gecko/gfx/angle/angle-faceforward-emu.patch

From: Jeff Gilbert <jgilbert@mozilla.com>
Bug 771406 - Add emulation for GLSL faceforward() to ANGLE - r=bjacob

diff --git a/gfx/angle/src/compiler/BuiltInFunctionEmulator.cpp b/gfx/angle/src/compiler/BuiltInFunctionEmulator.cpp
--- a/gfx/angle/src/compiler/BuiltInFunctionEmulator.cpp
+++ b/gfx/angle/src/compiler/BuiltInFunctionEmulator.cpp
@@ -26,16 +26,22 @@ const char* kFunctionEmulationVertexSour
     "#error no emulation for distance(vec3, vec3)",
     "#error no emulation for distance(vec4, vec4)",
 
     "#define webgl_dot_emu(x, y) ((x) * (y))",
     "#error no emulation for dot(vec2, vec2)",
     "#error no emulation for dot(vec3, vec3)",
     "#error no emulation for dot(vec4, vec4)",
 
+    // |faceforward(N, I, Nref)| is |dot(NRef, I) < 0 ? N : -N|
+    "#define webgl_faceforward_emu(N, I, Nref) (((Nref) * (I) < 0.0) ? (N) : -(N))",
+    "#error no emulation for faceforward(vec2, vec2, vec2)",
+    "#error no emulation for faceforward(vec3, vec3, vec3)",
+    "#error no emulation for faceforward(vec4, vec4, vec4)",
+
     "#define webgl_length_emu(x) ((x) >= 0.0 ? (x) : -(x))",
     "#error no emulation for length(vec2)",
     "#error no emulation for length(vec3)",
     "#error no emulation for length(vec4)",
 
     "#define webgl_normalize_emu(x) ((x) == 0.0 ? 0.0 : ((x) > 0.0 ? 1.0 : -1.0))",
     "#error no emulation for normalize(vec2)",
     "#error no emulation for normalize(vec3)",
@@ -58,16 +64,22 @@ const char* kFunctionEmulationFragmentSo
     "#error no emulation for distance(vec3, vec3)",
     "#error no emulation for distance(vec4, vec4)",
 
     "#define webgl_dot_emu(x, y) ((x) * (y))",
     "#error no emulation for dot(vec2, vec2)",
     "#error no emulation for dot(vec3, vec3)",
     "#error no emulation for dot(vec4, vec4)",
 
+    // |faceforward(N, I, Nref)| is |dot(NRef, I) < 0 ? N : -N|
+    "#define webgl_faceforward_emu(N, I, Nref) (((Nref) * (I) < 0.0) ? (N) : -(N))",
+    "#error no emulation for faceforward(vec2, vec2, vec2)",
+    "#error no emulation for faceforward(vec3, vec3, vec3)",
+    "#error no emulation for faceforward(vec4, vec4, vec4)",
+
     "#define webgl_length_emu(x) ((x) >= 0.0 ? (x) : -(x))",
     "#error no emulation for length(vec2)",
     "#error no emulation for length(vec3)",
     "#error no emulation for length(vec4)",
 
     "#define webgl_normalize_emu(x) ((x) == 0.0 ? 0.0 : ((x) > 0.0 ? 1.0 : -1.0))",
     "#error no emulation for normalize(vec2)",
     "#error no emulation for normalize(vec3)",
@@ -89,16 +101,20 @@ const bool kFunctionEmulationVertexMask[
     true,  // TFunctionDistance1_1
     false, // TFunctionDistance2_2
     false, // TFunctionDistance3_3
     false, // TFunctionDistance4_4
     true,  // TFunctionDot1_1
     false, // TFunctionDot2_2
     false, // TFunctionDot3_3
     false, // TFunctionDot4_4
+    true,  // TFunctionFaceForward1_1_1
+    false, // TFunctionFaceForward2_2_2
+    false, // TFunctionFaceForward3_3_3
+    false, // TFunctionFaceForward4_4_4
     true,  // TFunctionLength1
     false, // TFunctionLength2
     false, // TFunctionLength3
     false, // TFunctionLength4
     true,  // TFunctionNormalize1
     false, // TFunctionNormalize2
     false, // TFunctionNormalize3
     false, // TFunctionNormalize4
@@ -115,16 +131,20 @@ const bool kFunctionEmulationVertexMask[
     false, // TFunctionDistance1_1
     false, // TFunctionDistance2_2
     false, // TFunctionDistance3_3
     false, // TFunctionDistance4_4
     false, // TFunctionDot1_1
     false, // TFunctionDot2_2
     false, // TFunctionDot3_3
     false, // TFunctionDot4_4
+    false, // TFunctionFaceForward1_1_1
+    false, // TFunctionFaceForward2_2_2
+    false, // TFunctionFaceForward3_3_3
+    false, // TFunctionFaceForward4_4_4
     false, // TFunctionLength1
     false, // TFunctionLength2
     false, // TFunctionLength3
     false, // TFunctionLength4
     false, // TFunctionNormalize1
     false, // TFunctionNormalize2
     false, // TFunctionNormalize3
     false, // TFunctionNormalize4
@@ -146,16 +166,20 @@ const bool kFunctionEmulationFragmentMas
     true,  // TFunctionDistance1_1
     false, // TFunctionDistance2_2
     false, // TFunctionDistance3_3
     false, // TFunctionDistance4_4
     true,  // TFunctionDot1_1
     false, // TFunctionDot2_2
     false, // TFunctionDot3_3
     false, // TFunctionDot4_4
+    true,  // TFunctionFaceForward1_1_1
+    false, // TFunctionFaceForward2_2_2
+    false, // TFunctionFaceForward3_3_3
+    false, // TFunctionFaceForward4_4_4
     true,  // TFunctionLength1
     false, // TFunctionLength2
     false, // TFunctionLength3
     false, // TFunctionLength4
     true,  // TFunctionNormalize1
     false, // TFunctionNormalize2
     false, // TFunctionNormalize3
     false, // TFunctionNormalize4
@@ -172,16 +196,20 @@ const bool kFunctionEmulationFragmentMas
     false, // TFunctionDistance1_1
     false, // TFunctionDistance2_2
     false, // TFunctionDistance3_3
     false, // TFunctionDistance4_4
     false, // TFunctionDot1_1
     false, // TFunctionDot2_2
     false, // TFunctionDot3_3
     false, // TFunctionDot4_4
+    false, // TFunctionFaceForward1_1_1
+    false, // TFunctionFaceForward2_2_2
+    false, // TFunctionFaceForward3_3_3
+    false, // TFunctionFaceForward4_4_4
     false, // TFunctionLength1
     false, // TFunctionLength2
     false, // TFunctionLength3
     false, // TFunctionLength4
     false, // TFunctionNormalize1
     false, // TFunctionNormalize2
     false, // TFunctionNormalize3
     false, // TFunctionNormalize4
@@ -239,25 +267,37 @@ public:
                 case EOpReflect:
                 case EOpRefract:
                 case EOpMul:
                     break;
                 default:
                     return true;
             };
             const TIntermSequence& sequence = node->getSequence();
-            // Right now we only handle built-in functions with two parameters.
-            if (sequence.size() != 2)
+            bool needToEmulate = false;
+
+            if (sequence.size() == 2) {
+                TIntermTyped* param1 = sequence[0]->getAsTyped();
+                TIntermTyped* param2 = sequence[1]->getAsTyped();
+                if (!param1 || !param2)
+                    return true;
+                needToEmulate = mEmulator.SetFunctionCalled(
+                    node->getOp(), param1->getType(), param2->getType());
+            } else if (sequence.size() == 3) {
+                TIntermTyped* param1 = sequence[0]->getAsTyped();
+                TIntermTyped* param2 = sequence[1]->getAsTyped();
+                TIntermTyped* param3 = sequence[2]->getAsTyped();
+                if (!param1 || !param2 || !param3)
+                    return true;
+                needToEmulate = mEmulator.SetFunctionCalled(
+                    node->getOp(), param1->getType(), param2->getType(), param3->getType());
+            } else {
                 return true;
-            TIntermTyped* param1 = sequence[0]->getAsTyped();
-            TIntermTyped* param2 = sequence[1]->getAsTyped();
-            if (!param1 || !param2)
-                return true;
-            bool needToEmulate = mEmulator.SetFunctionCalled(
-                node->getOp(), param1->getType(), param2->getType());
+            }
+
             if (needToEmulate)
                 node->setUseEmulatedFunction();
         }
         return true;
     }
 
 private:
     BuiltInFunctionEmulator& mEmulator;
@@ -286,16 +326,23 @@ bool BuiltInFunctionEmulator::SetFunctio
 bool BuiltInFunctionEmulator::SetFunctionCalled(
     TOperator op, const TType& param1, const TType& param2)
 {
     TBuiltInFunction function = IdentifyFunction(op, param1, param2);
     return SetFunctionCalled(function);
 }
 
 bool BuiltInFunctionEmulator::SetFunctionCalled(
+    TOperator op, const TType& param1, const TType& param2, const TType& param3)
+{
+    TBuiltInFunction function = IdentifyFunction(op, param1, param2, param3);
+    return SetFunctionCalled(function);
+}
+
+bool BuiltInFunctionEmulator::SetFunctionCalled(
     BuiltInFunctionEmulator::TBuiltInFunction function) {
     if (function == TFunctionUnknown || mFunctionMask[function] == false)
         return false;
     for (size_t i = 0; i < mFunctions.size(); ++i) {
         if (mFunctions[i] == function)
             return true;
     }
     mFunctions.push_back(function);
@@ -377,16 +424,44 @@ BuiltInFunctionEmulator::IdentifyFunctio
     }
     if (function == TFunctionUnknown)
         return TFunctionUnknown;
     if (param1.isVector())
         function += param1.getNominalSize() - 1;
     return static_cast<TBuiltInFunction>(function);
 }
 
+BuiltInFunctionEmulator::TBuiltInFunction
+BuiltInFunctionEmulator::IdentifyFunction(
+    TOperator op, const TType& param1, const TType& param2, const TType& param3)
+{
+    // Check that all params have the same type, length,
+    // and that they're not too large.
+    if (param1.isVector() != param2.isVector() ||
+        param2.isVector() != param3.isVector() ||
+        param1.getNominalSize() != param2.getNominalSize() ||
+        param2.getNominalSize() != param3.getNominalSize() ||
+        param1.getNominalSize() > 4)
+        return TFunctionUnknown;
+
+    unsigned int function = TFunctionUnknown;
+    switch (op) {
+        case EOpFaceForward:
+            function = TFunctionFaceForward1_1_1;
+            break;
+        default:
+            break;
+    }
+    if (function == TFunctionUnknown)
+        return TFunctionUnknown;
+    if (param1.isVector())
+        function += param1.getNominalSize() - 1;
+    return static_cast<TBuiltInFunction>(function);
+}
+
 void BuiltInFunctionEmulator::MarkBuiltInFunctionsForEmulation(
     TIntermNode* root)
 {
     ASSERT(root);
 
     BuiltInFunctionEmulationMarker marker(*this);
     root->traverse(&marker);
 }
diff --git a/gfx/angle/src/compiler/BuiltInFunctionEmulator.h b/gfx/angle/src/compiler/BuiltInFunctionEmulator.h
--- a/gfx/angle/src/compiler/BuiltInFunctionEmulator.h
+++ b/gfx/angle/src/compiler/BuiltInFunctionEmulator.h
@@ -23,16 +23,18 @@ public:
     // Records that a function is called by the shader and might needs to be
     // emulated.  If the function's group is not in mFunctionGroupFilter, this
     // becomes an no-op.
     // Returns true if the function call needs to be replaced with an emulated
     // one.
     bool SetFunctionCalled(TOperator op, const TType& param);
     bool SetFunctionCalled(
         TOperator op, const TType& param1, const TType& param2);
+    bool SetFunctionCalled(
+        TOperator op, const TType& param1, const TType& param2, const TType& param3);
 
     // Output function emulation definition.  This should be before any other
     // shader source.
     void OutputEmulatedFunctionDefinition(TInfoSinkBase& out, bool withPrecision) const;
 
     void MarkBuiltInFunctionsForEmulation(TIntermNode* root);
 
     void Cleanup();
@@ -55,16 +57,21 @@ private:
         TFunctionDistance3_3,  // vec3 distance(vec3, vec3);
         TFunctionDistance4_4,  // vec4 distance(vec4, vec4);
 
         TFunctionDot1_1,  // float dot(float, float);
         TFunctionDot2_2,  // vec2 dot(vec2, vec2);
         TFunctionDot3_3,  // vec3 dot(vec3, vec3);
         TFunctionDot4_4,  // vec4 dot(vec4, vec4);
 
+        TFunctionFaceForward1_1_1,  // float faceforward(float, float, float);
+        TFunctionFaceForward2_2_2,  // vec2 faceforward(vec2, vec2, vec2);
+        TFunctionFaceForward3_3_3,  // vec3 faceforward(vec3, vec3, vec3);
+        TFunctionFaceForward4_4_4,  // vec4 faceforward(vec4, vec4, vec4);
+
         TFunctionLength1,  // float length(float);
         TFunctionLength2,  // float length(vec2);
         TFunctionLength3,  // float length(vec3);
         TFunctionLength4,  // float length(vec4);
 
         TFunctionNormalize1,  // float normalize(float);
         TFunctionNormalize2,  // vec2 normalize(vec2);
         TFunctionNormalize3,  // vec3 normalize(vec3);
@@ -76,16 +83,18 @@ private:
         TFunctionReflect4_4,  // vec4 reflect(vec4, vec4);
 
         TFunctionUnknown
     };
 
     TBuiltInFunction IdentifyFunction(TOperator op, const TType& param);
     TBuiltInFunction IdentifyFunction(
         TOperator op, const TType& param1, const TType& param2);
+    TBuiltInFunction IdentifyFunction(
+        TOperator op, const TType& param1, const TType& param2, const TType& param3);
 
     bool SetFunctionCalled(TBuiltInFunction function);
 
     std::vector<TBuiltInFunction> mFunctions;
 
     const bool* mFunctionMask;  // a boolean flag for each function.
     const char** mFunctionSource;
 };