Everybody who has a DVD-player on his / her computer and who tried to make a screenshot of it, probably found out that it somehow isn't possible.
For you people who don't know what I mean, here's the deal:
When you mkae a screenshot from a DVD-movie, and you paste it in Photoshop, you'll see something amazing, when you move the picture in Photoshop you'll see at the place where the DVD picture should be the DVD-player (which is still on), move the picture and the picture from the DVD will move with it!!
When you keep on playing the movie in the DVD player, you can just use Photoshop to watch the movie....
Now I was wondering, how is such a thing possible? In Delphi there's also such kind of a feature, which is to use the NoZOrder, which will grab the desktop image. In C++ I don't know any of such a feature...I was thinking about some kind of an Alpha channel it uses to point to the z-order, but after some thinking I don't think that is possible.
So, do any of you guys have any idea how this is done? I don't need source, just the theory behind it, and the names of some functions which might do this.
Thnx in advance.