Name
GrPoly -- Draw the perimeter of a polygon
Synopsis
void GrPoly (
  GR_DRAW_ID id,
  GR_GC_ID   gc,
  GR_COUNT   count,
  GR_POINT * pointtable
);
Parameters
- id
 The ID of the window or other drawable area.
- gc
 The graphics context to use when drawing the point.
- count
 The number of points in the polygon.
- pointtable
 An array of GR_POINT coordinates.
Description
The GrPoly function 
draws a polygon defined by the pointtabel array.
To draw a closed polygon, you must set the first and last points to the same
coordinates.