Introduce GrColorSpaceXform, for gamut conversion on textures

include/gpu/GrTextureAccess.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrTextureAccess_DEFINED
 #define GrTextureAccess_DEFINED
 
+#include "GrColorSpaceXform.h"
 #include "GrGpuResourceRef.h"
 #include "GrTexture.h"
 #include "GrTextureParams.h"
 #include "SkRefCnt.h"
 #include "SkShader.h"
 
 /** 
  * Used to represent a texture that is required by a GrProcessor. It holds a GrTexture along with
  * an associated GrTextureParams
  */
 class GrTextureAccess : public SkNoncopyable {

[bsalomon, 2016/07/15 15:09:24]

What do you think about having a constructor for this that doesn't take a xform
(and uses identity)? Too easy to forget to do the right thing when writing a new
effect?

[Brian Osman, 2016/07/15 15:29:01]

That was my thought process - I'd sure like to have these default to nullptr so
you don't need to always supply it - but even for this process of catching all
uses of the call-tree, I really needed to make it mandatory. I'm not strongly
opposed - it trades the ability to forget for much cleaner code in all the
places that we know it's never an issue (like any code path that's drawing
masks).

 public:
     /**
      * Must be initialized before adding to a GrProcessor's texture access list.
      */
     GrTextureAccess();
 
-    GrTextureAccess(GrTexture*, const GrTextureParams&);
+    GrTextureAccess(GrTexture*, sk_sp<GrColorSpaceXform> colorSpaceXform, const GrTextureParams&);
 
-    explicit GrTextureAccess(GrTexture*,
+    explicit GrTextureAccess(GrTexture*, sk_sp<GrColorSpaceXform> colorSpaceXform,
                              GrTextureParams::FilterMode = GrTextureParams::kNone_FilterMode,
                              SkShader::TileMode tileXAndY = SkShader::kClamp_TileMode,
                              GrShaderFlags visibility = kFragment_GrShaderFlag);
 
-    void reset(GrTexture*, const GrTextureParams&,
+    void reset(GrTexture*, sk_sp<GrColorSpaceXform> colorSpaceXform, const GrTextureParams&,
                GrShaderFlags visibility = kFragment_GrShaderFlag);
-    void reset(GrTexture*,
+    void reset(GrTexture*, sk_sp<GrColorSpaceXform> colorSpaceXform,
                GrTextureParams::FilterMode = GrTextureParams::kNone_FilterMode,
                SkShader::TileMode tileXAndY = SkShader::kClamp_TileMode,
                GrShaderFlags visibility = kFragment_GrShaderFlag);
 
     bool operator==(const GrTextureAccess& that) const {
         return this->getTexture() == that.getTexture() &&
                fParams == that.fParams &&
-               fVisibility == that.fVisibility;
+               fVisibility == that.fVisibility &&
+               fColorSpaceXform == that.fColorSpaceXform;
     }
 
     bool operator!=(const GrTextureAccess& other) const { return !(*this == other); }
 
     GrTexture* getTexture() const { return fTexture.get(); }
     GrShaderFlags getVisibility() const { return fVisibility; }
+    GrColorSpaceXform* getColorSpaceXform() const { return fColorSpaceXform.get(); }
 
     /**
      * For internal use by GrProcessor.
      */
     const GrGpuResourceRef* getProgramTexture() const { return &fTexture; }
 
     const GrTextureParams& getParams() const { return fParams; }
 
 private:
 
     typedef GrTGpuResourceRef<GrTexture> ProgramTexture;
 
     ProgramTexture                  fTexture;
     GrTextureParams                 fParams;
     GrShaderFlags                   fVisibility;
+    sk_sp<GrColorSpaceXform>        fColorSpaceXform;
 
     typedef SkNoncopyable INHERITED;
 };
 
 #endif