Java Code Examples for org.jbox2d.common.Vec2#length()

/**
 * Initialize the bodies, anchors, and length using the world anchors.
 * 
 * @param b1 First body
 * @param b2 Second body
 * @param anchor1 World anchor on first body
 * @param anchor2 World anchor on second body
 */
public void initialize(final Body b1, final Body b2, final Vec2 anchor1, final Vec2 anchor2) {
  bodyA = b1;
  bodyB = b2;
  localAnchorA.set(bodyA.getLocalPoint(anchor1));
  localAnchorB.set(bodyB.getLocalPoint(anchor2));
  Vec2 d = anchor2.sub(anchor1);
  length = d.length();
}
 

/**
 * Initialize the bodies, anchors, lengths, max lengths, and ratio using the world anchors.
 */
public void initialize(Body b1, Body b2, Vec2 ga1, Vec2 ga2, Vec2 anchor1, Vec2 anchor2, float r) {
  bodyA = b1;
  bodyB = b2;
  groundAnchorA = ga1;
  groundAnchorB = ga2;
  localAnchorA = bodyA.getLocalPoint(anchor1);
  localAnchorB = bodyB.getLocalPoint(anchor2);
  Vec2 d1 = anchor1.sub(ga1);
  lengthA = d1.length();
  Vec2 d2 = anchor2.sub(ga2);
  lengthB = d2.length();
  ratio = r;
  assert (ratio > Settings.EPSILON);
}
 

public float getCurrentLengthA() {
  final Vec2 p = pool.popVec2();
  m_bodyA.getWorldPointToOut(m_localAnchorA, p);
  p.subLocal(m_groundAnchorA);
  float length = p.length();
  pool.pushVec2(1);
  return length;
}
 

public float getCurrentLengthB() {
  final Vec2 p = pool.popVec2();
  m_bodyB.getWorldPointToOut(m_localAnchorB, p);
  p.subLocal(m_groundAnchorB);
  float length = p.length();
  pool.pushVec2(1);
  return length;
}
 

public float getLength1() {
  final Vec2 p = pool.popVec2();
  m_bodyA.getWorldPointToOut(m_localAnchorA, p);
  p.subLocal(m_groundAnchorA);

  float len = p.length();
  pool.pushVec2(1);
  return len;
}
 

public float getLength2() {
  final Vec2 p = pool.popVec2();
  m_bodyB.getWorldPointToOut(m_localAnchorB, p);
  p.subLocal(m_groundAnchorB);

  float len = p.length();
  pool.pushVec2(1);
  return len;
}
 

public float op(Vec2 argVec) {
  argVec.set(MathUtils.randomFloat(-100, 100), MathUtils.randomFloat(-100, 100));
  argVec.mulLocal(3.2f);
  float s = argVec.length();
  argVec.normalize();
  return s;
}
 

public float op(Vec2 argVec) {
  argVec.set(MathUtils.randomFloat(-100, 100), MathUtils.randomFloat(-100, 100));
  argVec.mulLocal(3.2f);
  float s = argVec.length();
  argVec.normalize();
  return s;
}
 

@Override
  public boolean solvePositionConstraints(final SolverData data) {
    Vec2 cA = data.positions[m_indexA].c;
    float aA = data.positions[m_indexA].a;
    Vec2 cB = data.positions[m_indexB].c;
    float aB = data.positions[m_indexB].a;
    final Rot qA = pool.popRot();
    final Rot qB = pool.popRot();
    final Vec2 temp = pool.popVec2();
    final Vec2 rA = pool.popVec2();
    final Vec2 rB = pool.popVec2();

    qA.set(aA);
    qB.set(aB);

    float mA = m_invMassA, mB = m_invMassB;
    float iA = m_invIA, iB = m_invIB;

    Rot.mulToOutUnsafe(qA, temp.set(m_localAnchorA).subLocal(m_localCenterA), rA);
    Rot.mulToOutUnsafe(qB, temp.set(m_localAnchorB).subLocal(m_localCenterB), rB);
    float positionError, angularError;

    final Mat33 K = pool.popMat33();
    final Vec2 C1 = pool.popVec2();
    final Vec2 P = pool.popVec2();

    K.ex.x = mA + mB + rA.y * rA.y * iA + rB.y * rB.y * iB;
    K.ey.x = -rA.y * rA.x * iA - rB.y * rB.x * iB;
    K.ez.x = -rA.y * iA - rB.y * iB;
    K.ex.y = K.ey.x;
    K.ey.y = mA + mB + rA.x * rA.x * iA + rB.x * rB.x * iB;
    K.ez.y = rA.x * iA + rB.x * iB;
    K.ex.z = K.ez.x;
    K.ey.z = K.ez.y;
    K.ez.z = iA + iB;
    if (m_frequencyHz > 0.0f) {
      C1.set(cB).addLocal(rB).subLocal(cA).subLocal(rA);

      positionError = C1.length();
      angularError = 0.0f;

      K.solve22ToOut(C1, P);
      P.negateLocal();

      cA.x -= mA * P.x;
      cA.y -= mA * P.y;
      aA -= iA * Vec2.cross(rA, P);

      cB.x += mB * P.x;
      cB.y += mB * P.y;
      aB += iB * Vec2.cross(rB, P);
    } else {
      C1.set(cB).addLocal(rB).subLocal(cA).subLocal(rA);
      float C2 = aB - aA - m_referenceAngle;

      positionError = C1.length();
      angularError = MathUtils.abs(C2);

      final Vec3 C = pool.popVec3();
      final Vec3 impulse = pool.popVec3();
      C.set(C1.x, C1.y, C2);

      K.solve33ToOut(C, impulse);
      impulse.negateLocal();
      P.set(impulse.x, impulse.y);

      cA.x -= mA * P.x;
      cA.y -= mA * P.y;
      aA -= iA * (Vec2.cross(rA, P) + impulse.z);

      cB.x += mB * P.x;
      cB.y += mB * P.y;
      aB += iB * (Vec2.cross(rB, P) + impulse.z);
      pool.pushVec3(2);
    }

//    data.positions[m_indexA].c.set(cA);
    data.positions[m_indexA].a = aA;
//    data.positions[m_indexB].c.set(cB);
    data.positions[m_indexB].a = aB;

    pool.pushVec2(5);
    pool.pushRot(2);
    pool.pushMat33(1);

    return positionError <= Settings.linearSlop && angularError <= Settings.angularSlop;
  }
 

@Override
  public boolean solvePositionConstraints(final SolverData data) {
    final Rot qA = pool.popRot();
    final Rot qB = pool.popRot();
    final Vec2 rA = pool.popVec2();
    final Vec2 rB = pool.popVec2();
    final Vec2 uA = pool.popVec2();
    final Vec2 uB = pool.popVec2();
    final Vec2 temp = pool.popVec2();
    final Vec2 PA = pool.popVec2();
    final Vec2 PB = pool.popVec2();

    Vec2 cA = data.positions[m_indexA].c;
    float aA = data.positions[m_indexA].a;
    Vec2 cB = data.positions[m_indexB].c;
    float aB = data.positions[m_indexB].a;

    qA.set(aA);
    qB.set(aB);

    Rot.mulToOutUnsafe(qA, temp.set(m_localAnchorA).subLocal(m_localCenterA), rA);
    Rot.mulToOutUnsafe(qB, temp.set(m_localAnchorB).subLocal(m_localCenterB), rB);

    uA.set(cA).addLocal(rA).subLocal(m_groundAnchorA);
    uB.set(cB).addLocal(rB).subLocal(m_groundAnchorB);

    float lengthA = uA.length();
    float lengthB = uB.length();

    if (lengthA > 10.0f * Settings.linearSlop) {
      uA.mulLocal(1.0f / lengthA);
    } else {
      uA.setZero();
    }

    if (lengthB > 10.0f * Settings.linearSlop) {
      uB.mulLocal(1.0f / lengthB);
    } else {
      uB.setZero();
    }

    // Compute effective mass.
    float ruA = Vec2.cross(rA, uA);
    float ruB = Vec2.cross(rB, uB);

    float mA = m_invMassA + m_invIA * ruA * ruA;
    float mB = m_invMassB + m_invIB * ruB * ruB;

    float mass = mA + m_ratio * m_ratio * mB;

    if (mass > 0.0f) {
      mass = 1.0f / mass;
    }

    float C = m_constant - lengthA - m_ratio * lengthB;
    float linearError = MathUtils.abs(C);

    float impulse = -mass * C;

    PA.set(uA).mulLocal(-impulse);
    PB.set(uB).mulLocal(-m_ratio * impulse);

    cA.x += m_invMassA * PA.x;
    cA.y += m_invMassA * PA.y;
    aA += m_invIA * Vec2.cross(rA, PA);
    cB.x += m_invMassB * PB.x;
    cB.y += m_invMassB * PB.y;
    aB += m_invIB * Vec2.cross(rB, PB);

//    data.positions[m_indexA].c.set(cA);
    data.positions[m_indexA].a = aA;
//    data.positions[m_indexB].c.set(cB);
    data.positions[m_indexB].a = aB;

    pool.pushRot(2);
    pool.pushVec2(7);

    return linearError < Settings.linearSlop;
  }