bgfx-imgui-glfw-rs-example

🦀 Example of bgfx-rs, imgui & glfw in Rust

Supported Platforms

• GNU/Linux (tested on Arch Linux x86_64, Kernel: 5.18.5-arch1-1)
• Windows (tested on Windows 11)
• Mac OS X (tested on M1, Mac OS X 12.4 Monterey)

Prerequisites

• rust nightly (to use #![feature(concat_idents)])
• cmake (to build dependencies)

How to build

Clone the repo and execute cargo run --release in the root directory.

Shaders

In main.rs #![feature(concat_idents)] is enabled, which needs rust nightly. The following macro then resolves to the correct shader, based on the renderer backend:

macro_rules! get_shader_code {
    ($name:ident) => {
        match bgfx::get_renderer_type() {
            RendererType::Direct3D9 => &concat_idents!($name, _DX9),
            RendererType::Direct3D11 => &concat_idents!($name, _DX11),
            RendererType::OpenGL => &concat_idents!($name, _GLSL),
            RendererType::Metal => &concat_idents!($name, _MTL),
            RendererType::OpenGLES => &concat_idents!($name, _ESSL),
            RendererType::Vulkan => &concat_idents!($name, _SPV),
            e => panic!("Unsupported renderer type {:#?}", e),
        }
    };
}

The macro can be used like this:

let vsh = bgfx::create_shader(&Memory::copy(get_shader_code!(VS_OCORNUT_IMGUI)));
let fsh = bgfx::create_shader(&Memory::copy(get_shader_code!(FS_OCORNUT_IMGUI)));

Shader code is generated using and manually modified to an rust array. Example usage (Windows batch file):

shaderc -i . -f %%f -o %%~nf_glsl.h --bin2c %%~nf_glsl --type %%t --platform linux
shaderc -i . -f %%f -o %%~nf_spv.h --bin2c %%~nf_spv --type %%t --platform linux -p spirv
if %%t==v (
shaderc -i . -f %%f -o %%~nf_dx9.h --bin2c %%~nf_dx9 --type %%t --platform windows -p vs_3_0 -O 3
shaderc -i . -f %%f -o %%~nf_dx11.h --bin2c %%~nf_dx11 --type %%t --platform windows -p vs_4_0 -O 3
) else (
shaderc -i . -f %%f -o %%~nf_dx9.h --bin2c %%~nf_dx9 --type %%t --platform windows -p ps_3_0 -O 3
shaderc -i . -f %%f -o %%~nf_dx11.h --bin2c %%~nf_dx11 --type %%t --platform windows -p ps_4_0 -O 3
)
shaderc -i . -f %%f -o %%~nf_mtl.h --bin2c %%~nf_mtl --type %%t --platform ios -p metal  -O 3

Modules

Module	Usage
imgui_bgfx_renderer	Module to render imgui components using bgfx-rs
imgui_glfw_support	Module to map glfw events to imgui events