Shader Compiler

A command line tool that compiles GLSL shaders to SPIRV, and optimizes them using glslang-zig.

Remap is also supported (results in better compression), SPIRV is validated before results are written.

Zig Version

main loosely tracks Zig master. For support for Zig 0.14.0, use v1.0.0.

Usage

Note that the initial compile will take quite while as it's building the shader C++ implementation of the shader compiler. Once this finishes it will be cached.

Example usage:

zig build run -- --target Vulkan-1.3 --optimize-perf input.glsl output.spv

Example usage from Zig's build system:

const compile_shader = b.addRunArtifact(shader_compiler_exe);
compile_shader.addArg("--scalar-block-layout");
compile_shader.addArgs(&.{
    "--target", "Vulkan-1.3",
});
switch (optimize) {
    .Debug => {},
    .ReleaseSafe, .ReleaseFast => compile_shader.addArgs(&.{
        "--optimize-perf",
    }),
    .ReleaseSmall => compile_shader.addArgs(&.{
        "--optimize-perf",
        "--optimize-size",
    }),
}
compile_shader.addFileArg(b.path(path));
return compile_shader.addOutputFileArg("compiled.spv");

GL_ARB_shading_language_include

glslang supports #include via the GL_ARB_shading_language_include extension. You can enable it in your shaders like this:

#extension GL_ARB_shading_language_include : require

You will also need to specify at least one include path via --include-path. Multiple can be specified by passing the arg more than once. If calling via Zig's build system, use '--write-deps' for proper caching behavior.

Command line:

zig build run -- --target Vulkan-1.3 --include-path include shader.vert shader.spv

Zig build system:

compile_shader.addArg("--include-path");
compile_shader.addDirectoryArg(b.path("include"));
compile_shader.addArg("--write-deps");
_ = compile_shader.addDepFileOutputArg("deps.d");

You can now include files in your shaders:

#include "foo.glsl"

For details on inclusion syntax and path resolution, see the extension specification.