Background

[Lagz]

[rabidhamster]

[Guest]

[Chris]

Really bad screenshot is quite an accurate reference to the way some programs do it. They copy the windows screen to a texture, and colorkey on the desktop color. You can find the evidence if you start a paint program and find the color their using (it's not your desktop color - it's changed, often to a dark ugly greeny blue)

There's a better way than this, but I got no idea about it, Seems the people who work it out stay tight lipped about it.

[rabidhamster]

I don't think that is copying to a texture though - its actually a feature of the video card known as overlay. I know most DVD players use it, as did my old Win/TV card (just do the aforementioned screenshot). It does colorkey, but without copying the windows desktop to a texture. The bad graphics quality is probably due to newer versions of windows trying to add a funky shadow behind the desktop text and hence corrupting the colour.

It seems OpenGL will do it via the use of (yet more ) extensions. There's a bit on how to do it here:



but this particular article seems to deal only with overlaying one openGL window on another - not overlaying it on a standard window or desktop. Still, we can rest assured that if there was a way, ATI will have half-implemented it and it will only work on NVidia cards

[Chris]

What about doing something like this - setting the desktop window as transparent, and then loading r4 full screen behind the desktop. You'd need another hack to to put your program under the desktop but should be possible.

[rabidhamster]

Seems like a plan. When i get some time i may see how well it works. Being able to find the List's handle is very useful though - presumably i can attach R4's window's handle to its parent and make it run behind the list.

It is a massive cludge, but it does seem that the vast majority of interesting windows API programming consists of cludges

- Gordon