// import processing.opengl.*;

int sx = 800;
int sy = 600;

int cantx = 20;
int canty = 14;

ArrayList oj;   // oivamente de ojebtos

float k2mult = 0;

void setup() {
  size (sx,sy);
  framerate(15);
  smooth();
  background(0);

  oj = new ArrayList(cantx*canty);


  // creo los ojebtos
  for (int i=-5; i<cantx+5; i++) {
    for (int j=-5; j<canty+5; j++) {
      oj.add(new DynaObject((sx/cantx)*i-sx/2, (sy/canty)*j-sy/2));
    }
  }

//directionalLight(204, 204, 204, 0, 0, -1); 
//ambientLight(102, 102, 102);

}

void draw() {
  background(0);

  if( (mousePressed == true) ){
    if (k2mult < 0.1) {
      k2mult++;
    } 
    else if (k2mult < 2) {
      k2mult = k2mult * 1.5;
    }
  } 
  else {
    k2mult = k2mult * 0.7;
  }

  for (int i=0; i<oj.size(); i++) {
    DynaObject doj = (DynaObject)oj.get(i);
    doj.step(); 
    doj.paint();
  }
}



//-----------------------------------------------------------------------

class  DynaObject {
  // color negro... color
  float cr = 20;
  float cg = 20;
  float cb = 120;

  // tiempo
  float lastTime = 0;
  float thisTime = 0;
  float T = 1;

  // equilibrio
  float xo,yo;

  // posicion
  float x,y;
  float z;
  float r;

  // variables de estado (x2,y2) = velocidad
  float x0, y0, x1, y1, x2, y2;

  float lx1 =  0.00025;
  float lx2 =  0.00025;
  float ly1 =  0.00025;
  float ly2 = 0.00025;
  float d = 1;
  float l = 1;
  double teta; 

  // constantes dinamicas
  float m = 15000;    // masa
  float br = 2000;
  float k1 = 2000;    // constante del resorte del objeto
  float k2 = 4000000; // constante del puntero del mouse 

  float a = br/(2*m);
  float b = sqrt(k1/m-pow(br/(2*m),2));

  // temporales 
  float A = 700;
  float B = 700;
  float C = 0.0002;
  float D = 0.001;


  // --------------------
  // constructor 
  DynaObject(float xo, float yo) {
    this.xo = xo;
    this.x = xo;
    this.yo = yo;
    this.y = yo;
    x1=x0;
    y1=y0;
    x2=x1;
    y2=y1;

    A = 1-exp(-a*T)*(cos(b*T)+a/b*sin(b*T));
    B = exp(-2*a*T)+exp(-a*T)*(a/b*sin(b*T)-cos(b*T));
    A = A*k2/(m*(a*a+b*b));
    B = B*k2/(m*(a*a+b*b));

    C = -2*exp(-a*T)*cos(b*T);
    D = exp(-2*a*T);

  }
  //--------------------
  void step() {
    thisTime = System.currentTimeMillis();
    this.T = 0.1;

    if (T > 0.001){
      calcNextPos();
    }
    lastTime = thisTime;
  }

  //---------------------
  void calcNextPos() {
    float xp = 10000;
    float yp = 10000;
    if ((abs(mouseX) < 1000) && (abs(mouseY) < 1000)) {
      xp = mouseX-sx/2;
      yp = mouseY-sy/2;
    } 

    x0 = (k2mult+1)*A*lx1 + (k2mult+1)*B*lx2 - C*x1 - D*x2;
    y0 = (k2mult+1)*A*ly1 + (k2mult+1)*B*ly2 - C*y1 - D*y2;

    //dejo preparados los proximos valores
    x = x0+xo;
    y = y0+yo;
    x2 = x1;
    y2 = y1;
    x1 = x0;
    y1 = y0;

    lx2 = lx1;
    ly2 = ly1;

    d = sqrt( pow((xp-x),2) + pow((yp-y),2) );
    l = 1 / (40 + d );

    lx1 = (xp-x) * pow(l,2) ;
    ly1 = (yp-y) * pow(l,2) ;
    
    z=10*dist(x,y,xo,yo);
    
    r=0; //r+z/1000;
  }

  //--------------
void paint() {
  
    fill(cr+10*abs(x2-x1)+10*abs(y2-y1),cr+2*abs(x2)+2*abs(y2),cb,180);
    noStroke();
    rect(x+sx/2,y+sy/2,sx/cantx,sy/canty);
}
  
    //-------------
/*
    void paintGl() {
    fill(cr+10*abs(x2-x1)+10*abs(y2-y1),cr+2*abs(x2)+2*abs(y2),cb,180);
    noStroke();
    //rect(x+sx/2,y+sy/2,sx/cantx,sy/canty);


    pushMatrix();

    rotateX(0.15);
    rotateY(0);

    translate(x+sx/2, y+sy/2, -z);

    pushMatrix();
    
    rotateY(r);
    
    pushMatrix();
    beginShape(POLYGON);
    vertex(-sx/cantx/2,-sy/canty/2);
    vertex(sx/cantx/2, -sy/canty/2);
    vertex(sx/cantx/2,  sy/canty/2);
    vertex(-sx/cantx/2, sy/canty/2);
    endShape();
    popMatrix();
        
    popMatrix();
    
    popMatrix();
  }
  */

}