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 Specifies the width of the texture subimage.

       _param6 Specifies the height of the texture subimage.

       _param7 Specifies the format of the pixel data.  The following  symbolic
               values  are accepted: GL_COLOR_INDEX, GL_RED, GL_GREEN, GL_BLUE,
               GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA,  GL_BGRA,  GL_LUMINANCE,  and
               GL_LUMINANCE_ALPHA.

       _param8 Specifies  the  data type of the pixel data.  The following sym‐
               bolic values are accepted: 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, and GL_UNSIGNED_INT_2_10_10_10_REV.

       _param9 Specifies a pointer to the image data in memory.

DESCRIPTION
       Texturing  maps a portion of a specified texture image onto each graphi‐
       cal primitive for which texturing is enabled.   To  enable  and  disable
       two-dimensional  texturing,  call  glEnable  and glDisable with argument
       GL_TEXTURE_2D.

       glTexSubImage2D redefines a contiguous subregion of an existing  two-di‐
       mensional  texture  image.  The texels referenced by _param9 replace the
       portion of the existing texture array with x indices _param3  and  _eqn‐
       param3+_eqnparam5−1,   inclusive,   and  y  indices  _param4  and  _eqn‐
       param4+_eqnparam6−1, inclusive.  This region may not include any  texels
       outside  the  range of 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.

NOTES
       glTexSubImage2D is available only if the GL version is 1.1 or greater.

       When  the  GL_ARB_multitexture  extension  is supported, glTexSubImage2D
       specifies a two-dimensional sub texture for the  current  texture  unit,
       specified with glActiveTextureARB.

       When  the  GL_ARB_imaging  extension  is  supported, the RGBA components
       specified in _param9 may be processed  by  the  imaging  pipeline.   See
       glTexImage1D for specific details.

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 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  _eqnparam3<−b,  (_eqnparam3+_eqn‐
       param5)>(w−b), _eqnparam4<−b, or (_eqnparam4+_eqnparam6)>(h−b), where  w
       is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT, and b is the border
       width of the texture image being modified.  Note that w  and  h  include
       twice the border width.

       GL_INVALID_VALUE is generated if _param5 or _param6 is less than 0.

       GL_INVALID_ENUM  is  generated if _param7 is not an accepted format con‐
       stant.

       GL_INVALID_ENUM is generated if _param8 is not a type constant.

       GL_INVALID_ENUM is generated if _param8 is GL_BITMAP and _param7 is  not
       GL_COLOR_INDEX.

       GL_INVALID_OPERATION is generated if glTexSubImage2D is executed between
       the execution of glBegin and the corresponding execution of glEnd.

       GL_INVALID_OPERATION   is   generated   if    _param8    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  _param7  is
       not GL_RGB.

       GL_INVALID_OPERATION    is    generated    if    _param8   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
       _param7 is neither GL_RGBA nor GL_BGRA.

ASSOCIATED GETS