axmol/cocos/physics/CCComponentPhysics2d.cpp

/****************************************************************************
 Copyright (c) 2015 Chukong Technologies Inc.
 
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 of this software and associated documentation files (the "Software"), to deal
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 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
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 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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#include "base/ccConfig.h" // to include defination of CC_USE_PHYSICS
#if CC_USE_PHYSICS

#include "physics/CCComponentPhysics2d.h"
#include "physics/CCPhysicsBody.h"
#include "physics/CCPhysicsManager.h"
#include "2d/CCNode.h"
#include "base/CCDirector.h"

NS_CC_BEGIN

const std::string ComponentPhysics2d::COMPONENT_NAME = "physics2d";

ComponentPhysics2d* ComponentPhysics2d::create()
{
    return create(nullptr);
}

ComponentPhysics2d* ComponentPhysics2d::create(PhysicsBody *physicsBody)
{
    auto ret = new (std::nothrow) ComponentPhysics2d(physicsBody);
    if (ret)
        ret->autorelease();
    
    return ret;
}

ComponentPhysics2d::ComponentPhysics2d()
: _physicsBody(nullptr)
, _physicsRotation(0.0f)
, _ownerOriginRotation(0.0f)
{
    _name = COMPONENT_NAME;
}

ComponentPhysics2d::ComponentPhysics2d(PhysicsBody* physicsBody)
: _physicsRotation(0.0f)
, _ownerOriginRotation(0.0f)
, _physicsBody(nullptr) // should set to null to invoke setPhysicsBody()
{
    _name = COMPONENT_NAME;
    setPhysicsBody(physicsBody);
}

ComponentPhysics2d::~ComponentPhysics2d()
{
    removePhysicsBody();
}

// true if two Vec3 equals, false else
bool ComponentPhysics2d::isVec3Equal(const cocos2d::Vec3 &v1, const cocos2d::Vec3 &v2) const
{
    return fabs(v1.x - v2.x) < FLT_EPSILON &&
    fabs(v1.x - v2.y) < FLT_EPSILON;
}

void ComponentPhysics2d::beforeSimulation()
{
    if (nullptr == _physicsBody)
        return;
    
    _nodeToWorldTransform = _owner->getNodeToWorldTransform();
    
    // set scale
    _nodeToWorldTransform.getScale(&_scale);
    if (! isVec3Equal(_scale, _recordScale))
    {
        _physicsBody->setScale(_scale.x, _scale.y);
        _recordScale = _scale;
    }
    
    // set rotation
    if (_owner->getParent())
    {
        _physicsRotation = getPhysicsRotation(_owner->getParent()) + _owner->getRotation();
    }
    _physicsBody->setRotation(_physicsRotation - _ownerOriginRotation);
    
    // set position
    auto worldPosition = _ownerCenterOffset;
    _nodeToWorldTransform.transformPoint(&worldPosition);
    _physicsBody->setPosition(Vec2(worldPosition.x, worldPosition.y));
    
    getParentToWorldTransform().getInversed().transformPoint(&worldPosition);
    _offset.x = worldPosition.x - _owner->getPosition().x;
    _offset.y = worldPosition.y - _owner->getPosition().y;
}

void ComponentPhysics2d::afterSimulation()
{
    if (nullptr == _physicsBody)
        return;
    
    // set Node position
    auto worldPosition = _physicsBody->getPosition();
    Vec3 positionInParent(worldPosition.x, worldPosition.y, 0);
    getParentToWorldTransform().getInversed().transformPoint(&positionInParent);
    _owner->setPosition(positionInParent.x - _offset.x, positionInParent.y - _offset.y);
    
    // set Node rotation
    _physicsRotation = _physicsBody->getRotation();
    _owner->setRotation(_physicsRotation - getPhysicsRotation(_owner->getParent()) + _ownerOriginRotation);
}

void ComponentPhysics2d::setPhysicsBody(PhysicsBody *physicsBody)
{
    removeFromPhysicsManager();
    
    if (physicsBody != _physicsBody)
    {
        if (nullptr != _physicsBody)
        {
            _physicsBody->release();
            _physicsBody->_componentBelongsTo = nullptr;
        }
        
        // two components should not share the same physics body
        if (physicsBody && physicsBody->_componentBelongsTo != nullptr)
            physicsBody->_componentBelongsTo->_physicsBody = nullptr;
        
        _physicsBody = physicsBody;
        
        if (nullptr != _physicsBody)
        {
            _physicsBody->retain();
            _physicsBody->_componentBelongsTo = this;
        }
    }
    
    addToPhysicsManager();
}

PhysicsBody* ComponentPhysics2d::getPhysicsBody() const
{
    return _physicsBody;
}

void ComponentPhysics2d::setEnabled(bool value)
{
    Component::setEnabled(value);
    
    if (value)
        addToPhysicsManager();
    else
        removeFromPhysicsManager();
}

void ComponentPhysics2d::onEnter()
{
    addToPhysicsManager();
}

void ComponentPhysics2d::onExit()
{
    removeFromPhysicsManager();
}

void ComponentPhysics2d::onAdd()
{
    auto contentSize = _owner->getContentSize();
    _ownerCenterOffset.x = 0.5 * contentSize.width;
    _ownerCenterOffset.y = 0.5 * contentSize.height;
    
    _ownerOriginRotation = _owner->getRotation();
    
    // component may be added after onEnter() has been invoked, so we should add
    // this line to make sure physics body is added to physics world
    addToPhysicsManager();
}

void ComponentPhysics2d::onRemove()
{
    removePhysicsBody();
}

void ComponentPhysics2d::removePhysicsBody()
{
    removeFromPhysicsManager();
    
    if (_physicsBody)
    {
        _physicsBody->_componentBelongsTo = nullptr;
        _physicsBody->release();
        _physicsBody = nullptr;
    }
}

void ComponentPhysics2d::addToPhysicsManager()
{
    if (_owner)
    {
        auto scene = _owner->getScene();
        if (scene)
            scene->getPhysicsManager()->addPhysicsComponent(this);
    }
    
}

void ComponentPhysics2d::removeFromPhysicsManager()
{
    if (_owner)
    {
        auto scene = _owner->getScene();
        if (scene)
            scene->getPhysicsManager()->removePhysicsComponent(this);
    }
}

Mat4 ComponentPhysics2d::getParentToWorldTransform() const
{
    if (_owner->getParent())
        return _owner->getParent()->getNodeToWorldTransform();
    else
        return _owner->getNodeToWorldTransform();
}

float ComponentPhysics2d::getPhysicsRotation(Node *node) const
{
    if (!node)
        return 0.0f;
    
    auto physicsComponent = node->getComponent<ComponentPhysics2d>();
    if (physicsComponent)
    {
        return physicsComponent->_physicsRotation;
    }
    else
    {
        auto parent = node->getParent();
        if (parent)
            return getPhysicsRotation(parent) + node->getRotation();
        else
            return 0.0f;
    }
}

NS_CC_END

#endif // CC_USE_PHYSICS