@gdsf/editor (livedough)

VSCode extension providing an interactive 2D photonic layout editor with live constraint optimization.

Running

1. Open the repo root in VSCode
2. Press F5 to launch the Extension Development Host
3. Cmd+Shift+P -> "Livedough: Open Routing Editor"

Controls

Architecture

src/
  extension/
    extension.ts           VSCode extension host (webview panel lifecycle)
  webview/
    main.ts                Frame loop: input -> optimizer -> render
    types.ts               Webview-specific types
    scene/
      scene.ts             Demo scene creation + state management
      hit-test.ts          Spatial picking for selection
    input/
      input-state.ts       Mouse/keyboard state tracking
      tools.ts             Tool mode handlers (select, add-instance, add-route)
    ui/
      context-menu.ts      Right-click menus for instances and route bends

Frame loop (dirty-flag guarded)

requestAnimationFrame:
  if scene.dirty:
    1. enforceRouteConstraints(scene)          TS: only dirty routes (manhattan H/V, terminal clamping)
    2. snapToGrid(scene)                       TS: only dirty vertices + their instances
    3. checkSpacingIncremental(dirtySegments)   TS: rebuild hash, narrow-phase only dirty neighborhoods
    4. expandBendIndicators(...)                TS: full re-expand (cheap linear scan)
    5. clear dirty flags
  always:
    6. 6 instanced draw calls                  WebGL2: grid, routes+bends, textures, SDF, labels, port triangles, vertex handles

All expensive per-frame work (constraint enforcement, grid snap, DRC spacing, bend indicators) is skipped when nothing changed. Mutations record which specific segments are dirty for incremental recomputation.

Routing

• Manhattan mode: toggled per-route via context menu. All segments follow strict H/V/H/V alternation. Segments are dragged as fragments (both endpoints move on the constrained axis). Terminal segment drag also moves the attached instance.
• Free mode: only terminal segments are locked to port orientation; interior vertices move freely.
• Terminal clamping: vertex 1 (and vertex 2) cannot cross behind the port plane, preventing segment inversion.
• Default vertex count: derived from port orientations — opposite ports → 2 (S-bend), orthogonal → 1 (L-bend), same direction → 4 (U-turn).
• PDK grid snap: configurable grid pitch (default 0.005 µm / 5 nm). Only dirty vertices and their instances are snapped.

Bend indicators

• Arc overlays shown only during route selection or instance/segment dragging (reduces clutter for bundles).
• Euler bends use a precomputed Reff/Rmin lookup table with bilinear interpolation for accurate effective radius.
• Segment violation thresholds: terminal segments at 1× effective radius, intermediate segments at 2×.
• Euler P parameter hidden in context menu when circular bend type is selected.

Live DRC spacing

• Inter-route spacing violations via spatial hash broad phase + general segment-to-segment narrow phase.
• Incremental: only dirty segments and their previous violation partners are rechecked. Hash is rebuilt cheaply (O(S), pre-allocated buffers); narrow phase runs only on dirty neighborhoods.
• Violating segments colored bright red; double-headed red arrows drawn between waveguide surfaces (not centerlines) showing the gap.
• Configurable minGap (default 1 µm). Violation threshold: halfWidth_i + halfWidth_j + minGap.
• Scales to thousands of segments via 4096-bucket spatial hash with linked-list chaining.

Both WASM modules (playdough-wasm for optimization, sax-wasm for circuit simulation) are inlined as data URLs in the bundle via esbuild's .wasm dataurl loader, avoiding path resolution issues in the VSCode webview sandbox.