Example #1
1
    public void applyForce() {
      // force is proportional to the diff between restLen and current idst

      // a vector from A --> B
      Vector diff = new Vector(endA.pos, endB.pos);

      // compute the current distance
      float dist = diff.getMagnitude();
      // compute dx, which is what the force depends on
      float dx = Math.abs(dist - restLen);

      // a vector containing just the direction component of A --> B
      Vector dir = diff.copy().normalize();

      Vector force = dir.copy().scale(-K * dx, -K * dx);

      if (restLen < getDistance()) {
        // forces go INWARDS

        endB.addForce(force);
        endA.addForce(force.reverse());
      } else {
        // forces go OUTWARDS

        endA.addForce(force);
        endB.addForce(force.reverse());
      }
    }
Example #2
1
    public void updatePosition(float dt) {
      if (fixed) {
        netForce.reset(); // Shouldn't accumulate forces if fixed
        return;
      }

      updateAcceleration(dt);
      updateVelocity(dt);

      Point prev = new Point(pos.x, pos.y);
      pos.add(vel.copy().scale(dt, dt));

      ensureInBounds();
    }
Example #3
1
    // f = m * a --> a = f / m
    private void updateAcceleration(float dt) {
      //    println("node = " + id + ", netforce = " + netForce);

      Vector prev = acc;

      Float f1 = new Float(netForce.x);
      Float f2 = new Float(netForce.y);

      if (f1.isNaN(f1) || f2.isNaN(f2)) {
        netForce = new Vector();
      }

      float scale = 1.0f / mass;
      this.acc = netForce.copy().scale(scale, scale);

      if (id.equals("*.1.0-10")) {
        // println("NewAcc = " + acc);
        // System.exit(1);
      }

      // reset netForce for next time
      netForce.reset();
    }
Example #4
1
    private void updateVelocity(float dt) {
      Vector prev = vel.copy();

      vel.add(acc.scale(dt, dt));
    }