Download http://www.antigrain.com/spheres.bmp before running this example.
Put it into the same folder as the executable and rename it to "spheres".
Use the sliders and the radio-buttons to change the parameters of 
the distortions. Drag the center of the distortions.
Don't try to understand the shamanic manipulations with affine matrices
because I composed it using the "hit-and-miss" method :-)
