OpenGL Renderer: use shaders cross-compiler

[Xottab-DUTY]

Source code compilers:

• glslang and SPIRV-Cross
  • We should check if it supports compilation from HLSL to SPIR-V for OpenGL. ([HLSL] Support SPIR-V from HLSL for OpenGL KhronosGroup/glslang#1417)
  • shaderc
• DirectXShaderCompiler and SPIRV-Cross
  • ShaderConductor
• vkd3d-shader
• hlsloptconv (HLSL Optimizing Converter, SM3.0 – SM4.0)
• hlslparser
  • HLSLParser (Only SM3.0, no preprocessor, so doesn't support #includes)
• hlsl2glslfork (Only SM3.0)
• shgen
• XShaderCompiler (SM4 – SM5) (won't work for us currently, see Interpolation modifier being recognized as keyword LukasBanana/XShaderCompiler#98)
• https://zz85.github.io/hlslparser/
• https://github.com/DiligentGraphics/DiligentCore/tree/master/Graphics/HLSL2GLSLConverterLib
  • https://diligentgraphics.com/diligent-engine/shader-converter/
  • http://diligentgraphics.com/diligent-engine/shader-converter/supported-features/
  • https://www.gamedeveloper.com/programming/state-of-the-art-hlsl-to-glsl-converter

Bytecode compilers are not suitable, we need to compile from sources.
However, here's the list of some bytecode compilers:

• HLSLCrossCompiler
  • Amazon's Lumberyard version
  • Unity's HLSLcc
• DXVK's DXBC reader – Supports SM 4.0 through SM 5.0.
• mojoshader – Supports SM 1.0 through SM 3.0
  • https://github.com/espes/mojoshader – fork

Other useful links:
Decompilers:

• https://github.com/etnlGD/HLSLDecompiler
• https://github.com/luxuia/dxbc_reader
• https://github.com/AndresTraks/HlslDecompiler/
• https://gitlab.winehq.org/fcasas/binary-d3dbc-parser

Other projects:

• https://github.com/felipeagc/tinyshader
• https://github.com/shader-slang/slang
• https://github.com/septag/glslcc
• https://github.com/julianrendell/GLSL2HLSL
• https://github.com/Kode/krafix
• https://github.com/KTXSoftware/kfx
• https://github.com/MicrosoftEdge/WebGL/tree/master/GLSLParse
• https://github.com/zigguratvertigo/hlsl-to-ispc
• https://github.com/mellinoe/ShaderGen
• https://github.com/DragonJoker/ShaderWriter
• https://github.com/polymonster/pmfx-shader
• https://github.com/cezbloch/shaderator

Playground, testing, live coding:

• https://github.com/tgjones/shader-playground
• https://github.com/astralis3d/HLSLexplorer
• https://github.com/atyuwen/hlsl_live_coding

Other suggestions?

This issue is a sub-task of #280

[ryao]

@Xottab-DUTY I don't think that the DXVK bytecode compiler supports SM 3.0. Also, DXBC is the name of HLSL bytecode. I believe stands for DirectX ByteCode.

[Xottab-DUTY]

I don't think that the DXVK bytecode compiler supports SM 3.0.

Oh, that was a typo..

Also, DXBC is the name of HLSL bytecode. I believe stands for DirectX ByteCode.

I just removed this text then, since HLSLcc is bytecode compiler too.

[375gnu]

2 additional, but i haven't work with them, just found accidentally:
https://github.com/Thekla/hlslparser
https://github.com/aras-p/hlsl2glslfork

[MerijnHendriks]

Looks like dxc now comes with a SPIR-V backend enabled.
The C++ API for cross compiling looks managable.

What simple converted program output looks like:

• HLSL to GLSL
• GLSL to HLSL

[Xottab-DUTY]

None of existing cross-compilers is capable of cross-compiling S.T.AL.K.E.R. shaders. And! we have a strong requirement to not change anything in the game assets (shaders are game assets too)...

We could try to improve dxc or glslang to make it work, but the fact that there are no compilers that can compile these shaders actually tempts me to make my own compiler.