Fix Vulkan constant buffer reflection data parsing by ThomasFOG · Pull Request #8941

Fix Vulkan constant buffer reflection data parsing by ThomasFOG · Pull Request #8941 · MonoGame/MonoGame

This fixes a regression introduced by #8544 in Vulkan constant buffers parsing.

This should repair shader building and usage (notably the stock shaders).

		// First gather the uniforms.
		VkStruct globals;
		if (structs.TryGetValue("%type__Globals", out globals))
		if (structs.TryGetValue("%type__MG_Globals", out globals))

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I would be fine with this, and that would allow shaders not built using the Macros.fxh.

I can edit that to throw an error with explanations if more than one cb is defined.

Alternatively... I could hack something like putting all constants into a unique buffer with an automatic 4-register aligned offset...

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@ThomasFOG

I can edit that to throw an error with explanations if more than one cb is defined.

An error may be best as multiple buffers likely means something is broken.

Alternatively... I could hack something like putting all constants into a unique buffer with an automatic 4-register aligned offset...

This would mean hacking at the incoming shader HLSL file?

Seems like a lot of work and really we need to switch to our goal of supporting multiple cbuffers natively. So maybe lets not spend time on that.

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Gotcha, I'll update the PR in a moment accordingly.

ThomasFOG marked this pull request as ready for review

August 7, 2025 20:37

@tomspilman I made the uniform buffer discovery generic. It tries to read the first cbuffer hit, and will fail with a message if more than one cbuffer is encountered. I've tested with different cbuffer, with and without Macros.fxh, and it seems fine.

EDIT: we have a stock effect failing, investigating... TextureCube are uniform buffers on Spir-v. Checking if I can do something about that...

@tomspilman Fixed it, stock shaders are a go. TextureCube are single buffers, so I worked around that by only gathering uniforms when there's a corresponding struct with the expected name. That should do it.

My only concern is that I don't think TextureCube will work, they are not _type_2d_image but _type_cube_image and this descriptor is currently not parsed. But I've noticed that it's not implemented in MGG_Texture_Create(), so I left that as-is.