C SPECIFICATION

       void GLAPIENTRY glGetTexImage( GLenum target,
                                      GLint leve )

PARAMETERS

       target  Specifies  which  texture  is  to  be obtained.  GL_TEXTURE_1D,
               GL_TEXTURE_2D, and GL_TEXTURE_3D  are accepted.

       leve    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 a pixel format for the returned data.  The  supported
               formats   are  GL_RED,  GL_GREEN,  GL_BLUE,  GL_ALPHA,  GL_RGB,
               GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, and GL_LUMINANCE_ALPHA.

       _param4 Specifies  a  pixel  type for the returned data.  The supported
               types   are   GL_UNSIGNED_BYTE,   GL_BYTE,   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, and GL_UNSIGNED_INT_2_10_10_10_REV.

       _param5 Returns the texture image.  Should be a pointer to an array  of
               the type specified by _param4.

DESCRIPTION

       glGetTexImage  returns  a texture image into _param5.  target specifies
       whether the desired texture image is one specified by  glTexImage1D  (-
       GL_TEXTURE_1D),   glTexImage2D   (GL_TEXTURE_2D),  or  glTexImage3D  (-
       GL_TEXTURE_3D).  leve  specifies  the  level-of-detail  number  of  the
       desired  image.  _param3 and _param4 specify the format and type of the
       desired  image  array.   See  the  reference  pages  glTexImage1D   and
       glDrawPixels for a description of the acceptable values for the _param3
       and _param4 parameters, respectively.

       To understand the operation of  glGetTexImage,  consider  the  selected
       internal  four-component  texture  image to be an RGBA color buffer the
       size of the image.  The semantics of glGetTexImage are  then  identical
       to  those  of  glReadPixels,  with the exception that no pixel transfer
       operations are  performed,  when  called  with  the  same  _param3  and
       _param4,  with  x and y set to 0, width set to the width of the texture
       image (including border if one was specified), and height set to 1  for
       1D  images,  or to the height of the texture image (including border if
       one was specified) for 2D images.  Because the internal  texture  image
       is  an  RGBA image, pixel formats GL_COLOR_INDEX, GL_STENCIL_INDEX, and
       GL_DEPTH_COMPONENT are not accepted, and pixel type  GL_BITMAP  is  not
       the  required  number of pixels by the storage required for each pixel,
       based on _param3 and _param4.  Be sure to take the pixel storage param-
       eters into account, especially GL_PACK_ALIGNMENT.

NOTES

       If an error is generated, no change is made to the contents of _param5.

       When the  GL_ARB_multitexture  extension  is  supported,  glGetTexImage
       returns the texture image for the active texture unit.

       The     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,  GL_UNSIGNED_INT_2_10_10_10_REV,  and   the
       formats GL_BGR, and GL_BGRA are available only if the GL version is 1.2
       or greater.

ERRORS

       GL_INVALID_ENUM is generated if target, _param3, or _param4 is  not  an
       accepted value.

       GL_INVALID_VALUE is generated if leve is less than 0.

       GL_INVALID_VALUE  may  be  generated  if  leve is greater than log2max,
       where max is the returned value of GL_MAX_TEXTURE_SIZE.

       GL_INVALID_OPERATION is generated if glGetTexImage is executed  between
       the execution of glBegin and the corresponding execution of glEnd.

       GL_INVALID_OPERATION    is    returned    if    _param4   is   one   of
       GL_UNSIGNED_BYTE_3_3_2,                     GL_UNSIGNED_BYTE_2_3_3_REV,
       GL_UNSIGNED_SHORT_5_6_5,  or GL_UNSIGNED_SHORT_5_6_5_REV and _param3 is
       not GL_RGB.

       GL_INVALID_OPERATION   is   returned   if    _param4    is    one    of
       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,   and
       _param3 is neither GL_RGBA or GL_BGRA.

ASSOCIATED GETS

       glGetTexLevelParameter with argument GL_TEXTURE_WIDTH
       glGetTexLevelParameter with argument GL_TEXTURE_HEIGHT
       glGetTexLevelParameter with argument GL_TEXTURE_BORDER
       glGetTexLevelParameter with argument GL_TEXTURE_INTERNALFORMAT
       glGet with arguments GL_PACK_ALIGNMENT and others

SEE ALSO

       glActiveTextureARB,  glDrawPixels,  glReadPixels,  glTexEnv,  glTexGen,