fgluBuild3DMipmapLevels(3G)

fgluBuild3DMipmapLevels - builds a subset of three-dimensional mipmap levels

As shipped in IRIX 6.5.15. Added in IRIX 6.5.15.

NAME
     fgluBuild3DMipmapLevels - builds a subset of three-dimensional mipmap
     levels


FORTRAN SPECIFICATION
     INTEGER*4 fgluBuild3DMipmapLevels( INTEGER*4 target,
                                        INTEGER*4 internalFormat,
                                        INTEGER*4 width,
                                        INTEGER*4 height,
                                        INTEGER*4 depth,
                                        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_3D.

     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, depth
                     Specifies in pixels the width, height and depth
                     respectively, 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.

     level           Specifies the mipmap level of the image data.

     base            Specifies the minimum mipmap level to pass to
                     glTexImage3D.

     max             Specifies the maximum mipmap level to pass to
                     glTexImage3D.

     data            Specifies a pointer to the image data in memory.

DESCRIPTION
     fgluBuild3DMipmapLevels 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 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 x 1 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 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, height is 8 and depth is 4,
     the following levels are possible: 16 x 8 x 4, 8 x 4 x 2, 4 x 2 x 1,
     2 x 1 x 1, 1 x 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 x 2, 4 x 2 x 1 and 2 x 1 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,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
     fgluBuild3DMipmapLevels 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 ALSO
     glDrawPixels, glTexImage1D, glTexImage2D, glTexImage3D,
     fgluBuild1DMipmaps, fgluBuild2DMipmaps, fgluBuild3DMipmaps,
     fgluErrorString, glGetTexImage, glGetTexLevelParameter,
     fgluBuild1DMipmapLevels, fgluBuild2DMipmapLevels