area static method
contour
-- 2D polygon. An array of Vector2()
Calculate area of a ( 2D ) contour polygon.
Implementation
static double area(List<Vector?> contour) {
final n = contour.length;
double a = 0.0;
for (int p = n - 1, q = 0; q < n; p = q++) {
if(contour[p] != null){
a += contour[p]!.x * contour[q]!.y - contour[q]!.x * contour[p]!.y;
}
}
return a * 0.5;
}