This shader originates from Granite 3D engine and has been adapted
to be used with Open GL and some GLSL ES specifics.
GLSL ES adaptation:
- remove Vulkan specifics: EXT_samplerless_texture_functions usage,
specialization constants, push constant usage
- inline bitextract.h
- always DECODE_8BIT and hardcode error color (for now)
- port to GLSL ES, required some type changes, explicit type
conversions and setting up precisions for types
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Nanley Chery <nanley.g.chery@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19886>
