axmol/cocos/physics/CCPhysicsBody.cpp

/****************************************************************************
 Copyright (c) 2013 Chukong Technologies Inc.
 
 http://www.cocos2d-x.org
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ****************************************************************************/
#include "CCPhysicsBody.h"
#if CC_USE_PHYSICS

#include <climits>
#include <algorithm>
#include <cmath>

#include "chipmunk.h"

#include "CCNode.h"

#include "CCPhysicsShape.h"
#include "CCPhysicsJoint.h"
#include "CCPhysicsWorld.h"

#include "chipmunk/CCPhysicsBodyInfo_chipmunk.h"
#include "chipmunk/CCPhysicsJointInfo_chipmunk.h"
#include "chipmunk/CCPhysicsWorldInfo_chipmunk.h"
#include "chipmunk/CCPhysicsShapeInfo_chipmunk.h"
#include "chipmunk/CCPhysicsHelper_chipmunk.h"

NS_CC_BEGIN
extern const float PHYSICS_INFINITY;

namespace
{
    static const float MASS_DEFAULT = 1.0;
    static const float MOMENT_DEFAULT = 200;
}

PhysicsBody::PhysicsBody()
: _node(nullptr)
, _world(nullptr)
, _info(nullptr)
, _dynamic(true)
, _enabled(true)
, _rotationEnabled(true)
, _gravityEnabled(true)
, _massDefault(true)
, _momentDefault(true)
, _mass(MASS_DEFAULT)
, _area(0.0f)
, _density(0.0f)
, _moment(MOMENT_DEFAULT)
, _isDamping(false)
, _linearDamping(0.0f)
, _angularDamping(0.0f)
, _tag(0)
, _categoryBitmask(UINT_MAX)
, _collisionBitmask(0)
, _contactTestBitmask(UINT_MAX)
, _group(0)
, _positionResetTag(false)
, _rotationResetTag(false)
, _rotationOffset(0)
{
}

PhysicsBody::~PhysicsBody()
{
    for (auto it = _joints.begin(); it != _joints.end(); ++it)
    {
        PhysicsJoint* joint = *it;
        
        PhysicsBody* other = joint->getBodyA() == this ? joint->getBodyB() : joint->getBodyA();
        other->removeJoint(joint);
        delete joint;
    }
    
    CC_SAFE_DELETE(_info);
}

PhysicsBody* PhysicsBody::create()
{
    PhysicsBody* body = new PhysicsBody();
    if (body && body->init())
    {
        body->autorelease();
        return body;
    }
    
    CC_SAFE_DELETE(body);
    return nullptr;
}

PhysicsBody* PhysicsBody::create(float mass)
{
    PhysicsBody* body = new PhysicsBody();
    if (body)
    {
        body->_mass = mass;
        body->_massDefault = false;
        if (body->init())
        {
            body->autorelease();
            return body;
        }
    }
    
    CC_SAFE_DELETE(body);
    return nullptr;
}

PhysicsBody* PhysicsBody::create(float mass, float moment)
{
    PhysicsBody* body = new PhysicsBody();
    if (body)
    {
        body->_mass = mass;
        body->_massDefault = false;
        body->_moment = moment;
        body->_momentDefault = false;
        if (body->init())
        {
            body->autorelease();
            return body;
        }
    }
    
    CC_SAFE_DELETE(body);
    return nullptr;
    
}

PhysicsBody* PhysicsBody::createCircle(float radius, const PhysicsMaterial& material, const Point& offset)
{
    PhysicsBody* body = new PhysicsBody();
    if (body && body->init())
    {
        body->addShape(PhysicsShapeCircle::create(radius, material, offset));
        body->autorelease();
        return body;
    }
    
    CC_SAFE_DELETE(body);
    return nullptr;
}

PhysicsBody* PhysicsBody::createBox(const Size& size, const PhysicsMaterial& material, const Point& offset)
{
    PhysicsBody* body = new PhysicsBody();
    if (body && body->init())
    {
        body->addShape(PhysicsShapeBox::create(size, material, offset));
        body->autorelease();
        return body;
    }
    
    CC_SAFE_DELETE(body);
    return nullptr;
}

PhysicsBody* PhysicsBody::createPolygon(const Point* points, int count, const PhysicsMaterial& material, const Point& offset)
{
    PhysicsBody* body = new PhysicsBody();
    if (body && body->init())
    {
        body->addShape(PhysicsShapePolygon::create(points, count, material, offset));
        body->autorelease();
        return body;
    }
    
    CC_SAFE_DELETE(body);
    return nullptr;
}

PhysicsBody* PhysicsBody::createEdgeSegment(const Point& a, const Point& b, const PhysicsMaterial& material, float border/* = 1*/)
{
    PhysicsBody* body = new PhysicsBody();
    if (body && body->init())
    {
        body->addShape(PhysicsShapeEdgeSegment::create(a, b, material, border));
        body->_dynamic = false;
        body->autorelease();
        return body;
    }
    
    CC_SAFE_DELETE(body);
    return nullptr;
}

PhysicsBody* PhysicsBody::createEdgeBox(const Size& size, const PhysicsMaterial& material, float border/* = 1*/, const Point& offset)
{
    PhysicsBody* body = new PhysicsBody();
    if (body && body->init())
    {
        body->addShape(PhysicsShapeEdgeBox::create(size, material, border, offset));
        body->_dynamic = false;
        body->autorelease();
        return body;
    }
    
    CC_SAFE_DELETE(body);
    
    return nullptr;
}

PhysicsBody* PhysicsBody::createEdgePolygon(const Point* points, int count, const PhysicsMaterial& material, float border/* = 1*/)
{
    PhysicsBody* body = new PhysicsBody();
    if (body && body->init())
    {
        body->addShape(PhysicsShapeEdgePolygon::create(points, count, material, border));
        body->_dynamic = false;
        body->autorelease();
        return body;
    }
    
    CC_SAFE_DELETE(body);
    
    return nullptr;
}

PhysicsBody* PhysicsBody::createEdgeChain(const Point* points, int count, const PhysicsMaterial& material, float border/* = 1*/)
{
    PhysicsBody* body = new PhysicsBody();
    if (body && body->init())
    {
        body->addShape(PhysicsShapeEdgeChain::create(points, count, material, border));
        body->_dynamic = false;
        body->autorelease();
        return body;
    }
    
    CC_SAFE_DELETE(body);
    
    return nullptr;
}

bool PhysicsBody::init()
{
    do
    {
        _info = new PhysicsBodyInfo();
        CC_BREAK_IF(_info == nullptr);
        
        _info->setBody(cpBodyNew(PhysicsHelper::float2cpfloat(_mass), PhysicsHelper::float2cpfloat(_moment)));
        
        CC_BREAK_IF(_info->getBody() == nullptr);
        
        return true;
    } while (false);
    
    return false;
}

void PhysicsBody::removeJoint(PhysicsJoint* joint)
{
    auto it = std::find(_joints.begin(), _joints.end(), joint);
    
    if (it != _joints.end())
    {
        _joints.erase(it);
    }
}

void PhysicsBody::setDynamic(bool dynamic)
{
    if (dynamic != _dynamic)
    {
        _dynamic = dynamic;
        if (dynamic)
        {
            cpBodySetMass(_info->getBody(), _mass);
            cpBodySetMoment(_info->getBody(), _moment);
            
            if (_world != nullptr)
            {
                // reset the gravity enable
                if (isGravityEnabled())
                {
                    _gravityEnabled = false;
                    setGravityEnable(true);
                }
                
                cpSpaceAddBody(_world->_info->getSpace(), _info->getBody());
            }
        }
        else
        {
            if (_world != nullptr)
            {
                cpSpaceRemoveBody(_world->_info->getSpace(), _info->getBody());
            }
            
            // avoid incorrect collion simulation.
            cpBodySetMass(_info->getBody(), PHYSICS_INFINITY);
            cpBodySetMoment(_info->getBody(), PHYSICS_INFINITY);
            cpBodySetVel(_info->getBody(), cpvzero);
            cpBodySetAngVel(_info->getBody(), 0.0f);
            resetForces();
        }
        
    }
}

void PhysicsBody::setRotationEnable(bool enable)
{
    if (_rotationEnabled != enable)
    {
        cpBodySetMoment(_info->getBody(), enable ? _moment : PHYSICS_INFINITY);
        _rotationEnabled = enable;
    }
}

void PhysicsBody::setGravityEnable(bool enable)
{
    if (_gravityEnabled != enable)
    {
        _gravityEnabled = enable;
        
        if (_world != nullptr)
        {
            if (enable)
            {
                applyForce(_world->getGravity() * _mass);
            }else
            {
                applyForce(-_world->getGravity() * _mass);
            }
        }
    }
}

void PhysicsBody::setPosition(Point position)
{
    if (!_positionResetTag)
    {
        cpBodySetPos(_info->getBody(), PhysicsHelper::point2cpv(position + _positionOffset));
    }
}

void PhysicsBody::setRotation(float rotation)
{
    if (!_rotationResetTag)
    {
        cpBodySetAngle(_info->getBody(), -PhysicsHelper::float2cpfloat((rotation + _rotationOffset) * (M_PI / 180.0f)));
    }
}

Point PhysicsBody::getPosition() const
{
    cpVect vec = cpBodyGetPos(_info->getBody());
    return PhysicsHelper::cpv2point(vec) - _positionOffset;
}

float PhysicsBody::getRotation() const
{
    return -PhysicsHelper::cpfloat2float(cpBodyGetAngle(_info->getBody()) * (180.0f / M_PI)) - _rotationOffset;
}

PhysicsShape* PhysicsBody::addShape(PhysicsShape* shape, bool addMassAndMoment/* = true*/)
{
    if (shape == nullptr) return nullptr;
    
    // add shape to body
    if (_shapes.getIndex(shape) == -1)
    {
        shape->setBody(this);
        
        // calculate the area, mass, and desity
        // area must update before mass, because the density changes depend on it.
        if (addMassAndMoment)
        {
            _area += shape->getArea();
            addMass(shape->getMass());
            addMoment(shape->getMoment());
        }
        
        if (_world != nullptr)
        {
            _world->addShape(shape);
        }
        
        _shapes.pushBack(shape);
        
        if (_group != CP_NO_GROUP && shape->getGroup() == CP_NO_GROUP)
        {
            shape->setGroup(_group);
        }
    }
    
    return shape;
}

void PhysicsBody::applyForce(const Vect& force)
{
    applyForce(force, Point::ZERO);
}

void PhysicsBody::applyForce(const Vect& force, const Point& offset)
{
    if (_dynamic && _mass != PHYSICS_INFINITY)
    {
        cpBodyApplyForce(_info->getBody(), PhysicsHelper::point2cpv(force), PhysicsHelper::point2cpv(offset));
    }
}

void PhysicsBody::resetForces()
{
    cpBodyResetForces(_info->getBody());
    
    // if _gravityEnabled is false, add a reverse of gravity force to body
    if (_world != nullptr && _dynamic && !_gravityEnabled && _mass != PHYSICS_INFINITY)
    {
        applyForce(-_world->getGravity() * _mass);
    }
}

void PhysicsBody::applyImpulse(const Vect& impulse)
{
    applyImpulse(impulse, Point());
}

void PhysicsBody::applyImpulse(const Vect& impulse, const Point& offset)
{
    cpBodyApplyImpulse(_info->getBody(), PhysicsHelper::point2cpv(impulse), PhysicsHelper::point2cpv(offset));
}

void PhysicsBody::applyTorque(float torque)
{
    cpBodySetTorque(_info->getBody(), PhysicsHelper::float2cpfloat(torque));
}

void PhysicsBody::setMass(float mass)
{
    if (mass <= 0)
    {
        return;
    }

    int oldMass = _mass;
    _mass = mass;
    _massDefault = false;
    
    // update density
    if (_mass == PHYSICS_INFINITY)
    {
        _density = PHYSICS_INFINITY;
    }
    else
    {
        if (_area > 0)
        {
            _density = _mass / _area;
        }else
        {
            _density = 0;
        }
    }
    
    // the static body's mass and moment is always infinity
    if (_dynamic)
    {
        updateMass(oldMass, _mass);
    }
}

void PhysicsBody::addMass(float mass)
{
    float oldMass = _mass;
    
    if (mass == PHYSICS_INFINITY)
    {
        _mass = PHYSICS_INFINITY;
        _massDefault = false;
        _density = PHYSICS_INFINITY;
    }
    else if (mass == -PHYSICS_INFINITY)
    {
        return;
    }
    else
    {
        if (_massDefault)
        {
            _mass = 0;
            _massDefault = false;
        }
        
        if (_mass + mass > 0)
        {
            _mass +=  mass;
        }else
        {
            _mass = MASS_DEFAULT;
            _massDefault = true;
        }
        
        if (_area > 0)
        {
            _density = _mass / _area;
        }
        else
        {
            _density = 0;
        }
    }
    
    // the static body's mass and moment is always infinity
    if (_dynamic)
    {
        updateMass(oldMass, _mass);
    }
}

void PhysicsBody::addMoment(float moment)
{
    if (moment == PHYSICS_INFINITY)
    {
        // if moment is PHYSICS_INFINITY, the moment of the body will become PHYSICS_INFINITY
        _moment = PHYSICS_INFINITY;
        _momentDefault = false;
    }
    else if (moment == -PHYSICS_INFINITY)
    {
        return;
    }
    else
    {
        // if moment of the body is PHYSICS_INFINITY is has no effect
        if (_moment != PHYSICS_INFINITY)
        {
            if (_momentDefault)
            {
                _moment = 0;
                _momentDefault = false;
            }
            
            if (_moment + moment > 0)
            {
                _moment += moment;
            }
            else
            {
                _moment = MOMENT_DEFAULT;
                _momentDefault = true;
            }
        }
    }
    
    // the static body's mass and moment is always infinity
    if (_rotationEnabled && _dynamic)
    {
        cpBodySetMoment(_info->getBody(), PhysicsHelper::float2cpfloat(_moment));
    }
}

void PhysicsBody::setVelocity(const Point& velocity)
{
    if (!_dynamic)
    {
        CCLOG("physics warning: your can't set velocity for a static body.");
        return;
    }
    
    cpBodySetVel(_info->getBody(), PhysicsHelper::point2cpv(velocity));
}

Point PhysicsBody::getVelocity()
{
    return PhysicsHelper::cpv2point(cpBodyGetVel(_info->getBody()));
}

Point PhysicsBody::getVelocityAtLocalPoint(const Point& point)
{
    return PhysicsHelper::cpv2point(cpBodyGetVelAtLocalPoint(_info->getBody(), PhysicsHelper::point2cpv(point)));
}

Point PhysicsBody::getVelocityAtWorldPoint(const Point& point)
{
    return PhysicsHelper::cpv2point(cpBodyGetVelAtWorldPoint(_info->getBody(), PhysicsHelper::point2cpv(point)));
}

void PhysicsBody::setAngularVelocity(float velocity)
{
    if (!_dynamic)
    {
        CCLOG("physics warning: your can't set angular velocity for a static body.");
        return;
    }
    
    cpBodySetAngVel(_info->getBody(), PhysicsHelper::float2cpfloat(velocity));
}

float PhysicsBody::getAngularVelocity()
{
    return PhysicsHelper::cpfloat2float(cpBodyGetAngVel(_info->getBody()));
}

void PhysicsBody::setVelocityLimit(float limit)
{
    cpBodySetVelLimit(_info->getBody(), PhysicsHelper::float2cpfloat(limit));
}

float PhysicsBody::getVelocityLimit()
{
    return PhysicsHelper::cpfloat2float(cpBodyGetVelLimit(_info->getBody()));
}

void PhysicsBody::setAngularVelocityLimit(float limit)
{
    cpBodySetAngVelLimit(_info->getBody(), PhysicsHelper::float2cpfloat(limit));
}

float PhysicsBody::getAngularVelocityLimit()
{
    return PhysicsHelper::cpfloat2float(cpBodyGetAngVelLimit(_info->getBody()));
}

void PhysicsBody::setMoment(float moment)
{
    _moment = moment;
    _momentDefault = false;
    
    // the static body's mass and moment is always infinity
    if (_rotationEnabled && _dynamic)
    {
        cpBodySetMoment(_info->getBody(), PhysicsHelper::float2cpfloat(_moment));
    }
}

PhysicsShape* PhysicsBody::getShape(int tag) const
{
    for (auto& shape : _shapes)
    {
        if (shape->getTag() == tag)
        {
            return shape;
        }
    }
    
    return nullptr;
}

void PhysicsBody::removeShape(int tag, bool reduceMassAndMoment/* = true*/)
{
    for (auto& shape : _shapes)
    {
        if (shape->getTag() == tag)
        {
            removeShape(shape, reduceMassAndMoment);
            return;
        }
    }
}

void PhysicsBody::removeShape(PhysicsShape* shape, bool reduceMassAndMoment/* = true*/)
{
    if (_shapes.getIndex(shape) != -1)
    {
        // deduce the area, mass and moment
        // area must update before mass, because the density changes depend on it.
        if (reduceMassAndMoment)
        {
            _area -= shape->getArea();
            addMass(-shape->getMass());
            addMoment(-shape->getMoment());
        }
        
        //remove
        if (_world)
        {
            _world->removeShape(shape);
        }
        
        // set shape->_body = nullptr make the shape->setBody will not trigger the _body->removeShape function call.
        shape->_body = nullptr;
        shape->setBody(nullptr);
        _shapes.eraseObject(shape);
    }
}

void PhysicsBody::removeAllShapes(bool reduceMassAndMoment/* = true*/)
{
    for (auto& child : _shapes)
    {
        PhysicsShape* shape = dynamic_cast<PhysicsShape*>(child);
        
        // deduce the area, mass and moment
        // area must update before mass, because the density changes depend on it.
        if (reduceMassAndMoment)
        {
            _area -= shape->getArea();
            addMass(-shape->getMass());
            addMoment(-shape->getMoment());
        }
        
        if (_world)
        {
            _world->removeShape(shape);
        }
        
        // set shape->_body = nullptr make the shape->setBody will not trigger the _body->removeShape function call.
        shape->_body = nullptr;
        shape->setBody(nullptr);
    }
    
    _shapes.clear();
}

void PhysicsBody::removeFromWorld()
{
    if (_world)
    {
        _world->removeBody(this);
    }
}

void PhysicsBody::setEnable(bool enable)
{
    if (_enabled != enable)
    {
        _enabled = enable;
        
        if (_world)
        {
            if (enable)
            {
                _world->addBodyOrDelay(this);
            }else
            {
                _world->removeBodyOrDelay(this);
            }
        }
    }
}

bool PhysicsBody::isResting() const
{
    return CP_PRIVATE(_info->getBody()->node).root != ((cpBody*)0);
}

void PhysicsBody::setResting(bool rest) const
{
    if (rest && !isResting())
    {
        cpBodySleep(_info->getBody());
    }else if(!rest && isResting())
    {
        cpBodyActivate(_info->getBody());
    }
}

void PhysicsBody::update(float delta)
{
    if (_node != nullptr)
    {
        Node* parent = _node->getParent();
        
        Point position = parent != nullptr ? parent->convertToNodeSpace(getPosition()) : getPosition();
        _positionResetTag = true;
        _rotationResetTag = true;
        _node->setPosition(position);
        _node->setRotation(getRotation());
        _positionResetTag = false;
        _rotationResetTag = false;
        
        // damping compute
        if (_isDamping && _dynamic && !isResting())
        {
            _info->getBody()->v.x *= cpfclamp(1.0f - delta * _linearDamping, 0.0f, 1.0f);
            _info->getBody()->v.y *= cpfclamp(1.0f - delta * _linearDamping, 0.0f, 1.0f);
            _info->getBody()->w *= cpfclamp(1.0f - delta * _angularDamping, 0.0f, 1.0f);
        }
    }
}

void PhysicsBody::setCategoryBitmask(int bitmask)
{
    _categoryBitmask = bitmask;
    
    for (auto& shape : _shapes)
    {
        shape->setCategoryBitmask(bitmask);
    }
}

void PhysicsBody::setContactTestBitmask(int bitmask)
{
    _contactTestBitmask = bitmask;
    
    for (auto& shape : _shapes)
    {
        shape->setContactTestBitmask(bitmask);
    }
}

void PhysicsBody::setCollisionBitmask(int bitmask)
{
    _collisionBitmask = bitmask;
    
    for (auto& shape : _shapes)
    {
        shape->setCollisionBitmask(bitmask);
    }
}

void PhysicsBody::setGroup(int group)
{
    for (auto& shape : _shapes)
    {
        shape->setGroup(group);
    }
}

void PhysicsBody::setPositionOffset(const Point& position)
{
    if (!_positionOffset.equals(position))
    {
        Point pos = getPosition();
        _positionOffset = position;
        setPosition(pos);
    }
}

Point PhysicsBody::getPositionOffset() const
{
    return _positionOffset;
}

void PhysicsBody::setRotationOffset(float rotation)
{
    if (std::abs(_rotationOffset - rotation) > 0.5f)
    {
        float rot = getRotation();
        _rotationOffset = rotation;
        setRotation(rot);
    }
}

float PhysicsBody::getRotationOffset() const
{
    return _rotationOffset;
}

Point PhysicsBody::world2Local(const Point& point)
{
    return PhysicsHelper::cpv2point(cpBodyWorld2Local(_info->getBody(), PhysicsHelper::point2cpv(point)));
}

Point PhysicsBody::local2World(const Point& point)
{
    return PhysicsHelper::cpv2point(cpBodyLocal2World(_info->getBody(), PhysicsHelper::point2cpv(point)));
}

void PhysicsBody::updateMass(float oldMass, float newMass)
{
    if (_dynamic && !_gravityEnabled && _world != nullptr && oldMass != PHYSICS_INFINITY)
    {
        applyForce(_world->getGravity() * oldMass);
    }
    
    cpBodySetMass(_info->getBody(), newMass);
    
    if (_dynamic && !_gravityEnabled && _world != nullptr && newMass != PHYSICS_INFINITY)
    {
        applyForce(-_world->getGravity() * newMass);
    }
}

NS_CC_END

#endif // CC_USE_PHYSICS