isConvex method
Implementation
bool isConvex() {
final length = points.length;
if (length <= 3) return true;
for (var i = 0; i < length; i++) {
final p1 = points[(i + 0) % length];
final p2 = points[(i + 1) % length];
final p3 = points[(i + 2) % length];
if (!_convex(p1.x, p1.y, p2.x, p2.y, p3.x, p3.y)) return false;
}
return true;
}