/*
* Code by Luke Loeffler
* based on example code by Daniel Schiffman (learningprocessing.com) which draws text along a circle.
*/



String message = "text on a curve";
PFont f;

ArrayList al = new ArrayList();

class P2 {
  float x; float y;
  public P2(float x, float y) { this.x=x; this.y=y; }
}


// The radius of a circle
float r = 100;

void setup() {
  size(800,600);
  f = createFont("Georgia",40,true);
  textFont(f);
  textAlign(LEFT);
  smooth();

}

float curveLength(float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4) {
  int steps = 50; // estimation steps more=more accurate
  float sum = 0;
  for(int i=0; i<steps-1; i++) {
    float x  = curvePoint(x1,x2,x3,x4, (i*1.0)/steps);
    float y  = curvePoint(y1,y2,y3,y4, (i*1.0)/steps);
    float xn  = curvePoint(x1,x2,x3,x4, ((i+1)*1.0)/steps);
    float yn  = curvePoint(y1,y2,y3,y4, ((i+1)*1.0)/steps);
    sum += dist(x,y,xn,yn);
  }
  return sum;
}

void draw() {
  curveTightness(map(mouseX, 0, width, -10, 10));
  background(255);
//  float x = 20;
//  for(int i=0; i<message.length(); i++) {
//    char curCh = message.charAt(i);
//    float chW = textWidth(curCh);
//    fill(0);
//    text(curCh, x, 30);
//    x+=chW;
//  }
  
  if(al.size() >= 4) {
    for(int i=0; i<=al.size()-4; i++) {
      P2 p0 = (P2)al.get(i);
      P2 p1 = (P2)al.get(i+1);
      P2 p2 = (P2)al.get(i+2);
      P2 p3 = (P2)al.get(i+3);

      noFill();
      strokeWeight(2.0);
      stroke(0,100);
      curve(p0.x, p0.y, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y);
    }

    P2 p0 = (P2)al.get(0);
    P2 p1 = (P2)al.get(1);
    P2 p2 = (P2)al.get(2);
    P2 p3 = (P2)al.get(3);
    float t=0;
    float curvelength = curveLength(p0.x, p0.y, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y);
    float textLength = textWidth(message);
    float textlensum = 0;

    for(int ch=0; ch < message.length(); ch++ ) {
       char curCh = message.charAt(ch);
       float chW = textWidth(curCh);
       
       textlensum += chW;
       
       float x  = curvePoint(p0.x, p1.x, p2.x, p3.x, t);
       float y  = curvePoint(p0.y, p1.y, p2.y, p3.y, t);
       float tx = curveTangent(p0.x, p1.x, p2.x, p3.x, t);
       float ty = curveTangent(p0.y, p1.y, p2.y, p3.y, t);
       float a = atan2(ty, tx);
       
       
       //a -= PI/2.0;
       pushMatrix();
       translate(x,y);
       rotate(a);
       
       strokeWeight(1.0);
       stroke(0);
       //line(0,0,0,30);
       //line(0,0, cos(a)*30, sin(a)*30);
       //line(x,y,tx,ty);
       //ellipse(tx,ty, 5,5);
       fill(0,100);
       text(curCh,0,0);
       popMatrix();
       t += (chW/curvelength); //1.0 / message.length();
    }
    //println("curve length is about: " + curvelength + " and text length is: " + textLength + " calculate len: " + textlensum);
  }

}

void mouseClicked() {
  al.add(new P2(mouseX, mouseY));
  println(al.size());
  print ("x=" + mouseX + " y=" + mouseY);
}