Name
NV_texture_npot_2D_mipmap
Name Strings
GL_NV_texture_npot_2D_mipmap
Contact
Ian Stewart, NVIDIA Corporation (istewart 'at' nvidia.com)
Notice
Copyright NVIDIA Corporation, 2011
Status
NVIDIA Proprietary
Version
Last Modifed Date: April 4, 2011 (version 1.0)
Number
XXX Unassigned XXX
Dependencies
This extension is written against the OpenGL ES 2.0 Specification.
Overview
Conventional OpenGL ES 2.0 allows the use of non-power-of-two (NPOT)
textures with the limitation that mipmap minification filters can not be
used. This extension relaxes this restriction and adds limited mipmap
support for 2D NPOT textures.
With this extension, NPOT textures are specified and applied identically to
mipmapped power-of-two 2D textures with the following limitations:
- The texture wrap modes must be CLAMP_TO_EDGE.
- Coordinates used for texture sampling on an NPOT texture using a
mipmapped minification filter must lie within the range [0,1]. Coordinate
clamping is not performed by the GL in this case, causing values outside
this range to produce undefined results.
IP Status
NVIDIA Proprietary
New Procedures and Functions
None.
New Tokens
None.
Changes to Chapter 3 of the GL Specification
Add the following to "Wrap Mode CLAMP_TO_EDGE" of section 3.7.6:
CLAMP_TO_EDGE is a valid wrap mode for non-power-of-two textures; however,
NPOT textures using a mipmapped minification filter will not have their
coordinates clamped by the GL. In this case, coordinates must be given in
the range [0,1]; values outside this range will produce undefined results.
Remove the following from section 3.7.11 (Mipmap Generation):
If either the width or height of the level zero array are not a power of
two, the error INVALID_OPERATION is generated.
Change the third bullet of Texture Access, section 3.8.2, as follows:
A two-dimensional sampler is called, the corresponding texture image is a
non-power-of-two image (as described in the Mipmapping discussion of
section 3.7.7), and the texture wrap mode is not CLAMP_TO_EDGE.
Errors
None.
New State
None.
Issues
None.
Revision History
Rev. Date Author Changes
---- -------- --------- --------------------------------------------
1 04/04/11 istewart First revision.
