Bridge bridge;
void setup() {
  size(1000, 700);
  frameRate(60);
  translate((width / 2) - (750 / 2), height / 2);

  bridge = new Bridge(5, 9);
}

void draw() {
}

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class Joint {
  float x, z;
  double Sx, Sz;
  String type;
  double[][] r;

  Joint() {
    r = new double[2][1];
    type = "kloub";
    x = 250;
    z = -250;
    x = random(0, 750);
    z = -random(0, height / 2);
  }
}
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class Bridge {
  ArrayList <Joint> joint_array = new ArrayList <Joint>();
  ArrayList <Prut> prut_array = new ArrayList <Prut>();

  Bridge(int joint_number, int rod_number) {

    for (int i = 0; i < joint_number; i++) {
      joint_array.add(new Joint());
}

    for (int i = 0; i < rod_number; i++) {
      prut_array.add(new Prut());

      if (i == 0) {
        prut_array.get(i).xa = joint_array.get(0).x;
        prut_array.get(i).za = joint_array.get(0).z;
        prut_array.get(i).xb = joint_array.get(1).x;
        prut_array.get(i).zb = joint_array.get(1).z;
      } else if (i == 1) {
        prut_array.get(i).xa = joint_array.get(0).x;
        prut_array.get(i).za = joint_array.get(0).z;
        prut_array.get(i).xb = joint_array.get(3).x;
        prut_array.get(i).zb = joint_array.get(3).z;
      }

      prut_array.get(i).aktivation();
    }
  }
}
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class Prut {
  String joint_A_type, joint_B_type;
  int joint_A, joint_B;
  float xa, za, xb, zb, colour;
  double A, E, I, l, s, c, z;

  Prut() {
    A = 0.0000494800842940392;
    E = 3176675.89592474;
    I = 2.18684301120977 * pow(10, -10);
    z = 0.00409807621135332;
  }

  void aktivation() {
    for (int i = 0; i < 5 - 1; i++) {
      for (int j = i + 1; j < 5; j++) {
        if (xa == bridge.joint_array.get(i).x & za == bridge.joint_array.get(i).z & xb == bridge.joint_array.get(j).x & zb == bridge.joint_array.get(j).z) {
          joint_A = i;
          joint_B = j;
          joint_A_type = bridge.joint_array.get(i).type;
          joint_B_type = bridge.joint_array.get(j).type;
        }
      }
    }
  }
}