The fill type enumerated value, AcGiFillType, can have one of two values:
Primitives that can be filled are circles, polygons, shells, meshes, text, arc sectors, and arc chords. Polylines and simple arcs cannot be filled.
Before AutoCAD calls worldDraw(), it sets the fill type depending on the regen type. If the regen type is kAcGiStandardDisplay, AutoCAD sets the fill type to kAcGiFillNever. Otherwise, AutoCAD sets the fill type to kAcGiFillAlways. This value is reinitialized according to the regen type before viewportDraw() is called.
If the user issues a FILL command specifying to turn Fill mode off, no objects are filled regardless of the regen type. Similarly, if the user explicitly turns Fill mode on, objects will be filled. If the user does not issue a FILL command, and AcGiSubEntityTraits::setFillType() has been set, that Fill mode is used regardless of the regen type.