initial commit

public/overlay.js

@@ -0,0 +1,28 @@
+const ws = new WebSocket("ws://" + location.hostname + ":3000");
+
+ws.addEventListener("message", (event) => {
+    const { type, key } = JSON.parse(event.data);
+    if (!key) return;
+
+    const el = document.getElementById(key);
+    if (!el) return;
+
+    if (type === "keydown") {
+        el.classList.add("active");
+    } else if (type === "keyup") {
+        el.classList.remove("active");
+    }
+});
+
+ws.addEventListener("open", () => {
+    fetch("/keymap.json")
+        .then(r => r.json())
+        .then(keymap => {
+            const mapped = new Set(Object.values(keymap).map(k => k.toUpperCase()));
+            document.querySelectorAll(".key").forEach(el => {
+                if (!mapped.has(el.id)) {
+                    el.style.visibility = "hidden";
+                }
+            });
+        });
+});