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Pattern Breeder 25th Anniversary Reprise

PostPosted: February 5th, 2011, 12:48 am
by ynotds
Pattern Breeder is a generalisation into arbitrary (initially up to 7x7) neighbourhoods of the Fredkin automata. Making use of QuickDraw's support for XORing bitmaps, it was released at San Francisco Macworld Expo in 1986 and described in the cover story of that September's Scientific American. Things got way too busy on other fronts to take it further at the time, but now Golly's ever more powerful user interface components have made it a relatively trivial exercise to create a reasonable demo, albeit one which is almost an abuse of Golly because it does not invoke any of Golly's generating algorithms.

To take a look you need a smallish pattern in Golly (Layer 0), e.g.
#CXRLE Pos=-7,-7
x = 15, y = 15, rule = B1357/S02468
then Add Layer (1) and from that layer open
Open in second Layer in Golly 2.2
(1.89 KiB) Downloaded 245 times
which will present a dialog in which you can enter a target generation. I'd suggest keeping that number under or not much over 100 and then hitting return to let it run past generation 128. If you optionally enter an initial delay it will automatically start generating when that delay is done. It imitates the handling of a core subset of Golly's keyboard shortcuts but becomes painfully slow once the generated pattern becomes fairly large.

If you want to keep playing, you will need to open that zip outside Golly and move to Golly/Scripts/Perl, then you can happily play with arbitrary neighbourhoods which are defined by the pattern in Layer 1, keeping in mind that generation time is proportional to the number of live cells in your chosen neighbourhood.