Well Xsp really could use some looking-into. After 6 hours of SDL hacking / testing i've learned more and made some progress:

The SDl documentation project has been a big help:

http://docs.mandragor.org/files/Comm...on_project_en/

Anything done with SDL_Flip seems to break it, as does calling SDL_LockSurface.

Initial Credits screen and Intro Videos are playing fine doubled.

Main game menu shows only currently selected menu item doubled, rest is single.

Configuration screen flips back and forth between double and single.

Planetary Navigation shows as mostly single, with occasional flickering doublesize flashes.

Conversations are strange beyond description.

Melee runs ~nice~ and ~fast~ now! Not noticeably slower than pc. But single size junk is being shown and ship status regions are flashing over the playing field.

Interstellar travel is displaying mostly doublesize, but coordinates upper left are single sizing and the display is shifting up and down like an earthquake effect.

Anyway, just wanted to let you know there's some progress after banging my head against this for the last few days.

Update 2007.04.02: No good news yet on the pixeldoubling. I'm still learning by trial and error what works, and what breaks with sdl and pixel doubling. It's like an impenetrable black box being steered by a malevolent demon-imp. Need to take a break from it for a while.

Update 2007.04.08: Here's a picture of the problem...