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
15class SkAAClip {
16public:
17    SkAAClip();
18    SkAAClip(const SkAAClip&);
19    ~SkAAClip();
20
21    SkAAClip& operator=(const SkAAClip&);
22    friend bool operator==(const SkAAClip&, const SkAAClip&);
23    friend bool operator!=(const SkAAClip& a, const SkAAClip& b) {
24        return !(a == b);
25    }
26
27    void swap(SkAAClip&);
28
29    bool isEmpty() const { return NULL == fRunHead; }
30    const SkIRect& getBounds() const { return fBounds; }
31
32    bool setEmpty();
33    bool setRect(const SkIRect&);
34    bool setRect(const SkRect&, bool doAA = true);
35    bool setPath(const SkPath&, const SkRegion* clip = NULL, bool doAA = true);
36    bool setRegion(const SkRegion&);
37    bool set(const SkAAClip&);
38
39    bool op(const SkAAClip&, const SkAAClip&, SkRegion::Op);
40
41    // Helpers for op()
42    bool op(const SkIRect&, SkRegion::Op);
43    bool op(const SkRect&, SkRegion::Op, bool doAA);
44    bool op(const SkAAClip&, SkRegion::Op);
45
46    bool translate(int dx, int dy, SkAAClip* dst) const;
47    bool translate(int dx, int dy) {
48        return this->translate(dx, dy, this);
49    }
50
51    /**
52     *  Allocates a mask the size of the aaclip, and expands its data into
53     *  the mask, using kA8_Format
54     */
55    void copyToMask(SkMask*) const;
56
57    // called internally
58
59    bool quickContains(int left, int top, int right, int bottom) const;
60    bool quickContains(const SkIRect& r) const {
61        return this->quickContains(r.fLeft, r.fTop, r.fRight, r.fBottom);
62    }
63
64    const uint8_t* findRow(int y, int* lastYForRow = NULL) const;
65    const uint8_t* findX(const uint8_t data[], int x, int* initialCount = NULL) const;
66
67    class Iter;
68    struct RunHead;
69    struct YOffset;
70    class Builder;
71
72#ifdef SK_DEBUG
73    void validate() const;
74#else
75    void validate() const {}
76#endif
77
78private:
79    SkIRect  fBounds;
80    RunHead* fRunHead;
81
82    void freeRuns();
83    bool trimBounds();
84    bool trimTopBottom();
85    bool trimLeftRight();
86
87    friend class Builder;
88    class BuilderBlitter;
89    friend class BuilderBlitter;
90};
91
92///////////////////////////////////////////////////////////////////////////////
93
94class SkAAClipBlitter : public SkBlitter {
95public:
96    SkAAClipBlitter() : fScanlineScratch(NULL) {}
97    virtual ~SkAAClipBlitter();
98
99    void init(SkBlitter* blitter, const SkAAClip* aaclip) {
100        SkASSERT(aaclip && !aaclip->isEmpty());
101        fBlitter = blitter;
102        fAAClip = aaclip;
103        fAAClipBounds = aaclip->getBounds();
104    }
105
106    virtual void blitH(int x, int y, int width) SK_OVERRIDE;
107    virtual void blitAntiH(int x, int y, const SkAlpha[],
108                           const int16_t runs[]) SK_OVERRIDE;
109    virtual void blitV(int x, int y, int height, SkAlpha alpha) SK_OVERRIDE;
110    virtual void blitRect(int x, int y, int width, int height) SK_OVERRIDE;
111    virtual void blitMask(const SkMask&, const SkIRect& clip) SK_OVERRIDE;
112    virtual const SkBitmap* justAnOpaqueColor(uint32_t* value) SK_OVERRIDE;
113
114private:
115    SkBlitter*      fBlitter;
116    const SkAAClip* fAAClip;
117    SkIRect         fAAClipBounds;
118
119    // point into fScanlineScratch
120    int16_t*        fRuns;
121    SkAlpha*        fAA;
122
123    enum {
124        kSize = 32 * 32
125    };
126    SkAutoSMalloc<kSize> fGrayMaskScratch;  // used for blitMask
127    void* fScanlineScratch;  // enough for a mask at 32bit, or runs+aa
128
129    void ensureRunsAndAA();
130};
131
132#endif
133