Changes

Co-authored-by: Reifonas <211114984+Reifonas@users.noreply.github.com>

src/lib/webrtc/broadcastSource.ts

@@ -0,0 +1,20 @@
+/**
+ * Lightweight registry that lets the XR mirror expose its offscreen canvas
+ * as the preferred broadcast source. ShareButton checks here first.
+ */
+let activeCanvas: HTMLCanvasElement | null = null;
+const listeners = new Set<(c: HTMLCanvasElement | null) => void>();
+
+export function setBroadcastSource(c: HTMLCanvasElement | null) {
+  activeCanvas = c;
+  listeners.forEach((cb) => cb(c));
+}
+
+export function getBroadcastSource(): HTMLCanvasElement | null {
+  return activeCanvas;
+}
+
+export function onBroadcastSourceChange(cb: (c: HTMLCanvasElement | null) => void) {
+  listeners.add(cb);
+  return () => listeners.delete(cb);
+}