Complex Led Patterns

Does anyone have some complex pattern code, or some sites that have some?

I'm specifically looking for a water ripple, but coded in such a way that i can set the start point.

for example, an 8*8 led matrix, with an 8*8 switch matrix... press switch 1,1 and the ripple starts from 1,1 and bounces out... hit switch 4,4 and the ripple centres from 4,4

I don’t have any pattern code but is this what your looking for?

You should only need one algorithm and the button press just set the algorithm centre X/Y position on the matrix.

that code would do beautifully! i can always tweak (ask questions) later!