Hey everyone,
I've never really dealt with the compressed limitation in Pico8, so this jam has been great. One thing I've noticed though, is sometimes I can add several characters worth of code and get barely any increase in compression size, and other characters add substantially more. Is there a rhyme or reason for this? Is it general ascii versus mathematics or functions?
Hiya,
Alas, I'm not the best to speak on this subject (hopefully Zep or someone else can speak with more authority)
But my basic understanding is that, like most forms of data compression - it works very well with "similar blocks of same data".
So, for example, if you have a string with 50 "X" chars in it - it'll compress well, because the compression routine will store something like (use an "X" 50 times).
Whereas, if you have data that is always very different - then there's little "similarities" for it to squeeze down.
In the meantime - see here and here for some info on how the PICO-8 can compress data.
But yes, the compression a definitely dark art - even Zep said so! 馃槄
Hope some of this helps!
Just released an online/itch.io tool PXAVIZ which lets you visualize the PICO-8's "PXA" compression as you type. Hope it helps folks develop an intuition for optimizing compressed code size in their carts. In short, PXA compresses very well with repeated blocks of characters, and does better than normal with recently used characters (that fall outside copied blocks).
