fix: 修复了冰块惯性问题和死亡效果

js/input.js

@@ -15,6 +15,7 @@ const BIND = {
 const down = new Set();      // 当前按住的原始 code
 const now = {};              // action 是否按下
 const prev = {};             // 上一帧
+const touch = {};            // action -> bool（来自触屏虚拟按键）
 const blocked = new Set(['Space', 'ArrowUp', 'ArrowDown', 'ArrowLeft', 'ArrowRight', 'Tab']);
 
 export const Input = {
@@ -44,10 +45,24 @@ function refresh() {
   for (const act in BIND) {
     let v = false;
     for (const c of BIND[act]) if (down.has(c)) { v = true; break; }
+    if (touch[act]) v = true;          // 触屏虚拟按键
     now[act] = Input.enabled ? v : false;
   }
 }
 
+// ---------------- 触屏虚拟按键接口 ----------------
+export function setTouch(action, on) {
+  if (!(action in touch)) touch[action] = false;
+  if (touch[action] === on) return;
+  touch[action] = on;
+  refresh();
+}
+export function clearTouch() {
+  let any = false;
+  for (const k in touch) if (touch[k]) { touch[k] = false; any = true; }
+  if (any) refresh();
+}
+
 addEventListener('keydown', e => {
   if (blocked.has(e.code)) e.preventDefault();
   if (e.repeat) return;