Implements Option B from docs/research/graph-rendering.md. sigma.js v3
(WebGL) is replaced by one canvas, one rAF loop with a dirty flag, and
d3-zoom for the camera — eliminating the entire bug class from the
sigma-era bolt-on architecture:
- Hull/node desync during pan (two independent render loops) is now
structurally impossible: hull fills, dashed hull strokes, edges with
arrowheads, node discs, region labels, node labels, and hover glow
are all drawn in ONE frame under ONE camera.
- The settings-change canvas-sizing race (everything shifting up-left)
is gone: settings changes only redraw; the canvas and camera persist
(verified live: camera identical to 15 decimals across a slider drag).
- The GPU floor is gone: idle schedules NO frames at all (verified via
pixel-identity over 600ms idle); pan redraws exactly once per frame.
components/graph-canvas.ts: GraphCanvasRenderer class plus pure helpers
(zoomRatioOf, labelAlpha, fitTransform, arrowGeometry, pickNearest).
The sigma camera-ratio convention (1 = fit, smaller = zoomed in) is kept
verbatim so persisted labelZoom settings survive the swap; node labels
and cluster region labels cross-fade over the same LABELS_FADE_SPAN
(0.5, unchanged). Picking is a nearest-node distance check with the
10px pad that replaces the old padded-picking vertex shader. Hull math
stays in components/cluster-geometry.ts, reused as-is. No ctx.filter,
ever.
graph-view.tsx keeps every feature: fetch/refetch on runs-empty, FA2
run-then-freeze layout, localStorage render settings + sanitizers,
search filtering with edge drops and card-close, detail card with
flipped anchoring and per-source provenance, settings panel, import
button, pipeline status chips. Only the renderer plumbing changed.
tests/graph-canvas.test.ts pins the pure math: ratio direction, label
gate + inverse complement (alphas sum to 1), fit transform padding,
arrowhead tip-on-disc-edge and symmetry, picking pad/ties/null cases.
Live-verified end-to-end on the real 338-node graph (dev server
port 3002): single canvas, paint at fit, hover cursor+glow+fade, click
card open/anchored/close, stage click, search filter to zero with hint,
label gate opens via slider and zoom, cluster-labels toggle, zoom-to-
cursor 0.56px anchor drift, camera persistence across settings, zero
idle repaints. sigma dependency removed from package.json; d3-zoom and
d3-selection added.
Note: the settings feed effect needed isEmpty in its deps — without it
the renderer mounted with settings=null and every draw early-returned
(blank canvas); caught live, not by typecheck.
amosblomqvist
4e48d13fac