RFGR-Shaders

Project to recreate the RFGR shader source code. The Shaders folder has the shaders. The code is very messy currently as its generated automatically by tools.

HLSL generation process

• Extract the DXBC bytecode from the games .fxo_kg files. See the ShaderFile class in RFGM.Formats. See the VertexShadersBytecode and PixelShadersBytecode fields.
• Use code from DXVK to decode the DXBC data and generate SPIRV from it. Specifically load the shader bytecode into dxvk::DxbcReader and pass that into dxvk::DxbcModule, then compile it into spirv bytecode. DXVK.
• Use SPIRV-Cross to generate HLSL code from the SPIRV.

The code for converting the DXBC -> SPIRV -> HLSL has unfortunately been lost. But it should be reasonably easy to recreate by using the DXBC classes from DXVK and the SPIRV-Cross library as described above. This repo was created in a fairly short time to test the idea, and has a lot of room for improvement.

There's information in the generated code thats missing or incomplete such as the vertex format definitions and the names & definitions of different input constants. There's also many ways the code could be simplified. Such as things like asfloat(1065353216u), which is just 1.0f. Ideally code cleanup like that would be automated with tools. Then manually clean up the code the rest of the way.

Shaders folder structure

• The top level folders such as "Terrain" and "Character" are the categories the game assigns to each of these shaders.
• Inside those folders you'll find many other folders. Each of those subfolders corresponds to one of the games .fxo_kg files. So for example /RFGR-Shaders/Shaders/Terrain/rl_terrain_height_mesh_blend_t/ corresponds to rl_terrain_height_mesh_blend_t.fxo_kg.
• Each fxo_kg file can have multiple vertex shaders and pixel shaders. Those are stored in the subfolders as separate .hlsl files with either the _vs or _ps postfix to indicate whether if they're a vertex or pixel shader, followed by their index.
• Inside each subfolder you'll find a ShaderMetadata.json file. These contain all the data from the source .fxo_kg file. Since some data gets lost during the HLSL generation process.