NV_texture_npot_2D_mipmap

GL_NV_texture_npot_2D_mipmap

Ian Stewart, NVIDIA Corporation (istewart 'at' nvidia.com)

Complete.

Last Modifed Date: April 4, 2011
NVIDIA Revision: 1.0

OpenGL ES Extension #96

This extension is written against the OpenGL ES 2.0 Specification.

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.

NVIDIA Proprietary

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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.

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Rev.    Date      Author       Changes
----   --------   ---------    -------------------------------------
 1     04/04/11   istewart     First revision.