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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 GrTextureMaker_DEFINED
      9 #define GrTextureMaker_DEFINED
     10 
     11 #include "GrTextureProducer.h"
     12 
     13 /**
     14  * Base class for sources that start out as something other than a texture (encoded image,
     15  * picture, ...).
     16  */
     17 class GrTextureMaker : public GrTextureProducer {
     18 public:
     19     enum class AllowedTexGenType : bool { kCheap, kAny };
     20 
     21     std::unique_ptr<GrFragmentProcessor> createFragmentProcessor(
     22             const SkMatrix& textureMatrix,
     23             const SkRect& constraintRect,
     24             FilterConstraint filterConstraint,
     25             bool coordsLimitedToConstraintRect,
     26             const GrSamplerState::Filter* filterOrNullForBicubic,
     27             SkColorSpace* dstColorSpace) override;
     28 
     29 protected:
     30     GrTextureMaker(GrContext* context, int width, int height, bool isAlphaOnly)
     31         : INHERITED(width, height, isAlphaOnly)
     32         , fContext(context) {}
     33 
     34     /**
     35      *  Return the maker's "original" texture. It is the responsibility of the maker to handle any
     36      *  caching of the original if desired.
     37      *  If "genType" argument equals AllowedTexGenType::kCheap and the texture is not trivial to
     38      *  construct then refOriginalTextureProxy should return nullptr (for example if texture is made
     39      *  by drawing into a render target).
     40      */
     41     virtual sk_sp<GrTextureProxy> refOriginalTextureProxy(bool willBeMipped,
     42                                                           SkColorSpace* dstColorSpace,
     43                                                           AllowedTexGenType genType) = 0;
     44 
     45     /**
     46      *  Returns the color space of the maker's "original" texture, assuming it was retrieved with
     47      *  the same destination color space.
     48      */
     49     virtual sk_sp<SkColorSpace> getColorSpace(SkColorSpace* dstColorSpace) = 0;
     50 
     51     /**
     52      *  Return a new (uncached) texture that is the stretch of the maker's original.
     53      *
     54      *  The base-class handles general logic for this, and only needs access to the following
     55      *  method:
     56      *  - refOriginalTextureProxy()
     57      *
     58      *  Subclass may override this if they can handle creating the texture more directly than
     59      *  by copying.
     60      */
     61     virtual sk_sp<GrTextureProxy> generateTextureProxyForParams(const CopyParams&,
     62                                                                 bool willBeMipped,
     63                                                                 SkColorSpace* dstColorSpace);
     64 
     65     GrContext* context() const { return fContext; }
     66 
     67 private:
     68     sk_sp<GrTextureProxy> onRefTextureProxyForParams(const GrSamplerState&,
     69                                                      SkColorSpace* dstColorSpace,
     70                                                      sk_sp<SkColorSpace>* proxyColorSpace,
     71                                                      SkScalar scaleAdjust[2]) override;
     72 
     73     GrContext*  fContext;
     74 
     75     typedef GrTextureProducer INHERITED;
     76 };
     77 
     78 #endif
     79