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extract genesis sprite maps?

Posted: Sun Sep 07, 2008 1:44 am
by baroughter
Sorry, this is an absolute newbie question. I have been messing around with Gens Kmod to look at sprites and to dump tiles.

There does not seem to be a good way to simple dump all of the sprites. I would like to dump all of Toejam's walk animations in Toejam and Earl. I would also like to understand how Sprites are stored. Are they stored on a map like the background tiles, or is each sprite stored separately? I am basically trying to replicate whatever method is used in my own simple Flash game.

Thanks for any help.

Posted: Sun Sep 07, 2008 6:29 am
by Shiru
SMD can display sprites of few predefined sizes, from 8x8 (1 tile) to 32x32 (4x4 tiles), with step of 8 pixels. Video controller construct sprites from one or few subsequent tiles, going through sprite list. Each sprite in the sprite list has X,Y position, size and other attributes (palette, etc), and number of first tile of this sprite in VRAM. Sprite list isn't static, it usually generated by game code every frame. Sprites larger than 32x32 can be displayed only as few hardware sprites. Only game code knows, how those combined sprites stored in memory, and uses that information to generate sprite list. Way of storing such information isn't defined by hardware and can be arbitrary, different for each game.

Posted: Sun Sep 07, 2008 1:42 pm
by TmEE co.(TM)
If the game uses DMA (directly from ROM) to update tiles that are used for the sprites (like in Sonic 3), you can track down the addresses and extract GFX data from the ROM... you may still have to fit tiles together to form a sprite as it look in the game.