Get offset of field within struct used in StructuredBuffer

[zopsicle]

Given a shader parameter of type StructuredBuffer<S>, where S is a struct, is it possible to obtain offsets of fields within S, using reflection?

I got this far:

Slang::ComPtr<slang::IComponentType> program;
compile_request->getProgram(program.writeRef());

auto program_layout = program->getLayout();

auto parameter_count = program_layout->getParameterCount();
for (auto i : std::ranges::views::iota(0u, parameter_count)) {
    auto parameter = program_layout->getParameterByIndex(i);
    std::cout
        << parameter->getName() << ' '
        << parameter->getCategory() << ' '
        << parameter->getBindingIndex() << '\n';
    auto element_type = parameter->getType()->getElementType();
    if (element_type->getKind() == slang::TypeReflection::Kind::Struct) {
        auto field_count = element_type->getFieldCount();
        for (auto j : std::ranges::views::iota(0u, field_count)) {
            auto field = element_type->getFieldByIndex(j);
            std::cout
                << "    "
                << field->getName() << ' '
                << field->getType()->getName() << '\n';
        }
    }
}

This prints the name and type of each field of each struct used in a structured buffer parameter. However, field->getType() returns TypeReflection*, not TypeLayoutReflection*, which seems to be necessary to get offset and stride information.

[zopsicle]

Ah, I found it! Simply use getTypeLayout instead of getType on parameter:

auto element_type = parameter->getTypeLayout()->getElementTypeLayout();