 
gleJoinStyle Documentation
   Subroutine Descriptions
int gleGetJoinStyle (void); 
void gleSetJoinStyle (int style);	      /* bitwise OR of flags */ 
 Query and Set the join style flags. This word is a bitwise OR of the flags
described below.
 Extrusion Join Styles 
TUBE_JN_RAWDraw polycylinders, polycones, extrusions, etc. 
    with no special treatment of the
    extrusion ends. 
 TUBE_JN_ANGLE        Draw polycylinders, polycones, extrusions, etc. 
    by extending the different segments until they 
    butt into each other with an angular style.
 TUBE_JN_CUT          Draw polycylinders, polycones, extrusions, etc. 
    by joining together the different segments and slicing off
    the joint at half the angle between the segments.  A cap is drawn.
    Note that the slicing plane runs through the origin of the contour
    coordinate system. Thus, the amount of slice can be varied by offsetting
    the contour with respect to the origin.
    
    Note that when two segments meet at a shallow angle, the cut join
    style will potentially shave off a whole lot of the contour,
    leading to "surprising" results...
 TUBE_JN_ROUND         Joints will be rounded. Strictly speaking, the part of the joint
   above the origin will be rounded. The part below the origin will come
   together in an angular join.
 TUBE_JN_MASK          Mask bits.  This can be used to mask off the bit field that defines
     the join style.
 End Caps 
 TUBE_JN_CAP           If this is set, a cap will be drawn at each end of the extrusion.
Automatic Normal Vector Generation 
 TUBE_NORM_FACET       A normal vector is generated per facet. Useful for having an
     extrusion have a "faceted" look, such as when extruding a square -- each
     of the four sides of the square will look flat.
 TUBE_NORM_EDGE        Normal vectors are generated so that they lie along edges. Useful
     for making angular things look rounded under lighting. For example,
     when extruding a hexagon and using this flag, the hexagonal
     extrusion will look (more like a) smooth perfectly round cylinder,
     rather than a six-sided shape.
 TUBE_NORM_PATH_EDGE   Normal vectors are generated so that they both lie on edges, and so
     that they interpolate between neighboring segments.  Useful for
     drawing "spaghetti" -- extrusions that follow a spline path.
     Because the spline path must be "tessellated" into small straight
     segments, each segment will look straight unless this flag is set.
 TUBE_NORM_MASK        A mask useful for masking out the "norm" bits.
Closed or Open Contours 
 TUBE_CONTOUR_CLOSED	 If this bit is set, the contour will be treated as a "closed"
contour, where the last point connects back up to the first.
It is useful to set this flag when drawing closed shapes (such as
extruded cylinders, star-shapes, I-Beams, 
etc.)  When drawing open
extrusions (
e.g. corrugated sheet metal), you DON'T want to set this
flag.
 The End 
Originally developed by Linas Vepstas in 1991
Version 2.0 -- port to OpenGL, 1993 
Version 2.1 -- assorted touch-ups, cleanups, 
etc.Version 2.1.1 -- additional demos 
