1991-2006
Silicon Graphics, Inc.
gluBuild1DMipmapLevels
3G
gluBuild1DMipmapLevels
builds a subset of one-dimensional mipmap levels
C Specification
GLint gluBuild1DMipmapLevels
GLenum target
GLint internalFormat
GLsizei width
GLenum format
GLenum type
GLint level
GLint base
GLint max
const void * data
Parameters
target
Specifies the target texture. Must be GLU_TEXTURE_1D.
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
Specifies the width in pixels of the texture image.
This 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 glTexImage1D.
max
Specifies the maximum mipmap level to pass to glTexImage1D.
data
Specifies a pointer to the image data in memory.
Description
gluBuild1DMipmapLevels builds a subset of prefiltered one-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
until size
1
×
1
is reached. At each level, each texel in the
halved mipmap level is an average of the corresponding two texels in the larger
mipmap level.
glTexImage1D 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, the
following levels are possible:
16
×
1
,
8
×
1
,
4
×
1
,
2
×
1
,
1
×
1
.
These correspond
to levels 2 through 6 respectively.
If base is 3 and max is 5, then only mipmap levels
8
×
1
,
4
×
1
and
2
×
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
⁡
width
×
2
level
.
See the glTexImage1D reference page for a description of the
acceptable values for type parameter. See the glDrawPixels
reference page for a description of the acceptable values
for level parameter.
Notes
gluBuild1DMipmapLevels 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 is < 1.
GLU_INVALID_ENUM is returned if internalFormat, format, or type are 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
gluBuild1DMipmaps,
gluBuild2DMipmapLevels,
gluBuild2DMipmaps,
gluBuild3DMipmapLevels,
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/.