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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 
     14 class GrContext;
     15 class GrTexture;
     16 
     17 /**
     18  *  There are at least 2 different ways to extract/retrieve YUV planar data...
     19  *  - SkPixelRef
     20  *  - SkImageGeneartor
     21  *
     22  *  To share common functionality around using the planar data, we use this abstract base-class
     23  *  to represent accessing that data.
     24  */
     25 class GrYUVProvider {
     26 public:
     27     virtual ~GrYUVProvider() {}
     28 
     29     /**
     30      *  On success, this returns a texture that has converted the YUV data from the provider
     31      *  into a form that is supported by the GPU (typically transformed into RGB). If useCache
     32      *  is true, then the texture will automatically have a key added, so it can be retrieved
     33      *  from the cache (assuming it is requested by a provider w/ the same genID).
     34      *
     35      *  On failure (e.g. the provider had no data), this returns NULL.
     36      */
     37     GrTexture* refAsTexture(GrContext*, const GrSurfaceDesc&, bool useCache);
     38 
     39     virtual uint32_t onGetID() = 0;
     40 
     41     enum {
     42         kY_Index = 0,
     43         kU_Index = 1,
     44         kV_Index = 2,
     45 
     46         kPlaneCount = 3
     47     };
     48 
     49     // These are not meant to be called by a client, only by the implementation
     50 
     51     /**
     52      *  Return the 3 dimensions for each plane and return true. On failure, return false and
     53      *  ignore the sizes parameter. Typical failure is that the provider does not contain YUV
     54      *  data, and may just be an RGB src.
     55      */
     56     virtual bool onGetYUVSizes(SkISize sizes[kPlaneCount]) = 0;
     57 
     58     /**
     59      *  On success, return true, and set sizes, rowbytes and colorspace to the appropriate values.
     60      *  planes[] will have already been allocated by the client (based on the worst-case sizes
     61      *  returned by onGetYUVSizes(). This method copies its planar data into those buffers.
     62      *
     63      *  On failure, return false and ignore other parameters.
     64      */
     65     virtual bool onGetYUVPlanes(SkISize sizes[kPlaneCount], void* planes[kPlaneCount],
     66                                 size_t rowBytes[kPlaneCount], SkYUVColorSpace*) = 0;
     67 };
     68 
     69 #endif
     70