/////////////////////////////////////////////////
/*
delayed magnets
2005
andreas gysin
www.ertdfgcvb.ch
*/

/////////////////////////////////////////////////
magnet[] magnets;
float molti = 0.0;
//int cMode = 0;

/////////////////////////////////////////////////
void setup(){
  //params
  int bordo = 24;
  float hgrid = 12;
  float vgrid = hgrid*sqrt(0.75);
  int hlines = 40;
  int vlines = 46;
  int maxlen = 10;//int(vgrid-2);
  magnets = new magnet[vlines * hlines];

  //screen setup
  int w = int(hgrid*(hlines-1)) + bordo*2;
  int h = int(vgrid*(vlines-1)) + bordo*2;
  println (h + "   " + w);
  //size(w, h);
  size(515 , 516);
  framerate(30);

  //obj array
  int c = 0;
  for (int j=0; j<vlines; j++){
    for (int i=0; i<hlines; i++){
    int x = int(i*hgrid) + int(hgrid/2)*(j%2-1) + bordo;
    int y = int(j*vgrid) + bordo;
      magnets[c] = new magnet(x, y, maxlen);
      c++;
    }
  }
}

/////////////////////////////////////////////////
void loop(){

  if (mousePressed) {
    molti += 0.001;
  }else{
    molti = max(0.0, molti-0.002);
  }

  background(255,255,255);
  stroke(0);
  for (int i=0; i<magnets.length; i++){
    magnets[i].step();
  }
}
/////////////////////////////////////////////////
/*void keyPressed(){
  if (key==' '){
    cMode++;
    if (cMode > 4){
      cMode = 0;
    }
  }
}
*/
/////////////////////////////////////////////////
class magnet {
  int   l;
  float x1, y1;
  float x2, y2;
  float m2 = 0.0;
  float damp = 0.06;
  float mdamp = 0.02;
  //////////
  magnet(int qx, int qy, int ql) {
    x1 = qx;
    y1 = qy;
    x2 = x1;
    y2 = y1;
    l  = ql;
  }
  //////////
  void step() {
    //x1 += random(-1, 1);
    //y1 += random(-1, 1);
    float x3 = mouseX - x1;//x1 - mouseX);
    float y3 = mouseY - y1;//y1 - mouseY;
    float m = sqrt(x3 * x3 + y3 * y3);
    if (m > l) {
      x3 = x1 + x3/m * l;
      y3 = y1 + y3/m * l;
    } else if (m < l){
      x3 = x1 + x3;
      y3 = y1 + y3;
    } else {
      x3 = x1;
      y3 = y1;
    }
    x2 += (x3 - x2) * damp;
    y2 += (y3 - y2) * damp;
    m2 += (m - m2) * mdamp;
    strokeWeight(sin(m2 * molti) * 3.0);
    /*
    if (cMode == 0) {stroke(0, 0, 0);
    } else if (cMode == 1) {stroke(255, 0, 0);
    } else if (cMode == 2) {stroke(160-m2, m2*0.6, m2*1.1);
    } else if (cMode == 3) {stroke(m2, 255-m2, m2*1.8);
    } else if (cMode == 4) {stroke(190, 100-m2, 255-m2);
    }
    */
    line(x1, y1, x2, y2);
  }
}