Add a class representing texture swizzle.

src/gpu/glsl/GrGLSLCaps.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 GrGLSLCaps_DEFINED
 #define GrGLSLCaps_DEFINED
 
 #include "GrCaps.h"
 #include "GrGLSL.h"
+#include "GrSwizzle.h"
 
 class GrGLSLCaps : public GrShaderCaps {
 public:
     
 
     /**
     * Indicates how GLSL must interact with advanced blend equations. The KHR extension requires
     * special layout qualifiers in the fragment shader.
     */
     enum AdvBlendEqInteraction {
@@ skipping 73 matching lines @@
     // extension is required. However, the return value of this function does not say whether dual
     // source blending is supported.
     const char* secondaryOutputExtensionString() const {
         return fSecondaryOutputExtensionString;
     }
 
     const char* externalTextureExtensionString() const {
         return fExternalTextureExtensionString;
     }
 
-    bool mustSwizzleInShader() const { return fMustSwizzleInShader; }
-
     /**
-     * Returns a string which represents how to map from an internal GLFormat to a given
-     * GrPixelConfig. The function mustSwizzleInShader determines whether this swizzle is applied
-     * in the generated shader code or using sample state in the 3D API.
+     * Given a texture's config, this determines what swizzle must be appended to accesses to the
+     * texture in generated shader code. Swizzling may be implemented in texture parameters or a
+     * sampler rather than in the shader. In this case the shader swizzle will always be "rgba".
      */
-    const char* getSwizzleMap(GrPixelConfig config) const { return fConfigSwizzle[config]; }
+    const GrSwizzle& configTextureSwizzle(GrPixelConfig config) const {
+        return fConfigTextureSwizzle[config];
+    }
 
     GrGLSLGeneration generation() const { return fGLSLGeneration; }
 
     /**
     * Returns a string containing the caps info.
     */
     SkString dump() const override;
 
 private:
     void onApplyOptionsOverrides(const GrContextOptions& options) override;
@@ skipping 16 matching lines @@
     const char* fShaderDerivativeExtensionString;
     const char* fFragCoordConventionsExtensionString;
     const char* fSecondaryOutputExtensionString;
     const char* fExternalTextureExtensionString;
 
     const char* fFBFetchColorName;
     const char* fFBFetchExtensionString;
 
     AdvBlendEqInteraction fAdvBlendEqInteraction;
 
-    bool        fMustSwizzleInShader;
-    const char* fConfigSwizzle[kGrPixelConfigCnt];
+    GrSwizzle fConfigTextureSwizzle[kGrPixelConfigCnt];
 
     friend class GrGLCaps;  // For initialization.
 
     typedef GrShaderCaps INHERITED;
 };
 
-
 #endif