GPOLYGON()
 Draw a polygon on screen
------------------------------------------------------------------------------
 Syntax

     GPOLYGON(<aVertex>, <lFilled>, <nMode>, <nOutLine>,
        <nFillColor>) --> NIL

 Arguments

     <aVertex> is an array value representing an array of polygon
     vertices coordinates.

     <lFilled> is a logical value that creates a filled or non-filled
     polygon.  LLG_FILL or LLG_FRAME are valid constants.

     <nMode> is a numeric value representing the video Mode.  The
     following are valid <nMode> values.  They are all # defines in Llibg.ch.

     Display Mode Constants
     ------------------------------------------------------------------------
     Constant       Description
     ------------------------------------------------------------------------
     LLG_MODE_SET   Display in SET mode (ignores any pixels present under the
                    line displayed).  This is the most common display mode.
     LLG_MODE_AND   Display in AND mode (executes an AND on pixels present
                    under the line at display time and on the display color).
     LLG_MODE_OR    Display in OR mode (executes an OR on pixels present
                    under the line at display time and on the display color).
     LLG_MODE_XOR   Display in XOR mode (executes an XOR on pixels present
                    under the line at display time and on the display color).
                    See note.
     ------------------------------------------------------------------------

     Note:  This method allows you to move objects around on the screen
     without damaging the background.  To retrieve the initial background,
     just repeat the call for display in XOR mode.  If the display mode
     parameter is missing, the last mode specified in a call to a CA-Clipper
     graphic function is used.

     <nOutLine> is a numeric value representing the outline color.

     <nFillColor> is a numeric value representing the fill color.

 Returns

     GPOLYGON() always returns NIL.

 Description

     GPOLYGON() can be used to create a polygon.  Simply pass an array of
     coordinates which make up the polygon.

 Examples

     .  The following array of vertices would draw a triangle:

        aVertex := {{1,5},;      // First point
        {20,45},;                  // Second point
        {65,145} ;               // Third point}

 Files   Library is LLIBG.LIB, the header file is Llibg.ch.