Squidge said:
Basically, DPS draws a line at a time, so when raster or transparency effects are used, it's easy to just change things for the next line.
SS draws a tile at a time, which results in a large speedup, but when rasters are involved, this means redrawing stuff that has already been drawn.
Hi, i've been following the SquidgeSNES and DrPocketSNES threads for a couple of months now and I've spent a couple of weeks wandering through the code. I tried to port DrPocketSnes to nokia 770, using SDL on the backend and dropping-in Snes9X components to replace the Gp2x-specific stuff, but the project kind of blew up in my face, and i'm looking for some advice.
The Nokia 770s are linux-based 'Internet Tablets' (High-res PDAs) with SDL capability (SWSURFACE only) Here's the specs on the CPU.
Processor : ARM926EJ-Sid(wb) rev 3 (v5l)
BogoMIPS : 125.76
Frequency : 250 Mhz
Getting Snes9x running was a piece of cake and it runs the Pac Man public domain game quite fast (20+ fps) but things like chrono trigger dive down to 5-6 fps. So I'm trying to solicit some help in porting the gp2x emus and I'm curious about where the major speedups in Squidge and DrPocketSNES are over the stock Snes9x. I'd be very grateful for some informed comment or speculation on these open questions
1) Has anyone compiled the straight Snes9x (SDL) for the gp2x and what kind of fps does it get on Chrono Trigger?
2) How much faster is Squidge/DrPocket vs Snes9x on raster+transparency games like CT? Is most of the gain in the PPU emulation?
3) How much of a speedup is due to rendering direct to framebuffer, vs SDL software surfaces?
4) Have you or Reesy built any unofficial versions (or partial ports) of DrPocketsnes or Squidgesnes for the PC? If i could get my hands on something that used SDL and regular linux libs for the I/O, i'd have a much greater chance at making a working port.
It would be a day of great rejoicing and frolicing if we could get 10-12+ FPS with sound for RPGs on the Nokia 770. If you're curious about them, the 770 is now discontinued and getting sold at blowout prices around $140 in the USA.
My site with works-in-progress is
http://www.pupnik.de
Cheers!