public void rotate (double vecx, double vecy, double anchorx, double anchory)

Concatenates this transform with a transform that rotates coordinates around an anchor point according to a rotation vector. All coordinates rotate about the specified anchor coordinates by the same amount. The amount of rotation is such that coordinates along the former positive X axis will subsequently align with the vector pointing from the origin to the specified vector coordinates. If both vecx and vecy are 0.0, the transform is not modified in any way. This method is equivalent to calling:

     rotate(Math.atan2(vecy, vecx), anchorx, anchory);
 

Parameters:

vecx		the X coordinate of the rotation vector
vecy		the Y coordinate of the rotation vector
anchorx		the X coordinate of the rotation anchor point
anchory		the Y coordinate of the rotation anchor point

Since:  1.6