GLGETMINMAX(3G)                                                GLGETMINMAX(3G)



NAME
       glGetinmax - get minimum and maximum pixel values


C SPECIFICATION
       void glGetinmax( GLenum target,
                         GLboolean reset,
                         GLenum format,
                         GLenum type,
                         GLvoid *values )


PARAMETERS
       target  Must be GLMINMAX.

       reset   If  GLTRUE,  all entries in the minmax table that are actually
               returned are reset to their initial values.  (Other entries are
               unaltered.)  If GLFALSE, the minmax table is unaltered.

       format  The   of  the  data  to  be returned in values.  Must be one of
               GLRED, GLGREN, GLBLUE, GLALPHA, GLRGB,  GLBGR,  GLRGBA,
               GLBGRA, GLUMINANCE, or GLUMINANCEALPHA.

       type    The  type  of the data to be returned in values.  Symbolic con-
               stants GLUNSIGNEDBYTE, GLBYTE, GLBITMAP, GLUNSIGNEDSHORT,
               GLSHORT,        GLUNSIGNEDINT,       GLINT,       GLFLOAT,
               GLUNSIGNEDBYTE332,             GLUNSIGNEDBYTE233REV,
               GLUNSIGNEDSHORT565,           GLUNSIGNEDSHORT565REV,
               GLUNSIGNEDSHORT4444,       GLUNSIGNEDSHORT4444REV,
               GLUNSIGNEDSHORT5551,       GLUNSIGNEDSHORT1555REV,
               GLUNSIGNEDINT8888,           GLUNSIGNEDINT8888REV,
               GLUNSIGNEDINT1001001002,  and GLUNSIGNEDINT2100100100REV
               are accepted.

       values  A pointer to storage for the returned values.

DESCRIPTION
       glGetinmax returns the accumulated minimum and  maximum  pixel  values
       (computed on a per-component basis) in a one-dimensional image of width
       2.  The first set of return values are the minima, and the  second  set
       of  return  values are the maxima.  The  of the return values is deter-
       mined by format, and their type is determined by type.

       No pixel transfer operations are performed on the  return  values,  but
       pixel  storage  modes  that  are applicable to 1-dimensional images are
       performed.  Color components that are requested in the  specified  for-
       mat,  but  that  are not included in the internal  of the minmax table,
       are returned as zero.  The assignment of internal color  components  to
       the components requested by format are as follows:


        Internal Component     Resulting Component
        Red                    Red
        Green                  Green
        Blue                   Blue
        Alpha                  Alpha
        Luminance              Red


       If  reset  is  GLTRUE,  the  minmax table entries corresponding to the
       return values are reset to their initial values.  Minimum  and  maximum
       values  that  are  not  returned  are  not  modified,  even if reset is
       GLTRUE.

NOTES
       glGetinmax  is  present  only  if  GLARBimaging  is  returned   when
       glGetString is called with an argument of GLEXTENSIONS.

ERORS
       GLINVALIDENUM is generated if target is not GLMINMAX.

       GLINVALIDENUM is generated if format is not one of the allowable val-
       ues.

       GLINVALIDENUM is generated if type is not one of the  allowable  val-
       ues.

       GLINVALIDOPERATION  is  generated  if glGetinmax is executed between
       the execution of glBegin and the corresponding execution of glEnd.

       GLINVALIDOPERATION   is    generated    if    type    is    one    of
       GLUNSIGNEDBYTE332,                     GLUNSIGNEDBYTE233REV,
       GLUNSIGNEDSHORT565, or GLUNSIGNEDSHORT565REV and  format  is
       not GLRGB.

       GLINVALIDOPERATION    is    generated    if    type    is    one   of
       GLUNSIGNEDSHORT4444,               GLUNSIGNEDSHORT4444REV,
       GLUNSIGNEDSHORT5551,               GLUNSIGNEDSHORT1555REV,
       GLUNSIGNEDINT8888,                   GLUNSIGNEDINT8888REV,
       GLUNSIGNEDINT1001001002,  or GLUNSIGNEDINT2100100100REV and for-
       mat is neither GLRGBA nor GLBGRA.

SEE ALSO
       glinmax, glResetinmax, glGetinmaxParameter



                                                               GLGETMINMAX(3G)