GP2X Allegro Problem


spoyser

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It has been brough to my attention that my port of o2em hangs at a black screen if it is the first application that is run after boot up.

I have tracked this down to a call to set_gfx_mode, I noticed there was a thread about this a while back (http://www.gp32x.de/board/index.php?showtopic=24143&hl=) but it seemed no solution was found.

From reading that thread it seems the set_gfx_mode call waits for the blitter to become inactive before returning, unfortuantely it seems this never happens unless some other application is run first, eg g2xmenu (I use this hence why I didn't come across the probelm originally).

Anyone got any ideas, or is there a simple way of making the blitter become inactive?

TIA
 
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Look up the low level blitter access methods and just do a dummy operation first?
 
Look up the low level blitter access methods and just do a dummy operation first?

Cheers for that, after a few false starts (wasn't enabling the blitter to start with!) finally got the "dummy" blit to work which has indeed worked around the bug in the allegro code

Maybe the allegro source/library should also be updated, I can't believe I'm the first person to have worked around this bug, and most likely won't be the last!
 
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Good that you got it working. Whoever ported allegro should indeed look into fixing the issue.
 
It's always worked fine for me, so I haven't really been able to fix it. :(

I did make some fixes for firmware 2.0 though, which I never released, too much hassle. I was going to add Allegro to the Open2x svn repository, but I didn't get round to that either, sorry! I ought to upload new patches or something but I really have trouble finding the time. I've also yet to find anyone who's willing to actually build the library themselves.

It would be great if you could compare Allegro's existing dummy blit to whatever you did to work around the problem, and figure out what's missing from Allegro's one.
 
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