I have encountered a strange problem, trying to create a DirectX game.

I am working in a 640 by 480 8bit color mode with DirectX and simple 2-dimensional drawing using DirectDraw.I use a 256 color palette.


When I run direct draw code that involves the Flip() function, sometimes all the colors
displayed get changed. So all the bitmaps, bobs, and other graphics are displayed, but the colors are not what they are supposed to be. This happens at the start of the program and continues unless I re-initialize direct draw.

Interestingly, this occurs only some of the time, so most of the time the program runs just fine. But sometimes, I turn it on and the colors are messed up.

Also, I have noticed that when I access a bitmap or something and then run my game, this weird
color changing effect has a much higher chance of occuring.

I even tried not drawing any bitmaps
and just having a black screen (fill the back_buffer with black). Still, the problem occurs. I get a light blue screen instead of black.


I am running this code on a Windows XP machine. When I ran the same code on Windows 98 (before upgrading my machine to XP), this never occurred. I tried this executable on another Windows Xp machine and the problem still occured. Also, this
doesn't happen for just my code. I tried Andre Lamothe's code (the alien prog11_6.cpp). My machine runs the executable provided on the Dummies CD fine. However, after I compile and link the code on my machine...
the resulting executable has this weird colors problem. Thus, I think that creating Directx executables on a WindowsXP machine causes this strange problem to occur.

Has anyone else encountered this problem? I upgraded to latest Directx SDK and the thing persists. I've been trying to figure this out for a week and to no avail!

It could be something with your compiler. Or a compiler setting.

I've seen comercial DirectDraw games not notice when they lost thier palette. I've seen it a few times in StarCraft. Either when tabbing out or another program like outlook bringing up a notification window. I've also seen it randomly. I can't tell you whats making it happen is your code, but are you watching for the device lost errors and recreating the device?

-Ed

I noticed that the WM_PALETTECHANGED message kept getting sent.

I tried to counter this by re-setting the palette to what I needed it to be after every such
message. However, whatever is responsible for sending it does it infinitely, so that it happens again about 3 secs after I change the palette to what it should be.

I have no idea what sends this message or how to stop it from affecting my palette.
This happens on 2 of my computers, which both have WindowsXP.

Why in the world would you want to use 256 colors on a nice, modern, Windows XP machine? That's just crazy.

I bet it has to do with that. DirectX Engineers probably don't test newer versions for such a thing, even though it should be backward-compatable. IDK, sounds crazy. Maybe something running in the background? Try starting it in safe mode. If it still works, it's probably some program in the background.