Lego(TM) fab
Download
Lego(TM) fab - a game-like lego fab ... Build with the Lego(TM) robots CPV cells, entaglement RX/TX tools, GW asteroids shifters, AND fight against evil !
Lego(TM) is a registrated trade mark of it's owners !

Shortest path for any kind of maze (even for "extreme" difficult ones)
Maximum [time] for longest shortest paths : width * height !

This algorighm I've implemented by myself haveing in mind an algorithm for my robot ...
To understand it you need to understand :
  • "filling" a path-having a border- with a color
  • propagation of signals through wires



    Algorithm is Gnupyrighted (G) 1996-2010, AlphaX (R) Co. - Mihai Barboi, Ro, Eu
    Free for non-criminal purposes !
    uses function movsb1(src, dst, length_in_bytes) to copy memory blocks ! Can use your own block mover !

    Sub getshortestpath_thread(img1 As Any Ptr,sx As Integer,sy As Integer, ex As Integer,ey As UInteger,diagonala As Integer, thesteps As Any Ptr, thestepstotal As Integer Ptr, map2 As UByte Ptr,slepy As Integer)
    Dim As Integer i,k,f,j,h,t,l,m,inserted
    Dim As Integer mx,my,map_size
    Dim As stepaside Ptr sa, sap, sap2
    Dim As Integer steps_total,mused
    Dim As String A
    Dim as double tt1,tt2
    Dim as ulongint td1,td2
    ImageInfo img1,mx,my
    map_size=mx*my
    Dim As UByte did(1 To mx, 1 To my)
    Dim As UInteger steps_count(1 To map_size+1024)
    Dim As stepaside Ptr steps(1 To map_size+1024)
    If map2=0 then
    map2=allocate(map_size+8)
    mused=1
    For k=0 To my-1
    For i=0 To mx-1
    map2[i +(k)*mx]=iif((Point(i,k,img1) And &hffffff)>0,1,0)
    Next i
    Next k
    End if
    steps_total=1
    steps_count(steps_total)=1
    steps(steps_total)=Allocate(Len(stepaside))
    sa=steps(steps_total)
    sa->parent=0
    sa->x=sx
    sa->y=sy
    sa->brother=0

    l=steps_total
    m=l+1
    sa=steps(l)
    If (sx=ex) And (sy=ey) Then
    Print "starting position is equal with final one ! No work to do ..."
    Exit Sub
    EndIf
    'print "starting ..." 'debugx
    'tt1=timer()
    'rdtsc1 @td1
    redo11122:
    inserted=0
    For k=1 To steps_count(L)
    If sa=0 Then Exit For
    If sa->x>1 Then 'left
    'If (map(sa->x-1,sa->y)= 0) And (did(sa->x-1,sa->y)=0) Then
    If (map2[sa->x-1 + (sa->y-1)*mx -1]= 0) And (did(sa->x-1,sa->y)=0) Then
    inserted=1
    steps_count(m)+=1
    did(sa->x-1,sa->y)=1
    If steps_count(m)=1 Then
    steps(m)=Allocate(Len(stepaside))
    sap=steps(m)
    Else
    sap->brother=Allocate(Len(stepaside))
    sap=sap->brother
    EndIf
    sap->parent=sa
    sap->x=sa->x-1
    sap->y=sa->y
    sap->brother=0
    If (sap->x=ex) And (sap->y=ey) Then GoTo Ifound122
    EndIf
    EndIf
    If sa->x < mx Then 'right
    'If (map(sa->x+1,sa->y)= 0) And (did(sa->x+1,sa->y)=0) Then
    If (map2[sa->x+1 + (sa->y-1)*mx -1]= 0) And (did(sa->x+1,sa->y)=0) Then
    inserted=1
    steps_count(m)+=1
    did(sa->x+1,sa->y)=1
    If steps_count(m)=1 Then
    steps(m)=Allocate(Len(stepaside))
    sap=steps(m)
    Else
    sap->brother=Allocate(Len(stepaside))
    sap=sap->brother
    EndIf
    sap->parent=sa
    sap->x=sa->x+1
    sap->y=sa->y
    sap->brother=0
    If (sap->x=ex) And (sap->y=ey) Then GoTo Ifound122
    EndIf
    End If
    If sa->y > 1 Then 'down (or "up of screen")
    'If (map(sa->x,sa->y-1)=0) And (did(sa->x,sa->y-1)=0) Then
    If (map2[sa->x + (sa->y-1-1)*mx -1]= 0) And (did(sa->x,sa->y-1)=0) Then
    inserted=1
    steps_count(m)+=1
    did(sa->x,sa->y-1)=1
    If steps_count(m)=1 Then
    steps(m)=Allocate(Len(stepaside))
    sap=steps(m)
    Else
    sap->brother=Allocate(Len(stepaside))
    sap=sap->brother
    EndIf
    sap->parent=sa
    sap->x=sa->x
    sap->y=sa->y-1
    sap->brother=0
    If (sap->x=ex) And (sap->y=ey) Then GoTo Ifound122
    EndIf
    End If
    If sa->y 'If (map(sa->x,sa->y+1)= 0) And (did(sa->x,sa->y+1)=0) Then
    If (map2[sa->x + (sa->y+1-1)*mx -1]= 0) And (did(sa->x,sa->y+1)=0) Then
    inserted=1
    steps_count(m)+=1
    did(sa->x,sa->y+1)=1
    If steps_count(m)=1 Then
    steps(m)=Allocate(Len(stepaside))
    sap=steps(m)
    Else
    sap->brother=Allocate(Len(stepaside))
    sap=sap->brother
    EndIf
    sap->parent=sa
    sap->x=sa->x
    sap->y=sa->y+1
    sap->brother=0
    If (sap->x=ex) And (sap->y=ey) Then GoTo Ifound122
    EndIf
    End If
    If diagonala=1 Then
    If (sa->x > 1) And (sa->y > 1) Then ' down and left (or "up" and left)
    'If (map(sa->x-1,sa->y-1)=0) And (did(sa->x-1,sa->y-1)=0) Then
    If (map2[sa->x-1 + (sa->y-1-1)*mx -1]= 0) And (did(sa->x-1,sa->y-1)=0) Then
    inserted=1
    steps_count(m)+=1
    did(sa->x-1,sa->y-1)=1
    If steps_count(m)=1 Then
    steps(m)=Allocate(Len(stepaside))
    sap=steps(m)
    Else
    sap->brother=Allocate(Len(stepaside))
    sap=sap->brother
    EndIf
    sap->parent=sa
    sap->x=sa->x-1
    sap->y=sa->y-1
    sap->brother=0
    If (sap->x=ex) And (sap->y=ey) Then GoTo Ifound122
    EndIf
    EndIf
    If (sa->x < mx) And (sa->y > 1) Then 'down and right (or "up" and right)
    'If (map(sa->x+1,sa->y-1)=0) And (did(sa->x+1,sa->y-1)=0) Then
    If (map2[sa->x+1 + (sa->y-1-1)*mx -1]= 0) And (did(sa->x+1,sa->y-1)=0) Then
    inserted=1
    steps_count(m)+=1
    did(sa->x+1,sa->y-1)=1
    If steps_count(m)=1 Then
    steps(m)=Allocate(Len(stepaside))
    sap=steps(m)
    Else
    sap->brother=Allocate(Len(stepaside))
    sap=sap->brother
    EndIf
    sap->parent=sa
    sap->x=sa->x+1
    sap->y=sa->y-1
    sap->brother=0
    If (sap->x=ex) And (sap->y=ey) Then GoTo Ifound122
    EndIf
    EndIf
    If (sa->x > 1) And (sa->y < my) Then 'up and left (or "down" and left)
    'If (map(sa->x-1,sa->y+1)=0) And (did(sa->x-1,sa->y+1)=0) Then
    If (map2[sa->x-1 + (sa->y+1-1)*mx -1]= 0) And (did(sa->x-1,sa->y+1)=0) Then
    inserted=1
    steps_count(m)+=1
    did(sa->x-1,sa->y+1)=1
    If steps_count(m)=1 Then
    steps(m)=Allocate(Len(stepaside))
    sap=steps(m)
    Else
    sap->brother=Allocate(Len(stepaside))
    sap=sap->brother
    EndIf
    sap->parent=sa
    sap->x=sa->x-1
    sap->y=sa->y+1
    sap->brother=0
    If (sap->x=ex) And (sap->y=ey) Then GoTo Ifound122
    EndIf
    EndIf
    If (sa->x < mx) And (sa->y < my) Then 'up and right (or "down" and right)
    'If (map(sa->x+1,sa->y+1)=0) And (did(sa->x+1,sa->y+1)=0) Then
    If (map2[sa->x+1 + (sa->y+1-1)*mx -1]= 0) And (did(sa->x+1,sa->y+1)=0) Then
    inserted=1
    steps_count(m)+=1
    did(sa->x+1,sa->y+1)=1
    If steps_count(m)=1 Then
    steps(m)=Allocate(Len(stepaside))
    sap=steps(m)
    Else
    sap->brother=Allocate(Len(stepaside))
    sap=sap->brother
    EndIf
    sap->parent=sa
    sap->x=sa->x+1
    sap->y=sa->y+1
    sap->brother=0
    If (sap->x=ex) And (sap->y=ey) Then GoTo Ifound122
    EndIf
    EndIf
    EndIf
    sa=sa->brother
    Next k
    If (inserted=0) Or (m=map_size+1000) Then goto finish22
    l=m
    sa=steps(l)
    steps_total=l
    m=l+1
    If slepy>0 Then Sleep slepy
    GoTo redo11122
    ifound122:

    steps_total=m
    'rdtsc1 @td2
    'tt2=timer()
    *thestepstotal=steps_total
    If thesteps=0 Then GoTo finish22
    Dim As stepaside Ptr ttt
    *CPtr(UInteger Ptr,thesteps)=Cast(UInteger,Allocate(Len(stepaside)*steps_total+4))
    ttt=*CPtr(UInteger Ptr,thesteps)
    While sap<>0
    m-=1
    sap->x-=1:sap->y-=1
    movsb1 sap,@ttt[m],Len(stepaside)
    sap=sap->parent
    Wend
    finish22:
    For i=1 to steps_total
    sa=steps(i)
    while sa<>0
    sap=sa
    sa=sa->brother
    deallocate sap
    wend
    Next i
    If mused=1 Then DeAllocate map2
    'Print "#!@$ !"
    End Sub

  • Made in Romania, EU