function c_gettile(x, y) {
	var thex = round((x-16)/ts.x);
	var they = round((y-16)/ts.y);
	if c_tileexists(thex, they) return mp[thex][they];
	return noone;
}

function c_tileexists(posx, posy) {
	if posx < array_length(mp) && posx >= 0 {
		if posy < array_length(mp[posx]) && posy >= 0 {
			return true;
		}
	}
	return false;
}