Squash Odysseus development history

static/js/editor/adjustments-worker.js

@@ -0,0 +1,26 @@
+/* Worker adapter for the shared pure adjustment pixel pass. */
+
+let applyAdjustment;
+
+async function render(source, adjustment) {
+  if (!applyAdjustment) {
+    // pixel-pass only needs document.createElement('canvas'), so provide the
+    // smallest worker-local adapter instead of maintaining a second renderer.
+    self.document = { createElement: () => new OffscreenCanvas(source.width, source.height) };
+    ({ applyAdjustment } = await import('./fx/pixel-pass.js'));
+  }
+  const input = new OffscreenCanvas(source.width, source.height);
+  input.getContext('2d').drawImage(source, 0, 0);
+  return applyAdjustment(input, adjustment);
+}
+
+self.onmessage = async event => {
+  try {
+    const { source, adjustment } = event.data;
+    const output = await render(source, adjustment);
+    const bitmap = output.transferToImageBitmap();
+    self.postMessage({ bitmap }, [bitmap]);
+  } catch (error) {
+    self.postMessage({ error: String(error?.message || error) });
+  }
+};