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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     /**
     22      *  Returns a texture that is safe for use with the params. If the size of the returned texture
     23      *  does not match width()/height() then the contents of the original must be scaled to fit
     24      *  the texture. Additionally, the 'scaleAdjust' must be applied to the texture matrix
     25      *  in order to correct the absolute texture coordinates.
     26      *  Places the color space of the texture in (*texColorSpace).
     27      */
     28     sk_sp<GrTextureProxy> refTextureProxyForParams(const GrSamplerState&,
     29                                                    SkColorSpace* dstColorSpace,
     30                                                    sk_sp<SkColorSpace>* texColorSpace,
     31                                                    SkScalar scaleAdjust[2]);
     32 
     33     std::unique_ptr<GrFragmentProcessor> createFragmentProcessor(
     34             const SkMatrix& textureMatrix,
     35             const SkRect& constraintRect,
     36             FilterConstraint filterConstraint,
     37             bool coordsLimitedToConstraintRect,
     38             const GrSamplerState::Filter* filterOrNullForBicubic,
     39             SkColorSpace* dstColorSpace) override;
     40 
     41 protected:
     42     GrTextureMaker(GrContext* context, int width, int height, bool isAlphaOnly)
     43         : INHERITED(width, height, isAlphaOnly)
     44         , fContext(context) {}
     45 
     46     /**
     47      *  Return the maker's "original" texture. It is the responsibility of the maker to handle any
     48      *  caching of the original if desired.
     49      *  If "genType" argument equals AllowedTexGenType::kCheap and the texture is not trivial to
     50      *  construct then refOriginalTextureProxy should return nullptr (for example if texture is made
     51      *  by drawing into a render target).
     52      */
     53     virtual sk_sp<GrTextureProxy> refOriginalTextureProxy(bool willBeMipped,
     54                                                           SkColorSpace* dstColorSpace,
     55                                                           AllowedTexGenType genType) = 0;
     56 
     57     /**
     58      *  Returns the color space of the maker's "original" texture, assuming it was retrieved with
     59      *  the same destination color space.
     60      */
     61     virtual sk_sp<SkColorSpace> getColorSpace(SkColorSpace* dstColorSpace) = 0;
     62 
     63     /**
     64      *  Return a new (uncached) texture that is the stretch of the maker's original.
     65      *
     66      *  The base-class handles general logic for this, and only needs access to the following
     67      *  method:
     68      *  - refOriginalTextureProxy()
     69      *
     70      *  Subclass may override this if they can handle creating the texture more directly than
     71      *  by copying.
     72      */
     73     virtual sk_sp<GrTextureProxy> generateTextureProxyForParams(const CopyParams&,
     74                                                                 bool willBeMipped,
     75                                                                 SkColorSpace* dstColorSpace);
     76 
     77     GrContext* context() const { return fContext; }
     78 
     79 private:
     80     GrContext*  fContext;
     81 
     82     typedef GrTextureProducer INHERITED;
     83 };
     84 
     85 #endif
     86