1991-2006 Silicon Graphics, Inc.
gluBuild3DMipmapLevels 3G
gluBuild3DMipmapLevels builds a subset of three-dimensional mipmap levels

## C Specification

GLint `gluBuild3DMipmapLevels` GLenum target GLint internalFormat GLsizei width GLsizei height GLsizei depth GLenum format GLenum type GLint level GLint base GLint max const void * data

## Parameters

target

  Specifies the target texture. Must be `GLU_TEXTURE_3D`.

internalFormat

  Requests the internal storage format of the texture image. The most current version of the SGI implementation of GLU does not check this value for validity before passing it on to the underlying OpenGL implementation. A value that is not accepted by the OpenGL implementation will lead to an OpenGL error. The benefit of not checking this value at the GLU level is that OpenGL extensions can add new internal texture formats without requiring a revision of the GLU implementation. Older implementations of GLU check this value and raise a GLU error if it is not 1, 2, 3, or 4 or one of the following symbolic constants: `GLU_ALPHA`, `GLU_ALPHA4`, `GLU_ALPHA8`, `GLU_ALPHA12`, `GLU_ALPHA16`, `GLU_LUMINANCE`, `GLU_LUMINANCE4`, `GLU_LUMINANCE8`, `GLU_LUMINANCE12`, `GLU_LUMINANCE16`, `GLU_LUMINANCE_ALPHA`, `GLU_LUMINANCE4_ALPHA4`, `GLU_LUMINANCE6_ALPHA2`, `GLU_LUMINANCE8_ALPHA8`, `GLU_LUMINANCE12_ALPHA4`, `GLU_LUMINANCE12_ALPHA12`, `GLU_LUMINANCE16_ALPHA16`, `GLU_INTENSITY`, `GLU_INTENSITY4`, `GLU_INTENSITY8`, `GLU_INTENSITY12`, `GLU_INTENSITY16`, `GLU_RGB`, `GLU_R3_G3_B2`, `GLU_RGB4`, `GLU_RGB5`, `GLU_RGB8`, `GLU_RGB10`, `GLU_RGB12`, `GLU_RGB16`, `GLU_RGBA`, `GLU_RGBA2`, `GLU_RGBA4`, `GLU_RGB5_A1`, `GLU_RGBA8`, `GLU_RGB10_A2`, `GLU_RGBA12`, or `GLU_RGBA16`.

width
height
depth

  Specifies in pixels the width, height and depth respectively, of the texture image. These should be a power of 2.

format

  Specifies the format of the pixel data. Must be one of `GLU_COLOR_INDEX`, `GLU_DEPTH_COMPONENT`, `GLU_RED`, `GLU_GREEN`, `GLU_BLUE`, `GLU_ALPHA`, `GLU_RGB`, `GLU_RGBA`, `GLU_BGR`, `GLU_BGRA`, `GLU_LUMINANCE`, or `GLU_LUMINANCE_ALPHA`.

type

  Specifies the data type for data. Must be one of `GLU_UNSIGNED_BYTE`, `GLU_BYTE`, `GLU_BITMAP`, `GLU_UNSIGNED_SHORT`, `GLU_SHORT`, `GLU_UNSIGNED_INT`, `GLU_INT`, `GLU_FLOAT`, `GLU_UNSIGNED_BYTE_3_3_2`, `GLU_UNSIGNED_BYTE_2_3_3_REV`, `GLU_UNSIGNED_SHORT_5_6_5`, `GLU_UNSIGNED_SHORT_5_6_5_REV`, `GLU_UNSIGNED_SHORT_4_4_4_4`, `GLU_UNSIGNED_SHORT_4_4_4_4_REV`, `GLU_UNSIGNED_SHORT_5_5_5_1`, `GLU_UNSIGNED_SHORT_1_5_5_5_REV`, `GLU_UNSIGNED_INT_8_8_8_8`, `GLU_UNSIGNED_INT_8_8_8_8_REV`, `GLU_UNSIGNED_INT_10_10_10_2`, or `GLU_UNSIGNED_INT_2_10_10_10_REV`.

level

  Specifies the mipmap level of the image data.

base

  Specifies the minimum mipmap level to pass to glTexImage3D.

max

  Specifies the maximum mipmap level to pass to glTexImage3D.

data

  Specifies a pointer to the image data in memory.

## Description

`gluBuild3DMipmapLevels` builds a subset of prefiltered three-dimensional texture maps of decreasing resolutions called a mipmap. This is used for the antialiasing of texture mapped primitives.

A return value of zero indicates success, otherwise a GLU error code is returned (see gluErrorString).

A series of mipmap levels from base to max is built by decimating data in half along both dimensions until size 1 × 1 × 1 is reached. At each level, each texel in the halved mipmap level is an average of the corresponding eight texels in the larger mipmap level. (If exactly one of the dimensions is 1, four texels are averaged. If exactly two of the dimensions are 1, two texels are averaged.) glTexImage3D is called to load these mipmap levels from base to max. If max is larger than the highest mipmap level for the texture of the specified size, then a GLU error code is returned (see gluErrorString) and nothing is loaded.

For example, if level is 2 and width is 16, height is 8 and depth is 4, the following levels are possible: 16 × 8 × 4 , 8 × 4 × 2 , 4 × 2 × 1 , 2 × 1 × 1 , 1 × 1 × 1 . These correspond to levels 2 through 6 respectively. If base is 3 and max is 5, then only mipmap levels 8 × 4 × 2 , 4 × 2 × 1 , and 2 × 1 × 1 are loaded. However, if max is 7, then an error is returned and nothing is loaded, since max is larger than the highest mipmap level which is, in this case, 6.

The highest mipmap level can be derived from the formula log 2 ⁡ max ⁡ width height depth × 2 level .

See the glTexImage1D reference page for a description of the acceptable values for format parameter. See the glDrawPixels reference page for a description of the acceptable values for type parameter.

## Notes

`gluBuild3DMipmapLevels` is only available if the GLU version is 1.3 or greater.

Formats `GLU_BGR`, and `GLU_BGRA`, and types `GLU_UNSIGNED_BYTE_3_3_2`, `GLU_UNSIGNED_BYTE_2_3_3_REV`, `GLU_UNSIGNED_SHORT_5_6_5`, `GLU_UNSIGNED_SHORT_5_6_5_REV`, `GLU_UNSIGNED_SHORT_4_4_4_4`, `GLU_UNSIGNED_SHORT_4_4_4_4_REV`, `GLU_UNSIGNED_SHORT_5_5_5_1`, `GLU_UNSIGNED_SHORT_1_5_5_5_REV`, `GLU_UNSIGNED_INT_8_8_8_8`, `GLU_UNSIGNED_INT_8_8_8_8_REV`, `GLU_UNSIGNED_INT_10_10_10_2`, and `GLU_UNSIGNED_INT_2_10_10_10_REV` are only available if the GL version is 1.2 or greater.

## Errors

`GLU_INVALID_VALUE` is returned if level > base, base < 0, max < base, or max is > the highest mipmap level for data.

`GLU_INVALID_VALUE` is returned if width, height, or depth is < 1.

`GLU_INVALID_ENUM` is returned if internalFormat, format, or type is not legal.

`GLU_INVALID_OPERATION` is returned if type is `GLU_UNSIGNED_BYTE_3_3_2` or `GLU_UNSIGNED_BYTE_2_3_3_REV` and format is not `GLU_RGB`.

`GLU_INVALID_OPERATION` is returned if type is `GLU_UNSIGNED_SHORT_5_6_5` or `GLU_UNSIGNED_SHORT_5_6_5_REV` and format is not `GLU_RGB`.

`GLU_INVALID_OPERATION` is returned if type is `GLU_UNSIGNED_SHORT_4_4_4_4` or `GLU_UNSIGNED_SHORT_4_4_4_4_REV` and format is neither `GLU_RGBA` nor `GLU_BGRA`.

`GLU_INVALID_OPERATION` is returned if type is `GLU_UNSIGNED_SHORT_5_5_5_1` or `GLU_UNSIGNED_SHORT_1_5_5_5_REV` and format is neither `GLU_RGBA` nor `GLU_BGRA`.

`GLU_INVALID_OPERATION` is returned if type is `GLU_UNSIGNED_INT_8_8_8_8` or `GLU_UNSIGNED_INT_8_8_8_8_REV` and format is neither `GLU_RGBA` nor `GLU_BGRA`.

`GLU_INVALID_OPERATION` is returned if type is `GLU_UNSIGNED_INT_10_10_10_2` or `GLU_UNSIGNED_INT_2_10_10_10_REV` and format is neither `GLU_RGBA` nor `GLU_BGRA`.

## See Also

gluBuild1DMipmapLevels, gluBuild1DMipmaps, gluBuild2DMipmapLevels, gluBuild2DMipmaps, gluBuild3DMipmaps, gluErrorString, glDrawPixels, glGetTexImage, glGetTexLevelParameter, glTexImage1D, glTexImage2D, glTexImage3D

## Copyright

Copyright 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.