Class LayerView2DRenderer

True when the current IR carries M600 color-change boundaries (DD-031 G6).

Retraction markers are a 3D-only overlay — the flat 2D layer view never shows them (DD-031 G6).

3D-only progressive preview; the 2D view draws on the final IR (§3 non-goal).

Read the current camera as a serializable snapshot (#268). Null when the renderer has no 3D pose (2D).

The flat 2D layer view produces no GPU/geometry render diagnostics (no WebGL backend, no tube geometry, no draw-call/parallelism story). Returning null is honest — never a fabricated stats object (DD-031 G1). A consumer's diagnostics UI should say diagnostics are unavailable in 2D mode.

Capability gate mirroring the 3D renderer (DD-001 honesty): unknown channel → unavailable.

Pick the IR segment under a pointer (normalized device coords in [-1, 1]), or null (#184). The 3D renderer raycasts the toolpath; the 2D renderer returns null (no picking yet).

Show/hide the build-volume wireframe cage independently of the bed/plate (#306/#6).

Perspective lens in degrees (DD-032 §4.2). Optional, so an existing custom renderer still satisfies the interface (the controller skips it when absent); the bundled 2D renderer discloses via renderer-unsupported.

Restore a camera snapshot verbatim (#268). 2D renderers disclose via renderer-unsupported.

Frame the printed 'object' (excl. skirt/prime) vs 'all' extrusion (#306/#6).

Interaction-aware quality: 'auto' reduces detail while the camera moves (#306/2, DD-020).

Resting pixel ratio of the interactive canvas: a number in (0, 4] or 'device'. Optional, so an existing custom renderer still satisfies the interface (the controller skips it when absent); the bundled 2D renderer discloses via renderer-unsupported.

During-parse preview curtain (#60): 'lines' | 'hold' | 'off'. Applies to the NEXT parse. 3D only; 2D is a no-op.

Fidelity policy (DD-023 §4 D6): 'full' | 'adaptive' | 'fast'. 3D only; 2D is a no-op.

Snap to a preset orientation (#268). 2D renderers disclose via renderer-unsupported.