内容介绍：

3.0以后最Box2d和chipmunk这两个物理引擎进行了封装，使用起来非常的便利。

offset：重心点
velocity：速度
dadamping：阻尼
rerestitution：弹力
mamaterial：材质
mass：质量
moment：力矩，当他碰到另一个刚体时候，会产生一股扭转力，做旋转运动
body：刚体，表示物理世界中的抽象实体，附带有物理属性
shape：刚体的形状，同一个body可以附加多个shape该shape们不会发生碰撞
joint：关节，可以连接>=2个刚体

【physicsBody】
/**创建一个bodymass和moment为默认值*/
staticPhysicsBody*create();
/**创建一个质量为mass的bodymoment为默认值.*/
staticPhysicsBody*create(floatmass);
/**创建一个body并为mass和moment赋值*/
staticPhysicsBody*create(floatmass,floatmoment);
/**创建一个shape为圆形的body*/
staticPhysicsBody*createCircle(floatradius,constPhysicsMaterial&material=PHYSICSBODY_MATERIAL_DEFAULT,constPoint&offset=Point::ZERO);
/**创建一个shape为四边形的body.*/
staticPhysicsBody*createBox(constSize&size,constPoint&offset=Point::ZERO);
/**创建一个动态多边形刚体，多边形的顶点存放在Pointarray[]中示例：Pointarray[]={point(1,1),point(2,2)}注意：顶点必须按顺时针存放，并且图形为凸状，不能是凹的*/
staticPhysicsBody*createPolygon(constPoint*points,intcount,constPoint&offset=Point::ZERO);

/**创建一个静态的线状刚体.*/
staticPhysicsBody*createEdgeSegment(constPoint&a,constPoint&b,floatborder=1);
/**创建一个静态四边形刚体.*/
staticPhysicsBody*createEdgeBox(constSize&size,floatborder=1,constPoint&offset=Point::ZERO);
/**创建一个静态多边形刚体.*/
staticPhysicsBody*createEdgePolygon(constPoint*points,floatborder=1);
/**创建一个链条状刚体*/
staticPhysicsBody*createEdgeChain(constPoint*points,floatborder=1);

/*
添加一个shapemass和moment赋值true
*/
virtualPhysicsShape*addShape(PhysicsShape*shape,booladdMassAndMoment=true);
/*通过shape移除shape*/
voidremoveShape(PhysicsShape*shape,boolreduceMassAndMoment=true);
/*通过tag移除shape*/
voidremoveShape(inttag,boolreduceMassAndMoment=true);
/*移除body的所有shape*/
voidremoveAllShapes(boolreduceMassAndMoment=true);
/*获取body的shapes*/
inlineconstVector<PhysicsShape*>&getShapes()const{return_shapes;}
/*获取第一个shape.*/
inlinePhysicsShape*getFirstShape()const{return_shapes.size()>=1?_shapes.at(0):nullptr;}
/*通过tag从body中获取shape*/
PhysicsShape*getShape(inttag)const;

/**给body施加一个循序渐进的力，物体会受加速度影响，越来越快，像火车一样*/
virtualvoidapplyForce(constVect&force);
/**offset为偏移度指碰到物体时body旋转偏移一般设为默认值值越大旋转越快偏移角度越大*/
virtualvoidapplyForce(constVect&force,constPoint&offset);
/**重置施加在body上的力清0了.*/
virtualvoidresetForces();
/**不会产生力，直接与body的速度叠加产生新的速度.*/
virtualvoidapplyImpulse(constVect&impulse);
/**Appliesacontinuousforcetobody.*/
virtualvoidapplyImpulse(constVect&impulse,constPoint&offset);
/**施加一个扭转力到刚体上就像向前翻转一块大石头一样.*/
virtualvoidapplyTorque(floattorque);

/**设置刚体的速度*/
virtualvoidsetVelocity(constVect&velocity);
/**获取刚体的速度*/
virtualPointgetVelocity();
/**设置刚体角速度就是单位时间内转动的弧度*/
virtualvoidsetAngularVelocity(floatvelocity);
/**通过一个局部点获取刚体的角速度*/
virtualPointgetVelocityAtLocalPoint(constPoint&point);
/**通过世界点获取刚体的角速度*/
virtualPointgetVelocityAtWorldPoint(constPoint&point);
/**获取刚体的角速度*/
virtualfloatgetAngularVelocity();
/**设置速度的极限值*/
virtualvoidsetVelocityLimit(floatlimit);
/**获取速度的极限值*/
virtualfloatgetVelocityLimit();
/**设置角速度极限值*/
virtualfloatgetAngularVelocityLimit();

/**从world中移除body*/
voidremoveFromWorld();

/**获取world*/
inlinePhysicsWorld*getWorld()const{return_world;}
/**获取body的所有关节*/
inlineconststd::vector<PhysicsJoint*>&getJoints()const{return_joints;}

/**取得body设置的sprite.*/
inlineNode*getNode()const{return_node;}

/**
*Amaskthatdefineswhichcategoriesthisphysicsbodybelongsto.
*Everyphysicsbodyinascenecanbeassignedtoupto32differentcategories,eachcorrespondingtoabitinthebitmask.Youdefinethemaskvaluesusedinyourgame.InconjunctionwiththecollisionBitMaskandcontactTestBitMaskproperties,youdefinewhichphysicsbodiesinteractwitheachotherandwhenyourgameisnotifiedoftheseinteractions.
*Thedefaultvalueis0xFFFFFFFF(allbitsset).
*/没搞懂
voidsetCategoryBitmask(intbitmask);
/**
*Amaskthatdefineswhichcategoriesofbodiescauseintersectionnotificationswiththisphysicsbody.
*Whentwobodiessharethesamespace,eachbody’scategorymaskistestedagainsttheotherbody’scontactmaskbyperformingalogicalANDoperation.Ifeithercomparisonresultsinanon-zerovalue,anPhysicsContactobjectiscreatedandpassedtothephysicsworld’sdelegate.Forbestperformance,onlysetbitsinthecontactsmaskforinteractionsyouareinterestedin.
*Thedefaultvalueis0x00000000(allbitscleared).
*/
voidsetContactTestBitmask(intbitmask);
/**
*Amaskthatdefineswhichcategoriesofphysicsbodiescancollidewiththisphysicsbody.
*Whentwophysicsbodiescontacteachother,acollisionmayoccur.Thisbody’scollisionmaskiscomparedtotheotherbody’scategorymaskbyperformingalogicalANDoperation.Iftheresultisanon-zerovalue,thenthisbodyisaffectedbythecollision.Eachbodyindependentlychooseswhetheritwantstobeaffectedbytheotherbody.Forexample,youmightusethistoavoidcollisioncalculationsthatwouldmakenegligiblechangestoabody’svelocity.
*Thedefaultvalueis0xFFFFFFFF(allbitsset).
*/
voidsetCollisionBitmask(intbitmask);
/**getthecategorybitmask*/
inlineintgetCategoryBitmask()const{return_categoryBitmask;}
/**getthecontacttestbitmask*/
inlineintgetContactTestBitmask()const{return_contactTestBitmask;}
/**getthecollisionbitmask*/
inlineintgetCollisionBitmask()const{return_collisionBitmask;}

/**
*setthegroupofbody
*Collisiongroupsletyouspecifyanintegralgroupindex.Youcanhaveallfixtureswiththesamegroupindexalwayscollide(positiveindex)ornevercollide(negativeindex)
*ithavehighprioritythanbitmasks
*/
voidsetGroup(intgroup);
/**getthegroupofbody*/
inlineintgetGroup()const{return_group;}

/**获取body坐标*/
PointgetPosition()const;
/**获取body角度.*/
floatgetRotation()const;

/**判断body是否静止*/
inlineboolisDynamic()const{return_dynamic;}
/**设置body状态false为静态true为动态*/
voidsetDynamic(booldynamic);

/**设置mass值如果需要增加mass有addmass方法不要在这里做加减*/
voidsetMass(floatmass);
/**取得mass.*/
inlinefloatgetMass()const{return_mass;}
/**
*@briefaddmasstobody.
*if_mass(massofthebody)==PHYSICS_INFINITY,itremains.
*ifmass==PHYSICS_INFINITY,_masswillbePHYSICS_INFINITY.
*ifmass==-PHYSICS_INFINITY,_masswillnotchange.
*ifmass+_mass<=0,_masswillequaltoMASS_DEFAULT(1.0)
*otherwise,mass=mass+_mass;
*/增加质量
voidaddMass(floatmass);

/**
*@briefsetthebodymomentofinertia.
*@noteifyouneedadd/subtractmomenttobody,don'tusesetMoment(getMoment()+/-moment),becausethemomentofbodymaybeequaltoPHYSICS_INFINITY,itwillcausesomeunexpectedresult,pleaseuseaddMoment()instead.
*/设置力矩
voidsetMoment(floatmoment);
/**获取惯性的力矩.*/
inlinefloatgetMoment(floatmoment)const{return_moment;}
/**
*@briefaddmomentofinertiatobody.
*if_moment(momentofthebody)==PHYSICS_INFINITY,itremains.
*ifmoment==PHYSICS_INFINITY,_momentwillbePHYSICS_INFINITY.
*ifmoment==-PHYSICS_INFINITY,_momentwillnotchange.
*ifmoment+_moment<=0,_momentwillequaltoMASS_DEFAULT(1.0)
*otherwise,moment=moment+_moment;
*/增加力矩
voidaddMoment(floatmoment);
/**取得线性阻尼*/
inlinefloatgetLinearDamping()const{return_linearDamping;}
/**
*设置阻尼值
*它用来模拟body在气体或者液体中的摩擦力
*取值范围是0.0fto1.0f.
*/
inlinevoidsetLinearDamping(floatdamping){_linearDamping=damping;}
/**获取角阻尼*/
inlinefloatgetAngularDamping()const{return_angularDamping;}
/**
*设置角阻尼
*它用来模拟body在气体或者液体中的角阻尼
*thevalueis0.0fto1.0f.
*/
inlinevoidsetAngularDamping(floatdamping){_angularDamping=damping;}

/**判断body是否是休息状态*/
boolisResting()const;
/**
*判断body能否在物理世界中模拟
*/
inlineboolisEnabled()const{return_enable;}
/**
设置body能否在物理世界中模拟
*/
voidsetEnable(boolenable);

/**whetherthebodycanrotation*/
inlineboolisRotationEnabled()const{return_rotationEnable;}
/**设置能否旋转*/
voidsetRotationEnable(boolenable);

/**判断body是否受引力影响*/
inlineboolisGravityEnabled()const{return_gravityEnable;}
/**设置body是否受引力影响*/
voidsetGravityEnable(boolenable);

/**取得body的tag值*/
inlineintgetTag()const{return_tag;}
/**设置bodytag值*/
inlinevoidsetTag(inttag){_tag=tag;}

/**转换世界点到局部点类似世界坐标和局部坐标的转换*/
Pointworld2Local(constPoint&point);
/**转换局部坐标到世界坐标*/
Pointlocal2World(constPoint&point);

【PhysicsShape】
/**通过shape取得body*/
inlinePhysicsBody*getBody()const{return_body;}
/**返回shape的类型*/
inlineTypegetType()const{return_type;}
/**返回shape的面积*/
inlinefloatgetArea()const{return_area;}
/**取得moment力矩*/
inlinefloatgetMoment()const{return_moment;}
/**Setmoment,itwillchangethebody'smomentthisshapeattaches*/
voidsetMoment(floatmoment);//设置力矩
inlinevoidsetTag(inttag){_tag=tag;}//设置标签tag
inlineintgetTag()const{return_tag;}//取得tag标签

/**获取质量*/
inlinefloatgetMass()const{return_mass;}
/**Setmass,itwillchangethebody'smassthisshapeattaches*/											
voidsetMass(floatmass);//设置质量
inlinefloatgetDensity()const{return_material.density;}//density为密度
voidsetDensity(floatdensity);//获取密度
inlinefloatgetRestitution()const{return_material.restitution;}//获取弹性
voidsetRestitution(floatrestitution);//设置弹性
inlinefloatgetFriction()const{return_material.friction;}//friction为摩擦力
voidsetFriction(floatfriction);//设置摩擦力
constPhysicsMaterial&getMaterial()const{return_material;}//Material为材质
voidsetMaterial(constPhysicsMaterial&material);设置材质

/**返回默认力矩其值为0*/
virtualfloatcalculateDefaultMoment(){return0.0f;}
/**取得重心初始值为zero*/
virtualPointgetOffset(){returnPoint::ZERO;}
/**获取shape的重心点*/
virtualPointgetCenter(){returngetOffset();}
/**shape是否包含该点*/
boolcontainsPoint(constPoint&point)const;

/**改变重心点*/
staticvoidrecenterPoints(Point*points,constPoint&center=Point::ZERO);
/**取得多边形的重心点*/
staticPointgetPolyonCenter(constPoint*points,intcount);

/**
*Amaskthatdefineswhichcategoriesthisphysicsbodybelongsto.
*Everyphysicsbodyinascenecanbeassignedtoupto32differentcategories,youdefinewhichphysicsbodiesinteractwitheachotherandwhenyourgameisnotifiedoftheseinteractions.
*Thedefaultvalueis0xFFFFFFFF(allbitsset).
*/
inlinevoidsetCategoryBitmask(intbitmask){_categoryBitmask=bitmask;}
inlineintgetCategoryBitmask()const{return_categoryBitmask;}
/**
*Amaskthatdefineswhichcategoriesofbodiescauseintersectionnotificationswiththisphysicsbody.
*Whentwobodiessharethesamespace,onlysetbitsinthecontactsmaskforinteractionsyouareinterestedin.
*Thedefaultvalueis0x00000000(allbitscleared).
*/
inlinevoidsetContactTestBitmask(intbitmask){_contactTestBitmask=bitmask;}
inlineintgetContactTestBitmask()const{return_contactTestBitmask;}
/**
*Amaskthatdefineswhichcategoriesofphysicsbodiescancollidewiththisphysicsbody.
*Whentwophysicsbodiescontacteachother,youmightusethistoavoidcollisioncalculationsthatwouldmakenegligiblechangestoabody’svelocity.
*Thedefaultvalueis0xFFFFFFFF(allbitsset).
*/
inlinevoidsetCollisionBitmask(intbitmask){_collisionBitmask=bitmask;}
inlineintgetCollisionBitmask()const{return_collisionBitmask;}

voidsetGroup(intgroup);
inlineintgetGroup(){return_group;}