paintersAlgorithm method
Implementation
int paintersAlgorithm(Triangle? a, Triangle? b){
//return b.sumOfZ.compareTo(a.sumOfZ);
if(a == null) return -1;
if(b == null) return -1;
final double az = a.z;
final double bz = b.z;
//return (az-bz).round();
if (bz > az) return 1;
if (bz < az) return -1;
return 0;
}