Merge changes from The Witness for iOS.

- Added better support for out and inout arguments in the MSL generator. Instead of passing these by reference, output arguments are wrapped in a temporary structure that's passed as return value. To make this work, the corresponding function call arguments need to be flattened and transformed into a list of statements.
- Added support for sample_id semantic.
- Added support for half, with an option to treat half as float in MSL. Support for half required better handling of type casts, since in many cases casts were not implicit as in HLSL.
- Added support for treating integers as 16 bit integers (int -> short, uint->usrhot).
- The generated MSL output is a bit cleaner and some unnecessary parenthesis have been removed.
- Fixed support for some const declarations.
- There's some work in progress to add support for static if and some new hlsl features that didn't make it for the iOS release.

Author: castano

src/GLSLGenerator.cpp

@@ -447,7 +447,7 @@ void GLSLGenerator::OutputExpressionList(HLSLExpression* expression, HLSLArgumen
 
 const HLSLType* commonScalarType(const HLSLType& lhs, const HLSLType& rhs)
 {
-    if (!isScalarType(lhs) || !isScalarType(rhs))
+    if (!IsScalarType(lhs) || !IsScalarType(rhs))
         return NULL;
 
     if (lhs.baseType == HLSLBaseType_Float || lhs.baseType == HLSLBaseType_Half ||
@@ -571,8 +571,8 @@ void GLSLGenerator::OutputExpression(HLSLExpression* expression, const HLSLType*
         const HLSLType* dstType2 = NULL;
 
 		//
-		bool vectorExpression = isVectorType( binaryExpression->expression1->expressionType ) || isVectorType( binaryExpression->expression2->expressionType );
-		if( vectorExpression && isCompareOp( binaryExpression->binaryOp ))
+		bool vectorExpression = IsVectorType( binaryExpression->expression1->expressionType ) || IsVectorType( binaryExpression->expression2->expressionType );
+		if( vectorExpression && IsCompareOp( binaryExpression->binaryOp ))
 		{
 			switch (binaryExpression->binaryOp)
 			{
@@ -586,9 +586,9 @@ void GLSLGenerator::OutputExpression(HLSLExpression* expression, const HLSLType*
 				ASSERT(0); // is so, check isCompareOp
 			}
 
-			if( isVectorType( binaryExpression->expression1->expressionType ) && isScalarType( binaryExpression->expression2->expressionType ) )
+			if( IsVectorType( binaryExpression->expression1->expressionType ) && IsScalarType( binaryExpression->expression2->expressionType ) )
 				dstType2 = &binaryExpression->expression1->expressionType;
-			else if( isScalarType( binaryExpression->expression1->expressionType ) && isVectorType( binaryExpression->expression2->expressionType ) )
+			else if( IsScalarType( binaryExpression->expression1->expressionType ) && IsVectorType( binaryExpression->expression2->expressionType ) )
 				dstType1 = &binaryExpression->expression2->expressionType;
 			// TODO if both expressions are vector but with different dimension handle it here or in parser?
 
@@ -619,8 +619,8 @@ void GLSLGenerator::OutputExpression(HLSLExpression* expression, const HLSLType*
 			case HLSLBinaryOp_And:          op = " && "; dstType1 = dstType2 = &binaryExpression->expressionType; break;
 			case HLSLBinaryOp_Or:           op = " || "; dstType1 = dstType2 = &binaryExpression->expressionType; break;
 			case HLSLBinaryOp_BitAnd:       op = " & "; dstType1 = dstType2 = commonScalarType(binaryExpression->expression1->expressionType, binaryExpression->expression2->expressionType); break;
-			case HLSLBinaryOp_BitOr:	op = " | "; dstType1 = dstType2 = commonScalarType(binaryExpression->expression1->expressionType, binaryExpression->expression2->expressionType); break;
-			case HLSLBinaryOp_BitXor:	op = " ^ "; dstType1 = dstType2 = commonScalarType(binaryExpression->expression1->expressionType, binaryExpression->expression2->expressionType); break;
+			case HLSLBinaryOp_BitOr:        op = " | "; dstType1 = dstType2 = commonScalarType(binaryExpression->expression1->expressionType, binaryExpression->expression2->expressionType); break;
+			case HLSLBinaryOp_BitXor:       op = " ^ "; dstType1 = dstType2 = commonScalarType(binaryExpression->expression1->expressionType, binaryExpression->expression2->expressionType); break;
 			default:
 				ASSERT(0);
 			}
@@ -634,7 +634,7 @@ void GLSLGenerator::OutputExpression(HLSLExpression* expression, const HLSLType*
     else if (expression->nodeType == HLSLNodeType_ConditionalExpression)
     {
         HLSLConditionalExpression* conditionalExpression = static_cast<HLSLConditionalExpression*>(expression);
-		if( isVectorType( conditionalExpression->condition->expressionType ) )
+		if( IsVectorType( conditionalExpression->condition->expressionType ) )
 		{
 			m_writer.Write( "%s", m_bvecTernary );
 			m_writer.Write( "( " );

src/HLSLGenerator.cpp

@@ -32,15 +32,15 @@ static const char* GetTypeName(const HLSLType& type)
     case HLSLBaseType_Float4x4:     return "float4x4";
     case HLSLBaseType_Float4x3:     return "float4x3";
     case HLSLBaseType_Float4x2:     return "float4x2";
-    case HLSLBaseType_Half:         return "half";
-    case HLSLBaseType_Half2:        return "half2";
-    case HLSLBaseType_Half3:        return "half3";
-    case HLSLBaseType_Half4:        return "half4";
-	case HLSLBaseType_Half2x2:      return "half2x2";
-    case HLSLBaseType_Half3x3:      return "half3x3";
-    case HLSLBaseType_Half4x4:      return "half4x4";
-    case HLSLBaseType_Half4x3:      return "half4x3";
-    case HLSLBaseType_Half4x2:      return "half4x2";
+    case HLSLBaseType_Half:        return "float";
+    case HLSLBaseType_Half2:       return "float2";
+    case HLSLBaseType_Half3:       return "float3";
+    case HLSLBaseType_Half4:       return "float4";
+    case HLSLBaseType_Half2x2:     return "float2x2";
+    case HLSLBaseType_Half3x3:     return "float3x3";
+    case HLSLBaseType_Half4x4:     return "float4x4";
+    case HLSLBaseType_Half4x3:     return "float4x3";
+    case HLSLBaseType_Half4x2:     return "float4x2";
     case HLSLBaseType_Bool:         return "bool";
 	case HLSLBaseType_Bool2:        return "bool2";
 	case HLSLBaseType_Bool3:        return "bool3";
@@ -750,6 +750,8 @@ void HLSLGenerator::OutputArguments(HLSLArgument* argument)
         case HLSLArgumentModifier_Uniform:
             m_writer.Write("uniform ");
             break;
+        default:
+            break;
         }
 
         const char * semantic = argument->sv_semantic ? argument->sv_semantic : argument->semantic;