Question about Parameter Block Reflection API (Vulkan) about slang HOT 5 CLOSED

I updated the documentation. Removed out of date doc on the API. Please check the user guide for the compilation and reflection API.

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You are right, it should be SUB_ELEMENT_REGISTER_SPACE. I have updated the documentation here: https://shader-slang.com/slang/user-guide/reflection.html

You are right that the "binding" for ordinary uniforms are byte offsets for that uniform in the constant buffer. All global uniforms are placed in a default constant buffer that has the same binding. You can query the binding with getGlobalConstantBufferBinding.

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When I add more parameters as follows:

uniform float a;
uniform float b;
ParameterBlock<Buffers> buffers;
ParameterBlock<Buffers> buffers2;

The GLSL is again what I'd expect (with a and b being located in the default set 0 now, and the parameter blocks occupying sets 1 and 2 respectively. However, again using the same loop as before, I see the following being printed:

set 0, binding 0: float a                                                                                               
set 0, binding 4: float b                                                                                               
set 0, binding 1: ParameterBlock buffers                                                                                
set 0, binding 2: ParameterBlock buffers2      

For some more context, I'm directly using Slang as a submodule (at the latest commit as of right now), and I'm using this as the target description:

slang::TargetDesc target_info = {
    .format = SLANG_SPIRV,
    .profile = global_session_->findProfile("glsl_450"),
    .flags = SLANG_TARGET_FLAG_GENERATE_SPIRV_DIRECTLY,
};

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You also need to add the result from calling variable->getOffset(SLANG_PARAMETER_CATEGORY_REGISTER_SPACE).

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Thank you for the quick response! I found that SLANG_PARAMETER_CATEGORY_SUB_ELEMENT_REGISTER_SPACE seems to provide the expected result over SLANG_PARAMETER_CATEGORY_REGISTER_SPACE. Or is it necessary to add both of them together?

In both cases, I'm still seeing the uniform float b having an index of 4 even though I'd expect it to have an index of 1 in the default set. Is there also an offset I should be adding to the index as well?

EDIT: I see the documentation mentions that the index is actually the byte offset in its parent if the type is a Uniform. Will all "ordinary" resources be bound to the same uniform?

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