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Zig OpenGL Binding

This is a pragmatic binding to different OpenGL versions.

It uses the official OpenGL Registry by Khronos to generate the Zig code.

Right now, it does minimal adjustments like removing the gl prefix from functions or the GL_ prefix from constants. Everything else is the same as the C API.

There is a single non-OpenGL function exported:

pub fn load(load_ctx: anytype, get_proc_address: fn(@TypeOf(load_ctx), [:0]const u8) ?*FunctionPointer) !void {

This function will load all OpenGL entry points with the help of get_proc_address. It receives the load_ctx as well as the function name.

NOTE: Please do not reference zig-opengl as a submodule or a package. Generate a binding and copy the output of that into your repository and update the file on demand. The OpenGL Registry is just too huge to be used conveniently.

Example

This example uses ZWL by @Aransentin.

const zwl = @import("zwl");

const Platform = zwl.Platform(…);

pub fn initAndDraw(window: Platform.Window) !void {
  try gl.load(window.platform, Platform.getOpenGlProcAddress);

  while(true) {
    gl.clearColor(1, 0, 1, 1);
    gl.clear(gl.COLOR_BUFFER_BIT);

    try window.present();
  }
}

Usage with mach-glfw

There is an example of mach-glfw + zig-opengl usage available here: https://github.com/hexops/mach-glfw-opengl-example

Pregenerated Loaders

This repository contains pre-generated bindings for all extension-free OpenGL versions.

Generating your own loader

From source

To generate your own loader, you have to clone this repository and build the generator with dotnet:

user@machine:~/zig-opengl$ dotnet run
Usage: generator <registry> <result> <api_version> [<extension>] [<extension>] ...
user@machine:~/zig-opengl$ dotnet run OpenGL-Registry/xml/gl.xml gl3v3.zig GL_VERSION_3_3
Final API has 344 commands and 818 enums types.
user@machine:~/zig-opengl$
dotnet run \
  OpenGL-Registry/xml/gl.xml \ # path to the opengl registry
  my_binding.zig             \ # path to the generated file
  GL_VERSION_3_3             \ # feature level, options listed below
  …                            # Add your extensions here, each as a single arg. Or let them out, you don't need extensions

Possible feature levels (at the time of writing) are:

  • GL_VERSION_1_0
  • GL_VERSION_1_1
  • GL_VERSION_1_2
  • GL_VERSION_1_3
  • GL_VERSION_1_4
  • GL_VERSION_1_5
  • GL_VERSION_2_0
  • GL_VERSION_2_1
  • GL_VERSION_3_0
  • GL_VERSION_3_1
  • GL_VERSION_3_2
  • GL_VERSION_3_3
  • GL_VERSION_4_0
  • GL_VERSION_4_1
  • GL_VERSION_4_2
  • GL_VERSION_4_3
  • GL_VERSION_4_4
  • GL_VERSION_4_5
  • GL_VERSION_4_6
  • GL_VERSION_ES_CM_1_0
  • GL_ES_VERSION_2_0
  • GL_ES_VERSION_3_0
  • GL_ES_VERSION_3_1
  • GL_ES_VERSION_3_2
  • GL_SC_VERSION_2_0

Contribution

This library uses a small C# script that generates the Zig bindings. It is located in src/Generator.cs

What is missing right now?

  • Option to specify core or compatibility profile.