Make GrGLConfigConversionEffect work for Imagination and some other GPUs.

src/gpu/effects/GrConfigConversionEffect.cpp

Index: src/gpu/effects/GrConfigConversionEffect.cpp
diff --git a/src/gpu/effects/GrConfigConversionEffect.cpp b/src/gpu/effects/GrConfigConversionEffect.cpp
index f33ad239c518b1de5f98ccec29e02394670a9dd0..5f33ae244a99b7cc23dae5c4d7897ab7190ed98b 100644
--- a/src/gpu/effects/GrConfigConversionEffect.cpp
+++ b/src/gpu/effects/GrConfigConversionEffect.cpp
@@ -29,6 +29,8 @@ public:
                           const char* inputColor,
                           const TransformedCoordsArray& coords,
                           const TextureSamplerArray& samplers) SK_OVERRIDE {
+        const char* outputColorH = "outputColorH";
+        builder->fsCodeAppendf("\thighp vec4 %s;\n", outputColorH);
         builder->fsCodeAppendf("\t\t%s = ", outputColor);
         builder->fsAppendTextureLookup(samplers[0], coords[0].c_str(), coords[0].type());
         builder->fsCodeAppend(";\n");
@@ -37,6 +39,7 @@ public:
             builder->fsCodeAppendf("\t%s = %s.bgra;\n", outputColor, outputColor);
         } else {
             const char* swiz = fSwapRedAndBlue ? "bgr" : "rgb";
+            builder->fsCodeAppendf("\t\t%s = %s;\n", outputColorH, outputColor);

[bsalomon, 2014/07/07 13:21:39]

Can we only emit this if one of the highp shaders is in use?

[changjun.yang, 2014/07/08 02:33:59]

Done.

             switch (fPMConversion) {
                 case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
                     builder->fsCodeAppendf(
@@ -60,6 +63,28 @@ public:
                     builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
                         outputColor, outputColor, outputColor, swiz, outputColor, outputColor);
                     break;
+                case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion_HIGHP:
+                    builder->fsCodeAppendf(
+                        "\t\t%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);\n",
+                        outputColorH, outputColorH, swiz, outputColorH, outputColorH);
+                    builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor, outputColorH);
+                    break;
+                case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion_HIGHP:
+                    builder->fsCodeAppendf(
+                        "\t\t%s = vec4(floor(%s.%s * %s.a * 255.0) / 255.0, %s.a);\n",
+                        outputColorH, outputColorH, swiz, outputColorH, outputColorH);
+                    builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor, outputColorH);
+                    break;
+                case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion_HIGHP:
+                    builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
+                        outputColorH, outputColorH, outputColorH, swiz, outputColorH, outputColorH);
+                    builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor, outputColorH);
+                    break;
+                case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion_HIGHP:
+                    builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
+                        outputColorH, outputColorH, outputColorH, swiz, outputColorH, outputColorH);
+                    builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor, outputColorH);
+                    break;
                 default:
                     SkFAIL("Unknown conversion op.");
                     break;
@@ -184,6 +209,8 @@ void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context
     static const PMConversion kConversionRules[][2] = {
         {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
         {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
+        {kDivByAlpha_RoundDown_PMConversion_HIGHP, kMulByAlpha_RoundUp_PMConversion_HIGHP},
+        {kDivByAlpha_RoundUp_PMConversion_HIGHP, kMulByAlpha_RoundDown_PMConversion_HIGHP},
     };
 
     GrContext::AutoWideOpenIdentityDraw awoid(context, NULL);