fgluBuild2DMipmapLevels(3G) OpenGL Reference fgluBuild2DMipmapLevels(3G)NAMEfgluBuild2DMipmapLevels - builds a subset of two-dimensional mipmap
levels
FORTRAN SPECIFICATION
INTEGER*4 fgluBuild2DMipmapLevels( INTEGER*4 target,
INTEGER*4 internalFormat,
INTEGER*4 width,
INTEGER*4 height,
INTEGER*4 format,
INTEGER*4 type,
INTEGER*4 level,
INTEGER*4 base,
INTEGER*4 max,
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,
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fgluBuild2DMipmapLevels(3G) OpenGL Reference fgluBuild2DMipmapLevels(3G)
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
glTexImage2D.
max Specifies the maximum mipmap level to pass to
glTexImage2D.
data Specifies a pointer to the image data in memory.
DESCRIPTIONfgluBuild2DMipmapLevels builds a subset of prefiltered two-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 fgluErrorString).
A series of mipmap levels from base to max is built by decimating data in
half along both dimensions until size 1 x 1 is reached. At each level,
each texel in the halved mipmap level is an average of the corresponding
four texels in the larger mipmap level. (In the case of rectangular
images, the decimation will ultimately reach an N x 1 or 1 x N
configuration. 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 fgluErrorString) and nothing is loaded.
For example, if level is 2 and width is 16 and height is 8, the following
levels are possible: 16 x 8, 8 x 4, 4 x 2, 2 x 1, 1 x 1. These correspond
to levels 2 through 6 respectively. If base is 3 and max is 5, then only
mipmap levels 8 x 4, 4 x 2 and 2 x 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)*(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.
NOTESfgluBuild2DMipmapLevels 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,
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fgluBuild2DMipmapLevels(3G) OpenGL Reference fgluBuild2DMipmapLevels(3G)
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_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 ALSO
glDrawPixels, glTexImage1D, glTexImage2D, glTexImage3D,
fgluBuild1DMipmaps, fgluBuild2DMipmaps, fgluBuild3DMipmaps,
fgluErrorString, glGetTexImage, glGetTexLevelParameter,
fgluBuild1DMipmapLevels, fgluBuild3DMipmapLevels
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