refactor: alignment UI and main wiring use PolyWarp

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/alignment-ui.ts

@@ -1,11 +1,11 @@
-import type { Vec2, Mat3, Alignment } from '../types';
+import type { Vec2, PolyWarp, Alignment } from '../types';
 import { imageToMachine, alignmentFromOrigin } from '../geometry/transform';
 
 export interface AlignmentDeps {
   panel: HTMLElement;
   overlay: HTMLCanvasElement;
   getAlignment: () => Alignment;
-  getHomography: () => Mat3 | null;
+  getWarp: () => PolyWarp | null;
   onChange: () => void;
 }
 
@@ -61,13 +61,13 @@ export function mountAlignment(deps: AlignmentDeps): void {
   let lastMachine: Vec2 | null = null;
 
   overlay.addEventListener('mousedown', (ev) => {
-    const H = deps.getHomography();
-    if (!H) return;
+    const warp = deps.getWarp();
+    if (!warp) return;
     // Another module (e.g. calibration) has armed the overlay for this click; don't hijack it.
     if (!armOrigin && overlay.classList.contains('interactive')) return;
     if (armOrigin) {
       const a = deps.getAlignment();
-      const m = imageToMachine(H, normFromEvent(overlay, ev));
+      const m = imageToMachine(warp, normFromEvent(overlay, ev));
       Object.assign(a, alignmentFromOrigin(m, a.rot));
       armOrigin = false;
       overlay.classList.remove('interactive');
@@ -77,15 +77,15 @@ export function mountAlignment(deps: AlignmentDeps): void {
     }
     dragging = true;
     overlay.classList.add('interactive');
-    lastMachine = imageToMachine(H, normFromEvent(overlay, ev));
+    lastMachine = imageToMachine(warp, normFromEvent(overlay, ev));
   });
 
   window.addEventListener('mousemove', (ev) => {
     if (!dragging) return;
-    const H = deps.getHomography();
-    if (!H || !lastMachine) return;
+    const warp = deps.getWarp();
+    if (!warp || !lastMachine) return;
     const a = deps.getAlignment();
-    const cur = imageToMachine(H, normFromEvent(overlay, ev));
+    const cur = imageToMachine(warp, normFromEvent(overlay, ev));
     if (ev.shiftKey) {
       // rotate about the work origin's current machine position (tx,ty)
       const angle = (p: Vec2) => Math.atan2(p[1] - a.ty, p[0] - a.tx);

src/app/overlay-interaction.test.ts

@@ -2,11 +2,14 @@
 import { describe, it, expect, beforeEach } from 'vitest';
 import { mountAlignment } from './alignment-ui';
 import { mountCalibration } from './calibration-ui';
-import type { Mat3, Alignment } from '../types';
+import type { Vec2, PolyWarp, Alignment } from '../types';
+import { estimatePolyWarp } from '../geometry/polywarp';
 
-// Identity homography: machine coords == normalized coords for this test, so a
+// Identity warp: machine coords == normalized coords for this test, so a
 // normalized click at fraction f over the 100px box maps to machine value f.
-const IDENT: Mat3 = [1, 0, 0, 0, 1, 0, 0, 0, 1];
+// We use degree 1 fitted on a unit square so the map is a near-perfect identity.
+const square: Vec2[] = [[0, 0], [1, 0], [1, 1], [0, 1]];
+const IDENT: PolyWarp = estimatePolyWarp(square, square, 1);
 
 function makeOverlay(): HTMLCanvasElement {
   const c = document.createElement('canvas');
@@ -39,7 +42,7 @@ describe('overlay interaction', () => {
       panel,
       overlay,
       getAlignment: () => alignment,
-      getHomography: () => IDENT,
+      getWarp: () => IDENT,
       onChange: () => {},
     });
     overlay.dispatchEvent(mouse('mousedown', 50, 50));
@@ -53,12 +56,12 @@ describe('overlay interaction', () => {
   it('while calibration is armed, a click is captured by calibration and does NOT drag the alignment', () => {
     const calibPanel = document.createElement('div');
     const alignPanel = document.createElement('div');
-    mountCalibration({ panel: calibPanel, overlay, onHomography: () => {} });
+    mountCalibration({ panel: calibPanel, overlay, onWarp: () => {} });
     mountAlignment({
       panel: alignPanel,
       overlay,
       getAlignment: () => alignment,
-      getHomography: () => IDENT,
+      getWarp: () => IDENT,
       onChange: () => {},
     });
     (calibPanel.querySelector('#cal-x') as HTMLInputElement).value = '10';

src/main.ts

@@ -51,8 +51,8 @@ fileInput.addEventListener('change', async () => {
 mountCalibration({
   panel: document.getElementById('calib-panel') as HTMLElement,
   overlay,
-  onHomography: (H) => {
-    state.setHomography(H);
+  onWarp: (w) => {
+    state.setWarp(w);
     statusEl.textContent = 'Calibrated (unsaved — paste JSON into config.json to persist).';
     render();
   },
@@ -62,7 +62,7 @@ mountAlignment({
   panel: document.getElementById('align-panel') as HTMLElement,
   overlay,
   getAlignment: () => state.alignment,
-  getHomography: () => state.homography,
+  getWarp: () => state.warp,
   onChange: render,
 });
 
@@ -71,7 +71,7 @@ async function boot(): Promise<void> {
     const cfg = await loadConfig('config.json');
     style = cfg.renderDefaults;
     if (cfg.streamUrl) stream.src = cfg.streamUrl;
-    if (cfg.calibration) state.setHomography(cfg.calibration.homography);
+    if (cfg.calibration) state.setWarp(cfg.calibration.warp);
     statusEl.textContent = cfg.calibration ? 'Ready. Open a G-code file.' : 'Not calibrated — calibrate first.';
   } catch (e) {
     statusEl.textContent = `Config error: ${(e as Error).message}`;