Pointer events for undo button

src/app.js

@@ -387,15 +387,9 @@ HTML.fastUndoButton.addEventListener("click", () => {
   }
 })
 
-HTML.undoButton.addEventListener("mouseup", () => {
-  clearInterval(undoInterval)
-})
-
-HTML.undoButton.addEventListener("mouseleave", () => {
-  clearInterval(undoInterval)
-})
+const undoButtonEnd = () => clearInterval(undoInterval)
 
-HTML.undoButton.addEventListener("mousedown", () => {
+const undoButtonStart = () => {
   undoInterval = setInterval(function() {
     if (room == null) return
 
@@ -406,7 +400,13 @@ HTML.undoButton.addEventListener("mousedown", () => {
       HTML.undoButton.classList.add("disabled")
     }
   }, 1000 / UNDO_RATE)
-})
+}
+
+HTML.undoButton.addEventListener("pointerup", undoButtonEnd)
+HTML.undoButton.addEventListener("pointerleave", undoButtonEnd)
+HTML.undoButton.addEventListener("mouseup", undoButtonEnd)
+
+HTML.undoButton.addEventListener("pointerdown", undoButtonStart)
 
 HTML.roomIDElem.addEventListener("keydown", (event) => {
   if (event.key == "Enter") {