Renderer Rules

renderer/ draws the current ImageDocument plus read-only editor overlays.
renderer.ts is the renderer entrypoint/orchestrator only; keep it small.
Extract feature rendering into focused files such as artboard.ts, checkerboard.ts, layers.ts, or backend helpers.
Do not place shape drawing, shader setup, hit testing, cache management, or feature-specific rendering loops directly in renderer.ts.
Rendering backend details, e.g. WebGL objects, stay isolated here.
Do not mutate document or editor state directly.
Renderer interactions may emit intents/events only; callers translate them into commands.
Do not import React components or view code.
Do not leak backend objects into core/, commands/, editor/, or React state.
Cache only derived rendering data; authoritative state lives in core/ and editor/.