` darkbasic pathfinder


`make a few arrays
DIM grid (100,100)
DIM scanner (100,100)
DIM solution (100,100)

`create a nice viewport
make camera 1
position camera 1,0,0,0
POINT camera 1,0,0,100
color backdrop 1,rgb (0,0,0)

`set the size of the maze
DATA 10,10
` set the maze
DATA 1,1,1,1,1,1,1,1,1,1
DATA 1,3,1,0,0,0,0,0,0,1
DATA 1,0,1,0,1,1,0,1,0,1
DATA 1,0,1,0,1,0,0,0,0,1
DATA 1,0,1,0,1,0,0,1,0,1
DATA 1,0,1,0,1,0,1,1,0,1
DATA 1,0,0,0,1,0,2,0,0,1
DATA 1,0,1,1,1,1,1,1,0,1
DATA 1,0,0,0,1,0,0,0,0,1
DATA 1,1,1,1,1,1,1,1,1,1


`READ the maze AND make some objects TO show it
READ maxx
READ maxy
FOR yt = 1 TO maxy
   FOR xt = 1 TO maxx
      an=an+1
      READ griddata
      grid(xt,yt) = griddata
      ypos = 45+(maxy)-(yt*10)
      xpos = 40+(maxx)-(xt*10)

      `whole lotta IF
      IF griddata = 1 THEN make object cube an,10 : position object an, xpos,ypos,100:color object an, rgb(145,57,144)
      IF griddata = 2 THEN make object sphere 400,9: position object 400,xpos,ypos,100: color object 400, rgb(0,0,255)
      IF griddata = 3 THEN make object sphere 401,9: position object 401,xpos,ypos,100: color object 401, rgb(255,0,0)
      IF griddata=2 THEN startcoordx=xt
      IF griddata=2 THEN startcoordy=yt
      IF griddata=3 THEN stopcoordx=xt
      IF griddata=3 THEN stopcoordy=yt

   NEXT xt
NEXT yt
sync

`DEBUGGING CRAP

`FOR yf = 1 TO maxy
`   FOR xf = 1 TO maxx
`      scanput = grid(xf,yf)
`      set cursor xf*16,yf*16
`      IF scanput=1 THEN PRINT "#"
`      IF scanput=2 THEN PRINT "F"
`      IF scanput=3 THEN PRINT "S"
`      NEXT
`      NEXT


`this does stuff
searchx=startcoordx
searchy=startcoordy

`CALLS the pathfinding FUNCTION (it's recursive)
scannert(searchx,searchy,99)

`some more stuff
upcount=scanner(stopcoordx,stopcoordy)
coordx=stopcoordx
coordy=stopcoordy

DO
sync
   `make a 250 ms pause between each LOOP TO make stuff visual
   SLEEP 250

   value=scanner(coordx,coordy)
   newvalue=scanner(coordx+1,coordy)
   gridvar=grid(coordx+1,coordy)

   IF value < newvalue  AND gridvar =0 THEN t=t+1:coordx=coordx+1:makeamark(coordx,coordy,maxx,maxy,t)

   value=scanner(coordx,coordy)
   newvalue=scanner(coordx-1,coordy)
   gridvar=grid(coordx-1,coordy)
   IF value < newvalue AND gridvar =0  THEN t=t+1:coordx=coordx-1:makeamark(coordx,coordy,maxx,maxy,t)

   value=scanner(coordx,coordy)
   newvalue=scanner(coordx,coordy+1)
   gridvar=grid(coordx,coordy+1)
   IF value < newvalue  AND gridvar =0 THEN t=t+1:coordy=coordy+1:makeamark(coordx,coordy,maxx,maxy,t)

   value=scanner(coordx,coordy)
   newvalue=scanner(coordx,coordy-1)
   gridvar=grid(coordx,coordy-1)
   IF value < newvalue  AND gridvar =0 THEN t=t+1:coordy=coordy-1:makeamark(coordx,coordy,maxx,maxy,t)

   value=scanner(coordx,coordy)
   IF value > 99 THEN GOTO theend


LOOP

theend:
DO:LOOP


FUNCTION makeamark(x,y,maxx,maxy,t)
`makes a square whwn it finds the right path

` MORE DEBUG CRAP
`set cursor x*16,y*16
`PRINT "X"

ypos = 45+(maxy)-(y*10)
xpos = 40+(maxx)-(x*10)

make object cube t+500,10: color object t+500,rgb(0,255,0)
position object t+500, xpos,ypos,100

endfunction



FUNCTION scannert(x,y,distance)
`the pathfinder

scanner(x, y) = distance    ` set the distance TO current location
sync


` YOU GUESSED IT, DEBUG
`FOR yf = 1 TO maxy
`   FOR xf = 1 TO maxx
`      scanput = scanner(xf,yf)
`      set cursor xf*16,140+yf*16
`      PRINT scanput
`   NEXT
`NEXT

`set cursor 0,200
`PRINT "x = ", x, "y = ", y, " distance = ", distance



` scan left
gridvar = grid(x-1, y)
scanvar = scanner(x-1, y)
IF scanvar < distance AND gridvar <> 1 THEN scannert(x-1, y, distance - 1)

` scan right
gridvar = grid(x+1, y)
scanvar = scanner(x+1, y)
IF scanvar < distance AND gridvar <> 1 THEN scannert(x+1, y, distance - 1)

` scan up
gridvar = grid(x, y-1)
scanvar = scanner(x, y-1)
IF scanvar < distance AND gridvar <> 1 THEN scannert(x, y-1, distance - 1)

` scan down
gridvar = grid(x, y+1)
scanvar = scanner(x, y+1)
IF scanvar < distance AND gridvar <> 1 THEN scannert(x, y+1, distance - 1)

endfunction