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      1 /*
      2  * Copyright 2012 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 SkImage_Base_DEFINED
      9 #define SkImage_Base_DEFINED
     10 
     11 #include "SkAtomics.h"
     12 #include "SkImage.h"
     13 #include "SkSurface.h"
     14 
     15 #include <new>
     16 
     17 class GrTextureParams;
     18 class SkImageCacherator;
     19 
     20 enum {
     21     kNeedNewImageUniqueID = 0
     22 };
     23 
     24 class SkImage_Base : public SkImage {
     25 public:
     26     SkImage_Base(int width, int height, uint32_t uniqueID);
     27     virtual ~SkImage_Base();
     28 
     29     virtual const void* onPeekPixels(SkImageInfo*, size_t* /*rowBytes*/) const { return nullptr; }
     30 
     31     // Default impl calls onDraw
     32     virtual bool onReadPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes,
     33                               int srcX, int srcY, CachingHint) const;
     34 
     35     virtual GrTexture* peekTexture() const { return nullptr; }
     36     virtual SkImageCacherator* peekCacherator() const { return nullptr; }
     37 
     38     // return a read-only copy of the pixels. We promise to not modify them,
     39     // but only inspect them (or encode them).
     40     virtual bool getROPixels(SkBitmap*, CachingHint = kAllow_CachingHint) const = 0;
     41 
     42     virtual SkSurface* onNewSurface(const SkImageInfo& info) const {
     43         return SkSurface::NewRaster(info);
     44     }
     45 
     46     // Caller must call unref when they are done.
     47     virtual GrTexture* asTextureRef(GrContext*, const GrTextureParams&) const = 0;
     48 
     49     virtual SkImage* onNewSubset(const SkIRect&) const = 0;
     50 
     51     // If a ctx is specified, then only gpu-specific formats are requested.
     52     virtual SkData* onRefEncoded(GrContext*) const { return nullptr; }
     53 
     54     virtual bool onAsLegacyBitmap(SkBitmap*, LegacyBitmapMode) const;
     55 
     56     virtual bool onIsLazyGenerated() const { return false; }
     57 
     58     // Return a bitmap suitable for passing to image-filters
     59     // For now, that means wrapping textures into SkGrPixelRefs...
     60     virtual bool asBitmapForImageFilters(SkBitmap* bitmap) const {
     61         return this->getROPixels(bitmap, kAllow_CachingHint);
     62     }
     63 
     64     // Call when this image is part of the key to a resourcecache entry. This allows the cache
     65     // to know automatically those entries can be purged when this SkImage deleted.
     66     void notifyAddedToCache() const {
     67         fAddedToCache.store(true);
     68     }
     69 
     70 private:
     71     // Set true by caches when they cache content that's derived from the current pixels.
     72     mutable SkAtomic<bool> fAddedToCache;
     73 
     74     typedef SkImage INHERITED;
     75 };
     76 
     77 static inline SkImage_Base* as_IB(SkImage* image) {
     78     return static_cast<SkImage_Base*>(image);
     79 }
     80 
     81 static inline const SkImage_Base* as_IB(const SkImage* image) {
     82     return static_cast<const SkImage_Base*>(image);
     83 }
     84 
     85 #endif
     86