specialized compression

[ssaamm]

Is there some kind of compression for gigantic things that's based on where different objects are, e.g., in this order:

object type
x
y
generation (period)
xflip
yflip
rotation

Instead of storing the cells themselves? It would be really useful to have something like this, for much faster, smaller downloads of the recent huge projects emerging. The only thing is, if there isn't, then there would require a huge amount of databasing to make it. I know almost nothing of programming, but I really think this would be a worthwhile project.

[PM 2Ring]

xlife did this with its #I format, see Life man page

But as Dave says, it's not fun to write a parser to read or write such files.

The other approach is to use a Python or perl script to build the pattern, and compress the script, an approach I've used with some of my Ticker patterns.

Here's an example script that creates its output in the form of a compressed Python script that decompresses itself, but unfortunately it doesn't work with modern versions of Golly. However, Andrew has fixed the output script so at least that should work on modern versions of Golly. p30 printer: update

Also see this thread for my Ticker patterns of Marilyn Monroe & John Conway. Marilyn

[calcyman]

Generally, the macrocell file format (*.mc) is an ideal compromise between compression and speed thereof.