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gltester
02-04-2004, 12:59 PM
HI, I'm trying to use the GL_ARB_point_parameters extension but I can't find any examples on Google. Best link I've found is http://oss.sgi.com/projects/ogl-sample/registry/ARB/point_parameters.txt
but that's written in Greek (to me).

I thought I read that Quake used GL_EXT_point_parameters for particle effect explosions etc, and GL_ARB_point_parameters should be almost identical to that.

Can anyone explain or provide links?

thanks

jra101
02-04-2004, 01:40 PM
If you take a look at this page:
http://www.opengl.org/resources/features/OGLextensions

there is an example on using the EXT_point_parameters extension, which is pretty much the same as the ARB version except the functions and tokens are renamed.

There is a GLUT demo referenced on that page, you can find the source here:
http://www.opengl.org/resources/features/OGLextensions/pointburst.c

gltester
02-04-2004, 02:21 PM
<burns>eeeeeeeeeeeexcellent</burns>

I was looking for ARB not EXT.

THANK YOU

Ostsol
02-04-2004, 02:37 PM
They're exactly the same except for the names of the functions and tokens.

gltester
02-05-2004, 11:55 AM
I should have known that, but forgot while I was searching.

New question: I got the extension to work as far as making the size of a point shrink based on distance from the camera. But the extension documentation (see link above) seems to suggest you can make points fade colorwise rather than merely shrinking in size.

Anybody know how to do that? I can't make my points fade no matter what I try.

gltester
02-05-2004, 07:21 PM
I now think that point fading requires the WGL_ARB_multisample extension, which is generally unsupported right now. Grrr.

idr
02-06-2004, 10:52 PM
Does adjusting GL_POINT_FADE_THRESHOLD_SIZE accomplish what you want?

gltester
02-11-2004, 04:21 PM
the fade threshold only works if you also have the multisampling extension, which is basically an SGI-only extension that nobody in the PC world has access to

as far as I can tell anyway

idr
02-11-2004, 10:28 PM
I don't think that's true at all. It works just fine on the open-source G400 driver for Linux. Look at the pointblast demo that is included with Mesa.

harsman
02-12-2004, 01:14 AM
WGL_ARB_multisample is widely supported and if it isn't, there is a large chance the driver supports a core OpenGL version that includes it.