Method constructBuiltIn

glslang/MachineIndependent/ParseHelper.cpp:9949–10328

Function for constructor implementation. Calls addUnaryMath with appropriate EOp value for the parameter to the constructor (passed to this function). Essentially, it converts the parameter types correctly. If a constructor expects an int (like ivec2) and is passed a float, then float is converted to int. Returns nullptr for an error or the constructed node.

// Returns nullptr for an error or the constructed node.
//
TIntermTyped* TParseContext::constructBuiltIn(const TType& type, TOperator op, TIntermTyped* node, const TSourceLoc& loc,
    bool subset)
{
    // If we are changing a matrix in both domain of basic type and to a non matrix,
    // do the shape change first (by default, below, basic type is changed before shape).
    // This avoids requesting a matrix of a new type that is going to be discarded anyway.
    // TODO: This could be generalized to more type combinations, but that would require
    // more extensive testing and full algorithm rework. For now, the need to do two changes makes
    // the recursive call work, and avoids the most egregious case of creating integer matrices.
    if (node->getType().isMatrix() && (type.isScalar() || type.isVector()) &&
            type.isFloatingDomain() != node->getType().isFloatingDomain()) {
        TType transitionType(node->getBasicType(), glslang::EvqTemporary, type.getVectorSize(), 0, 0, node->isVector());
        TOperator transitionOp = intermediate.mapTypeToConstructorOp(transitionType);
        node = constructBuiltIn(transitionType, transitionOp, node, loc, false);
    }

    TIntermTyped* newNode;
    TOperator basicOp;

    //
    // First, convert types as needed.
    //
    switch (op) {
    case EOpConstructVec2:
    case EOpConstructVec3:
    case EOpConstructVec4:
    case EOpConstructMat2x2:
    case EOpConstructMat2x3:
    case EOpConstructMat2x4:
    case EOpConstructMat3x2:
    case EOpConstructMat3x3:
    case EOpConstructMat3x4:
    case EOpConstructMat4x2:
    case EOpConstructMat4x3:
    case EOpConstructMat4x4:
    case EOpConstructFloat:
        basicOp = EOpConstructFloat;
        break;

    case EOpConstructIVec2:
    case EOpConstructIVec3:
    case EOpConstructIVec4:
    case EOpConstructInt:
        basicOp = EOpConstructInt;
        break;

    case EOpConstructUVec2:
        if (node->getType().getBasicType() == EbtReference) {
            requireExtensions(loc, 1, &E_GL_EXT_buffer_reference_uvec2, "reference conversion to uvec2");
            TIntermTyped* newNode = intermediate.addBuiltInFunctionCall(node->getLoc(), EOpConvPtrToUvec2, true, node,
                type);
            return newNode;
        } else if (node->getType().getBasicType() == EbtSampler) {
            requireExtensions(loc, 1, &E_GL_ARB_bindless_texture, "sampler conversion to uvec2");
            // force the basic type of the constructor param to uvec2, otherwise spv builder will
            // report some errors
            TIntermTyped* newSrcNode = intermediate.createConversion(EbtUint, node);
            newSrcNode->getAsTyped()->getWritableType().setVectorSize(2);