Pixel shaders support MRT output.

src/common/version.h

 #define MAJOR_VERSION 1
 #define MINOR_VERSION 1
 #define BUILD_VERSION 0
-#define BUILD_REVISION 1987
+#define BUILD_REVISION 1988
 
 #define STRINGIFY(x) #x
 #define MACRO_STRINGIFY(x) STRINGIFY(x)

src/compiler/OutputHLSL.cpp

@@ -217,7 +217,18 @@ void OutputHLSL::header()
         out << "// Varyings\n";
         out <<  varyings;
         out << "\n"
-               "static float4 gl_Color[1] = {float4(0, 0, 0, 0)};\n";
+               "static float4 gl_Color[" << numColorValues << "] =\n"
+               "{\n";
+        for (unsigned int i = 0; i < numColorValues; i++)
+        {
+            out << "    float4(0, 0, 0, 0)";
+            if (i + 1 != numColorValues)
+            {
+                out << ",";
+            }
+            out << "\n";
+        }
+        out << "};\n";
 
         if (mUsesFragCoord)
         {

src/libGLESv2/ProgramBinary.cpp

@@ -1162,6 +1162,15 @@ bool ProgramBinary::linkVaryings(InfoLog &infoLog, int registers, const Varying
         return false;
     }
 
+    bool usesMRT = fragmentShader->mUsesMultipleRenderTargets;
+    bool usesFragColor = fragmentShader->mUsesFragColor;
+    bool usesFragData = fragmentShader->mUsesFragData;
+    if (usesMRT && usesFragColor && usesFragData)
+    {
+        infoLog.append("Cannot use both gl_FragColor and gl_FragData in the same fragment shader.");
+        return false;
+    }
+
     // Write the HLSL input/output declarations
     const int shaderModel = mRenderer->getMajorShaderModel();
     const int maxVaryingVectors = mRenderer->getMaxVaryingVectors();
@@ -1213,6 +1222,8 @@ bool ProgramBinary::linkVaryings(InfoLog &infoLog, int registers, const Varying
     std::string targetSemantic = (shaderModel >= 4) ? "SV_Target" : "COLOR";
     std::string positionSemantic = (shaderModel >= 4) ? "SV_Position" : "POSITION";
 
+    const unsigned int renderTargetCount = usesMRT ? mRenderer->getMaxRenderTargets() : 1;
+
     // special varyings that use reserved registers
     int reservedRegisterIndex = registers;
     std::string fragCoordSemantic;
@@ -1459,11 +1470,16 @@ bool ProgramBinary::linkVaryings(InfoLog &infoLog, int registers, const Varying
     pixelHLSL += "};\n"
                  "\n"
                  "struct PS_OUTPUT\n"
-                 "{\n"
-                 "    float4 gl_Color[1] : " + targetSemantic + ";\n"
-                 "};\n"
+                 "{\n";
+
+    for (unsigned int i = 0; i < renderTargetCount; i++)
+    {
+        pixelHLSL += "    float4 gl_Color" + str(i) + " : " + targetSemantic + str(i) + ";\n";
+    }
+
+    pixelHLSL += "};\n"
                  "\n";
-    
+
     if (fragmentShader->mUsesFrontFacing)
     {
         if (shaderModel >= 4)
@@ -1565,9 +1581,16 @@ bool ProgramBinary::linkVaryings(InfoLog &infoLog, int registers, const Varying
     pixelHLSL += "\n"
                  "    gl_main();\n"
                  "\n"
-                 "    PS_OUTPUT output;\n"                 
-                 "    output.gl_Color[0] = gl_Color[0];\n"
-                 "\n"
+                 "    PS_OUTPUT output;\n";
+
+    for (unsigned int i = 0; i < renderTargetCount; i++)
+    {
+        unsigned int sourceColor = fragmentShader->mUsesFragData ? i : 0;
+
+        pixelHLSL += "    output.gl_Color" + str(i) + " = gl_Color[" + str(sourceColor) + "];\n";
+    }
+
+    pixelHLSL += "\n"
                  "    return output;\n"
                  "}\n";