fire rain wind

globals [
  initial-trees   ;; how many trees (green patches) we started with
  burned-trees    ;; how many have burned so far
  rain-zone
  rain-xstart
  rain-xend
  rain-ystart
  rain-yend
]

breed [fires fire]    ;; bright red turtles -- the leading edge of the fire
breed [embers ember]  ;; turtles gradually fading from red to near black

to setup
  clear-all
  set-default-shape turtles "square"
  ;; make some green trees
  ask patches with [(random-float 100) < density]
    [ set pcolor green ]
  ;; make a column of burning trees
  ask patches with [pxcor = min-pxcor]
    [ ignite ]
  ;; set tree counts
  set initial-trees count patches with [pcolor = green]
  set burned-trees 0
  
  ; Rain Area:
    set rain-xstart ( - max-pxcor / 2)
    set rain-xend (max-pxcor / 2)
    set rain-ystart ( - max-pxcor / 2)
    set rain-yend ( max-pxcor / 2)
end 

to go
  if not any? turtles  ;; either fires or embers
    [ stop ]
  
  ask fires
  [  
     
     ask neighbors4 with [pcolor = green]
     [
        ifelse rain and (pxcor < rain-xend) and (pxcor > rain-xstart) and (pycor > rain-ystart) and (pycor < rain-yend)
        [ set rain-zone TRUE ]
        [ set rain-zone FALSE ]
        
        ifelse rain-zone and ((random-float 100) < rain-chance)
        [ ]
        [ ignite ] 
     ]
     set breed embers   
    
     
     if wind and (pxcor < max-pxcor - 2) and (pxcor > min-pxcor + 2) and (pycor < max-pycor - 2) and (pycor > min-pycor + 2)
     [
        ask patch-at-heading-and-distance wind-angle 3 
        [ 
            ifelse rain and (pxcor < rain-xend) and (pxcor > rain-xstart) and (pycor > rain-ystart) and (pycor < rain-yend)
            [ set rain-zone TRUE ]
            [ set rain-zone FALSE ] 
            
            ifelse rain-zone and ((random-float 100) < rain-chance)
            [ ]
            [
               if pcolor = green
               [ ignite ] 
            ]
        ]
        set breed embers
     ]    
  ]
  fade-embers 
  tick
end 

;; creates the fire turtles

to ignite  ;; patch procedure
  sprout-fires 1
    [ set color red ]
  set pcolor black
  set burned-trees burned-trees + 1
end 


;; achieve fading color effect for the fire as it burns

to fade-embers
  ask embers
  [ 

    ifelse rain and (pxcor < rain-xend) and (pxcor > rain-xstart) and (pycor > rain-ystart) and (pycor < rain-yend)
    [ set rain-zone TRUE ]
    [ set rain-zone FALSE ] 
    
    ifelse rain-zone
    [
       set color color - 0.05  ;; make red darker but slower than when no rain.
       if color < red - 3.5     ;; are we almost at black?
       [ 
          set pcolor color
          die
       ]
    ] 
    [
       set color color - 0.3  ;; make red darker
       if color < red - 3.5     ;; are we almost at black?
       [ 
          set pcolor color
          die 
       ]
    ]  
  ]
end 


; *** NetLogo 4.1beta3 Model Copyright Notice ***
;
; This model was created as part of the project: CONNECTED MATHEMATICS:
; MAKING SENSE OF COMPLEX PHENOMENA THROUGH BUILDING OBJECT-BASED PARALLEL
; MODELS (OBPML).  The project gratefully acknowledges the support of the
; National Science Foundation (Applications of Advanced Technologies
; Program) -- grant numbers RED #9552950 and REC #9632612.
;
; Copyright 1997 by Uri Wilensky.  All rights reserved.
;
; Permission to use, modify or redistribute this model is hereby granted,
; provided that both of the following requirements are followed:
; a) this copyright notice is included.
; b) this model will not be redistributed for profit without permission
;    from Uri Wilensky.
; Contact Uri Wilensky for appropriate licenses for redistribution for
; profit.
;
; This model was converted to NetLogo as part of the projects:
; PARTICIPATORY SIMULATIONS: NETWORK-BASED DESIGN FOR SYSTEMS LEARNING
; IN CLASSROOMS and/or INTEGRATED SIMULATION AND MODELING ENVIRONMENT.
; The project gratefully acknowledges the support of the
; National Science Foundation (REPP & ROLE programs) --
; grant numbers REC #9814682 and REC-0126227.
; Converted from StarLogoT to NetLogo, 2001.
;
; To refer to this model in academic publications, please use:
; Wilensky, U. (1997).  NetLogo Fire model.
; http://ccl.northwestern.edu/netlogo/models/Fire.
; Center for Connected Learning and Computer-Based Modeling,
; Northwestern University, Evanston, IL.
;
; In other publications, please use:
; Copyright 1997 Uri Wilensky.  All rights reserved.
; See http://ccl.northwestern.edu/netlogo/models/Fire
; for terms of use.
;
; *** End of NetLogo 4.1beta3 Model Copyright Notice ***