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sofakng
05-29-2007, 01:26 PM
This probably seems like a silly question, but does glGetString(GL_EXTENSIONS) display every supported OpenGL extension supported by the video card?

I've run this program on my laptop and it does NOT show any of the following extensions:

WGL_ARB_pbuffer
WGL_ARB_pixel_format
GL_EXT_framebuffer_object

Does that mean the ONLY way I can render-to-texture is by using gltexSubImage2d and glReadPixels?

Thanks,
John

zed
05-29-2007, 02:13 PM
WGL_ ... extensions arent in thew extension string (theyre windows specific theres also linux/apple extensions as well)

glReadPixels doesnt update a texture
gltex(Sub)Image2d
glCopytex(Sub)Image2d
are what u want

GL_EXT_framebuffer_object also can do it,
but your card mightnt support it

look here
http://www.delphi3d.net/hardware/extsupport.php?extension=GL_EXT_framebuffer_object
(this is prolly not a complete list)
if its not here + youve got the latest drivers post what gpu u have + someone could tell u if it supports FBO

ZbuffeR
05-29-2007, 02:13 PM
Probably, yes.
Unless you have checked something like "limit OpenGL extension string" in Nvidia Control Panel...

Have a look here, to check whether your card really don't have any of these extensions :
http://www.delphi3d.net/hardware/index.php

mfort
05-29-2007, 10:25 PM
For complete list of extensions you must call
glGetString(GL_EXTENSIONS)
and then
wglGetExtensionsStringARB(wglGetCurrentDC())

The second call is extension function itself
which must be obtained before invocation.

PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB = (PFNWGLGETEXTENSIONSSTRINGARBPROC) wglGetProcAddress("wglGetExtensionsStringARB");