Octohash database

The octohash function is a hash function that returns the same value for any of the eight orientations of a pattern -- in other words, the octohash of any rotation or reflection of a pattern will always be the same as the octohash of the original pattern.

Several databases implemented using the octohash function can be used to search for active reactions that produce a given pattern (which may be active or settled). The databases are designed to work with Golly and Python, without other dependencies.

The octohash database, published in August 2020, catalogues every generation of every possible collision between a single glider and all possible constellations of up to two well-separated objects (excluding pseudo still lifes) fitting inside a 12 × 12 bounding box; the included objects are block, tub, boat, beehive, ship, loaf, eater, pond, long boat, and blinker.

The octo3obj database, finished in June 2022, catalogues every generation of every possible collision between a single glider and all possible constellations of up to three well-separated patterns fitting inside an 11 × 11 bounding box; the included objects and constellations are blinker, block, beehive, bi-block, half blockade, and teardrop ash (two beehives).

The octo3g database, completed in August 2022, catalogues every generation of every collision in a subset of three-glider collisions, making it possible to search active 3G collision patterns in the same way as active patterns in the previous octo3obj and octohash databases.

See also

• Tutorials/Glider syntheses
• Tutorials/Catagolue stdin symmetry