On Friday 29 August 2003 13:33, Alexander Maryanovsky wrote: > >they map each window as a texture map over > >a rectangular 3D object using the graphic's hardware 3D acceleration > > mode. > > I have a (perhaps offtopic, but I changed the topic :-)) question - > why is it that hardware acceleration for 3D operations so much better > than for 2D operations (which are presumably easier). Seeing as 2D > graphics is needed much more often than 3D, has been needed for much > longer and is probably much easier to implement, I'd expect 2D to > have the faster stuff. The above description implies that > QuartzExtreme is "cheating" by using 3D operations for tasks that are > essentially 2D. Why is the situation like this? To support all those > First Person Shooters?
Actually, for high end graphics hardware (say latest ATI/Nvidia cards) the very same hardware accelerated operations that are used for 3D are also used in 2D. In XFree86 speak, this is what the XAA (XFree86 Acceleration Architecture) layer does - intercept suitable 2D calls and implement them using available hardware acclerated features, the same ones that are used in 3D: thus XPutImage will get translated to the same hardware primitive and implments glCopyRegion etc. It's just that 3D is so much difficult to get fast/right, that's 2D accell and XAA are hardly ever gets talked about, especially since pure software implmentation are usually good enough anyways. Gilad -- Gilad Ben-Yossef <[EMAIL PROTECTED]> http://benyossef.com ================================================================= To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
