penpot/.opencode/skills/render-wasm/SKILL.md

name, description

name	description
penpot-render-wasm	Guidelines and workflows for the Penpot Rust to WebAssembly renderer.

Penpot Render-WASM Skill

This skill provides guidelines and workflows for the Penpot Rust to WebAssembly renderer.

Commands

• Build: ./build (Compiles Rust → WASM. Requires Emscripten environment. Automatically sources _build_env)
• Watch: ./watch (Incremental rebuild on file change)
• Test (All): ./test (Runs cargo test)
• Test (Single): cargo test my_test_name or cargo test shapes::
• Lint: ./lint (clippy -D warnings)
• Format: cargo fmt --check

Architecture & Conventions

• Global state: Accessed EXCLUSIVELY through with_state! / with_state_mut! macros. Never access unsafe static mut State directly.
• Tile-based rendering: Only 512×512 tiles within the viewport are drawn each frame.
• Two-phase updates: Shape data is written via exported setter functions, then a single render_frame() triggers the actual Skia draw calls.
• Frontend Integration: The WASM module is loaded by app.render-wasm.* namespaces. Do not change export function signatures without updating the corresponding ClojureScript bridge.