Re: Why no display lists in Quesa?

[Frank C. <dev...@ch...>]

On 18-Jun-05, at 6:55 PM, James W. Walker wrote:

> On Jun 18, 2005, at 11:45 AM, Mikey wrote:
>
>> I've just been going thru the Quesa source code and I don't see  
>> any use of OpenGL display lists.  I'm surprised by this since that  
>> seems like it should be a relatively straight-forward optimization  
>> when using retained mode.
>
> That's a good question.  I can think of one design decision that  
> wouldn't be very compatible with display lists: Quesa does its own  
> backface culling.  You wouldn't want a display list that you'd have  
> to rebuild whenever you move the camera.
>
> The founder of the Quesa project, Dair Grant, is no longer  
> participating.  Anyone else know the history of this?

Another problem is that retained or not, no mesh is guaranteed to be  
static. Even if you track data locks/replacements there's no "safe"  
time to build and use a display list (even without software backface  
culling). The best you can do is use something like VAR or VBOs,  
cause you certainly don't want to go compiling a new display list  
every time something changes.

The pre-processing is a bigger bottleneck than the rendering though -  
There's gotta be a way to avoid stuff like software backface culling  
when using an interactive renderer...

Frank.