View Full Version : opening off screen windows

01-20-2004, 10:46 AM
I haven't seen any reference to opening a bitmap that is off screen (and larger than the physical screen) in order to render a high resolution bitmap.

Any references would be greatly appreciated.


01-20-2004, 12:20 PM
What do you mean? Just load a bitmap into a texture. It doesn't matter if it's bigger than the screen, you could have a screen resolution of 400x400 and load a 2048x2048 texture, it doesn't matter.

If you're having a problem with loading textures, take a look at http://nehe.gamedev.net, he's got a lot of good opengl tutorials there and one on texture loading.

01-20-2004, 01:37 PM
This is probably the kind of thing you need. Even with offscreen buffers you can run into size limits that are implementatiosn dependent. You can render offscreen to pbuffers and assemble multiple images into one:

01-21-2004, 05:23 AM
Thanks dorbie, you gave me the beginnings of an answer. However, unfortunately you make it sound like there is no standard answer, other than tiling. It's not bad, because this is not a real-time application, but it would be much more convenient if there is some API that I could use to just render the picture at the desired resolution.

The first reference you cited shows how to do it in Windows, on X, and in SGI. Is there no wrapper for that? The only truly standard option seems to be tiling the bitmap and writing it out into main memory? Is that a correct assessment?