Whenever I run my allegro programs, I get a message that tells me its incompatible with Aero and must switch to basic. Does anybody know the reason for this or how it can be fixed?

I'm using Allegro 4.2.1 and whatever the newest VC++ Express 2005 is called. I'm also using FMODEx, but I doubt that has anything to do with it.

Here's my graphics initialization :

set_color_depth(32);
set_gfx_mode(MODE, WIDTH, HEIGHT, 0, 0);

where:

#define MODE GFX_AUTODETECT_WINDOWED/**/
#define WIDTH 640
#define HEIGHT 480

If you use a DX window with a different color depth than the desktop, it must shut down Aero.

Or in other words:
Use set_color_depth(get_desktop_color_depth()) to avoid this. You might want to check first if the color depth is acceptable, though.

Yes, that worked perfectly. Thank you.

By acceptable, I assume you mean acceptable for the application, ie. checking that its not 8 bit if my bitmaps are 24 bit? I mean, the desktop color depth has got to be acceptable for the PC if the desktop's using it.

Yep, I meant ok for your application. If you require an alpha channel (for example) you might run into a problem if the desktop runs in 15 bits.

Question: What if your program uses 8-bit colour? Will that still shut down Aero?

This is good to know so that my future games don't interfere with how Vista does things.

--- Kris Asick (Gemini)
--- http://www.pixelships.com

"so that my future games don't interfere with how Vista does things"

That's terrifically sporting of you old chap A less generous person would suggest that it's Vista interfering with your games.

Well, you know what they say. If you can't beat 'em...

Besides, I'd rather my games work than make something that doesn't work and blame someone else. That would just be counterproductive and stupid. In fact, I find it very humorous when a programmer blames Windows for doing something new which messes up their program because I think to myself, "Geeze, those people wouldn't last very long programming for video game consoles... every three to five years you have to learn to write for a whole new system..."

--- Kris Asick (Gemini)
--- http://www.pixelships.com

Right. Thats Microsoft's job.

Excuse me, but... Will I have to do the desktop pixel depth test if my game runs in fullscreen mode?

No. Going full screen requires exclusive access to the card, so it doesn't matter what depth you use.