SpvReflectInterfaceVariable seems to be missing a size property

[Saalvage]

So the only ways I can see of determing the size of a SpvReflectInterfaceVariable seems to be either:

1. Combining the numeric, array and members members manually which sounds pretty hard to get right and definitely cumbersome.
2. Using the format member and mapping it to a size manually, although I assume that'd disregard the possibility of the variable being an array or possessing members of its own.

This makes it very hard to determine the offset of vertex properties.

I could totally be missing something though, in which case I'm sorry!

[chaoticbob]

Hi,

No you're not missing any information. Figuring out the size of interface variables is a bit cumbersome. In most cases, SPIRV-Reflect can only understand simple case for this, i.e. variables are aways 4 components and 32-bits. There's some historical reason for this but I'm not able to recall precisely what it was.

Do you have an example of the shader code that I can use to examine the behavior?

Thanks,
Hai

[Saalvage]

Hey, thanks for getting back to me!

Hmm, in that case I assume it might be a good idea to provide some sort of utility function utilizing one of the methods I described above?

I'm sorry but I don't exactly understand what you mean by an example shader? I can't seem to find any way to get the total size of a SpvReflectInterfaceVariable in any way directly, be it as simple as can be.

If you just need any concrete example, here's a shader and the code we use to read the size of the vertex input variables.

If you could be a bit more concrete I'd happily provide some more concrete examples or isolate the issue further.