OptionaldprOptional device-pixel ratio. Defaults to window.devicePixelRatio || 1
when available, otherwise 1. Tests typically pin this to 1 or 2.
Per-node draw callback.
OptionalextraOptional commands appended after the scene-node output. Used for the minimap's visible-window indicator. Wrapped in the same view transform as scene commands.
Scene to walk. scene.renderOrder() provides the per-node order.
Camera view applied to scene + extras (both ride the same world→screen
transform; extras living in screen space should be supplied via a
separately-prepared extraCommands group or rendered outside this
helper).
CSS-pixel size. The drawing buffer is set to width × dpr and
height × dpr; CSS size to width / height.
The DOM canvas to paint into. The helper owns its WebGL2 context: the first call on a given canvas creates a renderer and stashes it; subsequent calls reuse the same renderer (and resize the drawing buffer on dim changes).