Yes, I dev for the GP32 (amongst others) but this IS the gp32 dev board, and this IS a GP32 question!
Yes, the framebuffer is rotated 90deg CCW on the GP32, this is a common fact:
http://www.cs.helsinki.fi/u/jikorhon/gp32/docs.html (SPIVs page)
http://www.gp32x.de/board/index.php?s=&am...st&p=315460
So the first pixel is BOTTOM LEFT
As you progress the framebuffer you move UPWARDS
And you end at the TOP RIGHT
So to scroll horizontally, you set the framebuffer at your image data and jump it around by
height pixels up or down.
And of course I have looked at Mirkos code, but rather than complain about it, I vastly improved it (writing a completely new set of graphics routines - Mirko had per-pixel bound checking) and used it as the basis for my own SDK.
LOL, my bad, I didn't realise I was in the GP32 forum, I thought we were talking about GP2X development. And yeah, the per-pixel bound checking in his function dedicated to writing pixels to surfaces is what horrified me the most.