class Lsystem {

  String axiom;
  int rc, rm, rint, rendercount;
  char[] sa;
  RuleSet ruleset;
  float renderindexfloat = 0.0;
  float startx;
  float starty;
  float unitsize;
  float anglechange;

  Lsystem(String axiom) {
    this.startx = random(width);//1024);// + 256;
    this.starty = random(50) + (height - 50);// 700;
    this.axiom = axiom;
    this.rc = 0;
    this.rendercount = 0;
    this.renderindexfloat = 0.0;
  };

  void registerRuleSet(RuleSet rs)  {    this.ruleset = rs;                  };  
  String getAxiom()                 {    return axiom;                       }
  void addStartF()                  {    this.axiom = "F" + this.axiom;      }    
  void setUnitsize(float us)        {    this.unitsize = us;                 }  
  void setAnglechange(float ac)     {    anglechange = ac;                   }

  void recurse(int maxi) {
    this.rm = maxi;
    this.rc ++;

    this.sa = this.axiom.toCharArray();
    String[] ta = new String[this.sa.length];

    for (int n=0; n<this.sa.length; n++) {
      String replace = this.ruleset.runRule(this.sa[n]);
      ta[n] = replace;
    };

    this.axiom = join(ta, "");

    if (this.rc < this.rm) {    this.recurse(this.rm);    
    } else                 {    this.rc = 0;            }; 
  };

  void render()     {    doRender();    };
  void doRender()   {
      gTurtle.setXY(this.startx, this.starty);
      gTurtle.setHeading(0);
      gTurtle.setBranchCount(0);
      gTurtle.setBranchesArrayIndex(0);
      gTurtle.setStartBranchWidth(15);
      gTurtle.setUnitsize (this.unitsize);
      gTurtle.setAnglechange (this.anglechange);
    
      if (gState == STATE_START)  {
        this.renderindexfloat = 0;
      }

      if (gState == STATE_GROWING)  {
        this.renderindexfloat += random(TREE_GROWTH_RATE);
        if (this.renderindexfloat > this.axiom.length())  {
          this.renderindexfloat = this.axiom.length();
        }
        
        int renderindex = floor(this.renderindexfloat);
        for (int i = 0; i < this.axiom.length(); i++)  {  //renderindex; i++)  {
          if (i < renderindex)  {
            gTurtle.process(this.axiom.charAt(i), true);
          } else {
            gTurtle.process(this.axiom.charAt(i), false);
          }
        } 
      }
           
      if (gState == STATE_GROWN)  {
        this.renderindexfloat = this.axiom.length() ;
        // draw entire structure
        for (int i = 0; i < this.axiom.length(); i++)  {
          gTurtle.process(this.axiom.charAt(i), true);
        }    
      }    
      
      if (gState == STATE_SHRINKING)  {
        this.renderindexfloat -= random(TREE_GROWTH_RATE * 2);
        if (this.renderindexfloat < 0.0)    {
          this.renderindexfloat = 0.0;
        }
        
        int renderindex = floor(this.renderindexfloat);
        for (int i = 0; i < this.axiom.length(); i++)  {
          if (i < renderindex)  {
            gTurtle.process(this.axiom.charAt(i), true);
          } else {
            gTurtle.process(this.axiom.charAt(i), false);
          }
        } 
      }
  };
};