case 0: altitude = bilinearInterpolate(fouralts, x, y); break;
case 1: altitude = bilinearInterpolate(fixVoid(fouralts), x, y); break;
case 2:
case 3: altitude = averageNonVoid(fouralts); break;
default: altitude = VOID_VAL;
}
case 0: altitude = bilinearInterpolate(fouralts, x, y); break;
case 1: altitude = bilinearInterpolate(fixVoid(fouralts), x, y); break;
case 2:
case 3: altitude = averageNonVoid(fouralts); break;
default: altitude = VOID_VAL;
}