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

/**
 * this returns pooled objects. don't keep or modify them
 * 
 * @return
 */
public void getClosestPoint(final Vec2 out) {
  switch (m_count) {
    case 0:
      assert (false);
      out.setZero();
      return;
    case 1:
      out.set(m_v1.w);
      return;
    case 2:
      case22.set(m_v2.w).mulLocal(m_v2.a);
      case2.set(m_v1.w).mulLocal(m_v1.a).addLocal(case22);
      out.set(case2);
      return;
    case 3:
      out.setZero();
      return;
    default:
      assert (false);
      out.setZero();
      return;
  }
}
 

public void MoveAABB(AABB aabb) {
	Vec2 d = new Vec2();
	d.x = MathUtils.randomFloat(rand, -0.5f, 0.5f);
	d.y = MathUtils.randomFloat(rand, -0.5f, 0.5f);
	// d.x = 2.0f;
	// d.y = 0.0f;
	aabb.lowerBound.addLocal(d);
	aabb.upperBound.addLocal(d);

	Vec2 c0 = aabb.lowerBound.add(aabb.upperBound).mulLocal(.5f);
	Vec2 min = new Vec2();
	min.set(-worldExtent, 0.0f);
	Vec2 max = new Vec2();
	max.set(worldExtent, 2.0f * worldExtent);
	Vec2 c = MathUtils.clamp(c0, min, max);

	aabb.lowerBound.addLocal(c.sub(c0));
	aabb.upperBound.addLocal(c.sub(c0));
}
 

@Override
public boolean reportParticle(int index) {
  Vec2 p = world.getParticlePositionBuffer()[index];
  if (shape.testPoint(xf, p)) {
    Vec2 v = world.getParticleVelocityBuffer()[index];
    v.set(velocity);
  }
  return true;
}
 

public final void computeCentroidToOut(final Vec2[] vs, final int count, final Vec2 out) {
  assert (count >= 3);

  out.set(0.0f, 0.0f);
  float area = 0.0f;

  // pRef is the reference point for forming triangles.
  // It's location doesn't change the result (except for rounding error).
  final Vec2 pRef = pool1;
  pRef.setZero();

  final Vec2 e1 = pool2;
  final Vec2 e2 = pool3;

  final float inv3 = 1.0f / 3.0f;

  for (int i = 0; i < count; ++i) {
    // Triangle vertices.
    final Vec2 p1 = pRef;
    final Vec2 p2 = vs[i];
    final Vec2 p3 = i + 1 < count ? vs[i + 1] : vs[0];

    e1.set(p2).subLocal(p1);
    e2.set(p3).subLocal(p1);

    final float D = Vec2.cross(e1, e2);

    final float triangleArea = 0.5f * D;
    area += triangleArea;

    // Area weighted centroid
    e1.set(p1).addLocal(p2).addLocal(p3).mulLocal(triangleArea * inv3);
    out.addLocal(e1);
  }

  // Centroid
  assert (area > Settings.EPSILON);
  out.mulLocal(1.0f / area);
}
 

@Override
public void initTest(boolean argDeserialized) {
	
	input.transformA = new Transform();
	input.transformB = new Transform();
	{
		m_transformA = new Transform();
		m_transformA.setIdentity();
		m_transformA.p.set(0.0f, -0.2f);
		m_polygonA = new PolygonShape();
		m_polygonA.setAsBox(10.0f, 0.2f);
	}
	
	{
		m_positionB = new Vec2();
		m_positionB.set(12.017401f, 0.13678508f);
		m_angleB = -0.0109265f;
		
		m_transformB = new Transform();
		m_transformB.set(m_positionB, m_angleB);
		
		m_polygonB = new PolygonShape();
		m_polygonB.setAsBox(2.0f, 0.1f);
	}
	for (int i = 0; i < v.length; i++) {
		v[i] = new Vec2();
	}
}
 

public void GetRandomAABB(AABB aabb) {
	Vec2 w = new Vec2();
	w.set(2.0f * m_proxyExtent, 2.0f * m_proxyExtent);
	// aabb.lowerBound.x = -m_proxyExtent;
	// aabb.lowerBound.y = -m_proxyExtent + worldExtent;
	aabb.lowerBound.x = MathUtils.randomFloat(rand, -worldExtent,
			worldExtent);
	aabb.lowerBound.y = MathUtils.randomFloat(rand, 0.0f,
			2.0f * worldExtent);
	aabb.upperBound.set(aabb.lowerBound).addLocal(w);
}
 

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 void solveVelocityConstraints(final SolverData data) {

    Vec2 vB = data.velocities[m_indexB].v;
    float wB = data.velocities[m_indexB].w;

    // Cdot = v + cross(w, r)
    final Vec2 Cdot = pool.popVec2();
    Vec2.crossToOutUnsafe(wB, m_rB, Cdot);
    Cdot.addLocal(vB);

    final Vec2 impulse = pool.popVec2();
    final Vec2 temp = pool.popVec2();

    temp.set(m_impulse).mulLocal(m_gamma).addLocal(m_C).addLocal(Cdot).negateLocal();
    Mat22.mulToOutUnsafe(m_mass, temp, impulse);

    Vec2 oldImpulse = temp;
    oldImpulse.set(m_impulse);
    m_impulse.addLocal(impulse);
    float maxImpulse = data.step.dt * m_maxForce;
    if (m_impulse.lengthSquared() > maxImpulse * maxImpulse) {
      m_impulse.mulLocal(maxImpulse / m_impulse.length());
    }
    impulse.set(m_impulse).subLocal(oldImpulse);

    vB.x += m_invMassB * impulse.x;
    vB.y += m_invMassB * impulse.y;
    wB += m_invIB * Vec2.cross(m_rB, impulse);

//    data.velocities[m_indexB].v.set(vB);
    data.velocities[m_indexB].w = wB;
    
    pool.pushVec2(3);
  }
 

public void getWitnessPoints(Vec2 pA, Vec2 pB) {
  switch (m_count) {
    case 0:
      assert (false);
      break;

    case 1:
      pA.set(m_v1.wA);
      pB.set(m_v1.wB);
      break;

    case 2:
      case2.set(m_v1.wA).mulLocal(m_v1.a);
      pA.set(m_v2.wA).mulLocal(m_v2.a).addLocal(case2);
      // m_v1.a * m_v1.wA + m_v2.a * m_v2.wA;
      // *pB = m_v1.a * m_v1.wB + m_v2.a * m_v2.wB;
      case2.set(m_v1.wB).mulLocal(m_v1.a);
      pB.set(m_v2.wB).mulLocal(m_v2.a).addLocal(case2);

      break;

    case 3:
      pA.set(m_v1.wA).mulLocal(m_v1.a);
      case3.set(m_v2.wA).mulLocal(m_v2.a);
      case33.set(m_v3.wA).mulLocal(m_v3.a);
      pA.addLocal(case3).addLocal(case33);
      pB.set(pA);
      // *pA = m_v1.a * m_v1.wA + m_v2.a * m_v2.wA + m_v3.a * m_v3.wA;
      // *pB = *pA;
      break;

    default:
      assert (false);
      break;
  }
}
 

@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 void getAnchorA(Vec2 argOut) {
  argOut.set(m_targetA);
}
 

@Override
public void getReactionForce(float inv_dt, Vec2 argOut) {
  argOut.set(m_impulse.x, m_impulse.y);
  argOut.mulLocal(inv_dt);
}
 

/**
   * @see org.jbox2d.dynamics.joints.Joint#initVelocityConstraints(org.jbox2d.dynamics.TimeStep)
   */
  @Override
  public void initVelocityConstraints(final SolverData data) {
    m_indexA = m_bodyA.m_islandIndex;
    m_indexB = m_bodyB.m_islandIndex;
    m_localCenterA.set(m_bodyA.m_sweep.localCenter);
    m_localCenterB.set(m_bodyB.m_sweep.localCenter);
    m_invMassA = m_bodyA.m_invMass;
    m_invMassB = m_bodyB.m_invMass;
    m_invIA = m_bodyA.m_invI;
    m_invIB = m_bodyB.m_invI;

    float aA = data.positions[m_indexA].a;
    Vec2 vA = data.velocities[m_indexA].v;
    float wA = data.velocities[m_indexA].w;

    float aB = data.positions[m_indexB].a;
    Vec2 vB = data.velocities[m_indexB].v;
    float wB = data.velocities[m_indexB].w;


    final Vec2 temp = pool.popVec2();
    final Rot qA = pool.popRot();
    final Rot qB = pool.popRot();

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

    // Compute the effective mass matrix.
    Rot.mulToOutUnsafe(qA, temp.set(m_localAnchorA).subLocal(m_localCenterA), m_rA);
    Rot.mulToOutUnsafe(qB, temp.set(m_localAnchorB).subLocal(m_localCenterB), m_rB);

    // J = [-I -r1_skew I r2_skew]
    // [ 0 -1 0 1]
    // r_skew = [-ry; rx]

    // Matlab
    // K = [ mA+r1y^2*iA+mB+r2y^2*iB, -r1y*iA*r1x-r2y*iB*r2x, -r1y*iA-r2y*iB]
    // [ -r1y*iA*r1x-r2y*iB*r2x, mA+r1x^2*iA+mB+r2x^2*iB, r1x*iA+r2x*iB]
    // [ -r1y*iA-r2y*iB, r1x*iA+r2x*iB, iA+iB]

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

    final Mat22 K = pool.popMat22();
    K.ex.x = mA + mB + iA * m_rA.y * m_rA.y + iB * m_rB.y * m_rB.y;
    K.ex.y = -iA * m_rA.x * m_rA.y - iB * m_rB.x * m_rB.y;
    K.ey.x = K.ex.y;
    K.ey.y = mA + mB + iA * m_rA.x * m_rA.x + iB * m_rB.x * m_rB.x;

    K.invertToOut(m_linearMass);

    m_angularMass = iA + iB;
    if (m_angularMass > 0.0f) {
      m_angularMass = 1.0f / m_angularMass;
    }

    if (data.step.warmStarting) {
      // Scale impulses to support a variable time step.
      m_linearImpulse.mulLocal(data.step.dtRatio);
      m_angularImpulse *= data.step.dtRatio;

      final Vec2 P = pool.popVec2();
      P.set(m_linearImpulse);

      temp.set(P).mulLocal(mA);
      vA.subLocal(temp);
      wA -= iA * (Vec2.cross(m_rA, P) + m_angularImpulse);

      temp.set(P).mulLocal(mB);
      vB.addLocal(temp);
      wB += iB * (Vec2.cross(m_rB, P) + m_angularImpulse);

      pool.pushVec2(1);
    } else {
      m_linearImpulse.setZero();
      m_angularImpulse = 0.0f;
    }
//    data.velocities[m_indexA].v.set(vA);
    if( data.velocities[m_indexA].w != wA) {
      assert(data.velocities[m_indexA].w != wA);
    }
    data.velocities[m_indexA].w = wA;
//    data.velocities[m_indexB].v.set(vB);
    data.velocities[m_indexB].w = wB;

    pool.pushRot(2);
    pool.pushVec2(1);
    pool.pushMat22(1);
  }
 

/**
 * Set the mass properties to override the mass properties of the fixtures. Note that this changes
 * the center of mass position. Note that creating or destroying fixtures can also alter the mass.
 * This function has no effect if the body isn't dynamic.
 * 
 * @param massData the mass properties.
 */
public final void setMassData(MassData massData) {
  // TODO_ERIN adjust linear velocity and torque to account for movement of center.
  assert (m_world.isLocked() == false);
  if (m_world.isLocked() == true) {
    return;
  }

  if (m_type != BodyType.DYNAMIC) {
    return;
  }

  m_invMass = 0.0f;
  m_I = 0.0f;
  m_invI = 0.0f;

  m_mass = massData.mass;
  if (m_mass <= 0.0f) {
    m_mass = 1f;
  }

  m_invMass = 1.0f / m_mass;

  if (massData.I > 0.0f && (m_flags & e_fixedRotationFlag) == 0) {
    m_I = massData.I - m_mass * Vec2.dot(massData.center, massData.center);
    assert (m_I > 0.0f);
    m_invI = 1.0f / m_I;
  }

  final Vec2 oldCenter = m_world.getPool().popVec2();
  // Move center of mass.
  oldCenter.set(m_sweep.c);
  m_sweep.localCenter.set(massData.center);
  // m_sweep.c0 = m_sweep.c = Mul(m_xf, m_sweep.localCenter);
  Transform.mulToOutUnsafe(m_xf, m_sweep.localCenter, m_sweep.c0);
  m_sweep.c.set(m_sweep.c0);

  // Update center of mass velocity.
  // m_linearVelocity += Cross(m_angularVelocity, m_sweep.c - oldCenter);
  final Vec2 temp = m_world.getPool().popVec2();
  temp.set(m_sweep.c).subLocal(oldCenter);
  Vec2.crossToOut(m_angularVelocity, temp, temp);
  m_linearVelocity.addLocal(temp);

  m_world.getPool().pushVec2(2);
}
 

/**
 * Get the target linear offset, in frame A, in meters.
 */
public void getLinearOffset(Vec2 out) {
  out.set(m_linearOffset);
}
 

@Override
public void getAnchorB(Vec2 out) {
  out.set(m_bodyB.getPosition());
}
 

@Override
public void getAnchorA(Vec2 out) {
  out.set(m_bodyA.getPosition());
}
 

/**
 * takes the screen coordinates and puts the corresponding world coordinates in argWorld.
 * 
 * @param screenX
 * @param screenY
 * @param argWorld
 */
public void getScreenToWorldToOut(float screenX, float screenY, Vec2 argWorld) {
  argWorld.set(screenX, screenY);
  viewportTransform.getScreenToWorld(argWorld, argWorld);
}
 

/**
 * Takes the world coordinates and puts the corresponding screen coordinates in argScreen.
 * 
 * @param worldX
 * @param worldY
 * @param argScreen
 */
public void getWorldToScreenToOut(float worldX, float worldY, Vec2 argScreen) {
  argScreen.set(worldX, worldY);
  viewportTransform.getWorldToScreen(argScreen, argScreen);
}