//pattern 1
float p=PI; //ratio by which random distances are determined
float xtf; //carrier for flipper
float ytf; //carrier for flipper
float o; //for calculating tan-1
float a; //for calculating tan-1
float theta; //for trigonometry
float L; //for trigonometry (hypotenuse)
float nL; //random new hypotenuse
int choice; //random choice
int q; //random child index
float xta; // carrier variable
float yta; // carrier variable
float xtb; // carrier variable
float ytb; // carrier variable
// child co-ord table
float [] xva=new float[200+int(random(100))];
float [] yva=new float[xva.length];
float [] xvb=new float[xva.length];
float [] yvb=new float[xva.length];
void setup (){
  size (500,300);
  background (255);
  //graph paper for 400x400
  //stroke(220);
  //for(int j=0; j<405; j+=5) {
  //  line (j,0,j,400);
  //  line (0,j,400,j);
  //}
  //stroke (180);
  //line (200,0,200,400);
  //line (0,200,400,200);
  xva[0]=200;
  yva[0]=200;
  xvb[0]=300;
  yvb[0]=100;
  stroke(0);
}
void loop () {
  noStroke();
  fill(255); 
  rect(0,0,width,height);
  //child co-ord creator
  for (int i=1; i<xva.length; i++){
    //carriers copy existing random line
      q=int(random(i));
      xta=xva[q];
      yta=yva[q];
      xtb=xvb[q];
      ytb=yvb[q];
      println ("child"+q);
    //flipper
    if (int(random(2))==1) {
      xtf=xta;
      xta=xtb;
      xtb=xtf;
      ytf=yta;
      yta=ytb;
      ytb=ytf;
    }
    // Trig
    a=(xtb-xta);
    o=(ytb-yta);
    theta=atan2(o,a);
    L=sqrt(sq(abs(a))+sq(abs(o)));
    nL=(L-(L/p))+random((L/p)*2);
    // Type of mutation
    choice=int(random(3));
    if (choice==0){
      displacer(); parallel();
    }
    if (choice==1){
      perpendicular ();
    }
    if (choice==2){
      displacer(); rotation ();
    }
    xva[i]=xta;
    xvb[i]=xtb;
    yva[i]=yta;
    yvb[i]=ytb;
  }
  // draw children
  //translate (200,200);
  //rotate (-(PI/2));
  int c=0;
  for (int i=0; i<xva.length; i++){
    stroke(c);
    //c+=10;
    line (xva[i],yva[i],xvb[i],yvb[i]);
  }
  while (overRect(0,0,width,height) && !mousePressed){ 
  }
}

//mutant co-ord generators

void displacer(){
  float dL=((L/p)/p)+random(L/p);
  float dTheta=random(TWO_PI);
  xta=(xta+(cos(dTheta)*dL));
  yta=(yta+(sin(dTheta)*dL));
}
void parallel() {
  xtb=(xta+(cos(theta)*nL));
  ytb=(yta+(sin(theta)*nL));
}
void perpendicular() {
  float intsect = random(L);
  float xc=xta+(cos(theta)*intsect);
  float yc=yta+(sin(theta)*intsect);
  intsect = random(nL);
  theta-=(TWO_PI/4);
  if (theta<0){
    theta+=TWO_PI;
  }
  xta=xc+(cos(theta)*intsect);
  yta=yc+(sin(theta)*intsect);
  theta+=PI;
  if (theta>TWO_PI){
    theta-=TWO_PI;
  }
  xtb=xta+(cos(theta)*nL);
  ytb=yta+(sin(theta)*nL);
}
void rotation() {
  float nTheta=(theta-(TWO_PI/p))+(random(TWO_PI/p)*2);
  if (theta<0){
    theta+=TWO_PI;
  } else if (theta>TWO_PI){
    theta-=TWO_PI;
  }
  xtb=(xta+(cos(nTheta)*nL));
  ytb=(yta+(sin(nTheta)*nL));
}
//Button
boolean overRect(int x, int y, int width, int height) 
{ 
  if (mouseX >= x && mouseX <= x+width && 
      mouseY >= y && mouseY <= y+height) { 
    return true; 
  } else { 
    return false; 
  } 
}