    кФФФФФФФФФФФФФФФФФФФФФФФФФФЗ                        PowerBASIC v3.20
 кФФД          DASoft          ЧФФФФФФФФФФФФФФФФФФФФФФТФФФФФФФФФФФФФФФФФФЗ
 Г  УФФФФФФФФФФФФФФФФФФФФФФФФФФЖ    Copyright 1995    Г DATE: 1995-10-01 ЧФЗ
 Г  Г FILE NAME   POLYGONS.TXT К          by          дЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭФ К К
 Г  Г                          К  Don Schullian, Jr.                     К К
 Г  дЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭМ                                         К К
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 Г as long as this code is not distributed in any compilable format.     К К
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 дЭбЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭМ К
   Г                ....................................                   К
   дЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭЭМ

  Here is a set of routines that will either  allow you to compute the
required points of a polygon or draw the object complete. In fact, the
use of the word polygon may not be totally correct as there is a star,
a circle, an arc, and a 3-D oval routine included! Most of these items
are geometrically complicated and require several variables. A TYPE is
used pass all the many variables into  and around the routines and the
PUBLIC variable pPi# is required.  You'll have to become familiar with
PolygonTYPE  and how it is used to traverse these waters but no worry!

  The logic used in these routines is plane geometry and a bit past my
kin, but all the figures are based on one or two circles. The star and
the 3-D polygon both use two circles to get things drawn.  There are a
few restrictions on the 3-D routine due to it's logic and some natural
blocks to all of them due to the composition of the universe we happen
to be stuck in!  The routines are not CAD quality and are not meant to
be but they get real useful every now and again and are very fast! The
best part is that the figures can be drawn using XORed logic! And that
brings us to PlotCircle.  By no means is this a replacement for CIRCLE
as it really doesn't do as good a job and is slower than dirt,  BUT it
can be XORed on and off! This makes it possible to use a dotted circle
until the correct position is found then use CIRCLE to do the finished
product.

  Once you have set the values for the members of PolygonTYPE you need
to call PolygonReady so the last four members can be computed.  Repeat
this if you change t.Radius,  t.Aspect, t.Points, and/or t.Start.  Any
changes here  will result in changes to at least  one of the last four
members also. Once you've got all this done you may compute all points
or any one point by calling PolygonPoints or PolygonPoint.  To capture
all the points you will require an INTEGER ARRAY XYs%(0:1,0:t.Points).
Elements 0,0 and 0,1 are loaded with the same values as the last point
so the last side of the polygon can be drawn. The last item to take in
to account is when you are drawing a 3-D figure or a STAR.  The second
TYPE for the back or inside does not always follow all the rules!  You
will want to pay particular attention to the screens for each of these
figures in regards to the different values.

  However you use these routines I am sure that you will find them not
only productive but also fun!  They are fast enough to create animated
sequences such as spinning stars, moving boxes, etc. This makes them a
favorite for preschooler games and educational demonstrations.
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