));
142    }
143
144    bool isWideOpen(const SkIRect& rect) const {
145        return (kWideOpen_ClipType == fClipType) ||
146               (kClipStack_ClipType == fClipType && this->clipStack()->isWideOpen()) ||
147               (kIRect_ClipType == fClipType && this->irect().contains(rect));
148    }
149
150    bool isWideOpen() const {
151        return (kWideOpen_ClipType == fClipType) ||
152               (kClipStack_ClipType == fClipType && this->clipStack()->isWideOpen());
153    }
154
155    bool quickContains(const SkRect& rect) const {
156        return (kWideOpen_ClipType == fClipType) ||
157               (kClipStack_ClipType == fClipType && this->clipStack()->quickContains(rect)) ||
158               (kIRect_ClipType == fClipType && this->irect().contains(rect));
159    }
160
161    void getConservativeBounds(int width, int height,
162                               SkIRect* devResult,
163                               bool* isIntersectionOfRects = NULL) const;
164
165    static const GrClip& WideOpen();
166
167    enum ClipType {
168        kClipStack_ClipType,
169        kWideOpen_ClipType,
170        kIRect_ClipType,
171    };
172
173    ClipType clipType() const { return fClipType; }
174
175private:
176    union Clip {
177        const SkClipStack* fStack;
178        SkIRect fIRect;
179    } fClip;
180
181    SkIPoint fOrigin;
182    ClipType fClipType;
183};
184
185#endif
186