View Full Version : Render To Texture with GeForce FX
is there an existing PBuffer class for Linux out there that can bind its color values directly to a texture? I think there were problems with the GLX version in the past? Has anything changed since then? I am using a GeForce FX. Can someone give me a link?
[This message has been edited by mako (edited 09-02-2003).]
09-02-2003, 08:40 AM
There is no OpenGL extension that allows you to render directly to a texture under Linux. There is one for Windows (WGL_ARB_render_texture) but there is no GLX equivalent yet.
09-03-2003, 03:55 PM
WGL_ARB_PBUFFER is supported by nvidia under linux. Check out their hw_shadowmaps_simple.cpp from the sdk. Of course this example copies the depth values to the pbuffer, but you could also copy the color buffer instead.
09-03-2003, 04:11 PM
Ooops - I meant GLX_SGIX_PBUFFER...Sorry. Anyway checkout the simple_pbuffer and simple_shared_pbuffer sample from the nvidia Linux sdk. The second one renders the glut teapot to a pbuffer and uses glCopyTexSubImage() to map it to a quad.
no WGL* stuff is supported under linux. For pbuffers is GLX_SGIX_pbuffer supported by nvidia and also in the core GLX 1.3
2 minuts to late http://www.opengl.org/discussion_boards/ubb/smile.gif
Yes, I already use this PBuffer extension and copy the color buffer about 16 times per frame via glCopyTexSubImage to a texture. Unfortunately, that consumes a lot of time. Time that I could spend elsewhere, if I could bind the PBuffer directly to a texture. Hope, there will be an appropriate extension in the near future.
09-04-2003, 12:24 AM
Yep, I'm waiting (patiently, so far) for GLX_ARB_render_texture, watching every set of ARB meeting minutes, watching every NVIDIA driver release... only to be disappointed.
It's almost enough to make me start writing software under Windows...
There will be no GLX_ARB_render_texture, see http://groups.google.com/groups?hl=en&lr...r%2Bto%2Btextur (http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=bhjpf8%241l6l9%241%40fido.engr.sgi.com&rnum=9&prev=/groups%3Fhl%3Den%26lr%3D%26ie%3DISO-8859-1%26q%3Drender%2Bto%2Btextur) e%2Blinux%26meta%3D
We call glCopyTexSubImage for pbuffers but that is just a function name, it does not say what happens on the card. Calling the same function is faster for none pbuffers. If it was so easy as just to copy a pointer would nvidia have done that a long time ago. http://www.opengl.org/discussion_boards/ubb/smile.gif
Both ATi and nVidia has render_to_texture
and pbuffers under Windows and the difference is not that big.
I dont think that the superbuffer extension will solve all problems for todays hardware.
09-04-2003, 03:35 AM
*Sigh*, oh well, at least I can stop waiting. Or rather I can start waiting for superbuffers under Linux (let me guess, July 2004).
OK, Windows here I come...
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