SkAAClip.h revision e36707a4a82a4dea7d480d969220f3ed223305dc 
1
2/*
3 * Copyright 2011 Google Inc.
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#ifndef SkAAClip_DEFINED
10#define SkAAClip_DEFINED
11
12#include "SkBlitter.h"
13#include "SkRegion.h"
14
15#define SkAAClip_gEmptyPtr   ((SkAAClip::RunHead*)-1)
16#define SkAAClip_gRectPtr    NULL
17
18class SkAAClip {
19public:
20    SkAAClip();
21    SkAAClip(const SkAAClip&);
22    ~SkAAClip();
23
24    SkAAClip& operator=(const SkAAClip&);
25    friend bool operator==(const SkAAClip&, const SkAAClip&);
26    friend bool operator!=(const SkAAClip& a, const SkAAClip& b) {
27        return !(a == b);
28    }
29
30    void swap(SkAAClip&);
31
32    bool isEmpty() const { return SkAAClip_gEmptyPtr == fRunHead; }
33    bool isRect() const { return SkAAClip_gRectPtr == fRunHead; }
34    bool isComplex() const { return !this->isEmpty() && !this->isRect(); }
35    const SkIRect& getBounds() const { return fBounds; }
36
37    bool setEmpty();
38    bool setRect(const SkIRect&);
39    bool setRect(const SkRect&);
40    bool setPath(const SkPath&, const SkRegion& clip);
41
42    bool op(const SkAAClip&, const SkAAClip&, SkRegion::Op);
43
44    // called internally
45
46    bool quickContains(int left, int top, int right, int bottom) const;
47    const uint8_t* findRow(int y, int* lastYForRow) const;
48    const uint8_t* findX(const uint8_t data[], int x, int* initialCount) const;
49
50private:
51    struct RunHead;
52    struct YOffset;
53
54    SkIRect  fBounds;
55    RunHead* fRunHead;
56
57    void freeRuns();
58
59    class Builder;
60    friend class Builder;
61    class BuilderBlitter;
62    friend class BuilderBlitter;
63};
64
65///////////////////////////////////////////////////////////////////////////////
66
67class SkAAClipBlitter : public SkBlitter {
68public:
69    SkAAClipBlitter() : fRuns(NULL) {}
70    virtual ~SkAAClipBlitter();
71
72    void init(SkBlitter* blitter, const SkAAClip* aaclip) {
73        SkASSERT(aaclip && !aaclip->isEmpty());
74        fBlitter = blitter;
75        fAAClip = aaclip;
76        fAAClipBounds = aaclip->getBounds();
77    }
78
79    virtual void blitH(int x, int y, int width) SK_OVERRIDE;
80    virtual void blitAntiH(int x, int y, const SkAlpha[],
81                           const int16_t runs[]) SK_OVERRIDE;
82    virtual void blitV(int x, int y, int height, SkAlpha alpha) SK_OVERRIDE;
83    virtual void blitRect(int x, int y, int width, int height) SK_OVERRIDE;
84    virtual void blitMask(const SkMask&, const SkIRect& clip) SK_OVERRIDE;
85    virtual const SkBitmap* justAnOpaqueColor(uint32_t* value) SK_OVERRIDE;
86
87private:
88    SkBlitter*      fBlitter;
89    const SkAAClip* fAAClip;
90    SkIRect         fAAClipBounds;
91
92    // lazily allocated
93    int16_t*        fRuns;
94    SkAlpha*        fAA;    // points into fRuns allocation
95
96    void ensureRunsAndAA();
97};
98
99#endif
100