opengl-function-loader

Defines a struct holding OpenGL function pointers as well as the corresponding functions. Designed for no_std use (with default-features = false).

You are responsible for loading the functions yourself:

fn main() {
    /// ...

    wglMakeContextCurrent(hDC, hRC);

    let context = GenericGlContext {
        glAccum: wglGetProcAddress("glAccum"),
        glActiveTexture: wglGetProcAddress("glActiveTexture"),
        glAlphaFunc: wglGetProcAddress("glAlphaFunc"),
        glAreTexturesResident: wglGetProcAddress("glAreTexturesResident"),
        ...
    };

    // function provided by this library - also available on no_std!
    context.clear_color(0.0, 0.0, 0.0, 0.0);
    context.flush();

    wglMakeContextCurrent(NULL, NULL);
}

If a function pointer is set to 0x00000 (i.e. the function is not loaded), this library will return a "default" value without panicking (i.e. Vec::new(), String::new() or 0). With stdlib support it will print a "missing function: X" to stdout before returning.

If stdlib support is enabled, GenericGlContext implements gleam::Gl!. The point of this is to make it possible to integrate crates that use gleam::Gl with custom OpenGL function pointer loaders while using custom loaders on no_std.

License

The code is somewhat copied from servo/gleam, so it retains the original Apache/MIT license.