Error drawing a polygon

Hello I am drawing a polygon in jogl and the polygon is being filled in incorrectly…

As you can see from the attached image I am line looping for the outline and polygon ing for the fill.

I is this an opengl bug or a driver bug or a code bug??

GL_POLYGON only draws convex polys. If you want to draw concave polys then you’ll have to break your mesh down into convex polys manually.