axmol/cocos/physics/CCPhysicsBody.cpp

/****************************************************************************
 Copyright (c) 2013 cocos2d-x.org
 
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 Permission is hereby granted, free of charge, to any person obtaining a copy
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 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,
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 THE SOFTWARE.
 ****************************************************************************/
#include "CCPhysicsBody.h"
#ifdef CC_USE_PHYSICS

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

#include "chipmunk.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)
, _enable(true)
, _rotationEnable(true)
, _gravityEnable(true)
, _massDefault(true)
, _momentDefault(true)
, _mass(MASS_DEFAULT)
, _area(0.0f)
, _density(0.0f)
, _moment(MOMENT_DEFAULT)
, _linearDamping(0.0f)
, _angularDamping(0.0f)
, _tag(0)
, _categoryBitmask(UINT_MAX)
, _collisionBitmask(UINT_MAX)
, _contactTestBitmask(UINT_MAX)
, _group(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())
                {
                    _gravityEnable = 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);
        }
        
    }
}

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

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

void PhysicsBody::setPosition(Point position)
{
    cpBodySetPos(_info->getBody(), PhysicsHelper::point2cpv(position));
}

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

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

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

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)
{
    cpBodyApplyForce(_info->getBody(), PhysicsHelper::point2cpv(force), PhysicsHelper::point2cpv(offset));
}

void PhysicsBody::resetForces()
{
    cpBodyResetForces(_info->getBody());
    
    // if _gravityEnable is false, add a reverse of gravity force to body
    if (_world != nullptr && !_gravityEnable)
    {
        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;
    }
    
    _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)
    {
        cpBodySetMass(_info->getBody(), PhysicsHelper::float2cpfloat(_mass));
    }
}

void PhysicsBody::addMass(float mass)
{
    if (mass == PHYSICS_INFINITY)
    {
        _mass = PHYSICS_INFINITY;
        _massDefault = false;
        _density = PHYSICS_INFINITY;
    }
    else if (mass == -PHYSICS_INFINITY)
    {
        return;
    }
    else if (_mass != PHYSICS_INFINITY)
    {
        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)
    {
        cpBodySetMass(_info->getBody(), PhysicsHelper::float2cpfloat(_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)
    {
        // if moment is -PHYSICS_INFINITY, it won't change
        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 (_rotationEnable && _dynamic)
    {
        cpBodySetMoment(_info->getBody(), PhysicsHelper::float2cpfloat(_moment));
    }
}

void PhysicsBody::setVelocity(const Point& velocity)
{
    if (!_dynamic)
    {
        CCLOG("physics warning: your cann'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 cann'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)
{
    cpBodySetVelLimit(_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 (_rotationEnable && _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.erase(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 (_enable != enable)
    {
        _enable = enable;
        
        if (_world)
        {
            if (enable)
            {
                _world->addBodyOrDelay(this);
            }else
            {
                _world->removeBodyOrDelay(this);
            }
        }
    }
}

bool PhysicsBody::isResting() const
{
    return cpBodyIsSleeping(_info->getBody()) == cpTrue;
}

void PhysicsBody::update(float delta)
{
    // damping compute
    if (_dynamic)
    {
        _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);
    }
}

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)));
}

NS_CC_END

#endif // CC_USE_PHYSICS