GLenum internalforma )

PARAMETERS
       target         The minmax table whose parameters are to be set.  Must be
                      GL_MINMAX.

       internalforma  The format of entries in the minmax table.  Must  be  one
                      of    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_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,   or
                      GL_RGBA16.

       _param3        If GL_TRUE, pixels will be consumed by the minmax process
                      and  no  drawing  or texture loading will take place.  If
                      GL_FALSE, pixels will proceed  to  the  final  conversion
                      process after minmax.

DESCRIPTION
       When  GL_MINMAX  is  enabled, the RGBA components of incoming pixels are
       compared to the minimum and maximum values for each component, which are
       stored  in  the  2-element  minmax table.  (The first element stores the
       minima, and the second element stores the maxima.)  If a pixel component
       is greater than the corresponding component in the maximum element, then
       the maximum element is updated with the pixel  component  value.   If  a
       pixel  component is less than the corresponding component in the minimum
       element, then the minimum element is updated with  the  pixel  component
       value.   (In  both cases, if the internal format of the minmax table in‐
       cludes luminance, then the R color component of incoming pixels is  used
       for comparison.)  The contents of the minmax table may be retrieved at a
       later time by calling glGetMinmax.  The minmax operation is  enabled  or
       disabled  by  calling glEnable or glDisable, respectively, with an argu‐
       ment of GL_MINMAX.

       glMinmax redefines the current minmax table to have entries of the  for‐
       mat specified by internalforma.  The maximum element is initialized with
       the smallest possible component values, and the minimum element is  ini‐
       tialized  with the largest possible component values.  The values in the
       previous minmax table, if any, are lost.  If _param3  is  GL_TRUE,  then
       pixels  are  discarded after minmax; no further processing of the pixels
       takes place, and no drawing, texture loading, or pixel readback will re‐
       sult.

NOTES
       glMinmax  is present only if GL_ARB_imaging is returned when glGetString
       is called with an argument of GL_EXTENSIONS.

       glGetMinmax, glResetMinmax

                                                                   GLMINMAX(3G)