GLenum internalforma )

       delim $$

PARAMETERS
       target         The   color   table   target.   Must  be  GL_COLOR_TABLE,
                      GL_POST_CONVOLUTION_COLOR_TABLE,                       or
                      GL_POST_COLOR_MATRIX_COLOR_TABLE.

       internalforma  The  internal  storage format of the texture image.  Must
                      be one of the  following  symbolic  constants:  GL_ALPHA,
                      GL_ALPHA4,     GL_ALPHA8,     GL_ALPHA12,     GL_ALPHA16,
                      GL_LUMINANCE,        GL_LUMINANCE4,        GL_LUMINANCE8,
                      GL_LUMINANCE12,    GL_LUMINANCE16,    GL_LUMINANCE_ALPHA,
                      GL_LUMINANCE4_ALPHA4,               GL_LUMINANCE6_ALPHA2,
                      GL_LUMINANCE8_ALPHA8,              GL_LUMINANCE12_ALPHA4,
                      GL_LUMINANCE12_ALPHA12,           GL_LUMINANCE16_ALPHA16,
                      GL_INTENSITY,        GL_INTENSITY4,        GL_INTENSITY8,
                      GL_INTENSITY12,  GL_INTENSITY16,   GL_R3_G3_B2,   GL_RGB,
                      GL_RGB4,  GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16,
                      GL_RGBA,  GL_RGBA2,   GL_RGBA4,   GL_RGB5_A1,   GL_RGBA8,
                      GL_RGB10_A2, GL_RGBA12, GL_RGBA16.

       _param3        The  x  coordinate  of the lower-left corner of the pixel
                      rectangle to be transferred to the color table.

       _param4        The y coordinate of the lower-left corner  of  the  pixel
                      rectangle to be transferred to the color table.

       _param5        The width of the pixel rectangle.

DESCRIPTION
       glCopyColorTable  loads  a  color  table  with  pixels  from the current
       GL_READ_BUFFER (rather than  from  main  memory,  as  is  the  case  for
       glColorTable).

       The   screen-aligned   pixel   rectangle   with   lower-left  corner  at
       (_param3, _param4) having width _param5 and height 1 is loaded into  the
       color  table.  If  any  pixels within this region are outside the window
       that is associated with the GL context, the values  obtained  for  those
       pixels are undefined.

       The  pixels  in the rectangle are processed just as if glReadPixels were
       called, with internalforma set to RGBA, but processing stops  after  the
       final conversion to RGBA.

       The  four scale parameters and the four bias parameters that are defined
       for the table are then used to scale and bias the R, G, B, and A  compo‐
       nents  of  each  pixel. The scale and bias parameters are set by calling
       glColorTableParameter.

       Next, the R, G, B, and A values are clamped to the  range  [0,1].   Each
       ────────────────────────────────────────────────────────────────────────

       Finally, the red, green, blue, alpha, luminance, and/or intensity compo‐
       nents  of the resulting pixels are stored in the color table.  They form
       a one-dimensional table with indices in the range [0, _param5 - 1].

NOTES
       glCopyColorTable is available only if GL_ARB_imaging  is  returned  from
       calling glGetString with an argument of GL_EXTENSIONS.

ERRORS
       GL_INVALID_ENUM  is  generated  when  target is not one of the allowable
       values.

       GL_INVALID_VALUE is generated if _param5 is less than zero.

       GL_INVALID_VALUE is generated if internalforma is not one of the  allow‐
       able values.

       GL_TABLE_TOO_LARGE  is  generated  if  the  requested color table is too
       large to be supported by the implementation.

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

ASSOCIATED GETS
       glGetColorTable, glGetColorTableParameter

SEE ALSO
       glColorTable, glColorTableParameter, glReadPixels

                                                           GLCOPYCOLORTABLE(3G)