Key shader on whether frag pos read is relative to top-left or bottom-left

src/gpu/gl/GrGLShaderBuilder.cpp

Index: src/gpu/gl/GrGLShaderBuilder.cpp
diff --git a/src/gpu/gl/GrGLShaderBuilder.cpp b/src/gpu/gl/GrGLShaderBuilder.cpp
index 98d7e4c97e80e486b9e837211fdff8a2e2939e0e..d15c974b2497f3c2a77c69d4b321056c5df3d383 100644
--- a/src/gpu/gl/GrGLShaderBuilder.cpp
+++ b/src/gpu/gl/GrGLShaderBuilder.cpp
@@ -112,7 +112,8 @@ GrGLShaderBuilder::GrGLShaderBuilder(const GrGLContextInfo& ctxInfo,
     , fSetupFragPosition(false)
     , fRTHeightUniform(GrGLUniformManager::kInvalidUniformHandle)
     , fDstCopyTopLeftUniform (GrGLUniformManager::kInvalidUniformHandle)
-    , fDstCopyScaleUniform (GrGLUniformManager::kInvalidUniformHandle) {
+    , fDstCopyScaleUniform (GrGLUniformManager::kInvalidUniformHandle)
+    , fTopLeftFragPosRead(kTopLeftFragPosRead_FragPosKey == desc.fFragPos) {
 
     fPositionVar = &fVSAttrs.push_back();
     fPositionVar->set(kVec2f_GrSLType, GrGLShaderVar::kAttribute_TypeModifier, "aPosition");
@@ -351,6 +352,14 @@ GrGLShaderBuilder::DstReadKey GrGLShaderBuilder::KeyForDstRead(const GrTexture*
     return static_cast<DstReadKey>(key);
 }
 

[robertphillips, 2013/05/10 13:53:58]

// Note: this method only be called if the fragment position is required

[bsalomon, 2013/05/13 15:16:49]

done (in the header)

+GrGLShaderBuilder::FragPosKey GrGLShaderBuilder::KeyForFragmentPosition(const GrRenderTarget* dst,
+                                                                        const GrGLCaps&) {
+    return kTopLeft_GrSurfaceOrigin == dst->origin() ?

[robertphillips, 2013/05/10 13:53:58]

rm space?

[bsalomon, 2013/05/13 15:16:49]

Changed to if/else.

+                                        kTopLeftFragPosRead_FragPosKey :
+                                        kBottomLeftFragPosRead_FragPosKey;
+}
+
+
 const GrGLenum* GrGLShaderBuilder::GetTexParamSwizzle(GrPixelConfig config, const GrGLCaps& caps) {
     if (caps.textureSwizzleSupport() && GrPixelConfigIsAlphaOnly(config)) {
         if (caps.textureRedSupport()) {
@@ -473,8 +482,16 @@ const char* GrGLShaderBuilder::fragmentPosition() {
             return "";
         }
     }
-#if 1
-    if (fCtxInfo.caps()->fragCoordConventionsSupport()) {
+    if (fTopLeftFragPosRead) {
+        if (!fSetupFragPosition) {
+            fFSInputs.push_back().set(kVec4f_GrSLType,
+                                      GrGLShaderVar::kIn_TypeModifier,
+                                      "gl_FragCoord",
+                                      GrGLShaderVar::kDefault_Precision);
+            fSetupFragPosition = true;
+        }
+        return "gl_FragCoord";
+    } else if (fCtxInfo.caps()->fragCoordConventionsSupport()) {
         if (!fSetupFragPosition) {
             SkAssertResult(this->enablePrivateFeature(kFragCoordConventions_GLSLPrivateFeature));
             fFSInputs.push_back().set(kVec4f_GrSLType,
@@ -506,18 +523,6 @@ const char* GrGLShaderBuilder::fragmentPosition() {
         GrAssert(GrGLUniformManager::kInvalidUniformHandle != fRTHeightUniform);
         return kCoordName;
     }
-#else
-    // This is the path we'll need to use once we have support for TopLeft
-    // render targets.
-    if (!fSetupFragPosition) {
-        fFSInputs.push_back().set(kVec4f_GrSLType,
-                                  GrGLShaderVar::kIn_TypeModifier,
-                                  "gl_FragCoord",
-                                  GrGLShaderVar::kDefault_Precision);
-        fSetupFragPosition = true;
-    }
-    return "gl_FragCoord";
-#endif
 }