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Splash screen

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takeshimiya:

--- Quote from: thomas on January 20, 2006, 06:40:44 pm ---For me, it looks different. The bitmap is drawn correctly, only the background is not redrawn properly.



This is normal layered window behaviour, nothing to do about.

--- End quote ---

No.
That is the way you can do "faking alpha compositing in linux", taking a screenshoot of what is below the window, thus simulating a real alpha on the image. Only recent cvs versions of X11R7 with alpha compositing activated and new video cards support real alpha compositing.

In windows is another history. Previos versions to Windows 2000 didn't have real transparency and had to do the same trick.
However, in 2000 it supports real transparency.

I wonder if some of you have noticed that wxAUI in 2000/XP haves real transparency when dragging a panel. That's not the case in other OS (Win 9x, Linux, etc).

So here the bug is only wxSplashScreen. Nothing to do with Bill Gates in this case (sadly). :)

sethjackson:
Interesting..... Yeah wxAUI has nice transparency......
I have seen windows apps do the same thing (messed up backgrounds, and weird stuff like that)......

thomas:
Oh darn! Sorry, I meant to quote, but pressed on "modify"... :oops:

...and there's no undo.

EDIT: guess that's a sign to go to bed...

sethjackson:

--- Quote from: thomas on January 21, 2006, 01:34:14 am ---Oh darn! Sorry, I meant to quote, but pressed on "modify"... :oops:

...and there's no undo.

EDIT: guess that's a sign to go to bed...

--- End quote ---

Ok not a problem let me fix it (I guess you wrote that other stuff so I'll leave it so you can copy and paste.)......

thomas:
Here goes, sorry again  :)


--- Quote from: sethjackson ---I have seen windows apps do the same thing (messed up backgrounds, and weird stuff like that)......
--- End quote ---

That is because they suffer from the same problem. The above screenshot was taken on a Windows XP system, and I could show you the same effect with Acrobat Reader or a dozen other programs.
There is no "real" transparency in Windows 2000/XP. Layered windows (that's what MS calls transparent windows) work exactly the way Takeshi described as "faking". The only difference is that the OS does the work, and you are not aware of it. In theory, layered windows should update the bitmap when the background changes by redrawing everything except the topmost window, but in practice, it does not work reliably.

It is of course still possible that wxWidgets adds to the problem by having its own problems. But it does not work properly if you program it in Win32, either. I have done it before, and it works 80% of the time, but not reliably.

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