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GLUBUILD1DMIPMAPLEVELS(3G)                                                        GLUBUILD1DMIPMAPLEVELS(3G)



NAME
       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 GL_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  pass-ing passing
                       ing  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  implementa-tions implementations
                       tions 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:  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           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:  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 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 res-olutions resolutions
       olutions 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 1x1 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: 16x1, 8x1, 4x1, 2x1,
       1x1. These correspond to levels 2 through 6 respectively.  If base is 3  and  max  is  5,  then  only
       mipmap levels 8x1, 4x1 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 (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   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 is < 1.

       GLU_INVALID_ENUM is returned if internalFormat, format, or type are 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(3G),  glTexImage1D(3G),  glTexImage2D(3G),   glTexImage3D(3G),   gluBuild1DMipmaps(3G),   gluBuild2DMipmaps(3G),
       gluBuild3DMipmaps(3G),  gluErrorString(3G),  glGetTexImage(3G),  glGetTexLevelParameter(3G),  gluBuild2DMipmapLevels(3G),
       gluBuild3DMipmapLevels(3G)




                                                                                  GLUBUILD1DMIPMAPLEVELS(3G)