使用变换矩阵旋转点

Question

如何使用变换矩阵旋转点？

var point = new PointF(100, 150); 
var center = new PointF(100, 100); 
var angle = 45; 

var rotateMat = Cv2.GetRotationMatrix2D(new Point2f(center.Y, center.X), angle, 1); 
??? 

Answer 1

var point = new PointF(100, 150); 
var center = new PointF(100, 100); 
var angle = 45; 

var rotateMat = Cv2.GetRotationMatrix2D(new Point2f(center.Y, center.X), angle, 1); 
var resultPoint = (rotateMat * point.ToMat()).ToMat().ToPointF(); 

static class Hlp 
{ 
    public static PointF ToPointF(this Mat mat) 
    { 
    return new PointF((float)mat.Get<double>(1, 0), (float)mat.Get<double>(0, 0)); 
    } 
    public static Mat ToMat(this PointF point) 
    { 
    return new Mat(3, 1, MatType.CV_64FC1, new double[] { point.Y, point.X, 1 }); 
    } 
}