Easy, fast and completed pathfinding in -80 lines (No media).

Are you a newbie in IA questions? With this code, you only must know how to use user defined types and arrays.

Comments: http://forum.thegamecreators.com/?m=forum_view&t=42787&b=6

                                    ` This code was downloaded from The Game Creators
                                    ` It is reproduced here with full permission
                                    ` http://www.thegamecreators.com
                                    
                                    rem Amoeba PAthfinding by Elthan 
rem (www.elthanart.tk // www.darkbasico.tk)
rem From Spanish Community
set display mode 800,600,32
sync on : sync rate 30

REM type user define for array mapa(=Map)
type datos
   obstaculo as integer
   generacion as integer
   xPadre as integer
   yPadre as integer
endtype

rem Map
dim mapa(6,6) as datos

rem Walls
mapa(3,1).obstaculo=1
mapa(3,2).obstaculo=1 : mapa(5,2).obstaculo=1
mapa(2,3).obstaculo=1 : mapa(3,3).obstaculo=1 : mapa(5,3).obstaculo=1
mapa(5,4).obstaculo=1
mapa(1,5).obstaculo=1 : mapa(2,5).obstaculo=1 : mapa(4,5).obstaculo=1 : mapa(5,5).obstaculo=1
mapa(4,6).obstaculo=1

rem Start and End squares.
rem Change to make test.
mapa(2,2).obstaculo=2 : mapa(5,6).obstaculo=3

for x=1 to 6
   for y=1 to 6
      if mapa(x,y).obstaculo=2
         mapa(x,y).generacion=1 : paso=1
         xP=x : yP=y
      endif
      if mapa(x,y).obstaculo=3 then xF=x : yF=y
   next y
next x

rem Main Loop
do
   cls
   gosub texto_informativo
   gosub dibujar_mapa
   if encontrado=0 and spacekey()=1 then gosub ameba
   sync
loop


rem Pathfinding sub
ameba:
   while encontrado=0
      rem Search in array
      for x=1 to 6
         for y=1 to 6
            if mapa(x,y).generacion=paso
               xA=x : yA=y
               rem First Square (like degrees)
               rem 4 3 2
               rem 5 * 1
               rem 6 7 8
               rem Check if fisrt square is into the array
               if xA+1<7
                  rem Check if first square is a wall and not processed
                  if mapa(xA+1,yA).obstaculo<>1 and mapa(xA+1,yA).generacion=0
                     rem Assign next generation
                     mapa(xA+1,yA).generacion=paso+1
                     rem Assign a father to this square
                     mapa(xA+1,yA).xPadre=xA : mapa(xA+1,yA).yPadre=yA
                     rem Check if we arrive to the end
                     if xA+1=xF and yA=yF then encontrado=1
                  endif
               endif
               rem 2nd
               if xA+1<7 and yA-1>0
                  if mapa(xA+1,yA-1).obstaculo<>1 and mapa(xA+1,yA-1).generacion=0
                     mapa(xA+1,yA-1).generacion=paso+1
                     mapa(xA+1,yA-1).xPadre=xA : mapa(xA+1,yA-1).yPadre=yA
                     if xA+1=xF and yA-1=yF then encontrado=1
                  endif
               endif
               rem 3rd
               if yA-1>0
                  if mapa(xA,yA-1).obstaculo<>1 and mapa(xA,yA-1).generacion=0
                     mapa(xA,yA-1).generacion=paso+1
                     mapa(xA,yA-1).xPadre=xA : mapa(xA,yA-1).yPadre=yA
                     if xA=xF and yA-1=yF then encontrado=1
                  endif
               endif
               rem 4th
               if xA-1>0 and yA-1>0
                  if mapa(xA-1,yA-1).obstaculo<>1 and mapa(xA-1,yA-1).generacion=0
                     mapa(xA-1,yA-1).generacion=paso+1
                     mapa(xA-1,yA-1).xPadre=xA : mapa(xA-1,yA-1).yPadre=yA
                     if xA-1=xF and yA-1=yF then encontrado=1
                  endif
               endif
               rem 5th
               if xA-1>0
                  if mapa(xA-1,yA).obstaculo<>1 and mapa(xA-1,yA).generacion=0
                     mapa(xA-1,yA).generacion=paso+1
                     mapa(xA-1,yA).xPadre=xA : mapa(xA-1,yA).yPadre=yA
                     if xA-1=xF and yA=yF then encontrado=1
                  endif
               endif
               rem 6th
               if xA-1>0 and yA+1<7
                  if mapa(xA-1,yA+1).obstaculo<>1 and mapa(xA-1,yA+1).generacion=0
                     mapa(xA-1,yA+1).generacion=paso+1
                     mapa(xA-1,yA+1).xPadre=xA : mapa(xA-1,yA+1).yPadre=yA
                     if xA-1=xF and yA+1=yF then encontrado=1
                  endif
               endif
               rem 7th
               if yA+1<7
                  if mapa(xA,yA+1).obstaculo<>1 and mapa(xA,yA+1).generacion=0
                     mapa(xA,yA+1).generacion=paso+1
                     mapa(xA,yA+1).xPadre=xA : mapa(xA,yA+1).yPadre=yA
                     if xA=xF and yA+1=yF then encontrado=1
                  endif
               endif
               rem 8th
               if xA+1<7 and yA+1<7
                  if mapa(xA+1,yA+1).obstaculo<>1 and mapa(xA+1,yA+1).generacion=0
                     mapa(xA+1,yA+1).generacion=paso+1
                     mapa(xA+1,yA+1).xPadre=xA : mapa(xA+1,yA+1).yPadre=yA
                     if xA+1=xF and yA+1=yF then encontrado=1
                  endif
               endif
            endif
         next y
      next x
      inc paso
   endwhile
   xA=xF : yA=yF
   rem Follow the path in inverse order
   while xA<>xP or yA<>yP
      x1=xA : y1=yA
      xA=mapa(x1,y1).xPadre
      yA=mapa(x1,y1).yPadre
      rem To draw a purple box on this square
      mapa(x1,y1).obstaculo=4
   endwhile
return

rem Draw map
dibujar_mapa:
   ink RGB(255,255,255),0
   box 48,48,351,351
   ink 0,0
   box 49,49,350,350
   set text size 20
   for x=1 to 6
      for y=1 to 6
         ink RGB(0,120,0),0
         if mapa(x,y).obstaculo=1 then ink RGB(255,0,0),0
         box x*50,y*50,x*50+49,y*50+49
         ink RGB(255,128,0),0
         center text (x*50)+25,(y*50)+10,str$(mapa(x,y).xPadre)+" : "+str$(mapa(x,y).yPadre)
         if mapa(x,y).obstaculo=2
            ink RGB(0,0,255),0
            box x*50,y*50,x*50+49,y*50+49
            ink RGB(255,128,0),0
            text (x*50)+18,(y*50)+10,"P"
         endif
         if mapa(x,y).obstaculo=3
            ink RGB(255,255,0),0
            box x*50,y*50,x*50+49,y*50+49
            ink RGB(255,128,0),0
            text (x*50)+18,(y*50)+10,"F"
         endif
         if mapa(x,y).obstaculo=4
            ink RGB(100,0,100),0
            box x*50,y*50,x*50+49,y*50+49
            ink RGB(255,128,0),0
            center text (x*50)+25,(y*50)+10,str$(mapa(x,y).xPadre)+" : "+str$(mapa(x,y).yPadre)
         endif
      next y
   next x
return

rem Show text
texto_informativo:
   set text size 20
   text 5,5,"AMOEBA PATHFINDING"
   text 400,50,"Press Espace to continue."
   text 400,70,"Each square shows coords of its father."
return