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      1 /*
      2  * Copyright 2016 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 SkSpecialImage_DEFINED
      9 #define SkSpecialImage_DEFINED
     10 
     11 #include "SkNextID.h"
     12 #include "SkRefCnt.h"
     13 
     14 // remove this when internal_getProxy goes away (see skbug.com/4965)
     15 #include "SkImageFilter.h"
     16 
     17 class GrTexture;
     18 class SkBitmap;
     19 class SkCanvas;
     20 class SkImage;
     21 struct SkImageInfo;
     22 class SkPaint;
     23 class SkSpecialSurface;
     24 
     25 enum {
     26     kNeedNewImageUniqueID_SpecialImage = 0
     27 };
     28 
     29 /**
     30  * This is a restricted form of SkImage solely intended for internal use. It
     31  * differs from SkImage in that:
     32  *      - it can only be backed by raster or gpu (no generators)
     33  *      - it can be backed by a GrTexture larger than its nominal bounds
     34  *      - it can't be drawn tiled
     35  *      - it can't be drawn with MIPMAPs
     36  * It is similar to SkImage in that it abstracts how the pixels are stored/represented.
     37  *
     38  * Note: the contents of the backing storage outside of the subset rect are undefined.
     39  */
     40 class SkSpecialImage : public SkRefCnt {
     41 public:
     42     int width() const { return fSubset.width(); }
     43     int height() const { return fSubset.height(); }
     44     const SkIRect& subset() const { return fSubset; }
     45 
     46     uint32_t uniqueID() const { return fUniqueID; }
     47     virtual bool isOpaque() const { return false; }
     48     virtual size_t getSize() const = 0;
     49 
     50     /**
     51      *  Draw this SpecialImage into the canvas.
     52      */
     53     void draw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*) const;
     54 
     55     static SkSpecialImage* NewFromImage(const SkIRect& subset, const SkImage*);
     56     static SkSpecialImage* NewFromRaster(SkImageFilter::Proxy*,
     57                                          const SkIRect& subset,
     58                                          const SkBitmap&);
     59     static SkSpecialImage* NewFromGpu(SkImageFilter::Proxy*,
     60                                       const SkIRect& subset,
     61                                       uint32_t uniqueID,
     62                                       GrTexture*,
     63                                       SkAlphaType at = kPremul_SkAlphaType);
     64 
     65     /**
     66      *  Create a new surface with a backend that is compatible with this image.
     67      */
     68     SkSpecialSurface* newSurface(const SkImageInfo&) const;
     69 
     70     // These three internal methods will go away (see skbug.com/4965)
     71     bool internal_getBM(SkBitmap* result);
     72     static SkSpecialImage* internal_fromBM(SkImageFilter::Proxy*, const SkBitmap&);
     73     SkImageFilter::Proxy* internal_getProxy();
     74 
     75 protected:
     76     SkSpecialImage(SkImageFilter::Proxy* proxy, const SkIRect& subset, uint32_t uniqueID)
     77         : fSubset(subset)
     78         , fUniqueID(kNeedNewImageUniqueID_SpecialImage == uniqueID ? SkNextID::ImageID()
     79                                                                    : uniqueID)
     80         , fProxy(proxy) {
     81     }
     82 
     83     // The following 2 are for testing and shouldn't be used.
     84     friend class TestingSpecialImageAccess;
     85     friend class TestingSpecialSurfaceAccess;
     86 
     87     /**
     88      *  If the SpecialImage is backed by cpu pixels, return the const address
     89      *  of those pixels and, if not null, return the ImageInfo and rowBytes.
     90      *  The returned address is only valid while the image object is in scope.
     91      *
     92      *  The returned ImageInfo represents the backing memory. Use 'subset'
     93      *  to get the active portion's dimensions.
     94      *
     95      *  On failure, return false and ignore the pixmap parameter.
     96      */
     97     bool peekPixels(SkPixmap*) const;
     98 
     99     /**
    100      *  If the SpecialImage is backed by a gpu texture, return that texture.
    101      *  The active portion of the texture can be retrieved via 'subset'.
    102      */
    103     GrTexture* peekTexture() const;
    104 
    105     // TODO: remove this ASAP (see skbug.com/4965)
    106     SkImageFilter::Proxy* proxy() const { return fProxy; }
    107 
    108 private:
    109     const SkIRect   fSubset;
    110     const uint32_t  fUniqueID;
    111 
    112     // TODO: remove this ASAP (see skbug.com/4965)
    113     SkImageFilter::Proxy* fProxy;
    114 
    115     typedef SkRefCnt INHERITED;
    116 };
    117 
    118 #endif
    119 
    120