Re: [Plib-users] clipping performance question.

[Curtis L. O. <cu...@me...>]

Gouthas, Themie writes:
> Just an optimization question for frustrum clipping, which would better be
> directed to an OpenGL format, but this forum is more convenient at this
> point in time.. 
> 
> For basic line strips, say of 100's to 1000's of points. Is it worthwhile
> going to the trouble of calculating a bounding spehere  for clipping to the
> view frustrum, or is line clipping pretty efficient. You would think that an
> intelligent implementation would check the end points of a line segment
> first and not attempt to draw it if both were out of the clipping rectangle.
> Anyone have an idea what OpenGL does? 

The middle of the line strip could intersect the view volume even if
niether end point was visible.  Also, there's nothing that says a set
of points have to be in a straight line, so it could wind in and out
of the view volume several times.

Curt.
-- 
Curtis Olson   Human Factors Research Lab       FlightGear Project
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