road_type = tilemap_get_at_pixel(global.road_tile, x, y);

if (road_type == ROAD_TYPE.TURRET)
	turret_cur = (instance_position(x+BLOCK_WIDTH/2, y+BLOCK_HEIGHT/2, obj_turret));
else
	turret_cur = noone;

if (turret_destroy > 0) {
	if (turret_cur != noone)
		turret_cur.visible = true;
	turret_destroy = 0;
}