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

src/gpu/gl/GrGLShaderBuilder.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gl/GrGLShaderBuilder.h"
 #include "gl/GrGLProgram.h"
 #include "gl/GrGLUniformHandle.h"
@@ skipping 94 matching lines @@
     , fUniformManager(uniformManager)
     , fFSFeaturesAddedMask(0)
 #if GR_GL_EXPERIMENTAL_GS
     , fUsesGS(desc.fExperimentalGS)
 #else
     , fUsesGS(false)
 #endif
     , 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");
     if (-1 != desc.fLocalCoordAttributeIndex) {
         fLocalCoordsVar = &fVSAttrs.push_back();
         fLocalCoordsVar->set(kVec2f_GrSLType,
                              GrGLShaderVar::kAttribute_TypeModifier,
                              "aLocalCoords");
     } else {
         fLocalCoordsVar = fPositionVar;
@@ skipping 217 matching lines @@
     if (!caps.textureSwizzleSupport() && GrPixelConfigIsAlphaOnly(dstCopy->config())) {
         // The fact that the config is alpha-only must be considered when generating code.
         key |= kUseAlphaConfig_DstReadKeyBit;
     }
     if (kTopLeft_GrSurfaceOrigin == dstCopy->origin()) {
         key |= kTopLeftOrigin_DstReadKeyBit;
     }
     GrAssert(static_cast<DstReadKey>(key) == key);
     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()) {
             static const GrGLenum gRedSmear[] = { GR_GL_RED, GR_GL_RED, GR_GL_RED, GR_GL_RED };
             return gRedSmear;
         } else {
             static const GrGLenum gAlphaSmear[] = { GR_GL_ALPHA, GR_GL_ALPHA,
                                                     GR_GL_ALPHA, GR_GL_ALPHA };
             return gAlphaSmear;
         }
@@ skipping 102 matching lines @@
 
 const char* GrGLShaderBuilder::fragmentPosition() {
     if (fCodeStage.inStageCode()) {
         const GrEffectRef& effect = *fCodeStage.effectStage()->getEffect();
         if (!effect->willReadFragmentPosition()) {
             GrDebugCrash("GrGLEffect asked for frag position but its generating GrEffect "
                          "did not request access.");
             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,
                                       GrGLShaderVar::kIn_TypeModifier,
                                       "gl_FragCoord",
                                       GrGLShaderVar::kDefault_Precision,
                                       GrGLShaderVar::kUpperLeft_Origin);
             fSetupFragPosition = true;
         }
         return "gl_FragCoord";
@@ skipping 11 matching lines @@
                                                 "RTHeight",
                                                 &rtHeightName);
 
             this->fFSCode.prependf("\tvec4 %s = vec4(gl_FragCoord.x, %s - gl_FragCoord.y, gl_FragCoord.zw);\n",
                                    kCoordName, rtHeightName);
             fSetupFragPosition = true;
         }
         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
 }
 
 
 void GrGLShaderBuilder::emitFunction(ShaderType shader,
                                      GrSLType returnType,
                                      const char* name,
                                      int argCnt,
                                      const GrGLShaderVar* args,
                                      const char* body,
                                      SkString* outName) {
@@ skipping 191 matching lines @@
     for (const AttributePair* attrib = this->getEffectAttributes().begin();
          attrib != attribEnd;
          ++attrib) {
         if (attrib->fIndex == attributeIndex) {
             return &attrib->fName;
         }
     }
 
     return NULL;
 }