- draw a rectangle



C SPECIFICATION


PARAMETERS

       _param1, _param2 Specify one vertex of a rectangle.

       _param3, _param4 Specify  the opposite vertex of the rect-
                        angle.


C SPECIFICATION


PARAMETERS

       _param1
              Specifies a pointer to one vertex of a rectangle.

       _param2
              Specifies a pointer to the opposite vertex  of  the
              rectangle.


DESCRIPTION

       glRect  supports  efficient specification of rectangles as
       two corner points.   Each  rectangle  command  takes  four
       arguments,  organized  either  as two consecutive pairs of
       (x,y) coordinates, or as two pointers to arrays, each con-
       taining an (x,y) pair.  The resulting rectangle is defined
       in the z = 0 plane.

       glRect(_param1(1), _param2(1), _param3(1), _param4(1))  is
       exactly  equivalent  to  the following sequence: glBegin(-
       GL_POLYGON);  glVertex2(_param1(1),  _param2(1));   glVer-
       tex2(_param3(1),     _param2(1));    glVertex2(_param3(1),
       _param4(1)); glVertex2(_param1(1),  _param4(1));  glEnd();
       Note  that  if the second vertex is above and to the right
       of the first vertex, the rectangle is constructed  with  a
       counterclockwise winding.


ERRORS

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


SEE ALSO

       glBegin, glVertex



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