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      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 SkRasterClip_DEFINED
      9 #define SkRasterClip_DEFINED
     10 
     11 #include "SkRegion.h"
     12 #include "SkAAClip.h"
     13 
     14 class SkRasterClip {
     15 public:
     16     SkRasterClip();
     17     SkRasterClip(const SkIRect&);
     18     SkRasterClip(const SkRasterClip&);
     19     ~SkRasterClip();
     20 
     21     bool isBW() const { return fIsBW; }
     22     bool isAA() const { return !fIsBW; }
     23     const SkRegion& bwRgn() const { SkASSERT(fIsBW); return fBW; }
     24     const SkAAClip& aaRgn() const { SkASSERT(!fIsBW); return fAA; }
     25 
     26     bool isEmpty() const;
     27     bool isRect() const;
     28     bool isComplex() const;
     29     const SkIRect& getBounds() const;
     30 
     31     bool setEmpty();
     32     bool setRect(const SkIRect&);
     33 
     34     bool setPath(const SkPath& path, const SkRegion& clip, bool doAA);
     35     bool setPath(const SkPath& path, const SkIRect& clip, bool doAA);
     36     bool setPath(const SkPath& path, const SkRasterClip&, bool doAA);
     37 
     38     bool op(const SkIRect&, SkRegion::Op);
     39     bool op(const SkRegion&, SkRegion::Op);
     40     bool op(const SkRasterClip&, SkRegion::Op);
     41     bool op(const SkRect&, SkRegion::Op, bool doAA);
     42 
     43     void translate(int dx, int dy, SkRasterClip* dst) const;
     44     void translate(int dx, int dy) {
     45         this->translate(dx, dy, this);
     46     }
     47 
     48     bool quickContains(const SkIRect& rect) const;
     49     bool quickContains(int left, int top, int right, int bottom) const {
     50         return quickContains(SkIRect::MakeLTRB(left, top, right, bottom));
     51     }
     52 
     53     /**
     54      *  Return true if this region is empty, or if the specified rectangle does
     55      *  not intersect the region. Returning false is not a guarantee that they
     56      *  intersect, but returning true is a guarantee that they do not.
     57      */
     58     bool quickReject(const SkIRect& rect) const {
     59         return this->isEmpty() || rect.isEmpty() ||
     60                !SkIRect::Intersects(this->getBounds(), rect);
     61     }
     62 
     63     // hack for SkCanvas::getTotalClip
     64     const SkRegion& forceGetBW();
     65 
     66 #ifdef SK_DEBUG
     67     void validate() const;
     68 #else
     69     void validate() const {}
     70 #endif
     71 
     72 private:
     73     SkRegion    fBW;
     74     SkAAClip    fAA;
     75     bool        fIsBW;
     76 
     77     void convertToAA();
     78 };
     79 
     80 class SkAutoRasterClipValidate : SkNoncopyable {
     81 public:
     82     SkAutoRasterClipValidate(const SkRasterClip& rc) : fRC(rc) {
     83         fRC.validate();
     84     }
     85     ~SkAutoRasterClipValidate() {
     86         fRC.validate();
     87     }
     88 private:
     89     const SkRasterClip& fRC;
     90 };
     91 
     92 #ifdef SK_DEBUG
     93     #define AUTO_RASTERCLIP_VALIDATE(rc)    SkAutoRasterClipValidate arcv(rc)
     94 #else
     95     #define AUTO_RASTERCLIP_VALIDATE(rc)
     96 #endif
     97 
     98 ///////////////////////////////////////////////////////////////////////////////
     99 
    100 /**
    101  *  Encapsulates the logic of deciding if we need to change/wrap the blitter
    102  *  for aaclipping. If so, getRgn and getBlitter return modified values. If
    103  *  not, they return the raw blitter and (bw) clip region.
    104  *
    105  *  We need to keep the constructor/destructor cost as small as possible, so we
    106  *  can freely put this guy on the stack, and not pay too much for the case when
    107  *  we're really BW anyways.
    108  */
    109 class SkAAClipBlitterWrapper {
    110 public:
    111     SkAAClipBlitterWrapper();
    112     SkAAClipBlitterWrapper(const SkRasterClip&, SkBlitter*);
    113     SkAAClipBlitterWrapper(const SkAAClip*, SkBlitter*);
    114 
    115     void init(const SkRasterClip&, SkBlitter*);
    116 
    117     const SkIRect& getBounds() const {
    118         SkASSERT(fClipRgn);
    119         return fClipRgn->getBounds();
    120     }
    121     const SkRegion& getRgn() const {
    122         SkASSERT(fClipRgn);
    123         return *fClipRgn;
    124     }
    125     SkBlitter* getBlitter() {
    126         SkASSERT(fBlitter);
    127         return fBlitter;
    128     }
    129 
    130 private:
    131     const SkAAClip* fAAClip;
    132     SkRegion        fBWRgn;
    133     SkAAClipBlitter fAABlitter;
    134     // what we return
    135     const SkRegion* fClipRgn;
    136     SkBlitter* fBlitter;
    137 };
    138 
    139 #endif
    140