Interactive drawing of a polygon row.

::draw_polygon produces an image. The region of that image spans exactly the imagepoints entered interactively by mouse clicks (gray values remain undefined).

Painting in the output window happens while pressing the left mouse button. Releasing the left mouse button and repressing it at another position effects drawing a line between these two points. Pressing the right mouse button terminates the input. Painting uses that color which has been set by ::set_color, ::set_rgb, etc. .

To put gray values on the created PolygonRegion for further processing, you may use the procedure ::reduce_domain.

The painted contour is not closed automatically, in particular it is not ``filled up'' either.

Output object's gray values are not defined.

draw_polygon(&Polygon,WindowHandle) ;
convex(Polygon,&Filled) ;
disp_region(Filled,WindowHandle) ;

If the window is valid, ::draw_polygon returns H_MSG_TRUE. If necessary, an exception handling is raised.

::open_window

::reduce_domain, ::disp_region, ::set_colored, ::set_line_width, ::set_draw

::draw_region, ::draw_circle, ::draw_rectangle1, ::draw_rectangle2, ::boundary

::reduce_domain, ::fill_up, ::set_color

System