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A 2D java physics engine, a port of the C++ Box2d engine. This is the core physics engine.
/*******************************************************************************
* Copyright (c) 2011, Daniel Murphy
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL DANIEL MURPHY BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
******************************************************************************/
package org.jbox2d.dynamics;
import org.jbox2d.callbacks.ContactFilter;
import org.jbox2d.callbacks.ContactListener;
import org.jbox2d.callbacks.DebugDraw;
import org.jbox2d.callbacks.DestructionListener;
import org.jbox2d.callbacks.QueryCallback;
import org.jbox2d.callbacks.RayCastCallback;
import org.jbox2d.callbacks.TreeCallback;
import org.jbox2d.callbacks.TreeRayCastCallback;
import org.jbox2d.collision.AABB;
import org.jbox2d.collision.RayCastInput;
import org.jbox2d.collision.RayCastOutput;
import org.jbox2d.collision.TimeOfImpact.TOIInput;
import org.jbox2d.collision.TimeOfImpact.TOIOutput;
import org.jbox2d.collision.TimeOfImpact.TOIOutputState;
import org.jbox2d.collision.broadphase.BroadPhase;
import org.jbox2d.collision.broadphase.DynamicTreeNode;
import org.jbox2d.collision.shapes.CircleShape;
import org.jbox2d.collision.shapes.PolygonShape;
import org.jbox2d.collision.shapes.ShapeType;
import org.jbox2d.common.Color3f;
import org.jbox2d.common.Settings;
import org.jbox2d.common.Sweep;
import org.jbox2d.common.Transform;
import org.jbox2d.common.Vec2;
import org.jbox2d.dynamics.contacts.Contact;
import org.jbox2d.dynamics.contacts.ContactEdge;
import org.jbox2d.dynamics.contacts.ContactRegister;
import org.jbox2d.dynamics.contacts.TOISolver;
import org.jbox2d.dynamics.joints.Joint;
import org.jbox2d.dynamics.joints.JointDef;
import org.jbox2d.dynamics.joints.JointEdge;
import org.jbox2d.dynamics.joints.PulleyJoint;
import org.jbox2d.pooling.IDynamicStack;
import org.jbox2d.pooling.IWorldPool;
import org.jbox2d.pooling.WorldPool;
import org.jbox2d.pooling.arrays.Vec2Array;
/**
* The world class manages all physics entities, dynamic simulation,
* and asynchronous queries. The world also contains efficient memory
* management facilities.
*
* @author Daniel Murphy
*/
public class World {
public static final int WORLD_POOL_SIZE = 100;
public static final int WORLD_POOL_CONTAINER_SIZE = 10;
public static final int NEW_FIXTURE = 0x0001;
public static final int LOCKED = 0x0002;
public static final int CLEAR_FORCES = 0x0004;
// statistics gathering
public int activeContacts = 0;
public int contactPoolCount = 0;
protected int m_flags;
protected ContactManager m_contactManager;
private Body m_bodyList;
private Joint m_jointList;
private int m_bodyCount;
private int m_jointCount;
private final Vec2 m_gravity = new Vec2();
private boolean m_allowSleep;
// private Body m_groundBody;
private DestructionListener m_destructionListener;
private DebugDraw m_debugDraw;
private final IWorldPool pool;
/**
* This is used to compute the time step ratio to
* support a variable time step.
*/
private float m_inv_dt0;
/**
* This is for debugging the solver.
*/
private boolean m_warmStarting;
/**
* This is for debugging the solver.
*/
private boolean m_continuousPhysics;
private ContactRegister[][] contactStacks = new ContactRegister[ShapeType.TYPE_COUNT][ShapeType.TYPE_COUNT];
public World(Vec2 gravity, boolean doSleep){
this(gravity, doSleep,
new WorldPool(WORLD_POOL_SIZE, WORLD_POOL_CONTAINER_SIZE));
}
/**
* Construct a world object.
*
* @param gravity
* the world gravity vector.
* @param doSleep
* improve performance by not simulating inactive bodies.
*/
public World(Vec2 gravity, boolean doSleep, IWorldPool argPool) {
pool = argPool;
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_allowSleep = doSleep;
m_gravity.set(gravity);
m_flags = CLEAR_FORCES;
m_inv_dt0 = 0f;
m_contactManager = new ContactManager(this);
initializeRegisters();
}
private void addType(IDynamicStack creator, ShapeType type1,
ShapeType type2) {
ContactRegister register = new ContactRegister();
register.creator = creator;
register.primary = true;
contactStacks[type1.intValue][type2.intValue] = register;
if (type1 != type2) {
ContactRegister register2 = new ContactRegister();
register2.creator = creator;
register2.primary = false;
contactStacks[type2.intValue][type1.intValue] = register2;
}
}
private void initializeRegisters() {
addType(pool.getCircleContactStack(), ShapeType.CIRCLE, ShapeType.CIRCLE);
addType(pool.getPolyCircleContactStack(), ShapeType.POLYGON, ShapeType.CIRCLE);
addType(pool.getPolyContactStack(), ShapeType.POLYGON, ShapeType.POLYGON);
}
public Contact popContact(Fixture fixtureA, Fixture fixtureB) {
final ShapeType type1 = fixtureA.getType();
final ShapeType type2 = fixtureB.getType();
final ContactRegister reg = contactStacks[type1.intValue][type2.intValue];
final IDynamicStack creator = reg.creator;
if (creator != null) {
if (reg.primary) {
Contact c = creator.pop();
c.init(fixtureA, fixtureB);
return c;
} else {
Contact c = creator.pop();
c.init(fixtureB, fixtureA);
return c;
}
} else {
return null;
}
}
public void pushContact(Contact contact) {
if (contact.m_manifold.pointCount > 0) {
contact.getFixtureA().getBody().setAwake(true);
contact.getFixtureB().getBody().setAwake(true);
}
ShapeType type1 = contact.getFixtureA().getType();
ShapeType type2 = contact.getFixtureB().getType();
IDynamicStack creator = contactStacks[type1.intValue][type2.intValue].creator;
creator.push(contact);
}
public IWorldPool getPool() {
return pool;
}
/**
* Register a destruction listener. The listener is owned by you and must
* remain in scope.
*
* @param listener
*/
public void setDestructionListener(DestructionListener listener) {
m_destructionListener = listener;
}
/**
* Register a contact filter to provide specific control over collision.
* Otherwise the default filter is used (_defaultFilter). The listener is
* owned by you and must remain in scope.
*
* @param filter
*/
public void setContactFilter(ContactFilter filter) {
m_contactManager.m_contactFilter = filter;
}
/**
* Register a contact event listener. The listener is owned by you and must
* remain in scope.
*
* @param listener
*/
public void setContactListener(ContactListener listener) {
m_contactManager.m_contactListener = listener;
}
/**
* Register a routine for debug drawing. The debug draw functions are called
* inside with World.DrawDebugData method. The debug draw object is owned
* by you and must remain in scope.
*
* @param debugDraw
*/
public void setDebugDraw(DebugDraw debugDraw) {
m_debugDraw = debugDraw;
}
/**
* create a rigid body given a definition. No reference to the definition
* is retained.
*
* @warning This function is locked during callbacks.
* @param def
* @return
*/
public Body createBody(BodyDef def) {
assert (isLocked() == false);
if (isLocked()) {
return null;
}
// TODO djm pooling
Body b = new Body(def, this);
// add to world doubly linked list
b.m_prev = null;
b.m_next = m_bodyList;
if (m_bodyList != null) {
m_bodyList.m_prev = b;
}
m_bodyList = b;
++m_bodyCount;
return b;
}
/**
* destroy a rigid body given a definition. No reference to the definition
* is retained. This function is locked during callbacks.
*
* @warning This automatically deletes all associated shapes and joints.
* @warning This function is locked during callbacks.
* @param body
*/
public void destroyBody(Body body) {
assert (m_bodyCount > 0);
assert (isLocked() == false);
if (isLocked()) {
return;
}
// Delete the attached joints.
JointEdge je = body.m_jointList;
while (je != null) {
JointEdge je0 = je;
je = je.next;
if (m_destructionListener != null) {
m_destructionListener.sayGoodbye(je0.joint);
}
destroyJoint(je0.joint);
}
body.m_jointList = null;
// Delete the attached contacts.
ContactEdge ce = body.m_contactList;
while (ce != null) {
ContactEdge ce0 = ce;
ce = ce.next;
m_contactManager.destroy(ce0.contact);
}
body.m_contactList = null;
Fixture f = body.m_fixtureList;
while (f != null) {
Fixture f0 = f;
f = f.m_next;
if (m_destructionListener != null) {
m_destructionListener.sayGoodbye(f0);
}
f0.destroyProxy(m_contactManager.m_broadPhase);
f0.destroy();
// TODO djm recycle fixtures (here or in that destroy method)
}
body.m_fixtureList = null;
body.m_fixtureCount = 0;
// Remove world body list.
if (body.m_prev != null) {
body.m_prev.m_next = body.m_next;
}
if (body.m_next != null) {
body.m_next.m_prev = body.m_prev;
}
if (body == m_bodyList) {
m_bodyList = body.m_next;
}
--m_bodyCount;
// TODO djm recycle body
}
/**
* create a joint to constrain bodies together. No reference to the definition
* is retained. This may cause the connected bodies to cease colliding.
*
* @warning This function is locked during callbacks.
* @param def
* @return
*/
public Joint createJoint(JointDef def) {
assert (isLocked() == false);
if (isLocked()) {
return null;
}
Joint j = Joint.create(this, def);
// Connect to the world list.
j.m_prev = null;
j.m_next = m_jointList;
if (m_jointList != null) {
m_jointList.m_prev = j;
}
m_jointList = j;
++m_jointCount;
// Connect to the bodies' doubly linked lists.
j.m_edgeA.joint = j;
j.m_edgeA.other = j.m_bodyB;
j.m_edgeA.prev = null;
j.m_edgeA.next = j.m_bodyA.m_jointList;
if (j.m_bodyA.m_jointList != null) {
j.m_bodyA.m_jointList.prev = j.m_edgeA;
}
j.m_bodyA.m_jointList = j.m_edgeA;
j.m_edgeB.joint = j;
j.m_edgeB.other = j.m_bodyA;
j.m_edgeB.prev = null;
j.m_edgeB.next = j.m_bodyB.m_jointList;
if (j.m_bodyB.m_jointList != null) {
j.m_bodyB.m_jointList.prev = j.m_edgeB;
}
j.m_bodyB.m_jointList = j.m_edgeB;
Body bodyA = def.bodyA;
Body bodyB = def.bodyB;
// If the joint prevents collisions, then flag any contacts for filtering.
if (def.collideConnected == false) {
ContactEdge edge = bodyB.getContactList();
while (edge != null) {
if (edge.other == bodyA) {
// Flag the contact for filtering at the next time step (where either
// body is awake).
edge.contact.flagForFiltering();
}
edge = edge.next;
}
}
// Note: creating a joint doesn't wake the bodies.
return j;
}
/**
* destroy a joint. This may cause the connected bodies to begin colliding.
*
* @warning This function is locked during callbacks.
* @param joint
*/
public void destroyJoint(Joint j) {
assert (isLocked() == false);
if (isLocked()) {
return;
}
boolean collideConnected = j.m_collideConnected;
// Remove from the doubly linked list.
if (j.m_prev != null) {
j.m_prev.m_next = j.m_next;
}
if (j.m_next != null) {
j.m_next.m_prev = j.m_prev;
}
if (j == m_jointList) {
m_jointList = j.m_next;
}
// Disconnect from island graph.
Body bodyA = j.m_bodyA;
Body bodyB = j.m_bodyB;
// Wake up connected bodies.
bodyA.setAwake(true);
bodyB.setAwake(true);
// Remove from body 1.
if (j.m_edgeA.prev != null) {
j.m_edgeA.prev.next = j.m_edgeA.next;
}
if (j.m_edgeA.next != null) {
j.m_edgeA.next.prev = j.m_edgeA.prev;
}
if (j.m_edgeA == bodyA.m_jointList) {
bodyA.m_jointList = j.m_edgeA.next;
}
j.m_edgeA.prev = null;
j.m_edgeA.next = null;
// Remove from body 2
if (j.m_edgeB.prev != null) {
j.m_edgeB.prev.next = j.m_edgeB.next;
}
if (j.m_edgeB.next != null) {
j.m_edgeB.next.prev = j.m_edgeB.prev;
}
if (j.m_edgeB == bodyB.m_jointList) {
bodyB.m_jointList = j.m_edgeB.next;
}
j.m_edgeB.prev = null;
j.m_edgeB.next = null;
Joint.destroy(j);
assert (m_jointCount > 0);
--m_jointCount;
// If the joint prevents collisions, then flag any contacts for filtering.
if (collideConnected == false) {
ContactEdge edge = bodyB.getContactList();
while (edge != null) {
if (edge.other == bodyA) {
// Flag the contact for filtering at the next time step (where either
// body is awake).
edge.contact.flagForFiltering();
}
edge = edge.next;
}
}
}
// djm pooling
private final TimeStep step = new TimeStep();
/**
* Take a time step. This performs collision detection, integration,
* and constraint solution.
*
* @param timeStep
* the amount of time to simulate, this should not vary.
* @param velocityIterations
* for the velocity constraint solver.
* @param positionIterations
* for the position constraint solver.
*/
public void step(float dt, int velocityIterations, int positionIterations) {
// log.debug("Starting step");
// If new fixtures were added, we need to find the new contacts.
if ((m_flags & NEW_FIXTURE) == NEW_FIXTURE) {
// log.debug("There's a new fixture, lets look for new contacts");
m_contactManager.findNewContacts();
m_flags &= ~NEW_FIXTURE;
}
m_flags |= LOCKED;
step.dt = dt;
step.velocityIterations = velocityIterations;
step.positionIterations = positionIterations;
if (dt > 0.0f) {
step.inv_dt = 1.0f / dt;
}
else {
step.inv_dt = 0.0f;
}
step.dtRatio = m_inv_dt0 * dt;
step.warmStarting = m_warmStarting;
// Update contacts. This is where some contacts are destroyed.
m_contactManager.collide();
// Integrate velocities, solve velocity constraints, and integrate positions.
if (step.dt > 0.0f) {
solve(step);
}
// Handle TOI events.
if (m_continuousPhysics && step.dt > 0.0f) {
solveTOI();
}
if (step.dt > 0.0f) {
m_inv_dt0 = step.inv_dt;
}
if ((m_flags & CLEAR_FORCES) == CLEAR_FORCES) {
clearForces();
}
m_flags &= ~LOCKED;
// log.debug("ending step");
}
/**
* Call this after you are done with time steps to clear the forces. You normally
* call this after each call to Step, unless you are performing sub-steps. By default,
* forces will be automatically cleared, so you don't need to call this function.
*
* @see setAutoClearForces
*/
public void clearForces() {
for (Body body = m_bodyList; body != null; body = body.getNext()) {
body.m_force.setZero();
body.m_torque = 0.0f;
}
}
private final Color3f color = new Color3f();
private final Transform xf = new Transform();
private final Vec2 cA = new Vec2();
private final Vec2 cB = new Vec2();
private final static Vec2Array avs = new Vec2Array();
/**
* Call this to draw shapes and other debug draw data.
*/
public void drawDebugData() {
if (m_debugDraw == null) {
return;
}
int flags = m_debugDraw.getFlags();
if ((flags & DebugDraw.e_shapeBit) == DebugDraw.e_shapeBit) {
for (Body b = m_bodyList; b != null; b = b.getNext()) {
xf.set(b.getTransform());
for (Fixture f = b.getFixtureList(); f != null; f = f.getNext()) {
if (b.isActive() == false) {
drawShape(f, xf, new Color3f(0.5f, 0.5f, 0.3f));
}
else if (b.getType() == BodyType.STATIC) {
drawShape(f, xf, new Color3f(0.5f, 0.9f, 0.5f));
}
else if (b.getType() == BodyType.KINEMATIC) {
drawShape(f, xf, new Color3f(0.5f, 0.5f, 0.9f));
}
else if (b.isAwake() == false) {
drawShape(f, xf, new Color3f(0.6f, 0.6f, 0.6f));
}
else {
drawShape(f, xf, new Color3f(0.9f, 0.7f, 0.7f));
}
}
}
}
if ((flags & DebugDraw.e_jointBit) == DebugDraw.e_jointBit) {
for (Joint j = m_jointList; j != null; j = j.getNext()) {
drawJoint(j);
}
}
if ((flags & DebugDraw.e_pairBit) == DebugDraw.e_pairBit) {
color.set(0.3f, 0.9f, 0.9f);
for (Contact c = m_contactManager.m_contactList; c != null; c = c.getNext()) {
Fixture fixtureA = c.getFixtureA();
Fixture fixtureB = c.getFixtureB();
fixtureA.getAABB().getCenterToOut(cA);
fixtureB.getAABB().getCenterToOut(cB);
m_debugDraw.drawSegment(cA, cB, color);
}
}
if ((flags & DebugDraw.e_aabbBit) == DebugDraw.e_aabbBit) {
color.set(0.9f, 0.3f, 0.9f);
for (Body b = m_bodyList; b != null; b = b.getNext()) {
if (b.isActive() == false) {
continue;
}
for (Fixture f = b.getFixtureList(); f != null; f = f.getNext()) {
AABB aabb = f.m_proxy.aabb;
Vec2[] vs = avs.get(4);
vs[0].set(aabb.lowerBound.x, aabb.lowerBound.y);
vs[1].set(aabb.upperBound.x, aabb.lowerBound.y);
vs[2].set(aabb.upperBound.x, aabb.upperBound.y);
vs[3].set(aabb.lowerBound.x, aabb.upperBound.y);
m_debugDraw.drawPolygon(vs, 4, color);
if ((b.m_flags & Body.e_toiFlag) == Body.e_toiFlag) {
// log.debug("toi is on");
Vec2 v = b.getWorldCenter();
m_debugDraw.drawPoint(v, 5, color);
// m_debugDraw.drawString(v.x, v.y, "toi is on", color);
}
}
}
}
if ((flags & DebugDraw.e_centerOfMassBit) == DebugDraw.e_centerOfMassBit) {
for (Body b = m_bodyList; b != null; b = b.getNext()) {
xf.set(b.getTransform());
xf.position.set(b.getWorldCenter());
m_debugDraw.drawTransform(xf);
}
}
if ((flags & DebugDraw.e_dynamicTreeBit) == DebugDraw.e_dynamicTreeBit) {
m_contactManager.m_broadPhase.drawTree(m_debugDraw);
}
}
private final WorldQueryWrapper wqwrapper = new WorldQueryWrapper();
/**
* Query the world for all fixtures that potentially overlap the
* provided AABB.
*
* @param callback
* a user implemented callback class.
* @param aabb
* the query box.
*/
public void queryAABB(QueryCallback callback, AABB aabb) {
wqwrapper.broadPhase = m_contactManager.m_broadPhase;
wqwrapper.callback = callback;
m_contactManager.m_broadPhase.query(wqwrapper, aabb);
}
private final WorldRayCastWrapper wrcwrapper = new WorldRayCastWrapper();
private final RayCastInput input = new RayCastInput();
/**
* Ray-cast the world for all fixtures in the path of the ray. Your callback
* controls whether you get the closest point, any point, or n-points.
* The ray-cast ignores shapes that contain the starting point.
*
* @param callback
* a user implemented callback class.
* @param point1
* the ray starting point
* @param point2
* the ray ending point
*/
public void raycast(RayCastCallback callback, Vec2 point1, Vec2 point2) {
wrcwrapper.broadPhase = m_contactManager.m_broadPhase;
wrcwrapper.callback = callback;
input.maxFraction = 1.0f;
input.p1.set(point1);
input.p2.set(point2);
m_contactManager.m_broadPhase.raycast(wrcwrapper, input);
}
/**
* Get the world body list. With the returned body, use Body.getNext to get
* the next body in the world list. A null body indicates the end of the list.
*
* @return the head of the world body list.
*/
public Body getBodyList() {
return m_bodyList;
}
/**
* Get the world joint list. With the returned joint, use Joint.getNext to get
* the next joint in the world list. A null joint indicates the end of the list.
*
* @return the head of the world joint list.
*/
public Joint getJointList() {
return m_jointList;
}
/**
* Get the world contact list. With the returned contact, use Contact.getNext to get
* the next contact in the world list. A null contact indicates the end of the list.
*
* @return the head of the world contact list.
* @warning contacts are
*/
public Contact getContactList() {
return m_contactManager.m_contactList;
}
/**
* Enable/disable warm starting. For testing.
*
* @param flag
*/
public void setWarmStarting(boolean flag) {
m_warmStarting = flag;
}
/**
* Enable/disable continuous physics. For testing.
*
* @param flag
*/
public void setContinuousPhysics(boolean flag) {
m_continuousPhysics = flag;
}
/**
* Get the number of broad-phase proxies.
*
* @return
*/
public int getProxyCount() {
return m_contactManager.m_broadPhase.getProxyCount();
}
/**
* Get the number of bodies.
*
* @return
*/
public int getBodyCount() {
return m_bodyCount;
}
/**
* Get the number of joints.
*
* @return
*/
public int getJointCount() {
return m_jointCount;
}
/**
* Get the number of contacts (each may have 0 or more contact points).
*
* @return
*/
public int getContactCount() {
return m_contactManager.m_contactCount;
}
/**
* Change the global gravity vector.
*
* @param gravity
*/
public void setGravity(Vec2 gravity) {
m_gravity.set(gravity);
}
/**
* Get the global gravity vector.
*
* @return
*/
public Vec2 getGravity() {
return m_gravity;
}
/**
* Is the world locked (in the middle of a time step).
*
* @return
*/
public boolean isLocked() {
return (m_flags & LOCKED) == LOCKED;
}
/**
* Set flag to control automatic clearing of forces after each time step.
*
* @param flag
*/
public void setAutoClearForces(boolean flag) {
if (flag) {
m_flags |= CLEAR_FORCES;
}
else {
m_flags &= ~CLEAR_FORCES;
}
}
/**
* Get the flag that controls automatic clearing of forces after each time step.
*
* @return
*/
public boolean getAutoClearForces() {
return (m_flags & CLEAR_FORCES) == CLEAR_FORCES;
}
private final Island island = new Island();
private Body[] stack = new Body[10]; // TODO djm find a good initial stack number;
private void solve(TimeStep step) {
// Size the island for the worst case.
island.init(m_bodyCount, m_contactManager.m_contactCount, m_jointCount, m_contactManager.m_contactListener);
// Clear all the island flags.
for (Body b = m_bodyList; b != null; b = b.m_next) {
b.m_flags &= ~Body.e_islandFlag;
}
for (Contact c = m_contactManager.m_contactList; c != null; c = c.m_next) {
c.m_flags &= ~Contact.ISLAND_FLAG;
}
for (Joint j = m_jointList; j != null; j = j.m_next) {
j.m_islandFlag = false;
}
// Build and simulate all awake islands.
int stackSize = m_bodyCount;
if (stack.length < stackSize) {
stack = new Body[stackSize];
}
for (Body seed = m_bodyList; seed != null; seed = seed.m_next) {
if ((seed.m_flags & Body.e_islandFlag) == Body.e_islandFlag) {
continue;
}
if (seed.isAwake() == false || seed.isActive() == false) {
continue;
}
// The seed can be dynamic or kinematic.
if (seed.getType() == BodyType.STATIC) {
continue;
}
// Reset island and stack.
island.clear();
int stackCount = 0;
stack[stackCount++] = seed;
seed.m_flags |= Body.e_islandFlag;
// Perform a depth first search (DFS) on the constraint graph.
while (stackCount > 0) {
// Grab the next body off the stack and add it to the island.
Body b = stack[--stackCount];
assert (b.isActive() == true);
island.add(b);
// Make sure the body is awake.
b.setAwake(true);
// To keep islands as small as possible, we don't
// propagate islands across static bodies.
if (b.getType() == BodyType.STATIC) {
continue;
}
// Search all contacts connected to this body.
for (ContactEdge ce = b.m_contactList; ce != null; ce = ce.next) {
Contact contact = ce.contact;
// Has this contact already been added to an island?
if ((contact.m_flags & Contact.ISLAND_FLAG) == Contact.ISLAND_FLAG) {
continue;
}
// Is this contact solid and touching?
if (contact.isEnabled() == false || contact.isTouching() == false) {
continue;
}
// Skip sensors.
boolean sensorA = contact.m_fixtureA.m_isSensor;
boolean sensorB = contact.m_fixtureB.m_isSensor;
if (sensorA || sensorB) {
continue;
}
island.add(contact);
contact.m_flags |= Contact.ISLAND_FLAG;
Body other = ce.other;
// Was the other body already added to this island?
if ((other.m_flags & Body.e_islandFlag) == Body.e_islandFlag) {
continue;
}
assert (stackCount < stackSize);
stack[stackCount++] = other;
other.m_flags |= Body.e_islandFlag;
}
// Search all joints connect to this body.
for (JointEdge je = b.m_jointList; je != null; je = je.next) {
if (je.joint.m_islandFlag == true) {
continue;
}
Body other = je.other;
// Don't simulate joints connected to inactive bodies.
if (other.isActive() == false) {
continue;
}
island.add(je.joint);
je.joint.m_islandFlag = true;
if ((other.m_flags & Body.e_islandFlag) == Body.e_islandFlag) {
continue;
}
assert (stackCount < stackSize);
stack[stackCount++] = other;
other.m_flags |= Body.e_islandFlag;
}
}
island.solve(step, m_gravity, m_allowSleep);
// Post solve cleanup.
for (int i = 0; i < island.m_bodyCount; ++i) {
// Allow static bodies to participate in other islands.
Body b = island.m_bodies[i];
if (b.getType() == BodyType.STATIC) {
b.m_flags &= ~Body.e_islandFlag;
}
}
}
// Synchronize fixtures, check for out of range bodies.
for (Body b = m_bodyList; b != null; b = b.getNext()) {
// If a body was not in an island then it did not move.
if ((b.m_flags & Body.e_islandFlag) == 0) {
continue;
}
if (b.getType() == BodyType.STATIC) {
continue;
}
// Update fixtures (for broad-phase).
b.synchronizeFixtures();
}
// Look for new contacts.
m_contactManager.findNewContacts();
}
private void solveTOI() {
// Prepare all contacts.
for (Contact c = m_contactManager.m_contactList; c != null; c = c.m_next) {
// Enable the contact
c.m_flags |= Contact.ENABLED_FLAG;
// Set the number of TOI events for this contact to zero.
c.m_toiCount = 0;
}
// Initialize the TOI flag.
for (Body body = m_bodyList; body != null; body = body.m_next) {
// Kinematic, and static bodies will not be affected by the TOI event.
// If a body was not in an island then it did not move.
if ((body.m_flags & Body.e_islandFlag) == 0 || body.getType() == BodyType.KINEMATIC
|| body.getType() == BodyType.STATIC) {
body.m_flags |= Body.e_toiFlag;
}
else {
body.m_flags &= ~Body.e_toiFlag;
}
}
// Collide non-bullets.
for (Body body = m_bodyList; body != null; body = body.m_next) {
if ((body.m_flags & Body.e_toiFlag) == Body.e_toiFlag) {
continue;
}
if (body.isBullet() == true) {
continue;
}
solveTOI(body);
body.m_flags |= Body.e_toiFlag;
}
// Collide bullets.
for (Body body = m_bodyList; body != null; body = body.m_next) {
if ((body.m_flags & Body.e_toiFlag) == Body.e_toiFlag) {
continue;
}
if (body.isBullet() == false) {
continue;
}
solveTOI(body);
body.m_flags |= Body.e_toiFlag;
}
}
private final TOIInput toiInput = new TOIInput();
private final TOIOutput toiOutput = new TOIOutput();
private final Sweep backup = new Sweep();
private final TOISolver toiSolver = new TOISolver();
private Contact[] m_contacts = new Contact[Settings.maxTOIContacts];
private void solveTOI(Body body) {
// Find the minimum contact.
Contact toiContact = null;
float toi = 1.0f;
Body toiOther = null;
boolean found;
int count;
int iter = 0;
boolean bullet = body.isBullet();
// Iterate until all contacts agree on the minimum TOI. We have
// to iterate because the TOI algorithm may skip some intermediate
// collisions when objects rotate through each other.
do {
count = 0;
found = false;
for (ContactEdge ce = body.m_contactList; ce != null; ce = ce.next) {
if (ce.contact == toiContact) {
continue;
}
Body other = ce.other;
BodyType type = other.getType();
// Only bullets perform TOI with dynamic bodies.
if (bullet == true) {
// Bullets only perform TOI with bodies that have their TOI resolved.
if ((other.m_flags & Body.e_toiFlag) == 0) {
continue;
}
// No repeated hits on non-static bodies
if (type != BodyType.STATIC && (ce.contact.m_flags & Contact.BULLET_HIT_FLAG) != 0) {
continue;
}
}
else if (type == BodyType.DYNAMIC) {
continue;
}
// Check for a disabled contact.
Contact contact = ce.contact;
if (contact.isEnabled() == false) {
continue;
}
// Prevent infinite looping.
if (contact.m_toiCount > 10) {
continue;
}
Fixture fixtureA = contact.m_fixtureA;
Fixture fixtureB = contact.m_fixtureB;
// Cull sensors.
if (fixtureA.isSensor() || fixtureB.isSensor()) {
continue;
}
Body bodyA = fixtureA.m_body;
Body bodyB = fixtureB.m_body;
// Compute the time of impact in interval [0, minTOI]
toiInput.proxyA.set(fixtureA.getShape());
toiInput.proxyB.set(fixtureB.getShape());
toiInput.sweepA.set(bodyA.m_sweep);
toiInput.sweepB.set(bodyB.m_sweep);
toiInput.tMax = toi;
pool.getTimeOfImpact().timeOfImpact(toiOutput, toiInput);
if (toiOutput.state == TOIOutputState.TOUCHING && toiOutput.t < toi) {
toiContact = contact;
toi = toiOutput.t;
toiOther = other;
found = true;
}
++count;
}
++iter;
}
while (found && count > 1 && iter < 50);
if (toiContact == null) {
body.advance(1.0f);
return;
}
backup.set(body.m_sweep);
body.advance(toi);
toiContact.update(m_contactManager.m_contactListener);
if (toiContact.isEnabled() == false) {
// Contact disabled. Backup and recurse.
body.m_sweep.set(backup);
solveTOI(body);
}
++toiContact.m_toiCount;
// Update all the valid contacts on this body and build a contact island.
if (m_contacts == null || m_contacts.length < Settings.maxTOIContacts){
m_contacts = new Contact[Settings.maxTOIContacts];
}
count = 0;
for (ContactEdge ce = body.m_contactList; ce != null && count < Settings.maxTOIContacts; ce = ce.next) {
Body other = ce.other;
BodyType type = other.getType();
// Only perform correction with static bodies, so the
// body won't get pushed out of the world.
if (type == BodyType.DYNAMIC) {
continue;
}
// Check for a disabled contact.
Contact contact = ce.contact;
if (contact.isEnabled() == false) {
continue;
}
Fixture fixtureA = contact.m_fixtureA;
Fixture fixtureB = contact.m_fixtureB;
// Cull sensors.
if (fixtureA.isSensor() || fixtureB.isSensor()) {
continue;
}
// The contact likely has some new contact points. The listener
// gives the user a chance to disable the contact.
if (contact != toiContact) {
contact.update(m_contactManager.m_contactListener);
}
// Did the user disable the contact?
if (contact.isEnabled() == false) {
// Skip this contact.
continue;
}
if (contact.isTouching() == false) {
continue;
}
m_contacts[count] = contact;
++count;
}
// Reduce the TOI body's overlap with the contact island.
toiSolver.initialize(m_contacts, count, body);
float k_toiBaumgarte = 0.75f;
// boolean solved = false;
for (int i = 0; i < 20; ++i) {
boolean contactsOkay = toiSolver.solve(k_toiBaumgarte);
if (contactsOkay) {
// solved = true;
break;
}
}
if (toiOther.getType() != BodyType.STATIC) {
toiContact.m_flags |= Contact.BULLET_HIT_FLAG;
}
}
private void drawJoint(Joint joint) {
Body bodyA = joint.getBodyA();
Body bodyB = joint.getBodyB();
Transform xf1 = bodyA.getTransform();
Transform xf2 = bodyB.getTransform();
Vec2 x1 = xf1.position;
Vec2 x2 = xf2.position;
Vec2 p1 = pool.popVec2();
Vec2 p2 = pool.popVec2();
joint.getAnchorA(p1);
joint.getAnchorB(p2);
color.set(0.5f, 0.8f, 0.8f);
switch (joint.getType()) {
// TODO djm write after writing joints
case DISTANCE :
m_debugDraw.drawSegment(p1, p2, color);
break;
case PULLEY : {
PulleyJoint pulley = (PulleyJoint) joint;
Vec2 s1 = pulley.getGroundAnchorA();
Vec2 s2 = pulley.getGroundAnchorB();
m_debugDraw.drawSegment(s1, p1, color);
m_debugDraw.drawSegment(s2, p2, color);
m_debugDraw.drawSegment(s1, s2, color);
}
break;
case CONSTANT_VOLUME :
case MOUSE :
// don't draw this
break;
default :
m_debugDraw.drawSegment(x1, p1, color);
m_debugDraw.drawSegment(p1, p2, color);
m_debugDraw.drawSegment(x2, p2, color);
}
pool.pushVec2(2);
}
// NOTE this corresponds to the liquid test, so the debugdraw can draw
// the liquid particles correctly. They should be the same.
private static Integer LIQUID_INT = new Integer(1234598372);
private float liquidLength = .12f;
private float averageLinearVel = -1;
private final Vec2 liquidOffset = new Vec2();
private final Vec2 circCenterMoved = new Vec2();
private final Color3f liquidColor = new Color3f(.4f,.4f,1f);
private final Vec2 center = new Vec2();
private final Vec2 axis = new Vec2();
private final Vec2Array tlvertices = new Vec2Array();
private void drawShape(Fixture fixture, Transform xf, Color3f color) {
switch (fixture.getType()) {
case CIRCLE : {
CircleShape circle = (CircleShape) fixture.getShape();
// Vec2 center = Mul(xf, circle.m_p);
Transform.mulToOut(xf, circle.m_p, center);
float radius = circle.m_radius;
axis.set(xf.R.col1);
if (fixture.getUserData() != null && fixture.getUserData().equals(LIQUID_INT)) {
Body b = fixture.getBody();
liquidOffset.set(b.m_linearVelocity);
float linVelLength = b.m_linearVelocity.length();
if(averageLinearVel == -1){
averageLinearVel = linVelLength;
}else{
averageLinearVel = .98f * averageLinearVel + .02f * linVelLength;
}
liquidOffset.mulLocal( liquidLength/averageLinearVel/2);
circCenterMoved.set(center).addLocal( liquidOffset);
center.subLocal(liquidOffset);
m_debugDraw.drawSegment(center, circCenterMoved, liquidColor);
return;
}
m_debugDraw.drawSolidCircle(center, radius, axis, color);
}
break;
case POLYGON : {
PolygonShape poly = (PolygonShape) fixture.getShape();
int vertexCount = poly.m_vertexCount;
assert (vertexCount <= Settings.maxPolygonVertices);
Vec2[] vertices = tlvertices.get(Settings.maxPolygonVertices);
for (int i = 0; i < vertexCount; ++i) {
// vertices[i] = Mul(xf, poly.m_vertices[i]);
Transform.mulToOut(xf, poly.m_vertices[i], vertices[i]);
}
m_debugDraw.drawSolidPolygon(vertices, vertexCount, color);
}
break;
}
}
}
class WorldQueryWrapper implements TreeCallback {
public boolean treeCallback(DynamicTreeNode node) {
Fixture fixture = (Fixture) node.userData;
return callback.reportFixture(fixture);
}
BroadPhase broadPhase;
QueryCallback callback;
};
class WorldRayCastWrapper implements TreeRayCastCallback {
// djm pooling
private final RayCastOutput output = new RayCastOutput();
private final Vec2 temp = new Vec2();
private final Vec2 point = new Vec2();
public float raycastCallback(RayCastInput input, DynamicTreeNode node) {
Object userData = node.userData;
Fixture fixture = (Fixture) userData;
boolean hit = fixture.raycast(output, input);
if (hit) {
float fraction = output.fraction;
// Vec2 point = (1.0f - fraction) * input.p1 + fraction * input.p2;
temp.set(input.p2).mulLocal(fraction);
point.set(input.p1).mulLocal(1 - fraction).addLocal(temp);
return callback.reportFixture(fixture, point, output.normal, fraction);
}
return input.maxFraction;
}
BroadPhase broadPhase;
RayCastCallback callback;
};