Function ArithmeticOpResultType

hlslparser/src/HLSLParser.cpp:1531–1579

static bool _initIntrinsics = InitIntrinsics();

HLSLBaseType ArithmeticOpResultType(HLSLBinaryOp binaryOp, HLSLBaseType t1, HLSLBaseType t2)
{
    // check that both are same numeric types

    // add, sub, div are similar
    // mul is it's own test

    // most mixing of types is invalid here

    if (IsNumericTypeEqual(t1, t2)) {
        bool isSameDimensions = IsDimensionEqual(t1, t2);

        if (IsScalarType(t1) && IsScalarType(t2)) {
            if (isSameDimensions) return t1;
        }
        else if (IsVectorType(t1) && IsVectorType(t2)) {
            if (isSameDimensions) return t1;
        }
        else if (IsMatrixType(t1) && IsMatrixType(t2)) {
            if (isSameDimensions) return t1;
        }

        else if ((binaryOp == HLSLBinaryOp_Add || binaryOp == HLSLBinaryOp_Sub) &&
                 (IsScalarType(t1) || IsScalarType(t2))) {
            // allow v + 1, and 1 - v
            return (IsVectorType(t1) || IsMatrixType(t1)) ? t1 : t2;
        }

        else if ((binaryOp == HLSLBinaryOp_Mul || binaryOp == HLSLBinaryOp_Div) &&
                 (IsScalarType(t1) || IsScalarType(t2))) {
            // v * s
            return (IsVectorType(t1) || IsMatrixType(t1)) ? t1 : t2;
        }

        // this has to check dimension across the mul
        else if (binaryOp == HLSLBinaryOp_Mul) {
            bool isSameCrossDimension = IsCrossDimensionEqual(t1, t2);

            if (IsMatrixType(t1) && IsVectorType(t2)) {
                if (isSameCrossDimension) return t2;
            }
            else if (IsVectorType(t1) && IsMatrixType(t2)) {
                if (isSameCrossDimension) return t1;
            }
        }
    }

    return HLSLBaseType_Unknown;
}

// Priority of the ? : operator.
const int _conditionalOpPriority = 1;