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      1 /*
      2  * Copyright 2011 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 SkAAClip_DEFINED
      9 #define SkAAClip_DEFINED
     10 
     11 #include "SkAutoMalloc.h"
     12 #include "SkBlitter.h"
     13 #include "SkRegion.h"
     14 
     15 class SkAAClip {
     16 public:
     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 nullptr == fRunHead; }
     30     const SkIRect& getBounds() const { return fBounds; }
     31 
     32     // Returns true iff the clip is not empty, and is just a hard-edged rect (no partial alpha).
     33     // If true, getBounds() can be used in place of this clip.
     34     bool isRect() const;
     35 
     36     bool setEmpty();
     37     bool setRect(const SkIRect&);
     38     bool setRect(const SkRect&, bool doAA = true);
     39     bool setPath(const SkPath&, const SkRegion* clip = nullptr, bool doAA = true);
     40     bool setRegion(const SkRegion&);
     41     bool set(const SkAAClip&);
     42 
     43     bool op(const SkAAClip&, const SkAAClip&, SkRegion::Op);
     44 
     45     // Helpers for op()
     46     bool op(const SkIRect&, SkRegion::Op);
     47     bool op(const SkRect&, SkRegion::Op, bool doAA);
     48     bool op(const SkAAClip&, SkRegion::Op);
     49 
     50     bool translate(int dx, int dy, SkAAClip* dst) const;
     51     bool translate(int dx, int dy) {
     52         return this->translate(dx, dy, this);
     53     }
     54 
     55     /**
     56      *  Allocates a mask the size of the aaclip, and expands its data into
     57      *  the mask, using kA8_Format
     58      */
     59     void copyToMask(SkMask*) const;
     60 
     61     // called internally
     62 
     63     bool quickContains(int left, int top, int right, int bottom) const;
     64     bool quickContains(const SkIRect& r) const {
     65         return this->quickContains(r.fLeft, r.fTop, r.fRight, r.fBottom);
     66     }
     67 
     68     const uint8_t* findRow(int y, int* lastYForRow = nullptr) const;
     69     const uint8_t* findX(const uint8_t data[], int x, int* initialCount = nullptr) const;
     70 
     71     class Iter;
     72     struct RunHead;
     73     struct YOffset;
     74     class Builder;
     75 
     76 #ifdef SK_DEBUG
     77     void validate() const;
     78     void debug(bool compress_y=false) const;
     79 #else
     80     void validate() const {}
     81     void debug(bool compress_y=false) const {}
     82 #endif
     83 
     84 private:
     85     SkIRect  fBounds;
     86     RunHead* fRunHead;
     87 
     88     void freeRuns();
     89     bool trimBounds();
     90     bool trimTopBottom();
     91     bool trimLeftRight();
     92 
     93     friend class Builder;
     94     class BuilderBlitter;
     95     friend class BuilderBlitter;
     96 };
     97 
     98 ///////////////////////////////////////////////////////////////////////////////
     99 
    100 class SkAAClipBlitter : public SkBlitter {
    101 public:
    102     SkAAClipBlitter() : fScanlineScratch(nullptr) {}
    103     ~SkAAClipBlitter() override;
    104 
    105     void init(SkBlitter* blitter, const SkAAClip* aaclip) {
    106         SkASSERT(aaclip && !aaclip->isEmpty());
    107         fBlitter = blitter;
    108         fAAClip = aaclip;
    109         fAAClipBounds = aaclip->getBounds();
    110     }
    111 
    112     void blitH(int x, int y, int width) override;
    113     void blitAntiH(int x, int y, const SkAlpha[], const int16_t runs[]) override;
    114     void blitV(int x, int y, int height, SkAlpha alpha) override;
    115     void blitRect(int x, int y, int width, int height) override;
    116     void blitMask(const SkMask&, const SkIRect& clip) override;
    117     const SkPixmap* justAnOpaqueColor(uint32_t* value) override;
    118 
    119 private:
    120     SkBlitter*      fBlitter;
    121     const SkAAClip* fAAClip;
    122     SkIRect         fAAClipBounds;
    123 
    124     // point into fScanlineScratch
    125     int16_t*        fRuns;
    126     SkAlpha*        fAA;
    127 
    128     enum {
    129         kSize = 32 * 32
    130     };
    131     SkAutoSMalloc<kSize> fGrayMaskScratch;  // used for blitMask
    132     void* fScanlineScratch;  // enough for a mask at 32bit, or runs+aa
    133 
    134     void ensureRunsAndAA();
    135 };
    136 
    137 #endif
    138