Hello! It's been a while since I've been on the Rom Hacking scene, and I decided that I'm finally going to sit down and figure out how to do some sprite hacking. The thing is... I have no idea where to start.
If you remember my previous post about IRQ's, at least with that I was able to look at a document, figure out the addresses and parameters, and just needed a little help doing the code.
Sprite Hacking... well... I don't know what the hell I'm doing! I can look at a disassembly document of a game and have that tell me the location of the ASM of the boss or enemy I want to change; but even that is just simply changing a LDA value so that the boss jumps higher, or runs faster. Not really that significant. The game jumps to the main thread, or goes into some different part of the ROM, and I don't know what it's doing!
I'm currently trying to modify some of the Megaman 4 bosses, and Matrix's Megaman 4 document talks about "Object ASM Private Memory 1 - 8" and "Sprite/Object Arrays". I mean, I understand what "Sprite/Object Arrays" are used for, but I don't really have a clue how to use any of this to my advantage. Especially the "Object ASM Private Memory 1 - 8". This just might be native to the Megaman series in particular, not every game might have this, but I have no idea.
I would like to be able to make minor ASM changes to the enemies and bosses, not crazy changes like a whole new AI, that would probably much later when I understand what I'm doing, and maybe if I understand how the CPU draws sprites on screen I would like to maybe add a tile or two to the enemy design. (But I also understand that could be a LOT more difficult that I think it might be)
Is someone willing to give me a quick seminar on where to start, or a document that I missed that gives a tutorial on the subject? I understand it's a little much, but any help would be appreciated!