Map rendering tweaking page -- I am unhappy with all of these
and am throwing it away. I will try a different approach. I am quite happy with the variety of patterns I get, especially because I haven't implemented an erosion algorithm yet.
The code here is not optimized and not tested across browsers -
Toggle render: switch between red points only (shiny), and red+blue points (detailed)
Weight: the step size used for algorithm 2 (which is also used in algorithm 3 and 4). It controls how quickly the rivers flow down.
Alpha: how far the red points are above the blue points