GML movement input script

function checkForInputs() {
    if !(x == destination_x and y == destination_y) {return}

    var _up =  keyboard_check(ord("W")) or keyboard_check(vk_up)
    var _left =  keyboard_check(ord("A")) or keyboard_check(vk_left)
    var _down =  keyboard_check(ord("S")) or keyboard_check(vk_down)
    var _right =  keyboard_check(ord("D")) or keyboard_check(vk_right)

    var _dest_x = x + (_right - _left) * 16
    var _dest_y = y + (_down - _up) * 16

    if (destination_x == _dest_x && destination_y == _dest_y) {return}

    var _list = ds_list_create();
    var _collision_num = collision_point_list(_dest_x, _dest_y, AbstractBlock, true, 1, _list, true)
    if (_collision_num != 0) {return}

    destination_x = _dest_x
    destination_y = _dest_y
}