ES 3.2: Varying packing rules on geometry shader inputs/outputs

[Jiawei-Shao]

Hi,

ESSL 3.2 SPEC provides an algorithm for varying packing on vertex shader outputs and fragment shader inputs (Chapter 12 Page 196 "Counting of Inputs and Outputs": This section applies to vertex shader outputs and fragment shader inputs.). How about the inputs and outputs of other shaders? For example, should this algorithm also be applied for geometry shader inputs and outputs?

Thanks!

[Jiawei-Shao]

@qjia7

[pdaniell-nv]

We discussed this in the OpenGL/ES WG meeting today. We're leaning toward removing chapter 12 entirely, but we want to make sure this doesn't inadvertently affect any implementations. We'll resolve this inside Khronos.

https://gitlab.khronos.org/opengl/GLSL/issues/30

[pdaniell-nv]

After discussion internally we decided that we can't remove this appendix since some implementations need it. The clarification we need to make is that the appendix only applies to the interface between the last vertex processing shader stage and the fragment shader. So when a geometry shader is present, it applies to the interface between the geometry shader and the fragment shader, and it does not apply to the interfaces between the shaders up to and including the geometry shader input.

[pdaniell-nv]

This was resolved in the latest ESSL spec here: https://www.khronos.org/registry/OpenGL/specs/es/3.2/GLSL_ES_Specification_3.20.html#counting-of-inputs-and-outputs