public static Transformation2D CreateScaleAround(float pivotX, float pivotY, float scaleX, float scaleY)
{
var t = new Transformation2D();
t.TranslateGlobal(-pivotX, -pivotY);
t.ScaleGlobal(scaleX, scaleY);
t.TranslateGlobal(pivotX, pivotY);
return(t);
}
/// <summary>
/// create a rotation matrix that rotates around a given rotation center (pivot point)
/// </summary>
/// <param name="pivotX">rotation center x</param>
/// <param name="pivotY">rotation center y</param>
/// <param name="angle">radiant</param>
/// <returns></returns>
public static Transformation2D CreateRotationAround(float pivotX, float pivotY, float degrees)
{
var t = new Transformation2D();
t.TranslateGlobal(-pivotX, -pivotY);
t.RotateGlobal(degrees);
t.TranslateGlobal(pivotX, pivotY);
return(t);
}