Proper support for fragment output variables for GLSL ES shader version 300.

TRAC #22704

Signed-off-by: Geoff Lang
Signed-off-by: Nicolas Capens
Authored-by: Jamie Madill

include/GLSLANG/ShaderLang.h

@@ -37,7 +37,7 @@ extern "C" {
 
 // Version number for shader translation API.
 // It is incremented everytime the API changes.
-#define ANGLE_SH_VERSION 113
+#define ANGLE_SH_VERSION 114
 
 //
 // The names of the following enums have been derived by replacing GL prefix
@@ -132,6 +132,7 @@ typedef enum {
   SH_ACTIVE_UNIFORMS_ARRAY       =  0x6004,
   SH_SHADER_VERSION              =  0x6005,
   SH_ACTIVE_INTERFACE_BLOCKS_ARRAY =  0x6006,
+  SH_ACTIVE_OUTPUT_VARIABLES_ARRAY =  0x6007,
 } ShShaderInfo;
 
 // Compile options.

src/compiler/OutputHLSL.cpp

@@ -156,6 +156,11 @@ const ActiveInterfaceBlocks &OutputHLSL::getInterfaceBlocks() const
     return mActiveInterfaceBlocks;
 }
 
+const ActiveShaderVariables &OutputHLSL::getOutputVariables() const
+{
+    return mActiveOutputVariables;
+}
+
 int OutputHLSL::vectorSize(const TType &type) const
 {
     int elementSize = type.isMatrix() ? type.getCols() : 1;
@@ -391,23 +396,44 @@ void OutputHLSL::header()
         TExtensionBehavior::const_iterator iter = mContext.extensionBehavior().find("GL_EXT_draw_buffers");
         const bool usingMRTExtension = (iter != mContext.extensionBehavior().end() && (iter->second == EBhEnable || iter->second == EBhRequire));
 
-        const unsigned int numColorValues = usingMRTExtension ? mNumRenderTargets : 1;
-
         out << "// Varyings\n";
         out <<  varyings;
-        out << "\n"
-               "static float4 gl_Color[" << numColorValues << "] =\n"
-               "{\n";
-        for (unsigned int i = 0; i < numColorValues; i++)
+        out << "\n";
+
+        if (mContext.getShaderVersion() >= 300)
         {
-            out << "    float4(0, 0, 0, 0)";
-            if (i + 1 != numColorValues)
+            for (auto outputVariableIt = mReferencedOutputVariables.begin(); outputVariableIt != mReferencedOutputVariables.end(); outputVariableIt++)
             {
-                out << ",";
+                const TString &variableName = outputVariableIt->first;
+                const TType &variableType = outputVariableIt->second->getType();
+                const TLayoutQualifier &layoutQualifier = variableType.getLayoutQualifier();
+
+                out << "static " + typeString(variableType) + " out_" + variableName + arrayString(variableType) +
+                       " = " + initializer(variableType) + ";\n";
+
+                ShaderVariable outputVar(glVariableType(variableType), glVariablePrecision(variableType), variableName.c_str(),
+                                         (unsigned int)variableType.getArraySize(), layoutQualifier.location);
+                mActiveOutputVariables.push_back(outputVar);
             }
-            out << "\n";
         }
-        out << "};\n";
+        else
+        {
+            const unsigned int numColorValues = usingMRTExtension ? mNumRenderTargets : 1;
+
+            out << "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)
         {
@@ -1407,7 +1433,12 @@ void OutputHLSL::visitSymbol(TIntermSymbol *node)
             mReferencedVaryings[name] = node;
             out << decorate(name);
         }
-        else if (qualifier == EvqFragColor || qualifier == EvqFragmentOutput)
+        else if (qualifier == EvqFragmentOutput)
+        {
+            mReferencedOutputVariables[name] = node;
+            out << "out_" << name;
+        }
+        else if (qualifier == EvqFragColor)
         {
             out << "gl_Color[0]";
             mUsesFragColor = true;

src/compiler/OutputHLSL.h

@@ -34,6 +34,7 @@ class OutputHLSL : public TIntermTraverser
     TInfoSinkBase &getBodyStream();
     const ActiveUniforms &getUniforms();
     const ActiveInterfaceBlocks &getInterfaceBlocks() const;
+    const ActiveShaderVariables &getOutputVariables() const;
 
     TString typeString(const TType &type);
     TString textureString(const TType &type);
@@ -88,6 +89,7 @@ class OutputHLSL : public TIntermTraverser
     ReferencedSymbols mReferencedInterfaceBlocks;
     ReferencedSymbols mReferencedAttributes;
     ReferencedSymbols mReferencedVaryings;
+    ReferencedSymbols mReferencedOutputVariables;
 
     // Parameters determining what goes in the header output
     bool mUsesTexture2D;
@@ -192,6 +194,7 @@ class OutputHLSL : public TIntermTraverser
 
     ActiveUniforms mActiveUniforms;
     ActiveInterfaceBlocks mActiveInterfaceBlocks;
+    ActiveShaderVariables mActiveOutputVariables;
 };
 }
 

src/compiler/ParseHelper.cpp

@@ -2028,6 +2028,11 @@ TIntermTyped* TParseContext::addIndexExpression(TIntermTyped *baseExpression, TS
                 error(location, "", "[", "array indexes for interface blocks arrays must be constant integeral expressions");
                 recover();
             }
+            else if (baseExpression->getQualifier() == EvqFragmentOutput)
+            {
+                error(location, "", "[", "array indexes for output variables must be constant integeral expressions");
+                recover();
+            }
 
             indexedExpression = intermediate.addIndex(EOpIndexIndirect, baseExpression, indexExpression, location);
         }

src/compiler/ShaderLang.cpp

@@ -379,6 +379,9 @@ void ShGetInfoPointer(const ShHandle handle, ShShaderInfo pname, void** params)
     case SH_ACTIVE_INTERFACE_BLOCKS_ARRAY:
         *params = (void*)&translator->getInterfaceBlocks();
         break;
+    case SH_ACTIVE_OUTPUT_VARIABLES_ARRAY:
+        *params = (void*)&translator->getOutputVariables();
+        break;
     default: UNREACHABLE();
     }
 }

src/compiler/TranslatorHLSL.cpp

@@ -22,4 +22,5 @@ void TranslatorHLSL::translate(TIntermNode *root)
     outputHLSL.output();
     mActiveUniforms = outputHLSL.getUniforms();
     mActiveInterfaceBlocks = outputHLSL.getInterfaceBlocks();
+    mActiveOutputVariables = outputHLSL.getOutputVariables();
 }

src/compiler/TranslatorHLSL.h

@@ -17,12 +17,14 @@ public:
     virtual TranslatorHLSL *getAsTranslatorHLSL() { return this; }
     const sh::ActiveUniforms &getUniforms() { return mActiveUniforms; }
     const sh::ActiveInterfaceBlocks &getInterfaceBlocks() const { return mActiveInterfaceBlocks; }
+    const sh::ActiveShaderVariables &getOutputVariables() { return mActiveOutputVariables; }
 
 protected:
     virtual void translate(TIntermNode* root);
 
     sh::ActiveUniforms mActiveUniforms;
     sh::ActiveInterfaceBlocks mActiveInterfaceBlocks;
+    sh::ActiveShaderVariables mActiveOutputVariables;
     ShShaderOutput mOutputType;
 };
 

src/compiler/Uniform.cpp

@@ -11,6 +11,15 @@
 namespace sh
 {
 
+ShaderVariable::ShaderVariable(GLenum type, GLenum precision, const char *name, unsigned int arraySize, int location)
+    : type(type),
+      precision(precision),
+      name(name),
+      arraySize(arraySize),
+      location(location)
+{
+}
+
 Uniform::Uniform(GLenum type, GLenum precision, const char *name, unsigned int arraySize, unsigned int registerIndex)
 {
     this->type = type;

src/compiler/Uniform.h

@@ -17,6 +17,19 @@
 namespace sh
 {
 
+struct ShaderVariable
+{
+    ShaderVariable(GLenum type, GLenum precision, const char *name, unsigned int arraySize, int location);
+
+    GLenum type;
+    GLenum precision;
+    std::string name;
+    unsigned int arraySize;
+    int location;
+};
+
+typedef std::vector<ShaderVariable> ActiveShaderVariables;
+
 struct Uniform
 {
     Uniform(GLenum type, GLenum precision, const char *name, unsigned int arraySize, unsigned int registerIndex);

src/libGLESv2/ProgramBinary.cpp

@@ -41,6 +41,11 @@ std::string arrayString(int i)
     return "[" + str(i) + "]";
 }
 
+std::string arrayString(unsigned int i)
+{
+    return (i == GL_INVALID_INDEX ? "" : "[" + str(i) + "]");
+}
+
 namespace gl_d3d
 {
     std::string TypeString(GLenum type)
@@ -1055,6 +1060,32 @@ int ProgramBinary::packVaryings(InfoLog &infoLog, const Varying *packing[][4], F
     return registers;
 }
 
+void ProgramBinary::defineOutputVariables(FragmentShader *fragmentShader)
+{
+    const sh::ActiveShaderVariables &outputVars = fragmentShader->getOutputVariables();
+
+    for (unsigned int outputVariableIndex = 0; outputVariableIndex < outputVars.size(); outputVariableIndex++)
+    {
+        const sh::ShaderVariable &outputVariable = outputVars[outputVariableIndex];
+        const int baseLocation = outputVariable.location == -1 ? 0 : outputVariable.location;
+
+        if (outputVariable.arraySize > 0)
+        {
+            for (unsigned int elementIndex = 0; elementIndex < outputVariable.arraySize; elementIndex++)
+            {
+                const int location = baseLocation + elementIndex;
+                ASSERT(mOutputVariables.count(location) == 0);
+                mOutputVariables[location] = VariableLocation(outputVariable.name, elementIndex, outputVariableIndex);
+            }
+        }
+        else
+        {
+            ASSERT(mOutputVariables.count(baseLocation) == 0);
+            mOutputVariables[baseLocation] = VariableLocation(outputVariable.name, GL_INVALID_INDEX, outputVariableIndex);
+        }
+    }
+}
+
 bool ProgramBinary::linkVaryings(InfoLog &infoLog, int registers, const Varying *packing[][4],
                                  std::string& pixelHLSL, std::string& vertexHLSL,
                                  FragmentShader *fragmentShader, VertexShader *vertexShader)
@@ -1355,9 +1386,28 @@ bool ProgramBinary::linkVaryings(InfoLog &infoLog, int registers, const Varying
                  "struct PS_OUTPUT\n"
                  "{\n";
 
-    for (unsigned int renderTargetIndex = 0; renderTargetIndex < numRenderTargets; renderTargetIndex++)
+    if (mShaderVersion < 300)
     {
-        pixelHLSL += "    float4 gl_Color" + str(renderTargetIndex) + " : " + targetSemantic + str(renderTargetIndex) + ";\n";
+        for (unsigned int renderTargetIndex = 0; renderTargetIndex < numRenderTargets; renderTargetIndex++)
+        {
+            pixelHLSL += "    float4 gl_Color" + str(renderTargetIndex) + " : " + targetSemantic + str(renderTargetIndex) + ";\n";
+        }
+    }
+    else
+    {
+        defineOutputVariables(fragmentShader);
+
+        const sh::ActiveShaderVariables &outputVars = fragmentShader->getOutputVariables();
+        for (auto locationIt = mOutputVariables.begin(); locationIt != mOutputVariables.end(); locationIt++)
+        {
+            const VariableLocation &outputLocation = locationIt->second;
+            const sh::ShaderVariable &outputVariable = outputVars[outputLocation.index];
+            const std::string &elementString = (outputLocation.element == GL_INVALID_INDEX ? "" : str(outputLocation.element));
+
+            pixelHLSL += "    " + gl_d3d::TypeString(outputVariable.type) +
+                         " out_" + outputLocation.name + elementString +
+                         " : " + targetSemantic + str(locationIt->first) + ";\n";
+        }
     }
 
     pixelHLSL += "};\n"
@@ -1473,11 +1523,26 @@ bool ProgramBinary::linkVaryings(InfoLog &infoLog, int registers, const Varying
                  "\n"
                  "    PS_OUTPUT output;\n";
 
-    for (unsigned int renderTargetIndex = 0; renderTargetIndex < numRenderTargets; renderTargetIndex++)
+    if (mShaderVersion < 300)
     {
-        unsigned int sourceColorIndex = broadcast ? 0 : renderTargetIndex;
+        for (unsigned int renderTargetIndex = 0; renderTargetIndex < numRenderTargets; renderTargetIndex++)
+        {
+            unsigned int sourceColorIndex = broadcast ? 0 : renderTargetIndex;
 
-        pixelHLSL += "    output.gl_Color" + str(renderTargetIndex) + " = gl_Color[" + str(sourceColorIndex) + "];\n";
+            pixelHLSL += "    output.gl_Color" + str(renderTargetIndex) + " = gl_Color[" + str(sourceColorIndex) + "];\n";
+        }
+    }
+    else
+    {
+        for (auto locationIt = mOutputVariables.begin(); locationIt != mOutputVariables.end(); locationIt++)
+        {
+            const VariableLocation &outputLocation = locationIt->second;
+            const std::string &variableName = "out_" + outputLocation.name;
+            const std::string &outVariableName = variableName + (outputLocation.element == GL_INVALID_INDEX ? "" : str(outputLocation.element));
+            const std::string &staticVariableName = variableName + arrayString(outputLocation.element);
+
+            pixelHLSL += "    output." + outVariableName + " = " + staticVariableName + ";\n";
+        }
     }
 
     pixelHLSL += "\n"

src/libGLESv2/ProgramBinary.h

@@ -164,7 +164,8 @@ class ProgramBinary : public RefCountObject
     void defineUniformBlockMembers(const sh::ActiveUniforms &uniforms, const std::string &prefix, int blockIndex, BlockInfoItr *blockInfoItr, std::vector<unsigned int> *blockUniformIndexes);
     bool defineUniformBlock(InfoLog &infoLog, GLenum shader, const sh::InterfaceBlock &interfaceBlock);
     bool assignUniformBlockRegister(InfoLog &infoLog, UniformBlock *uniformBlock, GLenum shader, unsigned int registerIndex);
-    
+    void defineOutputVariables(FragmentShader *fragmentShader);
+
     std::string generateGeometryShaderHLSL(int registers, const Varying *packing[][4], FragmentShader *fragmentShader, VertexShader *vertexShader) const;
     std::string generatePointSpriteHLSL(int registers, const Varying *packing[][4], FragmentShader *fragmentShader, VertexShader *vertexShader) const;
 
@@ -206,6 +207,8 @@ class ProgramBinary : public RefCountObject
     UniformBlockArray mUniformBlocks;
     typedef std::vector<VariableLocation> UniformIndex;
     UniformIndex mUniformIndex;
+    typedef std::map<int, VariableLocation> ShaderVariableIndex;
+    ShaderVariableIndex mOutputVariables;
 
     bool mValidated;
 

src/libGLESv2/Shader.cpp

@@ -706,5 +706,26 @@ void FragmentShader::compile()
     compileToHLSL(mFragmentCompiler);
     parseVaryings();
     mVaryings.sort(compareVarying);
+
+    const char *hlsl = getHLSL();
+    if (hlsl)
+    {
+        void *activeOutputVariables;
+        ShGetInfoPointer(mFragmentCompiler, SH_ACTIVE_OUTPUT_VARIABLES_ARRAY, &activeOutputVariables);
+        mActiveOutputVariables = *(sh::ActiveShaderVariables*)activeOutputVariables;
+    }
 }
+
+void FragmentShader::uncompile()
+{
+    Shader::uncompile();
+
+    mActiveOutputVariables.clear();
+}
+
+const sh::ActiveShaderVariables &FragmentShader::getOutputVariables() const
+{
+    return mActiveOutputVariables;
+}
+
 }

src/libGLESv2/Shader.h

@@ -188,9 +188,13 @@ class FragmentShader : public Shader
 
     virtual GLenum getType();
     virtual void compile();
+    virtual void uncompile();
+    const sh::ActiveShaderVariables &getOutputVariables() const;
 
   private:
     DISALLOW_COPY_AND_ASSIGN(FragmentShader);
+
+    sh::ActiveShaderVariables mActiveOutputVariables;
 };
 }