C SPECIFICATION
GLint GLAPIENTRY gluBuild2DMipmapLevels( GLenum target,
GLint internalFormat,
GLsizei width,
GLsizei height,
GLenum format,
GLenum type,
GLint level,
GLint base,
GLint max,
const void *data )
PARAMETERS
target Specifies the target texture. Must be GL_TEXTURE_2D.
internalFormat Requests the internal storage format of the texture
image. Must be 1, 2, 3, 4, or one of the following
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 Specifies the width and height, respectively, in pixels
of the texture image. These should be a power of 2.
format Specifies the format 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.
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 1x1 is reached. At each level,
each texel in the halved mipmap level is an average of the correspond-
ing four texels in the larger mipmap level. (In the case of rectangular
images, the decimation will ultimately reach an Nx1 or 1xN configura-
tion. Here, two texels are averaged instead.) glTexImage2D 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 and height is 8, the follow-
ing levels are possible: 16x8, 8x4, 4x2, 2x1, 1x1. These correspond to
levels 2 through 6 respectively. If base is 3 and max is 5, then only
mipmap levels 8x4, 4x2 and 2x1 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)*(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
gluBuild2DMipmapLevels 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 or height 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_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 ALSO
glDrawPixels, glTexImage1D, glTexImage2D, glTexImage3D,
gluBuild1DMipmaps, gluBuild2DMipmaps, gluBuild3DMipmaps,
gluErrorString, glGetTexImage, glGetTexLevelParameter,
gluBuild1DMipmapLevels, gluBuild3DMipmapLevels
GLUBUILD2DMIPMAPLEVELS(3G)
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