js/keypad.js

// TOUCH CONTROLS – simulate real keyCode events
if ('ontouchstart' in window || navigator.maxTouchPoints > 0) {
  const pressed = new Set();  // track which "keyCodes" are down

  function dispatchKey(type, keyCodeStr) {
    const keyCode = parseInt(keyCodeStr, 10);
    if (!keyCode) return;

    // Create old-style KeyboardEvent with keyCode (needed for this emulator)
    const event = document.createEvent ? document.createEvent('KeyboardEvent') : new KeyboardEvent(type);

    // Modern way to set keyCode (works in most browsers)
    if (event.initKeyboardEvent) {
      event.initKeyboardEvent(
        type, true, true, window,
        false, false, false, false,
        keyCode, keyCode
      );
    } else {
      // Fallback for newer KeyboardEvent constructors
      Object.defineProperties(event, {
        keyCode: { value: keyCode, writable: true },
        which:   { value: keyCode, writable: true }
      });
    }

    // Also try dispatching on document, window, and canvas
    document.dispatchEvent(event);
    window.dispatchEvent(event);
    document.getElementById('screen')?.dispatchEvent(event);
  }

  document.querySelectorAll('[data-keycode]').forEach(el => {
    const keyCode = el.dataset.keycode;

    el.addEventListener('touchstart', e => {
      e.preventDefault();           // stops scrolling/zoom on mobile
      if (!pressed.has(keyCode)) {
        pressed.add(keyCode);
        dispatchKey('keydown', keyCode);
      }
    }, { passive: false });

    el.addEventListener('touchend', e => {
      e.preventDefault();
      if (pressed.has(keyCode)) {
        pressed.delete(keyCode);
        dispatchKey('keyup', keyCode);
      }
    }, { passive: false });

    el.addEventListener('touchcancel', e => {
      e.preventDefault();
      if (pressed.has(keyCode)) {
        pressed.delete(keyCode);
        dispatchKey('keyup', keyCode);
      }
    }, { passive: false });

    // Optional: visual feedback on press
    el.addEventListener('touchstart', () => el.classList.add('pressed'));
    el.addEventListener('touchend touchcancel', () => el.classList.remove('pressed'));
  });
}