Function updateVirtualButton

src/mobile/index.ts:201–241

(btn: VirtualButton)

}

export function updateVirtualButton(btn: VirtualButton): void {
  const touchCount = getTouchCount();
  const wasActive = btn.active;

  // Check if any unclaimed touch is inside the button
  let nowActive = false;
  let activeIndex = -1;

  for (let i = 0; i < touchCount; i++) {
    if (claimedTouches.has(i)) continue;
    const tx = getTouchX(i);
    const ty = getTouchY(i);
    if (tx === 0 && ty === 0) continue;

    const dx = tx - btn.x;
    const dy = ty - btn.y;
    if (dx * dx + dy * dy <= btn.radius * btn.radius) {
      nowActive = true;
      activeIndex = i;
      break;
    }
  }

  if (nowActive) {
    claimedTouches.add(activeIndex);
    btn.touchIndex = activeIndex;
  }

  if (nowActive && !wasActive) {
    // Just pressed
    btn.active = true;
    if (btn.key !== null) injectKeyDown(btn.key);
    if (btn.gamepadButton !== null) injectGamepadButtonDown(btn.gamepadButton);
  } else if (!nowActive && wasActive) {
    // Just released
    btn.active = false;
    btn.touchIndex = -1;
    if (btn.key !== null) injectKeyUp(btn.key);
    if (btn.gamepadButton !== null) injectGamepadButtonUp(btn.gamepadButton);
  }
}

export function drawVirtualButton(btn: VirtualButton): void {
  const bgColor: Color = btn.active