rotatePoint static method
Implementation
static Offset rotatePoint(Offset point, double angle, Offset center) {
final s = sin(angle);
final c = cos(angle);
double x1 = point.dx - center.dx;
double y1 = point.dy - center.dy;
double x2 = x1 * c - y1 * s;
double y2 = x1 * s + y1 * c;
return Offset(x2 + center.dx, y2 + center.dy);
}