There is something like this elsewhere, in the code archives under graphics maybe...
In general I think it would be needed to write pixel by pixel, then storing the product in an image. perhaps find the distance between the starting pixel and the current pixel then color it accordingly (a = y1-y2, b = x1-x2, dist = sqrt(a*a+b*b))...There is probably a better way somewhere, these are just some thoughts.
In general I think it would be needed to write pixel by pixel, then storing the product in an image. perhaps find the distance between the starting pixel and the current pixel then color it accordingly (a = y1-y2, b = x1-x2, dist = sqrt(a*a+b*b))...There is probably a better way somewhere, these are just some thoughts.