How to use

ParticleSystem

in

org.jbox2d.particle

public World(Vec2 gravity, IWorldPool pool, BroadPhase broadPhase) {
 this.pool = pool;
 m_destructionListener = null;
 m_debugDraw = null;
 m_bodyList = null;
 m_jointList = null;
 m_bodyCount = 0;
 m_jointCount = 0;
 m_warmStarting = true;
 m_continuousPhysics = true;
 m_subStepping = false;
 m_stepComplete = true;
 m_allowSleep = true;
 m_gravity.set(gravity);
 m_flags = CLEAR_FORCES;
 m_inv_dt0 = 0f;
 m_contactManager = new ContactManager(this, broadPhase);
 m_profile = new Profile();
 m_particleSystem = new ParticleSystem(this);
 initializeRegisters();
}

public void joinParticleGroups(ParticleGroup groupA, ParticleGroup groupB) {
 assert (groupA != groupB);
 RotateBuffer(groupB.m_firstIndex, groupB.m_lastIndex, m_count);
 assert (groupB.m_lastIndex == m_count);
 RotateBuffer(groupA.m_firstIndex, groupA.m_lastIndex, groupB.m_firstIndex);
 assert (groupA.m_lastIndex == groupB.m_firstIndex);
 updateContacts(true);
 if ((particleFlags & k_pairFlags) != 0) {
  for (int k = 0; k < m_contactCount; k++) {
  diagram.generate(getParticleStride() / 2);
  JoinParticleGroupsCallback callback = new JoinParticleGroupsCallback();
  callback.system = this;
 groupA.m_lastIndex = groupB.m_lastIndex;
 groupB.m_firstIndex = groupB.m_lastIndex;
 destroyParticleGroup(groupB);
  computeDepthForGroup(groupA);

 int i = proxy.index;
 Vec2 pos = m_positionBuffer.data[i];
 proxy.tag = computeTag(m_inverseDiameter * pos.x, m_inverseDiameter * pos.y);
for (int i = 0; i < m_proxyCount; i++) {
 Proxy a = m_proxyBuffer[i];
 long rightTag = computeRelativeTag(a.tag, 1, 0);
 for (int j = i + 1; j < m_proxyCount; j++) {
  Proxy b = m_proxyBuffer[j];
   break;
  addContact(a.index, b.index);
 long bottomLeftTag = computeRelativeTag(a.tag, -1, 1);
 for (; c_index < m_proxyCount; c_index++) {
  Proxy c = m_proxyBuffer[c_index];
 long bottomRightTag = computeRelativeTag(a.tag, 1, 1);
   break;
  addContact(a.index, b.index);

public void queryAABB(ParticleQueryCallback callback, final AABB aabb) {
 if (m_proxyCount == 0) {
  return;
 }
 final float lowerBoundX = aabb.lowerBound.x;
 final float lowerBoundY = aabb.lowerBound.y;
 final float upperBoundX = aabb.upperBound.x;
 final float upperBoundY = aabb.upperBound.y;
 int firstProxy =
   lowerBound(m_proxyBuffer, m_proxyCount,
     computeTag(m_inverseDiameter * lowerBoundX, m_inverseDiameter * lowerBoundY));
 int lastProxy =
   upperBound(m_proxyBuffer, m_proxyCount,
     computeTag(m_inverseDiameter * upperBoundX, m_inverseDiameter * upperBoundY));
 for (int proxy = firstProxy; proxy < lastProxy; ++proxy) {
  int i = m_proxyBuffer[proxy].index;
  final Vec2 p = m_positionBuffer.data[i];
  if (lowerBoundX < p.x && p.x < upperBoundX && lowerBoundY < p.y && p.y < upperBoundY) {
   if (!callback.reportParticle(i)) {
    break;
   }
  }
 }
}

public ParticleGroup createParticleGroup(ParticleGroupDef groupDef) {
 float stride = getParticleStride();
 final Transform identity = tempTransform;
 identity.setIdentity();
     Vec2.crossToOutUnsafe(groupDef.angularVelocity, p, particleDef.velocity);
     particleDef.velocity.addLocal(groupDef.linearVelocity);
     createParticle(particleDef);
 updateContacts(true);
 if ((groupDef.flags & k_pairFlags) != 0) {
  for (int k = 0; k < m_contactCount; k++) {
  computeDepthForGroup(group);

 system.m_proxyBuffer,
 system.m_proxyCount,
 computeTag(system.m_inverseDiameter * aabblowerBoundx, system.m_inverseDiameter
 system.m_proxyBuffer,
 system.m_proxyCount,
 computeTag(system.m_inverseDiameter * aabbupperBoundx, system.m_inverseDiameter
av.x = vx;
av.y = vy;
final float particleMass = system.getParticleMass();
final float ax = particleMass * (av.x - vx);
final float ay = particleMass * (av.y - vy);

 system.m_proxyBuffer,
 system.m_proxyCount,
 computeTag(system.m_inverseDiameter * aabblowerBoundx, system.m_inverseDiameter
 system.m_proxyBuffer,
 system.m_proxyCount,
 computeTag(system.m_inverseDiameter * aabbupperBoundx, system.m_inverseDiameter
float invAm =
  (system.m_flagsBuffer.data[a] & ParticleType.b2_wallParticle) != 0 ? 0 : system
    .getParticleInvMass();
final float rpx = ap.x - bp.x;
final float rpy = ap.y - bp.y;

public void destroyParticlesInGroup(ParticleGroup group, boolean callDestructionListener) {
 for (int i = group.m_firstIndex; i < group.m_lastIndex; i++) {
  destroyParticle(i, callDestructionListener);
 }
}

 /**
  * Compute the kinetic energy that can be lost by damping force
  * 
  * @return
  */
 public float computeParticleCollisionEnergy() {
  return m_particleSystem.computeParticleCollisionEnergy();
 }
}

/**
 * Create a particle group whose properties have been defined. No reference to the definition is
 * retained.
 * 
 * @warning This function is locked during callbacks.
 */
public ParticleGroup createParticleGroup(ParticleGroupDef def) {
 assert (isLocked() == false);
 if (isLocked()) {
  return null;
 }
 ParticleGroup g = m_particleSystem.createParticleGroup(def);
 return g;
}

/**
 * Create a particle whose properties have been defined. No reference to the definition is
 * retained. A simulation step must occur before it's possible to interact with a newly created
 * particle. For example, DestroyParticleInShape() will not destroy a particle until Step() has
 * been called.
 * 
 * @warning This function is locked during callbacks.
 * @return the index of the particle.
 */
public int createParticle(ParticleDef def) {
 assert (isLocked() == false);
 if (isLocked()) {
  return 0;
 }
 int p = m_particleSystem.createParticle(def);
 return p;
}

  lowerBound(
    m_proxyBuffer,
    m_proxyCount,
    computeTag(m_inverseDiameter * MathUtils.min(point1.x, point2.x) - 1, m_inverseDiameter
      * MathUtils.min(point1.y, point2.y) - 1));
int lastProxy =
  upperBound(
    m_proxyBuffer,
    m_proxyCount,
    computeTag(m_inverseDiameter * MathUtils.max(point1.x, point2.x) + 1, m_inverseDiameter
      * MathUtils.max(point1.y, point2.y) + 1));
float fraction = 1;

public ParticleGroup createParticleGroup(ParticleGroupDef groupDef) {
 float stride = getParticleStride();
 final Transform identity = tempTransform;
 identity.setIdentity();
     Vec2.crossToOutUnsafe(groupDef.angularVelocity, p, particleDef.velocity);
     particleDef.velocity.addLocal(groupDef.linearVelocity);
     createParticle(particleDef);
 updateContacts(true);
 if ((groupDef.flags & k_pairFlags) != 0) {
  for (int k = 0; k < m_contactCount; k++) {
  computeDepthForGroup(group);

 system.m_proxyBuffer,
 system.m_proxyCount,
 computeTag(system.m_inverseDiameter * aabblowerBoundx, system.m_inverseDiameter
 system.m_proxyBuffer,
 system.m_proxyCount,
 computeTag(system.m_inverseDiameter * aabbupperBoundx, system.m_inverseDiameter
av.x = vx;
av.y = vy;
final float particleMass = system.getParticleMass();
final float ax = particleMass * (av.x - vx);
final float ay = particleMass * (av.y - vy);

 system.m_proxyBuffer,
 system.m_proxyCount,
 computeTag(system.m_inverseDiameter * aabblowerBoundx, system.m_inverseDiameter
 system.m_proxyBuffer,
 system.m_proxyCount,
 computeTag(system.m_inverseDiameter * aabbupperBoundx, system.m_inverseDiameter
float invAm =
  (system.m_flagsBuffer.data[a] & ParticleType.b2_wallParticle) != 0 ? 0 : system
    .getParticleInvMass();
final float rpx = ap.x - bp.x;
final float rpy = ap.y - bp.y;

/**
 * Destroy a particle. The particle is removed after the next step.
 * 
 * @param Index of the particle to destroy.
 * @param Whether to call the destruction listener just before the particle is destroyed.
 */
public void destroyParticle(int index, boolean callDestructionListener) {
 m_particleSystem.destroyParticle(index, callDestructionListener);
}

 /**
  * Compute the kinetic energy that can be lost by damping force
  * 
  * @return
  */
 public float computeParticleCollisionEnergy() {
  return m_particleSystem.computeParticleCollisionEnergy();
 }
}

/**
 * Create a particle group whose properties have been defined. No reference to the definition is
 * retained.
 * 
 * @warning This function is locked during callbacks.
 */
public ParticleGroup createParticleGroup(ParticleGroupDef def) {
 assert (isLocked() == false);
 if (isLocked()) {
  return null;
 }
 ParticleGroup g = m_particleSystem.createParticleGroup(def);
 return g;
}

/**
 * Create a particle whose properties have been defined. No reference to the definition is
 * retained. A simulation step must occur before it's possible to interact with a newly created
 * particle. For example, DestroyParticleInShape() will not destroy a particle until Step() has
 * been called.
 * 
 * @warning This function is locked during callbacks.
 * @return the index of the particle.
 */
public int createParticle(ParticleDef def) {
 assert (isLocked() == false);
 if (isLocked()) {
  return 0;
 }
 int p = m_particleSystem.createParticle(def);
 return p;
}

public void joinParticleGroups(ParticleGroup groupA, ParticleGroup groupB) {
 assert (groupA != groupB);
 RotateBuffer(groupB.m_firstIndex, groupB.m_lastIndex, m_count);
 assert (groupB.m_lastIndex == m_count);
 RotateBuffer(groupA.m_firstIndex, groupA.m_lastIndex, groupB.m_firstIndex);
 assert (groupA.m_lastIndex == groupB.m_firstIndex);
 updateContacts(true);
 if ((particleFlags & k_pairFlags) != 0) {
  for (int k = 0; k < m_contactCount; k++) {
  diagram.generate(getParticleStride() / 2);
  JoinParticleGroupsCallback callback = new JoinParticleGroupsCallback();
  callback.system = this;
 groupA.m_lastIndex = groupB.m_lastIndex;
 groupB.m_firstIndex = groupB.m_lastIndex;
 destroyParticleGroup(groupB);
  computeDepthForGroup(groupA);