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      1 /*
      2  * Copyright 2015 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 GrYUVProvider_DEFINED
      9 #define GrYUVProvider_DEFINED
     10 
     11 #include "GrTypes.h"
     12 #include "SkImageInfo.h"
     13 #include "SkYUVSizeInfo.h"
     14 
     15 class GrContext;
     16 class GrTexture;
     17 class GrTextureProxy;
     18 
     19 /**
     20  *  There are at least 2 different ways to extract/retrieve YUV planar data...
     21  *  - SkPixelRef
     22  *  - SkImageGenerator
     23  *
     24  *  To share common functionality around using the planar data, we use this abstract base-class
     25  *  to represent accessing that data.
     26  */
     27 class GrYUVProvider {
     28 public:
     29     virtual ~GrYUVProvider() {}
     30 
     31     /**
     32      *  On success, this returns a texture proxy that has converted the YUV data from the provider
     33      *  into a form that is supported by the GPU (typically transformed into RGB). The texture will
     34      *  automatically have a key added, so it can be retrieved from the cache (assuming it is
     35      *  requested by a provider w/ the same genID). If srcColorSpace and dstColorSpace are
     36      *  specified, then a color conversion from src to dst will be applied to the pixels.
     37      *
     38      *  On failure (e.g. the provider had no data), this returns NULL.
     39      */
     40     sk_sp<GrTextureProxy> refAsTextureProxy(GrContext*, const GrSurfaceDesc&,
     41                                             const SkColorSpace* srcColorSpace,
     42                                             const SkColorSpace* dstColorSpace);
     43 
     44     virtual uint32_t onGetID() = 0;
     45 
     46     // These are not meant to be called by a client, only by the implementation
     47 
     48     /**
     49      *  If decoding to YUV is supported, this returns true.  Otherwise, this
     50      *  returns false and does not modify any of the parameters.
     51      *
     52      *  @param sizeInfo   Output parameter indicating the sizes and required
     53      *                    allocation widths of the Y, U, and V planes.
     54      *  @param colorSpace Output parameter.
     55      */
     56     virtual bool onQueryYUV8(SkYUVSizeInfo* sizeInfo, SkYUVColorSpace* colorSpace) const = 0;
     57 
     58     /**
     59      *  Returns true on success and false on failure.
     60      *  This always attempts to perform a full decode.  If the client only
     61      *  wants size, it should call onQueryYUV8().
     62      *
     63      *  @param sizeInfo   Needs to exactly match the values returned by the
     64      *                    query, except the WidthBytes may be larger than the
     65      *                    recommendation (but not smaller).
     66      *  @param planes     Memory for each of the Y, U, and V planes.
     67      */
     68     virtual bool onGetYUV8Planes(const SkYUVSizeInfo& sizeInfo, void* planes[3]) = 0;
     69 };
     70 
     71 #endif
     72