关于点绕点旋转

[weeksun23]

下面这个函数实现对点pt绕center逆时针旋转72°，那么顺时针旋转的话应该怎么修改呢？？另外这个函数的原理是什么？求解！！

public Point roate(Point center, Point pt)
{
int x = (int)(center.X + (pt.X - center.X) * Math.Cos(72.0 * Math.PI / 180) - (pt.Y - center.Y) * Math.Sin(72.0 * Math.PI / 180));
int y = (int)(center.Y + (pt.X - center.X) * Math.Sin(72.0 * Math.PI / 180) + (pt.Y - center.Y) * Math.Cos(72.0 * Math.PI / 180));
return new Point(x, y);
}

[weeksun23]

自己顶起！！

[wuyq11]

static PointF Rotate(PointF center, PointF point, float angleInDegree)
{
System.Drawing.Drawing2D.Matrix matrix = new System.Drawing.Drawing2D.Matrix();
matrix.Rotate(angleInDegree); // 逆时针旋转的矩阵

PointF[] points = { new PointF( point.X - center.X, point.Y - center.Y) };
matrix.TransformPoints( points );
return new PointF(center.X + points[0].X, center.Y + points[0].Y);
}