GL_EXT_vertex_buffer not supported
by Duncan Gray · in Torque Game Engine · 07/18/2006 (1:41 am) · 7 replies
The GL_EXT_vertex_buffer is not correctly implemented on Windows it seems. The Mac source at least checks for it however the actual extention itself does not seem to exist.
Its quite important, just search through the code and see how often dglDoesSupportVertexBuffer() gets called, yet this extension is non-functional by the look of it.
I searched google and got nothing, it does not even exist.
I suspect the extention which was meant to be implement was ARB_vertex_buffer_object
Can anyone shed some light on what the situation is because ARB_vertex_buffer_object does seem like a HUGE performance boost for TGE.
.
Its quite important, just search through the code and see how often dglDoesSupportVertexBuffer() gets called, yet this extension is non-functional by the look of it.
I searched google and got nothing, it does not even exist.
I suspect the extention which was meant to be implement was ARB_vertex_buffer_object
Can anyone shed some light on what the situation is because ARB_vertex_buffer_object does seem like a HUGE performance boost for TGE.
.
About the author
#2
I have implemented GL_ARB_vertex_buffer_object. In fact you get a big (not HUGE) performance boost, but in order to get it you need to make significant changes in the rendering code of at least meshes and terrain. The terrain is particularly interesting. I wrote a new code path where the whole terrain block is simply drawn as one single huge triangle strip stored in a static vertex buffer, thus by-passing ALL the lod/culling stuff. I expected performances to be worse, but... the framerate actually increased by a lot (about 30%) on my ATI X1600. Anyway my test was with only one single terrain texture, using more textures will require more work. Moreover, this code path can't replace the "normal" one because not all video cards have that much (fast) video memory.
07/18/2006 (3:28 am)
Yup. The programmers had better named it GL_GG_vertex_buffer or something like that, as they would have avoided a lot of confusion. BTW that would have been consistent with the GL naming convention that reserves _EXT_ for extensions used by more than one vendor.I have implemented GL_ARB_vertex_buffer_object. In fact you get a big (not HUGE) performance boost, but in order to get it you need to make significant changes in the rendering code of at least meshes and terrain. The terrain is particularly interesting. I wrote a new code path where the whole terrain block is simply drawn as one single huge triangle strip stored in a static vertex buffer, thus by-passing ALL the lod/culling stuff. I expected performances to be worse, but... the framerate actually increased by a lot (about 30%) on my ATI X1600. Anyway my test was with only one single terrain texture, using more textures will require more work. Moreover, this code path can't replace the "normal" one because not all video cards have that much (fast) video memory.
#3
07/18/2006 (4:17 am)
Damn, google did not find that earlier GG thread. Good to know though. Thanks
#4
07/18/2006 (4:25 am)
@Alberto, how about a resource on your GL_ARB_vertex_buffer_object implementation.
#5
07/18/2006 (9:28 am)
@Duncan, I am actually considering doing that. I only have a little problem: I have extensively rewritten the whole GL extensions binding code, so I need some time to get back to something that works right from the TGE code base. BTW, I also wrote code for EXT_framebuffer_object which might also interest you for your shadows ;)
#6
Did Joti's changes (version 7) make any improvement to your shadow test?
07/18/2006 (1:51 pm)
@Alberto, yeah I already added EXT_framebuffer_object and render to texture to the shadow resource. I'm still busy doing QA on it and will upload the new version in a few days.Did Joti's changes (version 7) make any improvement to your shadow test?
#7
07/18/2006 (2:14 pm)
@Duncan, as I said in the other thread, I finally chose to follow a completely different approach, so I did not even try Joti's changes. I'm sorry. 
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