C SPECIFICATION

       void GLAPIENTRY glCopyTexSubImage1D( GLenum target,
                                            GLint leve )

PARAMETERS

       target  Specifies the target texture.  Must be GL_TEXTURE_1D.

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

       _param3 Specifies the texel offset within the texture array.

       _param4, _param5
               Specify the window coordinates of the left corner of the row of
               pixels to be copied.

       _param6 Specifies the width of the texture subimage.

DESCRIPTION

       glCopyTexSubImage1D  replaces  a  portion  of a one-dimensional texture
       image with pixels from the current  GL_READ_BUFFER  (rather  than  from
       main memory, as is the case for glTexSubImage1D).

       The  screen-aligned  pixel  row with left corner at (_param4, _param5),
       and with length _param6 replaces the portion of the texture array  with
       x  indices _param3 through _eqnparam3+_eqnparam6-1, inclusive. The des-
       tination in the texture array may not include any  texels  outside  the
       texture array as it was originally specified.

       The pixels in the row are processed exactly as if glCopyPixels had been
       called, but the process stops just before final  conversion.   At  this
       point  all  pixel  component values are clamped to the range [0, 1] and
       then converted to the texture's internal  format  for  storage  in  the
       texel array.

       It  is not an error to specify a subtexture with zero width, but such a
       specification has no effect.  If any of the pixels within the specified
       row  of  the current GL_READ_BUFFER are outside the read window associ-
       ated with the current rendering context, then the values  obtained  for
       those pixels are undefined.

       No change is made to the internalformat, width, or border parameters of
       the specified texture array or to texel values  outside  the  specified
       subregion.

NOTES

       glCopyTexSubImage1D  is  available  only  if  the  GL version is 1.1 or
       greater.

       Texturing has no effect in color index mode.
       GL_INVALID_VALUE is generated if leve is less than 0.

       GL_INVALID_VALUE may be generated if leve>log2 max, where  max  is  the
       returned value of GL_MAX_TEXTURE_SIZE.

       GL_INVALID_VALUE  is  generated if _param5<-b or if _param6<-b, where b
       is the border width of the texture array.

       GL_INVALID_VALUE is generated if  _eqnparam3<-b,  or  (_eqnparam3+_eqn-
       param6)>(w-b),   where   w  is  the  GL_TEXTURE_WIDTH,  and  b  is  the
       GL_TEXTURE_BORDER of the texture image being  modified.   Note  that  w
       includes twice the border width.

ASSOCIATED GETS

       glGetTexImage
       glIsEnabled with argument GL_TEXTURE_1D

SEE ALSO

       glCopyPixels,  glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage2D,
       glCopyTexSubImage3D,   glPixelStore,   glPixelTransfer,   glReadBuffer,
       glTexEnv,    glTexGen,    glTexImage1D,   glTexImage2D,   glTexImage3D,
       glTexParameter, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D



                                                       GLCOPYTEXSUBIMAGE1D(3G)