I have been playing around with hacking 7th saga for years and have been slowly increasing my skills. I have a projects page on RHDN that
I usually post different things I work on but I figuard I can post some of this stuff here as well. Here is the last thing I posted for 7th saga.
I started game planing how I want to change some of the battle system so I made a little test rom to test how I want the layers, sprites, and some hdma to be. Here is what I came up with.
It uses 7th Saga characters and enemies, Mystic Ark formations, Treasure of Rudras background, slightly modified Final Fantasy 3 battle menu merged with Star Oceans message box all combined together. This is a mock up test rom to test the layers and hdma. For the most part everything seems to be working good and it does work on real hardware. Looks really cool on a crt.
Here is some pics of the games I used.
I would prefer bg1 for extra spell effects but it wouldn't work due to needing one bg layer for the extra enemies.
If I use a bg layer for the characters, and sprites for all enemies, then I could make a spell effect that makes the characters disappear while the spell is cast and then that bg layer would be free to also use for the spell effects and when the spell is done then the characters reappear. Im pretty sure FF3/6 does this for some spells or at least the characters disappear while the spell is cast. If I did that then I think I can add some of the nicer looking spells from other snes rpg's.
Another good reason for me to possibly change the characters to the bg layer is because of the color math limitation with sprites at pal #0-3. 0-3 color math doesn't work but 4-7 it does which is why some characters color math is working for and some its not.
If the characters remain as sprites then I could possibly be limited to one palette for certain spell effects that go over the battle menu. More than one palette could make the effect go over the menu just like in the image above with kamil and olvan. If the characters are moved to a bg layer then the color palettes that could possibly be used moves to 4 instead of 1.
Something I found while playing around with mystic arks enemies is the hermit from 7th saga has one extra sprite in mystic ark that is not in the 7th saga. Its the 3rd image with the staff in the air. Im sure Ill be adding this extra sprite to the hermit at some point down the road.
