Make GPU coord transforms automatic

src/gpu/gl/GrGLShaderBuilder.h

Index: src/gpu/gl/GrGLShaderBuilder.h
diff --git a/src/gpu/gl/GrGLShaderBuilder.h b/src/gpu/gl/GrGLShaderBuilder.h
index d73a731a7cd9aaf52d7518d5dfb66413553740b8..7ddf46f9872548e0ca89f1b17fd2bfd5121430c1 100644
--- a/src/gpu/gl/GrGLShaderBuilder.h
+++ b/src/gpu/gl/GrGLShaderBuilder.h
@@ -13,6 +13,7 @@
 #include "GrColor.h"
 #include "GrEffect.h"
 #include "SkTypes.h"
+#include "gl/GrGLCoordTransform.h"
 #include "gl/GrGLSL.h"
 #include "gl/GrGLUniformManager.h"
 
@@ -96,8 +97,10 @@ public:
         friend class GrGLShaderBuilder; // to call init().
     };
 
+    typedef SkTArray<GrGLCoordTransform::TransformedCoords> TransformedCoordsArray;
     typedef SkTArray<TextureSampler> TextureSamplerArray;
     typedef GrTAllocator<GrGLShaderVar> VarArray;
+    typedef GrBackendEffectFactory::EffectKey EffectKey;
 
     enum ShaderVisibility {
         kVertex_Visibility   = 0x1,
@@ -175,8 +178,7 @@ public:
     /** Generates a EffectKey for the shader code based on the texture access parameters and the
         capabilities of the GL context.  This is useful for keying the shader programs that may
         have multiple representations, based on the type/format of textures used. */
-    static GrBackendEffectFactory::EffectKey KeyForTextureAccess(const GrTextureAccess&,
-                                                                 const GrGLCaps&);
+    static EffectKey KeyForTextureAccess(const GrTextureAccess&, const GrGLCaps&);
 
     typedef uint8_t DstReadKey;
     typedef uint8_t FragPosKey;
@@ -225,6 +227,13 @@ public:
         return this->getUniformVariable(u).c_str();
     }
 
+    /**
+     * This returns a variable name to access the 2D, perspective correct version of the coords in
+     * the fragment shader. If the coordinates at index are 3-dimensional, it emits a perspective
+     * divide (xy / z) to convert them to 2D.
+     */
+    SkString ensureFSCoords2D(const TransformedCoordsArray&, int index);

[bsalomon, 2013/09/27 20:04:25]

Might want to document that this may emit code into the FS so some unknowning
caller doesn't invoke it when they've emitted a half-finished line of code.

[Chris Dalton, 2013/09/27 23:33:45]

Done.

+
     /** Returns a variable name that represents the position of the fragment in the FS. The position
         is in device space (e.g. 0,0 is the top left and pixel centers are at half-integers). */
     const char* fragmentPosition();
@@ -255,10 +264,11 @@ public:
      * effectStages.
      */
     void emitEffects(const GrEffectStage* effectStages[],
-                     const GrBackendEffectFactory::EffectKey effectKeys[],
+                     const EffectKey effectKeys[],
                      int effectCnt,
                      SkString*  inOutFSColor,
                      GrSLConstantVec* fsInOutColorKnownValue,
+                     SkTArray<GrGLCoordTransform, false>* effectCoordTransformArrays[],
                      SkTArray<GrGLUniformManager::UniformHandle, true>* effectSamplerHandles[],
                      GrGLEffect* glEffects[]);