GLint leve )

PARAMETERS
       target  Specifies the target texture.  Must be GL_TEXTURE_2D.

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

       _param3 Specifies a texel offset in the x direction within  the  texture
               array.

       _param4 Specifies  a  texel offset in the y direction within the texture
               array.

       _param5, _param6
               Specify the window coordinates of the lower left corner  of  the
               rectangular region of pixels to be copied.

       _param7 Specifies the width of the texture subimage.

       _param8 Specifies the height of the texture subimage.

DESCRIPTION
       glCopyTexSubImage2D  replaces a rectangular portion of a two-dimensional
       texture image with pixels from the current GL_READ_BUFFER  (rather  than
       from main memory, as is the case for glTexSubImage2D).

       The   screen-aligned   pixel   rectangle   with  lower  left  corner  at
       (_param5, _param6) and with width _param7 and  height  _param8  replaces
       the  portion  of  the  texture  array  with  x  indices  _param3 through
       _param3+_param7−1,   inclusive,   and   y   indices   _param4    through
       _param4+_param8−1, inclusive, at the mipmap level specified by leve.

       The pixels in the rectangle 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.

       The  destination rectangle in the texture array may not include any tex‐
       els outside the texture array as it was originally specified.  It is not
       an  error  to specify a subtexture with zero width or height, but such a
       specification has no effect.

       If any of the pixels within  the  specified  rectangle  of  the  current
       GL_READ_BUFFER  are  outside the read window associated with the current
       rendering context, then the values obtained for those pixels  are  unde‐
       fined.

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

ERRORS
       GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D.

       GL_INVALID_OPERATION  is generated if the texture array has not been de‐
       fined by a previous glTexImage2D or glCopyTexImage2D operation.

       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_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, (_param3+_param7)>(w−b),
       _param4<−b, or (_param4+_param8)>(h−b), where w is the GL_TEXTURE_WIDTH,
       h is the  GL_TEXTURE_HEIGHT, and b is the GL_TEXTURE_BORDER of the  tex‐
       ture  image  being modified.  Note that w and h include twice the border
       width.

       GL_INVALID_OPERATION is generated if glCopyTexSubImage2D is executed be‐
       tween the execution of glBegin and the corresponding execution of glEnd.

ASSOCIATED GETS
       glGetTexImage
       glIsEnabled with argument GL_TEXTURE_2D

SEE ALSO
       glCopyPixels,  glCopyTexImage1D,  glCopyTexImage2D, glCopyTexSubImage1D,
       glCopyTexSubImage3D,   glPixelStore,   glPixelTransfer,    glReadBuffer,
       glTexEnv,    glTexGen,    glTexImage1D,    glTexImage2D,   glTexImage3D,
       glTexParameter, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D

                                                        GLCOPYTEXSUBIMAGE2D(3G)