Management

void centralFieldManagement()
{

  PVector grav_atract = new PVector(0, 0);
  float dem = 0, dividerx = 0, dividery = 0, Distance, G_const = 0.6673;
  ArrayList<PVector> reverseGravity = new ArrayList<PVector>(cir.size());

  if (centralAction)
  {
    for (int i = 0; i<cir.size(); i++)
    {
      reverseGravity.add(new PVector(0, 0));
    }

    for (int i = 0; i<cir.size(); i++)
    {
      //Calculation of the mass center
      dem += cir.get(i).mass;
      dividerx += cir.get(i).mass * cir.get(i).point.x;
      dividery += cir.get(i).mass * cir.get(i).point.y;

      for (int j = i + 1; j<cir.size(); j++)
      {

        //calculating distance between object
        PVector lengthFrom_i_to_j = PVector.sub( cir.get(j).point, cir.get(i).point);
        PVector lengthFrom_j_to_i = PVector.sub( cir.get(i).point, cir.get(j).point);

        Distance = lengthFrom_i_to_j.mag();
        lengthFrom_i_to_j.normalize();
        lengthFrom_j_to_i.normalize();

        //adding gravity
        float strength = (G_const * cir.get(i).mass * cir.get(j).mass)/(Distance * Distance);
        lengthFrom_i_to_j.mult(strength);
        lengthFrom_j_to_i.mult(strength);

        reverseGravity.get(j).add(lengthFrom_j_to_i);

        grav_atract.add(lengthFrom_i_to_j);
      }

      grav_atract.add(reverseGravity.get(i));
      cir.get(i).setSpeed(grav_atract);
      grav_atract.mult(0);

      for (int k = 0; k<reverseGravity.size(); k++)
      {
        reverseGravity.get(k).mult(0);
      }
    }
  }

  checkForCollision();

  for (int i = 0; i < cir.size(); i++)
  {
    cir.get(i).drawing();

    fill(50, 0, 255 );
    stroke(255, 0, 50);
    textAlign(CENTER, CENTER);
    text(i, cir.get(i).point.x, cir.get(i).point.y);
  }

  //Drawing a center of mass
  pushMatrix();
  strokeWeight(6);
  fill(50, 0, 255 );
  stroke(255, 0, 50);
  point((dividerx/dem), (dividery/dem));
  popMatrix();
}

void homogeneousFieldManagement()
{
  PVector air_replica = new PVector(0.004, 0.004);
  PVector grav = new PVector(0.00, 9.00);
  PVector air;

  if (homogeneousAction)
  {
    for (int i = 0; i < cir.size(); i++)
    {//Adding gravity
      cir.get(i).setSpeed(grav);
      air = air_replica.copy();

      if (cir.get(i).velocity.x > 0 ||cir.get(i).velocity.y > 0)
      {
        air.mult(-1);
      }
      //adding motion resistance
      cir.get(i).setSpeed(air);
    }
  }

  checkForCollision();

  for (int j = 0; j < cir.size(); j++)
  {
    cir.get(j).drawing();
    strokeWeight(6);
    fill(50, 0, 255 );
    stroke(255, 0, 50);
    textAlign(CENTER, CENTER);
    text(j, cir.get(j).point.x, cir.get(j).point.y);
  }
}

void singlePendulumManagement()
{

  for (int i = 0; i < singlePend.size(); i++)
  {
    if (singleAction)
    {
      singlePend.get(i).update();
    }
    singlePend.get(i).drawing();
  }
  circle(0, 0, 10);
}

void dublePendulumManagement()
{

  for (int i = 0; i < doublePend.size(); i++)
  {
    doublePend.get(i).drowing(i, howManyDoublePen);
  }
  //drawing center ball
  fill(82, 0, 14);
  stroke(153, 0, 26);
  circle(0, 0, 20);
}