From: Steve B. <sjb...@ai...> - 2003-09-30 13:56:24
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Nigel Stewart and Fiona Smith wrote: >> A quick test suggests that sin() only takes twice as long as a lookup >> of sin on the 800MHz P3 I happen to be sitting in front of. > > > I would assume that would include interpolation. No. That was a straight lookup. I didn't even include time to do a cast from float to int. > But what concerned me more about the FreeGLUT 2.0.0 > cone was the poor glBegin/glEnd layout and no use > of strips and fans. That's a MUCH bigger concern. A capped cone could be made of just two triangle fans. BUT if it's to be smooth shaded, there is a problem with the point of the cone. Pointing it straight 'up' along the axis of the cone doesn't look good for cones that subtend small angles because the shading that's applied is appropriate for a hemisphere and the point of the cone looks very wrong. I suspect that's why GLUT didn't use a triangle fan for that. If you use individual triangles, you can point each triangle's normals radially outwards - which looks much nicer for 'pointy' cones. ---------------------------- Steve Baker ------------------------- HomeEmail: <sjb...@ai...> WorkEmail: <sj...@li...> HomePage : http://www.sjbaker.org Projects : http://plib.sf.net http://tuxaqfh.sf.net http://tuxkart.sf.net http://prettypoly.sf.net -----BEGIN GEEK CODE BLOCK----- GCS d-- s:+ a+ C++++$ UL+++$ P--- L++++$ E--- W+++ N o+ K? w--- !O M- V-- PS++ PE- Y-- PGP-- t+ 5 X R+++ tv b++ DI++ D G+ e++ h--(-) r+++ y++++ -----END GEEK CODE BLOCK----- |