#80456 - Dan_attacker - Sat Apr 22, 2006 1:24 pm
I just started porting a game I made for the GBA to the DS and I can't get the rotoscale background to do anything. I'm using mode 1 and I can see all backgrounds fine, but when I change the registers (REG_BG2X_SUB, REG_BG2Y_SUB, REG_BG2PA_SUB, REG_BG2PB_SUB, REG_BG2PC_SUB, REG_BG2PD_SUB), nothing happens. Does it not work like on the GBA? How do I fix it? Thanks.
#80640 - Dan_attacker - Mon Apr 24, 2006 11:07 am
Ok, I got it to work and here was the problem...
The information from this tutorial (http://www.dspassme.com/programmers_guide/tutorial/modes.html) says that BG2 on Mode 1 is a rot/scal BG. I believed this to be true, but after looking through this (http://nocash.emubase.de/gbatek.htm#dsvideo), it says this...
Mode BG0 BG1 BG2 BG3
0 Text/3D Text Text Text
1 Text/3D Text Text Affine
2 Text/3D Text Affine Affine
3 Text/3D Text Text Extended
...
BG2 on Mode 1 is just a text BG. I just set it to Mode 2, where BG2 is a rot/scal BG and everything worked great. So, that tutorial should be fixed. Also, Dualis doesn't appear to emulate rot/scal backgrounds at all.