Tools needed for this tutorial:
Pokemon Fire Red Rom (Unmodified and modified)
Pokemon Fire Red Hacked Engine
Hex Editor – I will be using Translhextion.
Free Space Finder
Overworld Editor: Rebirth Edition
Nameless Sprite Editor (I will be using classic)
(For HackMew's Tools, I suggest downloading PGE)
I also suggest having a backup of your rom.
Step 1-Applying the hacked engine.
Step 2 – Understanding the data.
When typing pointers, you need to break the original address into three blocks of two and rearrange them like so. 80 00 00 -> 00 00 80 80. You had the 80 because it is located within the rom.
20 is actually 32 in hex, so make sure you convert. I would use the calculator that came with your computer.
Step 3 – Finding the free space needed
Each palette takes up 64 bytes. So multiply 64 by the number of palettes you will be inserting.
EX. 64 * 12 = 768
You would need 768 bytes of free space to insert 12 new palettes. But for simplicity, I will be adding 1 so I need 64 bytes of free space.
I will be using 0x800000.
Step 4 – Editing Palette
Open your unmodified rom in NSE. Then edit a palette to your liking.
I just edit the palette of the hero, as it is the first sprite. Once you’re done we can finally move into Hex! Take note that the palette offset is at $H35B968 or x35B968.
Step 5 – Hex editing
Go to the end of the table and insert your pointer before the 00000000 FF110000 as shown. I just rewrote the ending afterwards. Make sure your table ends with that or else in will NOT work at all.
Now open your unmodified rom in a hex editor. Navigate to the palette offset and copy 64 bytes.
Go back to your hex editor with the modified rom and navigate to 0x800000 and paste the data.
Step 6 – Editing the sprites.
Go to that address in the modified rom. The palette number is the third byte over. So change that to a 20.
Now open your Overworld Editor Rebirth sprites.ini file. Go down to the English Fire red and change the SpritePaletteHeader pointer to 1A2400.
Open the rom in Overworld Editor Rebirth and go to Ruby hero sprite. As you can see, the palette number is now 32. Edit away. Im just inserting the male Fire Red hero since it will look nice.
Step 7 – Fixing a glitch!
Also, another "problem" arises from the mist weather. palette slot 0x1, 0x6 to 0x9 and 0xb are reserved for the mist weather effect. If you don't plan on using it on your hack, and need the extra palettes, you can use them after disabling the effect.
at 0x0805f680 place 22 e0 (for palette slots 0x6-0x9 + 0xb),
at 0x0805f60c place 20 e0 (for palette slot 0x1, the player mist slot).
If you wish to have the player enter misty areas, do not apply the last one.
As a side note, the offset you should use is whatever the offset is but drop the 0x08. Sorry for the confusion. For example; 0x5E5E0.
And now you are done! Here is the finished product.
If you have any questions, have suggestions about thread cleanliness, or this tutorial is unclear, be sure to say something! I hope I was able to help!