Signature
Parameters
Variables | Description |
---|---|
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, in pixels
of the texture image.
|
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
.
|
data |
Specifies a pointer to the image data in memory.
|
Description
gluBuild3DMipmaps
builds a series 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
).
Initially, the
width
,
height
and
depth
of
data
are checked to
see if they are a power of 2. If not, a copy of
data
is made and
scaled up or down to the nearest power of 2. (If
width
,
height
, or
depth
is exactly between powers of 2, then the copy of
data
will
scale upwards.) This copy will be used for subsequent mipmapping
operations described below. For example, if
width
is 57,
height
is
23, and
depth
is 24, then a copy of
data
will scale up to 64 in
width, down to 16 in height, and up to 32 in depth before mipmapping
takes place.
Then, proxy textures (see
glTexImage3D
) are used to determine if
the implementation can fit the requested texture. If not, all three dimensions
are continually halved until it fits.
Next, a series of mipmap levels is built by decimating a copy of
data
in half along all three dimensions until size
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 each of these mipmap levels.
Level 0 is a copy of
data
. The highest level is
.
For example, if
width
is 64,
height
is
16, and
depth
is 32, and the implementation can store a texture of this
size, the following mipmap levels are built:
,
,
,
,
,
,
and
.
These correspond
to levels 0 through 6, respectively.
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
Note that there is no direct way of querying the maximum level. This can
be derived indirectly via
glGetTexLevelParameter
. First, query
the width, height, and depth actually used at level 0. (The width,
height, and depth may not be equal to
width
,
height
, and
depth
respectively since proxy textures might have scaled them to fit the
implementation.) Then the maximum level can be derived from the formula
.
gluBuild3DMipmaps
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_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
.
See Also
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/
.