Radial path

breed [lefties lefty]
breed [righties righty]
breed [centers center]
globals[centerx centery sigma]
turtles-own[nom xrel yrel moves_since_fork must_fork_left must_fork_right ]

;left path shifts x+0 and y+1 and forks to right every 4 steps
;right path shifts x+1 and y+1 and forks to left every 3 steps
;center path is 2 rows shifting x+1 and y+2 and forks to left and right every 2 steps
;the first center item is different : forks both left and right on the first step

to setup
  clear-all
  resize-world 0 100 0 70
  set-patch-size 10
  set sigma 1
  set centerx 2
  set centery 1
  create-lefties 1
  ask lefty 0 [
    set nom "L1"
    set xrel 0
    set yrel 1
    set color blue
    set xcor centerx + 0
    set ycor centery + 1
    set must_fork_left false
    set must_fork_right true
  ]
  create-righties 1
  ask righty 1 [
    set nom "R1"
    set xrel 1
    set yrel 1
    set color orange
    set xcor centerx + 1
    set ycor centery + 1
    set must_fork_left true
    set must_fork_right false
  ]
  create-centers 1
  ask center 2 [
    set nom "C1"
    set xrel 1
    set yrel 2
    set moves_since_fork 1 ;;first step is different
    set color green
    set xcor centerx + 1
    set ycor centery + 2
    set must_fork_left true
    set must_fork_right true
  ]
  create-centers 1
  ask center 3 [
    set nom "C2"
    set xrel 1
    set yrel 2
    set xcor centerx + 1
    set ycor centery + 3
    set color 125
    set must_fork_left true
    set must_fork_right false
  ]
  create-centers 1
  ask center 4 [
    set nom "C3"
    set xrel 1
    set yrel 2
    set xcor centerx + 2
    set ycor centery + 3
    set color 115
    set must_fork_left false
    set must_fork_right true
  ]
  reset-ticks
end 

to go
  test
  tick
end 

to test
  ;;coloriage de la case ou l'agent passe
  ask turtles [
    let c color
    ask patch-at 0 0 [set pcolor c ]
    set moves_since_fork (moves_since_fork + 1)
    let newx (xcor + xrel)
    let newy (ycor + yrel)
    let r  sqrt ( newx * newx + newy * newy)
    ;;show word  "radius=" r
    if r < max_radius [
      set xcor newx
      set ycor newy
      ;;forks
      if breed = lefties and moves_since_fork = 4 and must_fork_right [
        ;les Left se décalent de 0 1 et fork a droite tous les 4
        ;show "Forking left to right"
        set must_fork_right false
        set moves_since_fork 0
        let x xcor
        let y ycor
        hatch-lefties 1 [
          set xrel 0
          set yrel 1
          set color random-normal blue sigma
          set xcor x + 1
          set ycor y + 0
          set must_fork_left false
          set must_fork_right true
        ]
      ]
      if breed = righties and moves_since_fork = 3 and must_fork_left[
        ;les Right se décalent de 1,1 et fork a gauche tous les 3
        ;show "Forking right to left"
        set must_fork_left false
        set moves_since_fork 0
        let x xcor
        let y ycor
        hatch-righties 1 [
          set xrel 1
          set yrel 1
          set color random-normal orange sigma
          set xcor x + 0
          set ycor y + 1
          set must_fork_left true
          set must_fork_right false
        ]
      ]
      if breed = centers and moves_since_fork = 2  [
        let cc color
        ;les Center se décalent de 1,2 et fork tous les 2
        if must_fork_left[
          ;show "Forking center to left "
          set must_fork_left false
          set moves_since_fork 0
          let x xcor
          let y ycor
          hatch-centers 1 [
            set xrel 1
            set yrel 2
            set color random-normal cc sigma
            set xcor x - 1
            set ycor y + 0
            set must_fork_left true
            set must_fork_right false
          ]
        ]
        if must_fork_right [
          ;show "Forking center to right "
          set must_fork_right false
          set moves_since_fork 0
          let x xcor
          let y ycor
          hatch-centers 1 [
            set xrel 1
            set yrel 2
            set color random-normal cc sigma
            set xcor x + 1
            set ycor y + 0
            set must_fork_left false
            set must_fork_right true
          ]
        ]
      ]
    ]
  ]
end