It's mainly sprite drawing/generating.
The first is just blitting columns of the same sprite, but the second is more interesting : I'm generating a sprite on-the-fly. I was inspired from xor texture, but couldn't grasp the true form of it in a B&W screen, I remebered of the munching squares demo. It's principally the same mecanism, but animating it is more easier and fun.
EDIT : Some news. I have to take a lot of informations in the original Game.
Here what I know:
-GBA data is little endian. That make resd the data easier... (In fact no)
-Xp caps are 32-bit encoded, in little endian. 100 levels/character... :D
-Stats are semi-random : with each level we have different and random stats bonus. Eqch 10 levels the game tries to adjust your stats to a predfined stats stored in data... Yup, I need to collect 10*6 stats/character.
-PSI learning table...
-I get more or less 324 bytes to collect and understand per character.
-Line/move/IA databasrs planned... That's again a lot of data... :/
Oh, and I use now the Text Axiom. I certainly use Pucrunch too. There is a lot of data in this game. FYI the original game barely stays in a 32MB cartridge, the max for a GBA. And it's mostly compressed... Imagine what could they do if they had to do M3 on a 128MB DS cartridge, or 8GB 3DS one!
I'm planning on 24*24 sprites max for monsters, more animated backgrounds (certainly a fire for the third), But for now, I'll start on rolling meters, the main part of the battle engine.
I played again the game, and I noted some near things with these rollers, here is the most interesting:
Some ennemies are littlrally livings bombs-on-legs, and explodes dealing generally mortal damage, but there isn't enough time for our players to die because once the message "YOU WON" is displayed, the odometers stop instantly, even if you litteraly were blown off...
I hope a day playing a lot with this engine. I love how thr odometer add a stressing critical strategy core.
Oh, and what pc/calc tool is available for 24*24 sprites? (Preferably with 8*8 chunks, thanks)
EDIT 2: I started working on game logic (UI and key reaction), It's quite hard and new, because there are only non-modal UI, I need to constantly update game state, not only UI logic. So I started working on the game structure, and that seems quite nice at the moment. I can "select" bash, guard and PSI for character that have the right options... Only the dialog box is shown when selecting PSI. I need simple stats and at least an ennemy to be fully capable of correctly working...
EDIT 3: I'm now, at this moment, getting some data. I'm getting level stats, and experience level curve. Little endian, so reversed. RomHacking, here I come.