-  return texture parameter values for a specific level of
       detail



C SPECIFICATION


PARAMETERS

       _param1  Specifies the symbolic name of  the  target  tex-
                ture,    either   GL_TEXTURE_1D,   GL_TEXTURE_2D,
                GL_TEXTURE_3D,               GL_PROXY_TEXTURE_1D,
                GL_PROXY_TEXTURE_2D, or GL_PROXY_TEXTURE_3D.

       _param2  Specifies   the  level-of-detail  number  of  the
                desired image.  Level 0 is the base image  level.
                Level n is the nth mipmap reduction image.

       _param3  Specifies  the symbolic name of a texture parame-
                ter.     GL_TEXTURE_WIDTH,     GL_TEXTURE_HEIGHT,
                GL_TEXTURE_DEPTH,     GL_TEXTURE_INTERNAL_FORMAT,
                GL_TEXTURE_BORDER,           GL_TEXTURE_RED_SIZE,
                GL_TEXTURE_GREEN_SIZE,      GL_TEXTURE_BLUE_SIZE,
                GL_TEXTURE_ALPHA_SIZE, GL_TEXTURE_LUMINANCE_SIZE,
                and GL_TEXTURE_INTENSITY_SIZE are accepted.

       _param4  Returns the requested data.


DESCRIPTION

       glGetTexLevelParameter  returns in _param4 texture parame-
       ter values for a specific level-of-detail value, specified
       as  _param2.   _param1  defines the target texture, either
       GL_TEXTURE_1D,        GL_TEXTURE_2D,        GL_TEXTURE_3D,
       GL_PROXY_TEXTURE_1D,        GL_PROXY_TEXTURE_2D,        or
       GL_PROXY_TEXTURE_3D.

       GL_MAX_TEXTURE_SIZE, and  GL_MAX_3D_TEXTURE_SIZE  are  not
       really  descriptive  enough.  It has to report the largest
       square texture image that can be accommodated with mipmaps
       and borders, but a long skinny texture, or a texture with-
       out mipmaps and borders, may easily fit in texture memory.
       The  proxy targets allow the user to more accurately query
       whether the GL can accommodate a texture of a  given  con-
       figuration.   If  the  texture cannot be accommodated, the
       texture  state  variables,  which  may  be  queried   with
       glGetTexLevelParameter,  are set to 0.  If the texture can
       be accommodated, the texture state values will be  set  as
       they would be set for a non-proxy target.

       _param3  specifies  the  texture  parameter whose value or
       values will be returned.

       The accepted parameter names are as follows:

       GL_TEXTURE_WIDTH

       GL_TEXTURE_INTERNAL_FORMAT
                 _param4 returns a single value, the internal  of
                 the texture image.

       GL_TEXTURE_BORDER
                 _param4 returns a single  value,  the  width  in
                 pixels  of  the border of the texture image. The
                 initial value is 0.

       GL_TEXTURE_RED_SIZE,

       GL_TEXTURE_GREEN_SIZE,

       GL_TEXTURE_BLUE_SIZE,

       GL_TEXTURE_ALPHA_SIZE,

       GL_TEXTURE_LUMINANCE_SIZE,

       GL_TEXTURE_INTENSITY_SIZE
                 The internal storage resolution of an individual
                 component.  The resolution chosen by the GL will
                 be a close match for the resolution requested by
                 the   user   with   the  component  argument  of
                 glTexImage1D,    glTexImage2D,     glTexImage3D,
                 glCopyTexImage1D, and glCopyTexImage2D. The ini-
                 tial value is 0.


NOTES

       If an error is generated, no change is made  to  the  con-
       tents of _param4.

       GL_TEXTURE_INTERNAL_FORMAT  is  available  only  if the GL
       version  is  1.1  or  greater.   In   version   1.0,   use
       GL_TEXTURE_COMPONENTS instead.

       GL_PROXY_TEXTURE_1D  and GL_PROXY_TEXTURE_2D are available
       only if the GL version is 1.1 or greater.

       GL_TEXTURE_3D, GL_PROXY_TEXTURE_3D,  and  GL_TEXTURE_DEPTH
       are available only if the GL version is 1.2 or greater.

       When   the  GL_ARB_multitexture  extension  is  supported,
       glGetTexLevelParameter returns the texture  level  parame-
       ters for the active texture unit.


ERRORS

       GL_INVALID_ENUM  is generated if _param1 or _param3 is not
       an accepted value.

       GL_INVALID_VALUE is generated if _param2 is less than 0.
       glTexSubImage1D,     glTexSubImage2D,     glTexSubImage3D,
       glTexParameter



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