backends/sdlgpu3/build_instructions.txt

Instructions to rebuild imgui_impl_sdlgpu3_shaders.h
(You don't need to copy this folder if you are using the backend as-is)

1) Compile the raw shader files to SPIRV:

    glslc -o vertex.spv -c shader.vert
    glslc -o fragment.spv -c shader.frag


2) Build SDL_shadercross (https://github.com/libsdl-org/SDL_shadercross)


3-A) Compiling for the Vulkan Driver:

    Nothing to do, you just need the previous vertex.spv/fragment.spv, proceed to step 4


3-B) Compiling for the DirectX 12 Driver:

    ./shadercross vertex.spv -s SPIRV -d DXBC -t vertex -e main -o vertex.dxbc
    ./shadercross fragment.spv -s SPIRV -d DXBC -t fragment -e main -o fragment.dxbc

    Proceed to step 4


3-C) Compiling for Metal (On windows you'll need the Metal Developer Tools for Windows, on linux you might use wine, but I never tested it):

    ./shadercross vertex.spv -s SPIRV -d MSL -t vertex -e main -o vertex.metal
    ./shadercross fragment.spv -s SPIRV -d MSL -t fragment -e main -o fragment.metal

    xcrun -sdk macosx metal -o vertex.ir -c vertex.metal
    xcrun -sdk macosx metal -o fragment.ir -c fragment.metal
    xcrun -sdk macosx metallib -o vertex.metallib -c vertex.ir
    xcrun -sdk macosx metallib -o fragment.metallib -c fragment.ir

    Proceed to step 4


4) Use a tool like https://notisrac.github.io/FileToCArray/ or misc/fonts/binary_to_compressed_c.cpp in imgui repository to convert the file to a uint8_t array.