91 lines
2.5 KiB
Text
91 lines
2.5 KiB
Text
#include "crt.bi"
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Screen 20
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Window (-20,-20)-(30,30)
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Type Point
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As Single x,y
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As Long done
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End Type
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#macro rotate(pivot,p,a,scale)
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Type<Point>(scale*(Cos(a*.0174533)*(p.x-pivot.x)-Sin(a*.0174533)*(p.y-pivot.y))+pivot.x, _
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scale*(Sin(a*.0174533)*(p.x-pivot.x)+Cos(a*.0174533)*(p.y-pivot.y))+pivot.y)
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#endmacro
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Dim As Point p(1 To ...)={(16,3),(12,17),(0,6),(-4,-6),(16,6),(16,-7),(16,-3),(17,-4),(5,19), _
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(19,-8),(3,16),(12,13),(3,-4),(17,5),(-3,15),(-3,-9),(0,11),(-9,-3),(-4,-2),(12,10)}
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Function south(p() As Point,Byref idx As Long) As Point
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Dim As Point s=Type(0,100)
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For n As Long=Lbound(p) To Ubound(p)
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Circle(p(n).x,p(n).y),.2,7,,,,f
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If s.y>p(n).y Then s=p(n):idx=n
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Next n
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Return s
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End Function
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Function segment_distance(lx1 As Single, _
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ly1 As Single, _
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lx2 As Single, _
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ly2 As Single, _
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px As Single,_
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py As Single, _
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Byref ox As Single=0,_
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Byref oy As Single=0) As Single
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Dim As Single M1,M2,C1,C2,B
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B=(Lx2-Lx1):If B=0 Then B=1e-20
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M2=(Ly2-Ly1)/B:If M2=0 Then M2=1e-20
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M1=-1/M2
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C1=py-M1*px
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C2=(Ly1*Lx2-Lx1*Ly2)/B
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Var L1=((px-lx1)*(px-lx1)+(py-ly1)*(py-ly1)),L2=((px-lx2)*(px-lx2)+(py-ly2)*(py-ly2))
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Var a=((lx1-lx2)*(lx1-lx2) + (ly1-ly2)*(ly1-ly2))
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Var a1=a+L1
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Var a2=a+L2
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Var f1=a1>L2,f2=a2>L1
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If f1 Xor f2 Then
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Var d1=((px-Lx1)*(px-Lx1)+(py-Ly1)*(py-Ly1))
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Var d2=((px-Lx2)*(px-Lx2)+(py-Ly2)*(py-Ly2))
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If d1<d2 Then Ox=Lx1:Oy=Ly1 : Return Sqr(d1) Else Ox=Lx2:Oy=Ly2:Return Sqr(d2)
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End If
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Var M=M1-M2:If M=0 Then M=1e-20
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Ox=(C2-C1)/(M1-M2)
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Oy=(M1*C2-M2*C1)/M
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Return Sqr((px-Ox)*(px-Ox)+(py-Oy)*(py-Oy))
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End Function
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Dim As Long idx
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Var s= south(p(),idx)
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p(idx).done=1
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Redim As Point ans(1 To 1)
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ans(1)=s
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Dim As Point e=s
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e.x=1000
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Dim As Long count=1
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Dim As Single z
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Circle(s.x,s.y),.4,5
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Do
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z+=.05
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Var pt=rotate(s,e,z,1)
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For n As Long=Lbound(p) To Ubound(p)
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If segment_distance(s.x,s.y,pt.x,pt.y,p(n).x,p(n).y)<.05 Then
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s=p(n)
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If p(n).done=0 Then
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count+=1
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Redim Preserve ans(1 To count)
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ans(count)=p(n)
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p(n).done=1
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End If
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End If
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Circle(s.x,s.y),.4,5
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Next n
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Loop Until z>360
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For n As Long=Lbound(ans) To Ubound(ans)
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printf (!"(%2.0f , %2.0f )\n", ans(n).x, ans(n).y)
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Next
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Sleep
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