Angus Dorbie (dorbie++at++sgi.com)
Fri, 26 Nov 1999 03:37:43 -0800
> ...... But if you are just drawing points, I don't imagine there is
> much to optimize.
:-)
Famous last words.
I could say the same for triangles. You'd be surprised how many people
when drawing points do something slow like:
glBegin(GL_POINTS);
for(i = 0; i<numpoints; i++) glVertex3fv(particle_array[i*3]);
glEnd();
But even that might not be so bad compared to the horror which could be
inflicted. Even ignoring loop unrolling and potentially baroque data
access, I'm sure changing point size is really popular in a particle
model and if you have an OpenGL 3D point extension there to help
anyway......
Many developers just don't think about performance at this level or have
bigger fish to fry, even real-time graphics programmers. Your reply is
perhaps a good illustration of this. I don't mean that last remark to
sound as harsh as it perhaps does. I'm just trying to emphasize that
there's a lot of low level subtle stuff in Performer which is easy to
take for granted.
Cheers,Angus.
-- "Success is the ability to go from one failure to another with no loss of enthusiasm." - Winston Churchill.Performer + OpenGL examples and tutors: http://www.dorbie.com/
This archive was generated by hypermail 2.0b2 on Fri Nov 26 1999 - 03:38:04 PST