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Author Topic: Protected Tile Data?  (Read 1511 times)

Arima

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Protected Tile Data?
« on: September 20, 2016, 02:05:24 am »
I've been contemplating about trying to make a Graphics Hack.
I have a very good understanding of Tile Data and how to find what I'm looking for inside of a ROM Image.
But there is one serious Question that I need to ask in regards to SNES ROMs.



What programs do I need to use to view and edit Protected Tile Data?
Because I've learned from my experience that there are lots of ROMs out there that are protected against normal programs such as TileMolestor, TileLayerPro, and YY-CHR.

MathUser2929

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Re: Protected Tile Data?
« Reply #1 on: September 20, 2016, 02:29:56 am »
I dunno, but this one guy who made a hack had to leave part of the Toad Sprite on the winning screen as he couldn't find the rest of the sprite. So it was kirby with toads legs. Some people did get it working I think tho. There's been complete graphic hacks since then.

Arima

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Re: Protected Tile Data?
« Reply #2 on: September 20, 2016, 03:05:26 am »
I dunno, but this one guy who made a hack had to leave part of the Toad Sprite on the winning screen as he couldn't find the rest of the sprite. So it was kirby with toads legs. Some people did get it working I think tho. There's been complete graphic hacks since then.

You're referring to the "Mario Kart R" hack. I've already seen that problem.
The reason why he couldn't make a complete edit for Toad's sprites is because some of the relevant Tile Data is encrypted/scrambled and he simply lacked the knowledge and understanding on how to find and modify it, hence the reason why I call it Protected Tile Data.

DarkSamus993

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Re: Protected Tile Data?
« Reply #3 on: September 20, 2016, 10:40:55 am »
What programs do I need to use to view and edit Protected Tile Data?
Because I've learned from my experience that there are lots of ROMs out there that are protected against normal programs such as TileMolestor, TileLayerPro, and YY-CHR.

What you are referring to is compressed data, which was mainly done to save space. When tile data is stored uncompressed it is usually when those graphics needed to be loaded to VRAM quickly and there wasn't time to decompress them before the next frame was needed (ex: playable characters). There are ways around that though, such as the case with Super Castlevania 4. The player graphics are compressed, but they are decompressed to WRAM when the game boots up and just uploads from WRAM to VRAM as needed.

To answer your question, there is no single program that can deal with compressed data, mainly because each game handles things differently (most SNES games used a variant of RLE or LZ/LZSS compression). If no one has already created a tool for the game you want to edit, you are going to have to get a debugger emulator (Geiger's or BSNES+ in the case of the SNES) and learn to read and understand ASM. Once you locate the decompression routine and understand what it does, then you can program a tool to decompress the graphics. Decompression is the easy part, the game gives you the blueprint for that, coding a recompressor can be a bit more difficult. It takes a lot of work, but it's doable if you put your mind to it.

RetroHelix

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Re: Protected Tile Data?
« Reply #4 on: September 20, 2016, 02:25:04 pm »

Bahamut ZERO

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Re: Protected Tile Data?
« Reply #5 on: September 20, 2016, 02:35:49 pm »
I'm about 60% sure Lunar Compress would be quite helpful in this situation.

It's a command line tool, but a DAMN good one. I've used it to edit compressed Starfox graphics in the past.
Like Super Mario Land? Then you'll love my first completed Rom Hack: Maniac on the Run!

Arima

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Re: Protected Tile Data?
« Reply #6 on: September 20, 2016, 04:10:48 pm »
Thanks for all the helpful information, everyone.
This Decompression and Recompression aspect of Graphics Hacking is definitely as hard as I was expecting it to be.
I now have a new respect for the people who make Graphics Hacks: They make it LOOK Easy when it really Isn't.