Static Sub EdgeFlag ( Flag As Boolean )
Flag edges as either boundary or nonboundary.
Specifies the current edge flag value,
either Gl.TRUE or Gl.FALSE. The initial value is Gl.TRUE.
Specifies a pointer to an array that contains a single boolean element,
which replaces the current edge flag value.
Each vertex of a polygon,
or separate quadrilateral specified between a Gl.Begin/Gl.End
is marked as the start of either a boundary or nonboundary edge.
If the current edge flag is true when the vertex is specified,
the vertex is marked as the start of a boundary edge.
Otherwise, the vertex is marked as the start of a nonboundary edge.
sets the edge flag bit to Gl.TRUE if flag
and to Gl.FALSE otherwise.
The vertices of connected triangles and connected quadrilaterals are always
marked as boundary,
regardless of the value of the edge flag.
Boundary and nonboundary edge flags on vertices are significant only if
Gl.POLYGON_MODE is set to Gl.POINT or Gl.LINE.
The current edge flag can be updated at any time.
can be called between a call to Gl.Begin
and the corresponding
call to Gl.End
with argument Gl.EDGE_FLAG
See original documentation on OpenGL website