vml_type: vml_polygon
Polygon features must have at least four coordinates, with the last coordinate equal to the first coordinate. The vml_polygon features may not contain holes. The VML writer writes out a vml_polygon feature in the output file as a predefined VML polyline element. By default, the VML writer does not set the z-index attribute. When it’s not set, the web browser interprets the polygon—the VML filled polyline element—to the have a z-index of 0. Polygons produced by the VML writer, therefore, by default do not obscure other objects with the exception of overlapping polygons with the same z-index value. Objects drawn later with equal z-indexes obscure earlier ones.