cruise.nlogo

NETLOGO

to go
  if ticks = 0 [if (count turtles) = 0 [setup]]
  set ticks ticks + 1
  ask turtles [
    move-forward
  ]
end

to move-forward  ; turtle proc
  locals [n p l]
  set n neighbors with [on-road?]
  ifelse count n = 0 [go-home] [
    set l []
    ask patch-left-and-ahead  90 3 [if on-road? [set l lput self l]]
    ask patch-right-and-ahead 90 3 [if on-road? [set l lput self l]]
    if (length l != 0) and (0 = random 3) [ set p random-one-of l ]
    if p = 0      [ set p one-of n with [(heading-angle myself) = 0] ]
    if p = nobody [ set p random-one-of n with [(heading-angle myself) <= 45] ]
    if p = nobody [ set p random-one-of n with [(heading-angle myself) <= 90] ]
    if p = nobody [ set p min-one-of n [heading-angle myself] ]
    set heading towards p
    forward distance p
  ]
end

to-report heading-angle [t] ; patch proc
  locals [h]
  ;set h abs (heading-of t - (towards t + 180) mod 360)
  set h (towards t + 180 - heading-of t) mod 360
  if h > 180 [set h 360 - h]
  report h
end

; ---------------------------------------------------------------------------
;        Can delete; only used to build map data. Not used by model.
; ---------------------------------------------------------------------------
; These are called by hand to create the compressed (.dat) form of the map.
; To create the file, call: create-dat "mapname" (w/o .dat)
; Can remove once the .dat is created.  Here to explain the stunt.
; Note: patchcolors proc below is an array form of the .dat file.
; ---------------------------------------------------------------------------

to init-map
  create-dat mapname
end

to create-dat [mapfile]
  print "..creating patches, I'll print 'done' when completed"