Jump to content
  • Advertisement


This topic is now archived and is closed to further replies.


Can you do destination alpha reads from the frame buffer?

This topic is 6013 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hello. I hope someone can help me with this. There was some running code that did an alpha blend using the destination alpha of the render target, which was simply the back buffer of the display surface. This was on an ATI card. However, all the dest alpha reads on my new NVidia card (GF4MX) simply act as if the dest alpha was a uniform one. I posted the same topic before, but with a different slant becaue I asumed something might be wrong with my card or somethin. But the code produces the same "error" on the reference driver (as someone suggested). It was also suggested that destination alpha reads could only be performed on a render-to-texture setup. I would really like to steer away from this if at all possible, to avoid the extra copy. Also, some cards do not support large, oddly shaped textures nessesary to reproduce the dimentions of the frame buffer. A lot of cards don't support render-to-texture at all, or at least not very well. There are ways around all this, I know, but I'm trying to determine if I'm missing something that might give a clean, simple solution to this. Does anyone know if it is a defined operation to perform destination alpha reads from the back-buffer of the display surface? If not, can you point me to some links on how to best support destination alpha reads (I couldn't find anything in the forums or the articles)? Thanks for your help. [edited by - SH on June 5, 2002 1:52:03 PM]

Share this post

Link to post
Share on other sites

  • Advertisement

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!