1a. Stronger data encoding


There's a possibility that re-compressing the set of runes will not
fit in-place.

#1 = $4d57f-4da80 ($502)
#2 = $4da81-4def1 ($471)
#3 = $4def2-4e3ed ($4fc)

Note: The first byte is a selection byte.


Memory report for 'sylvan.gg', flag = 0xff, limit = 0x30
-----------------------------------------------
00000389 @ $0000BC77-0000BFFF (*1)
00001624 @ $0004E9DC-0004FFFF (*2)

; ________________________________________________________

We have room to add code for a stronger bitmap compression (see *1).

Usage    Size   Desc.
Raw      $ce0   Normal 4-bpp bitmap data
PS1      $7ac   RLE
PSG      $52c   RLE / LZ
ST (*)   $502   LZ
SFG:FC   $4b6   LZ 2-bpp interleaved

Not much potentially gained.


Or just use the padding space (see *2). Easier.