handleTouchStartPan method
void
handleTouchStartPan()
Implementation
void handleTouchStartPan() {
if (pointers.length == 1) {
panStart.setValues(pointers[0].pageX, pointers[0].pageY);
} else {
final x = 0.5 * (pointers[0].pageX + pointers[1].pageX);
final y = 0.5 * (pointers[0].pageY + pointers[1].pageY);
panStart.setValues(x, y);
}
}