glow

glow (“GL on Whatever”) is a set of Rust bindings that let you run GL code anywhere: desktop OpenGL, OpenGL ES, and WebGL all sit behind a single, consistent API. The goal is to let graphics developers write rendering code once and target native and web platforms without target-specific branches.

By abstracting over the underlying GL implementation, glow provides a thin, low-level layer that mirrors the GL command set while smoothing over the differences between native contexts and the browser’s WebGL via web-sys.

What You Get

• One unified API over OpenGL, OpenGL ES, and WebGL
• A HasContext trait that maps closely to raw GL commands
• Native and wasm32/web-sys backends from the same source
• A thin, low-overhead abstraction with no heavy runtime
• Optional call tracing and automatic glGetError debug features

Common Use Cases

• Writing cross-platform renderers that target desktop and the web
• Building higher-level graphics engines and UI toolkits on a portable GL layer
• Porting existing OpenGL code to WebGL without rewriting call sites
• Prototyping shaders and rendering pipelines across native and browser

Under The Hood

Architecture — glow defines a HasContext trait and a Context enum in src/lib.rs that dispatches to platform backends: native.rs (loading GL function pointers), gl46.rs (the native command tables), and web_sys.rs (browser WebGL through web-sys), with version.rs handling GL/GLES version detection. Tech Stack — Rust edition 2021 (MSRV 1.86) with an almost dependency-free core (log is the only optional dependency); the web backend relies on web-sys and the native backend on raw GL loaders supplied by the consumer. Code Quality — The crate is mature and widely used as the GL layer beneath projects like egui and wgpu tooling, with CI across many targets and optional debug features (debug_trace_calls, debug_automatic_glGetError). API Design — The API deliberately mirrors the GL command set, so it is low-level and unsafe like GL itself, but this fidelity makes it predictable for anyone who already knows OpenGL while enabling write-once cross-platform rendering.