[Graphics] Editing .tilemap files in PokeYellow?

I'm kinda surprised nobody did this before, but I want to create a hack of Yellow with Eevee instead of Pikachu. Most GFX are .png files, so they can be edited easily. However, for the title screen, they are in .tilemap format. I used Tilemap Studio to see the following files: ''pikachu.tilemap'' and ''pika_bubble''... but nothing appears on TileMap Studio. I thought it was because the source code lacked .png files for them. So, how do I edit the .tilemap files to make an Eevee instead of Pikachu? It's 12:30 AM where I am, so I'll check if someone has the answer tomorrow morning.

NitroHedgehog said:

I'm kinda surprised nobody did this before

Click to expand...

Actually, a hack like that does exist. It's not complete though.
Pikachu's cry plays in the titlescreen, and also whenever you interact with Pikachu in the overworld.
It's missing mugshot sprites too. Whenever you interact with Eevee, Pikachu shows up.
If you intend to do something better or more complete, that could be cool.

NitroHedgehog said:

but I want to create a hack of Yellow with Eevee instead of Pikachu. Most GFX are .png files, so they can be edited easily. However, for the title screen, they are in .tilemap format. I used Tilemap Studio to see the following files: ''pikachu.tilemap'' and ''pika_bubble''... but nothing appears on TileMap Studio. I thought it was because the source code lacked .png files for them. So, how do I edit the .tilemap files to make an Eevee instead of Pikachu? It's 12:30 AM where I am, so I'll check if someone has the answer tomorrow morning.

Click to expand...

I cloned Pokeyellow to check it myself.
You load the tilemap first, and then its tileset starting at the tile(?) $080.
Basically, you want to open Tilemap Studio and then:
Tilemap -> Open -> gfx\title\pikachu.tilemap as Plain Tiles.
Tileset -> Add -> gfx\title\pikachu_bg.png, Start at ID $080
Once you've done that, you set the Width to 12 and start to edit.

Thanks! I successfully cloned the repo you gave me, I did some edits, but now I am getting the following error when trying to compile.
error: Unable to place 'OAM Buffer' (WRAM0 section) at $C300
I dunno what to do for that. Also I use RGBDS 3.5 for this one, because newer ones don't seem to work...