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Author Topic: Help editing graphics (compression?)  (Read 453 times)

Iredc

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Help editing graphics (compression?)
« on: November 22, 2020, 01:37:41 pm »
I've recently translated a GBA game: Fullmetal Alchemist-Sonata of Memories. But there are some graphics that I still can't edit.
At first glance, they seem uncompressed. But there is code inserted in the middle of the graphic. I think these codes control the offset shifts between one tile and the next (not all tiles of the graphic are at the same offset).
It's better seen in the image below. On the left, it's the tile as it appears in-game. On the right, it's the tile in Tile Layer Pro.



As you can see, the code appears as strange pixels that aren't part of the actual graphic.
The problem is I can't delete those pixels without messing the entire graphic, and they often get in the way when drawing English letters.
Other than this, even when the tile is clean enough, the drawing may behave in unexpected ways. For example, pixels may appear mirrored, or shifted to the left in-game.

Anyone knows what's this about? Is it some kind of compression? I don't know how to get around this. I could edit some with much difficulty, but others seem impossible.

FAST6191

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Re: Help editing graphics (compression?)
« Reply #1 on: November 22, 2020, 03:01:01 pm »
If it is just a few control bytes between tiles (odd but not unheard of) you might want to grab a copy of Crystaltile2. Its tile editor/viewer has the option to skip bytes for just this sort of reason.

Failing that most of them should have the option to start bytes at different locations with keyboard commands of some form. Tiled2002 is one of my other go to editors and it has things like this (though with GBA modes its offset slider is a bit crash prone). Might get annoying doing a bit of finger wizardry between tiles but should still be enough to get something done.

Iredc

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Re: Help editing graphics (compression?)
« Reply #2 on: November 25, 2020, 06:23:20 am »
I've been trying several things, but still can't achieve anything.
Sometimes, even erasing the pixels that are part of the picture messes the entire graphic.
So I don't know how to proceed, if I can't even erase the Japanese letters.
That's why I thought that maybe there's some sort of compression going on. And that trying to directly edit these graphics in a tile editor isn't the right approach. Honestly, I've never seen graphic tiles that behave in this strange way. :o