public void SetRotation(float r, float x_0, float y_1)
{
if (rotation != r)
{
this.CallTransform(Matrix.CreateRotateTransform(
rotation = (r / 180f * MathUtils.PI), x_0, y_1));
}
}
public void SetRotation(float r)
{
if (rotation != r)
{
this.CallTransform(Matrix.CreateRotateTransform(
rotation = (r / 180f * MathUtils.PI), this.center[0],
this.center[1]));
}
}
public static Matrix CreateRotateTransform(float angle, float x, float y)
{
Matrix temp = Matrix.CreateRotateTransform(angle);
float sinAngle = temp.matrixs[3];
float oneMinusCosAngle = 1.0f - temp.matrixs[4];
temp.matrixs[2] = x * oneMinusCosAngle + y * sinAngle;
temp.matrixs[5] = y * oneMinusCosAngle - x * sinAngle;
return(temp);
}