GLUBUILD3DMIPMAPLEVELS(3G)GLUBUILD3DMIPMAPLEVELS(3G)NAME
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 GL_TEXTURE_3D.
internalFormat Requests the internal storage of the texture image.
The most current version of the SGI implementation of
GLU does not check this value for validity before pass‐
ing 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 follow‐
ing symbolic constants: GL_ALPHA, GL_ALPHA4, GL_ALPHA8,
GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4,
GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16,
GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4,
GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8,
GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12,
GL_LUMINANCE16_ALPHA16, GL_INTENSITY, GL_INTENSITY4,
GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_RGB,
GL_R3_G3_B2, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10,
GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4,
GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or
GL_RGBA16.
width, height, depth
Specifies in pixels the width, height and depth respec‐
tively, of the texture image. These should be a power
of 2.
format Specifies the of the pixel data. Must be one of
GL_COLOR_INDEX, GL_DEPTH_COMPONENT, GL_RED, GL_GREEN,
GL_BLUE, GL_ALPHA, GL_RGB, GL_RGBA, GL_BGR, GL_BGRA,
GL_LUMINANCE, or GL_LUMINANCE_ALPHA.
type Specifies the data type for data. Must be one of
GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP,
GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT,
GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2,
GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5,
GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1,
GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, or
GL_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 glTexIm‐
age3D.
max Specifies the maximum mipmap level to pass to glTexIm‐
age3D.
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 cor‐
responding 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
log2(max(width,height,depth)2level).
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 GL_BGR, and GL_BGRA, and types GL_UNSIGNED_BYTE_3_3_2,
GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5,
GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4,
GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1,
GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8,
GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and
GL_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 GL_UNSIGNED_BYTE_3_3_2 or
GL_UNSIGNED_BYTE_2_3_3_REV and format is not GL_RGB.
GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_SHORT_5_6_5 or
GL_UNSIGNED_SHORT_5_6_5_REV and format is not GL_RGB.
GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_SHORT_4_4_4_4
or GL_UNSIGNED_SHORT_4_4_4_4_REV and format is neither GL_RGBA nor
GL_BGRA.
GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_SHORT_5_5_5_1
or GL_UNSIGNED_SHORT_1_5_5_5_REV and format is neither GL_RGBA nor
GL_BGRA.
GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_INT_8_8_8_8 or
GL_UNSIGNED_INT_8_8_8_8_REV and format is neither GL_RGBA nor GL_BGRA.
GLU_INVALID_OPERATION is returned if type is GL_UNSIGNED_INT_10_10_10_2
or GL_UNSIGNED_INT_2_10_10_10_REV and format is neither GL_RGBA nor
GL_BGRA.
SEE ALSOglDrawPixels(3G), glTexImage1D(3G), glTexImage2D(3G), glTexImage3D(3G),
gluBuild1DMipmaps(3G), gluBuild2DMipmaps(3G), gluBuild3DMipmaps(3G),
gluErrorString(3G), glGetTexImage(3G), glGetTexLevelParameter(3G),
gluBuild1DMipmapLevels(3G), gluBuild2DMipmapLevels(3G)GLUBUILD3DMIPMAPLEVELS(3G)