00001
00002 c
00003 c Copyright (c) 1986,1987,1988,1989,1990,1991,1992,1993,
00004 c by Steve McMillan, Drexel University, Philadelphia, PA.
00005 c
00006 c All rights reserved.
00007 c
00008 c Redistribution and use in source and binary forms are permitted
00009 c provided that the above copyright notice and this paragraph are
00010 c duplicated in all such forms and that any documentation,
00011 c advertising materials, and other materials related to such
00012 c distribution and use acknowledge that the software was developed
00013 c by the author named above.
00014 c
00015 c THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
00016 c IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
00017 c WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
00018 c
00019
00020 subroutine ngon(rcall,scall,h,n,thoff)
00021 save
00022 c
00023 c Draws |n|-sided polygons (n = 0 ==> "."
00024 c 1 "+"
00025 c 2 "x".
00026 c or "stars" (for n < 0)
00027 c
00028 real*4 rr,ss,r,s,h,thoff
00029 integer*4 n
00030 common /findex/ index
00031 dimension rpoly(0:100),spoly(0:100),cth1(0:100),sth1(0:100)
00032 c
00033 data n1/0/
00034 c
00035 r=rcall
00036 s=scall
00037 go to 1
00038 c
00039 entry ungon(rcall,scall,h,n,thoff)
00040 entry userngon(rcall,scall,h,n,thoff)
00041 call fr inches(rcall,scall,r,s)
00042 c
00043 1 if(h.lt.0..and.n.ne.0)then
00044 hh=-h
00045 rr=r+.7071*hh
00046 ss=s+.7071*hh
00047 else
00048 hh=h
00049 rr=r
00050 ss=s
00051 end if
00052 c
00053 if(n.eq.0.or.h.eq.0.)then
00054 call point(rr,ss)
00055 else if(abs(n).eq.1)then
00056 call plot(rr-hh,ss,3)
00057 call plot(rr+hh,ss,2)
00058 call plot(rr,ss-hh,3)
00059 call plot(rr,ss+hh,2)
00060 else if(abs(n).eq.2)then
00061 hh=.7071*hh
00062 call plot(rr-hh,ss-hh,3)
00063 call plot(rr+hh,ss+hh,2)
00064 call plot(rr-hh,ss+hh,3)
00065 call plot(rr+hh,ss-hh,2)
00066 else
00067 nn=abs(n)
00068 nn1=nn
00069 if(n.lt.0)then
00070 nn2=nn/2
00071 ieven=0
00072 if(2*nn2.eq.nn)ieven=1
00073 if(ieven.eq.1)nn1=nn2
00074 end if
00075 th0=thoff
00076 dth=360./float(nn)
00077 th0=th0-90.-.5*dth
00078 th0=.017453*th0
00079 dth=.017453*dth
00080 th=th0-dth
00081 ipen=3
00082 do 100 i=0,nn1
00083 if(nn.ne.n1)then
00084 th=th+dth
00085 cth1(i)=cos(th)
00086 sth1(i)=sin(th)
00087 end if
00088 hc=hh*cth1(i)
00089 hs=hh*sth1(i)
00090 r1=rr+hc
00091 s1=ss+hs
00092 if(n.gt.0)then
00093 if(index.lt.0)then
00094 call plot(r1,s1,ipen)
00095 ipen=2
00096 else
00097 rpoly(i)=r1
00098 spoly(i)=s1
00099 end if
00100 else
00101 if(ieven.eq.0)then
00102 call plot(rr,ss,3)
00103 else
00104 call plot(rr-hc,ss-hs,3)
00105 end if
00106 call plot(r1,s1,2)
00107 end if
00108 100 continue
00109 if(index.ge.0.and.n.gt.0)call polyfill(rpoly,spoly,n+1)
00110 n1=nn
00111 end if
00112 c
00113 end
