winding static method
Implementation
static int winding(
double p1x, double p1y, double p2x, double p2y, double p3x, double p3y) {
final double px = p2x - p1x, py = p2y - p1y;
return p3x * py - p3y * px + px * p1y - p1x * py >= 0 ? 1 : -1;
}