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Chris Lux
07-07-2004, 03:53 AM
according to the 1.5spec ARB_texture_non_power_of_two is specified by the ARB. i am a little bit confused, does this include the EXT/NV_texture_rectangle? in my opinion not!

p.s. does there exist a EXT_texture_rectangle? because the latest glext.h does not include it. i know it is the same as NV_tr, but is it only available in the ATi headers?

-NiCo-
07-07-2004, 04:23 AM
There is absolutely no difference between the EXT and NV texture rectangle.

from glext.h:

#ifndef GL_NV_texture_rectangle
#define GL_TEXTURE_RECTANGLE_NV 0x84F5
#define GL_TEXTURE_BINDING_RECTANGLE_NV 0x84F6
#define GL_PROXY_TEXTURE_RECTANGLE_NV 0x84F7
#define GL_MAX_RECTANGLE_TEXTURE_SIZE_NV 0x84F8
#endif

from glati.h

#ifndef GL_EXT_texture_rectangle
#define GL_EXT_texture_rectangle 1
#define GL_TEXTURE_RECTANGLE_EXT 0x84F5
#define GL_TEXTURE_BINDING_RECTANGLE_EXT 0x84F6
#define GL_PROXY_TEXTURE_RECTANGLE_EXT 0x84F7
#define GL_MAX_RECTANGLE_TEXTURE_SIZE_EXT 0x84F8
#endif /* GL_EXT_texture_rectangle */

Nico

-NiCo-
07-07-2004, 04:26 AM
Also, from the extension spec:

5. How is a conventional NPOT target different from the texture rectangle
target?

STATUS: RESOLVED

RESOLUTION:
The biggest practical difference is that coventional targets use
normalized texture coordinates (ie, [0..1]) while the texture
rectangle target uses unnormalized (ie, [0..w]x[0..h]) texture
coordinates.

Differences include:

+ In ARB_texture_non_power_of_two:
* mipmapping is allowed, default filter remains unchanged.
* all wrap modes are allowed, default wrap mode remains unchanged.
* borders are supported.
* paletted textures are not unsupported.
* texture coordinates are addressed parametrically [0..1],[0..1]
+ In EXT_texture_rectangle:
* mipmapping is not allowed, default filter is changed to LINEAR.
* only CLAMP* wrap modes are allowed, default is CLAMP_TO_EDGE.
* borders are not supported.
* paletted textures are unsupported.
* texture coordinates are addressed non-parametrically [0..w],[0..h].

Nico

Chris Lux
07-07-2004, 09:45 PM
Originally posted by -NiCo-:
There is absolutely no difference between the EXT and NV texture rectangle.i know, but i ask myself, why isn't the EXT stuff in the latest glext.h and only in the (proprietary) ati header file.

-NiCo-
07-08-2004, 01:18 AM
The EXT extension is an apple specification which hasn't been added to the extension registry. As you can see on http://oss.sgi.com/projects/ogl-sample/registry/

Contributors to the specification include Mark Kilgard from nvidia and Geoff Stahl from apple. Maybe it's an intellectual property issue.

Greetz,

Nico