Prevent atan2 from generating a NaN

src/compiler/OutputHLSL.cpp

@@ -50,6 +50,7 @@ OutputHLSL::OutputHLSL(TParseContext &context) : TIntermTraverser(true, true, tr
     mUsesEqualBVec2 = false;
     mUsesEqualBVec3 = false;
     mUsesEqualBVec4 = false;
+    mUsesAtan2 = false;
 
     mArgumentIndex = 0;
 }
@@ -675,6 +676,15 @@ void OutputHLSL::header()
                "    return v.x == u.x && v.y == u.y && v.z == u.z && v.w == u.w;\n"
                "}\n";
     }
+
+    if (mUsesAtan2)
+    {
+        out << "float atanyx(float y, float x)\n"
+               "{\n"
+               "    if(x == 0 && y == 0) x = 1;\n"   // Avoid producing a NaN
+               "    return atan2(y, x);\n"
+               "}\n";
+    }
 }
 
 void OutputHLSL::footer()
@@ -1450,15 +1460,9 @@ bool OutputHLSL::visitAggregate(Visit visit, TIntermAggregate *node)
       case EOpMod:              outputTriplet(visit, "mod(", ", ", ")");               break;
       case EOpPow:              outputTriplet(visit, "pow(", ", ", ")");               break;
       case EOpAtan:
-        if (node->getSequence().size() == 1)
-        {
-            outputTriplet(visit, "atan(", ", ", ")");
-        }
-        else if (node->getSequence().size() == 2)
-        {
-            outputTriplet(visit, "atan2(", ", ", ")");
-        }
-        else UNREACHABLE();
+        ASSERT(node->getSequence().size() == 2);   // atan(x) is a unary operator
+        mUsesAtan2 = true;
+        outputTriplet(visit, "atanyx(", ", ", ")");
         break;
       case EOpMin:           outputTriplet(visit, "min(", ", ", ")");           break;
       case EOpMax:           outputTriplet(visit, "max(", ", ", ")");           break;

src/compiler/OutputHLSL.h

@@ -89,6 +89,7 @@ class OutputHLSL : public TIntermTraverser
     bool mUsesEqualBVec2;
     bool mUsesEqualBVec3;
     bool mUsesEqualBVec4;
+    bool mUsesAtan2;
 
     struct Constructor   // Describes a constructor signature
     {

src/libGLESv2/Program.cpp

@@ -895,7 +895,7 @@ ID3DXBuffer *Program::compileToBinary(const char *hlsl, const char *profile, ID3
     ID3DXBuffer *binary = NULL;
     ID3DXBuffer *errorMessage = NULL;
 
-    HRESULT result = D3DXCompileShader(hlsl, (UINT)strlen(hlsl), NULL, 0, "main", profile, 0, &binary, &errorMessage, constantTable);
+    HRESULT result = D3DXCompileShader(hlsl, (UINT)strlen(hlsl), NULL, NULL, "main", profile, 0, &binary, &errorMessage, constantTable);
 
     if (SUCCEEDED(result))
     {