axmol/cocos/physics/CCPhysicsShape.cpp

/****************************************************************************
 Copyright (c) 2013 Chukong Technologies Inc.
 
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 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,
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 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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#include "physics/CCPhysicsShape.h"
#if CC_USE_PHYSICS

#include <climits>
#include <unordered_map>

#include "chipmunk.h"
#include "chipmunk_unsafe.h"

#include "CCPhysicsBody.h"
#include "CCPhysicsWorld.h"
#include "CCPhysicsHelper.h"

NS_CC_BEGIN
extern const float PHYSICS_INFINITY;
std::unordered_map<cpShape*, PhysicsShape*> s_physicsShapeMap;
static cpBody* s_sharedBody = nullptr;

PhysicsShape::PhysicsShape()
: _body(nullptr)
, _type(Type::UNKNOWN)
, _area(0.0f)
, _mass(0.0f)
, _moment(0.0f)
, _sensor(false)
, _scaleX(1.0f)
, _scaleY(1.0f)
, _newScaleX(1.0f)
, _newScaleY(1.0f)
, _tag(0)
, _categoryBitmask(UINT_MAX)
, _collisionBitmask(UINT_MAX)
, _contactTestBitmask(0)
, _group(0)
{
    if (s_sharedBody == nullptr)
    {
        s_sharedBody = cpBodyNewStatic();
    }
}

PhysicsShape::~PhysicsShape()
{
    for (auto shape : _cpShapes)
    {
        s_physicsShapeMap.erase(shape);

        cpShapeFree(shape);
    }
}

void PhysicsShape::setMass(float mass)
{
    if (mass < 0)
    {
        return;
    }
    
    if (_body)
    {
        _body->addMass(-_mass);
        _body->addMass(mass);
    };
    
    _mass = mass;
}

void PhysicsShape::setMoment(float moment)
{
    if (moment < 0)
    {
        return;
    }
    
    if (_body)
    {
        _body->addMoment(-_moment);
        _body->addMoment(moment);
    };
    
    _moment = moment;
}

void PhysicsShape::setMaterial(const PhysicsMaterial& material)
{
    setDensity(material.density);
    setRestitution(material.restitution);
    setFriction(material.friction);
}

void PhysicsShape::setScale(float scaleX, float scaleY)
{
    if (fabs(_scaleX - scaleX) > FLT_EPSILON || fabs(_scaleY - scaleY) > FLT_EPSILON)
    {
        if (_type == Type::CIRCLE && scaleX != scaleY)
        {
            CCLOG("PhysicsShapeCircle WARNING: CANNOT support setScale with different x and y");
            return;
        }
        _newScaleX = scaleX;
        _newScaleY = scaleY;
        
        updateScale();
        
        // re-calculate area and mass
        _area = calculateArea();
        _mass = _material.density * _area;
        _moment = calculateDefaultMoment();
    }
}

void PhysicsShape::updateScale()
{
    _scaleX = _newScaleX;
    _scaleY = _newScaleY;
}

void PhysicsShape::addShape(cpShape* shape)
{
    if (shape)
    {
        cpShapeSetGroup(shape, _group);
        _cpShapes.push_back(shape);
        s_physicsShapeMap.insert(std::pair<cpShape*, PhysicsShape*>(shape, this));
    }
}

PhysicsShapeCircle::PhysicsShapeCircle()
{
    
}

PhysicsShapeCircle::~PhysicsShapeCircle()
{
    
}

PhysicsShapeBox::PhysicsShapeBox()
{
    
}

PhysicsShapeBox::~PhysicsShapeBox()
{
    
}

PhysicsShapePolygon::PhysicsShapePolygon()
{
    
}

PhysicsShapePolygon::~PhysicsShapePolygon()
{
    
}

PhysicsShapeEdgeBox::PhysicsShapeEdgeBox()
{
    
}

PhysicsShapeEdgeBox::~PhysicsShapeEdgeBox()
{
    
}

PhysicsShapeEdgeChain::PhysicsShapeEdgeChain()
{
    
}

PhysicsShapeEdgeChain::~PhysicsShapeEdgeChain()
{
    
}

PhysicsShapeEdgePolygon::PhysicsShapeEdgePolygon()
{
    
}

PhysicsShapeEdgePolygon::~PhysicsShapeEdgePolygon()
{
    
}

PhysicsShapeEdgeSegment::PhysicsShapeEdgeSegment()
{
    
}

PhysicsShapeEdgeSegment::~PhysicsShapeEdgeSegment()
{
    
}

void PhysicsShape::setDensity(float density)
{
    if (density < 0)
    {
        return;
    }
    
    _material.density = density;
    
    if (_material.density == PHYSICS_INFINITY)
    {
        setMass(PHYSICS_INFINITY);
    }else if (_area > 0)
    {
        setMass(_material.density * _area);
    }
}

void PhysicsShape::setRestitution(float restitution)
{
    _material.restitution = restitution;
    
    for (cpShape* shape : _cpShapes)
    {
        cpShapeSetElasticity(shape, restitution);
    }
}

void PhysicsShape::setFriction(float friction)
{
    _material.friction = friction;
    
    for (cpShape* shape : _cpShapes)
    {
        cpShapeSetFriction(shape, friction);
    }
}

void PhysicsShape::setSensor(bool sensor)
{
    if (sensor != _sensor)
    {
        for (cpShape* shape : _cpShapes)
        {
            cpShapeSetSensor(shape, sensor);
        }
        _sensor = sensor;
    }
}

void PhysicsShape::recenterPoints(Vec2* points, int count, const Vec2& center)
{
    cpVect* cpvs = new (std::nothrow) cpVect[count];
    cpRecenterPoly(count, PhysicsHelper::points2cpvs(points, cpvs, count));
    PhysicsHelper::cpvs2points(cpvs, points, count);
    delete[] cpvs;
    
    if (center != Vec2::ZERO)
    {
        for (int i = 0; i < count; ++i)
        {
            points[i] += center;
        }
    }
}

Vec2 PhysicsShape::getPolyonCenter(const Vec2* points, int count)
{
    cpVect* cpvs = new (std::nothrow) cpVect[count];
    cpVect center = cpCentroidForPoly(count, PhysicsHelper::points2cpvs(points, cpvs, count));
    delete[] cpvs;
    
    return PhysicsHelper::cpv2point(center);
}

void PhysicsShape::setBody(PhysicsBody *body)
{
    // already added
    if (body && _body == body)
    {
        return;
    }
    
    if (_body)
    {
        _body->removeShape(this);
    }
    
    for (auto shape : _cpShapes)
    {
        cpShapeSetBody(shape, body == nullptr ? s_sharedBody : body->_cpBody);
    }
    _body = body;
}

// PhysicsShapeCircle
PhysicsShapeCircle* PhysicsShapeCircle::create(float radius, const PhysicsMaterial& material/* = MaterialDefault*/, const Vec2& offset/* = Vec2(0, 0)*/)
{
    PhysicsShapeCircle* shape = new (std::nothrow) PhysicsShapeCircle();
    if (shape && shape->init(radius, material, offset))
    {
        shape->autorelease();
        return shape;
    }
    
    CC_SAFE_DELETE(shape);
    return nullptr;
}

bool PhysicsShapeCircle::init(float radius, const PhysicsMaterial& material/* = MaterialDefault*/, const Vec2& offset /*= Vec2(0, 0)*/)
{
    do
    {
        _type = Type::CIRCLE;
        
        auto shape = cpCircleShapeNew(s_sharedBody, radius, PhysicsHelper::point2cpv(offset));
        
        CC_BREAK_IF(shape == nullptr);
        
        addShape(shape);
        
        _area = calculateArea();
        _mass = material.density == PHYSICS_INFINITY ? PHYSICS_INFINITY : material.density * _area;
        _moment = calculateDefaultMoment();
        
        setMaterial(material);
        return true;
    } while (false);
    
    return false;
}

float PhysicsShapeCircle::calculateArea(float radius)
{
    return PhysicsHelper::cpfloat2float(cpAreaForCircle(0, radius));
}

float PhysicsShapeCircle::calculateMoment(float mass, float radius, const Vec2& offset)
{
    return mass == PHYSICS_INFINITY ? PHYSICS_INFINITY
    : PhysicsHelper::cpfloat2float(cpMomentForCircle(mass,
                                                     0,
                                                     radius,
                                                     PhysicsHelper::point2cpv(offset)));
}

float PhysicsShapeCircle::calculateArea()
{
    return PhysicsHelper::cpfloat2float(cpAreaForCircle(0, cpCircleShapeGetRadius(_cpShapes.front())));
}

float PhysicsShapeCircle::calculateDefaultMoment()
{
    auto shape = _cpShapes.front();
    
    return _mass == PHYSICS_INFINITY ? PHYSICS_INFINITY
    : PhysicsHelper::cpfloat2float(cpMomentForCircle(_mass,
                                                     0,
                                                     cpCircleShapeGetRadius(shape),
                                                     cpCircleShapeGetOffset(shape)));
}

float PhysicsShapeCircle::getRadius() const
{
    return PhysicsHelper::cpfloat2float(cpCircleShapeGetRadius(_cpShapes.front()));
}

Vec2 PhysicsShapeCircle::getOffset()
{
    return PhysicsHelper::cpv2point(cpCircleShapeGetOffset(_cpShapes.front()));
}

void PhysicsShapeCircle::updateScale()
{
    cpFloat factor = std::abs(_newScaleX / _scaleX);

    cpShape* shape = _cpShapes.front();
    cpVect v = cpCircleShapeGetOffset(shape);
    v = cpvmult(v, factor);
    ((cpCircleShape*)shape)->c = v;

    cpCircleShapeSetRadius(shape, cpCircleShapeGetRadius(shape) * factor);

    PhysicsShape::updateScale();
}

// PhysicsShapeEdgeSegment
PhysicsShapeEdgeSegment* PhysicsShapeEdgeSegment::create(const Vec2& a, const Vec2& b, const PhysicsMaterial& material/* = MaterialDefault*/, float border/* = 1*/)
{
    PhysicsShapeEdgeSegment* shape = new (std::nothrow) PhysicsShapeEdgeSegment();
    if (shape && shape->init(a, b, material, border))
    {
        shape->autorelease();
        return shape;
    }
    
    CC_SAFE_DELETE(shape);
    return nullptr;
}

bool PhysicsShapeEdgeSegment::init(const Vec2& a, const Vec2& b, const PhysicsMaterial& material/* = MaterialDefault*/, float border/* = 1*/)
{
    do
    {
        _type = Type::EDGESEGMENT;
        
        auto shape = cpSegmentShapeNew(s_sharedBody,
                                           PhysicsHelper::point2cpv(a),
                                           PhysicsHelper::point2cpv(b),
                                           border);
        
        CC_BREAK_IF(shape == nullptr);
        
        addShape(shape);
        
        _mass = PHYSICS_INFINITY;
        _moment = PHYSICS_INFINITY;
        
        setMaterial(material);
        
        return true;
    } while (false);
    
    return false;
}

Vec2 PhysicsShapeEdgeSegment::getPointA() const
{
    return PhysicsHelper::cpv2point(((cpSegmentShape*)(_cpShapes.front()))->ta);
}

Vec2 PhysicsShapeEdgeSegment::getPointB() const
{
    return PhysicsHelper::cpv2point(((cpSegmentShape*)(_cpShapes.front()))->tb);
}

Vec2 PhysicsShapeEdgeSegment::getCenter()
{
    auto a = PhysicsHelper::cpv2point(cpSegmentShapeGetA(_cpShapes.front()));
    auto b = PhysicsHelper::cpv2point(cpSegmentShapeGetB(_cpShapes.front()));
    return ( a + b ) / 2;
}

void PhysicsShapeEdgeSegment::updateScale()
{
    cpFloat factorX = _newScaleX / _scaleX;
    cpFloat factorY = _newScaleY / _scaleY;

    cpShape* shape = _cpShapes.front();
    cpVect a = cpSegmentShapeGetA(shape);
    a.x *= factorX;
    a.y *= factorY;
    cpVect b = cpSegmentShapeGetB(shape);
    b.x *= factorX;
    b.y *= factorY;
    cpSegmentShapeSetEndpoints(shape, a, b);

    PhysicsShape::updateScale();
}

// PhysicsShapeBox
PhysicsShapeBox* PhysicsShapeBox::create(const Size& size, const PhysicsMaterial& material/* = MaterialDefault*/, const Vec2& offset/* = Vec2(0, 0)*/)
{
    PhysicsShapeBox* shape = new (std::nothrow) PhysicsShapeBox();
    if (shape && shape->init(size, material, offset))
    {
        shape->autorelease();
        return shape;
    }
    
    CC_SAFE_DELETE(shape);
    return nullptr;
}

bool PhysicsShapeBox::init(const Size& size, const PhysicsMaterial& material/* = MaterialDefault*/, const Vec2& offset /*= Vec2(0, 0)*/)
{
    do
    {
        _type = Type::BOX;
        
        auto wh = PhysicsHelper::size2cpv(size);
        cpVect vec[4] =
        {
            {-wh.x/2.0f, -wh.y/2.0f}, {-wh.x/2.0f, wh.y/2.0f}, {wh.x/2.0f, wh.y/2.0f}, {wh.x/2.0f, -wh.y/2.0f}
        };
        
        auto shape = cpPolyShapeNew(s_sharedBody, 4, vec, PhysicsHelper::point2cpv(offset));
        
        CC_BREAK_IF(shape == nullptr);
        
        addShape(shape);
        
        _area = calculateArea();
        _mass = material.density == PHYSICS_INFINITY ? PHYSICS_INFINITY : material.density * _area;
        _moment = calculateDefaultMoment();
        
        setMaterial(material);
        
        return true;
    } while (false);
    
    return false;
}

Size PhysicsShapeBox::getSize() const
{
    cpShape* shape = _cpShapes.front();
    return PhysicsHelper::cpv2size(cpv(cpvdist(cpPolyShapeGetVert(shape, 1), cpPolyShapeGetVert(shape, 2)),
                                       cpvdist(cpPolyShapeGetVert(shape, 0), cpPolyShapeGetVert(shape, 1))));
}

// PhysicsShapePolygon
PhysicsShapePolygon* PhysicsShapePolygon::create(const Vec2* points, int count, const PhysicsMaterial& material/* = MaterialDefault*/, const Vec2& offset/* = Vec2(0, 0)*/)
{
    PhysicsShapePolygon* shape = new (std::nothrow) PhysicsShapePolygon();
    if (shape && shape->init(points, count, material, offset))
    {
        shape->autorelease();
        return shape;
    }
    
    CC_SAFE_DELETE(shape);
    return nullptr;
}

bool PhysicsShapePolygon::init(const Vec2* points, int count, const PhysicsMaterial& material/* = MaterialDefault*/, const Vec2& offset/* = Vec2(0, 0)*/)
{
    do
    {
        _type = Type::POLYGEN;
        
        auto vecs = new (std::nothrow) cpVect[count];
        PhysicsHelper::points2cpvs(points, vecs, count);
        auto shape = cpPolyShapeNew(s_sharedBody, count, vecs, PhysicsHelper::point2cpv(offset));
        CC_SAFE_DELETE_ARRAY(vecs);
        
        CC_BREAK_IF(shape == nullptr);
        
        addShape(shape);
        
        _area = calculateArea();
        _mass = material.density == PHYSICS_INFINITY ? PHYSICS_INFINITY : material.density * _area;
        _moment = calculateDefaultMoment();
        
        setMaterial(material);
        
        return true;
    } while (false);
    
    return false;
}

float PhysicsShapePolygon::calculateArea(const Vec2* points, int count)
{
    cpVect* vecs = new (std::nothrow) cpVect[count];
    PhysicsHelper::points2cpvs(points, vecs, count);
    float area = PhysicsHelper::cpfloat2float(cpAreaForPoly(count, vecs));
    CC_SAFE_DELETE_ARRAY(vecs);
    
    return area;
}

float PhysicsShapePolygon::calculateMoment(float mass, const Vec2* points, int count, const Vec2& offset)
{
    cpVect* vecs = new (std::nothrow) cpVect[count];
    PhysicsHelper::points2cpvs(points, vecs, count);
    float moment = mass == PHYSICS_INFINITY ? PHYSICS_INFINITY
    : PhysicsHelper::cpfloat2float(cpMomentForPoly(mass, count, vecs, PhysicsHelper::point2cpv(offset)));
    CC_SAFE_DELETE_ARRAY(vecs);
    
    return moment;
}

float PhysicsShapePolygon::calculateArea()
{
    auto shape = _cpShapes.front();
    return PhysicsHelper::cpfloat2float(cpAreaForPoly(((cpPolyShape*)shape)->numVerts, ((cpPolyShape*)shape)->verts));
}

float PhysicsShapePolygon::calculateDefaultMoment()
{
    auto shape = _cpShapes.front();
    return _mass == PHYSICS_INFINITY ? PHYSICS_INFINITY
    : PhysicsHelper::cpfloat2float(cpMomentForPoly(_mass, ((cpPolyShape*)shape)->numVerts, ((cpPolyShape*)shape)->verts, cpvzero));
}

Vec2 PhysicsShapePolygon::getPoint(int i) const
{
    return PhysicsHelper::cpv2point(cpPolyShapeGetVert(_cpShapes.front(), i));
}

void PhysicsShapePolygon::getPoints(Vec2* outPoints) const
{
    auto shape = _cpShapes.front();
    PhysicsHelper::cpvs2points(((cpPolyShape*)shape)->verts, outPoints, ((cpPolyShape*)shape)->numVerts);
}

int PhysicsShapePolygon::getPointsCount() const
{
    return ((cpPolyShape*)_cpShapes.front())->numVerts;
}

Vec2 PhysicsShapePolygon::getCenter()
{
    return PhysicsHelper::cpv2point(cpCentroidForPoly(((cpPolyShape*)_cpShapes.front())->numVerts, ((cpPolyShape*)_cpShapes.front())->verts));
}

void PhysicsShapePolygon::updateScale()
{
    cpFloat factorX = _newScaleX / _scaleX;
    cpFloat factorY = _newScaleY / _scaleY;

    auto shape = _cpShapes.front();
    int count = cpPolyShapeGetNumVerts(shape);
    cpVect* vects = ((cpPolyShape*)shape)->verts;
    cpSplittingPlane* planes = ((cpPolyShape*)shape)->planes;

    for (int i = 0; i < count; ++i)
    {
        vects[i].x *= factorX;
        vects[i].y *= factorY;
    }

    // convert hole to clockwise
    if (factorX * factorY < 0)
    {
        for (int i = 0; i < count / 2; ++i)
        {
            cpVect v = vects[i];
            vects[i] = vects[count - i - 1];
            vects[count - i - 1] = v;
        }
    }

    for (int i = 0; i < count; ++i)
    {
//        cpVect n = cpvnormalize(cpvperp(cpvsub(vects[i], vects[(i + 1) % count])));
//
//        planes[i].n = n;
//        planes[i].d = cpvdot(n, vects[i]);
        
        // FIXED ME: if update 'planes[i]' as the above codes, then can not query polygon shape by PhysicsWorld::getShapes().
        // But modified like this, then ray test can not work correctly on some cases.
        planes[i].d = cpvdot(planes[i].n, vects[i]);
    }
    
    PhysicsShape::updateScale();
}

// PhysicsShapeEdgeBox
PhysicsShapeEdgeBox* PhysicsShapeEdgeBox::create(const Size& size, const PhysicsMaterial& material/* = MaterialDefault*/, float border/* = 1*/, const Vec2& offset/* = Vec2(0, 0)*/)
{
    PhysicsShapeEdgeBox* shape = new (std::nothrow) PhysicsShapeEdgeBox();
    if (shape && shape->init(size, material, border, offset))
    {
        shape->autorelease();
        return shape;
    }
    
    CC_SAFE_DELETE(shape);
    return nullptr;
}

bool PhysicsShapeEdgeBox::init(const Size& size, const PhysicsMaterial& material/* = MaterialDefault*/, float border/* = 1*/, const Vec2& offset/*= Vec2(0, 0)*/)
{
    do
    {
        _type = Type::EDGEBOX;
        
        cpVect vec[4] = {};
        vec[0] = PhysicsHelper::point2cpv(Vec2(-size.width/2+offset.x, -size.height/2+offset.y));
        vec[1] = PhysicsHelper::point2cpv(Vec2(+size.width/2+offset.x, -size.height/2+offset.y));
        vec[2] = PhysicsHelper::point2cpv(Vec2(+size.width/2+offset.x, +size.height/2+offset.y));
        vec[3] = PhysicsHelper::point2cpv(Vec2(-size.width/2+offset.x, +size.height/2+offset.y));
        
        int i = 0;
        for (; i < 4; ++i)
        {
            auto shape = cpSegmentShapeNew(s_sharedBody, vec[i], vec[(i + 1) % 4], border);
            CC_BREAK_IF(shape == nullptr);
            addShape(shape);
        }
        CC_BREAK_IF(i < 4);
        
        _mass = PHYSICS_INFINITY;
        _moment = PHYSICS_INFINITY;
        
        setMaterial(material);
        
        return true;
    } while (false);
    
    return false;
}

// PhysicsShapeEdgeBox
PhysicsShapeEdgePolygon* PhysicsShapeEdgePolygon::create(const Vec2* points, int count, const PhysicsMaterial& material/* = MaterialDefault*/, float border/* = 1*/)
{
    PhysicsShapeEdgePolygon* shape = new (std::nothrow) PhysicsShapeEdgePolygon();
    if (shape && shape->init(points, count, material, border))
    {
        shape->autorelease();
        return shape;
    }
    
    CC_SAFE_DELETE(shape);
    return nullptr;
}

bool PhysicsShapeEdgePolygon::init(const Vec2* points, int count, const PhysicsMaterial& material/* = MaterialDefault*/, float border/* = 1*/)
{
    cpVect* vec = nullptr;
    do
    {
        _type = Type::EDGEPOLYGEN;
        
        vec = new (std::nothrow) cpVect[count];
        PhysicsHelper::points2cpvs(points, vec, count);
        
        int i = 0;
        for (; i < count; ++i)
        {
            auto shape = cpSegmentShapeNew(s_sharedBody, vec[i], vec[(i + 1) % count], border);
            CC_BREAK_IF(shape == nullptr);
            cpShapeSetElasticity(shape, 1.0f);
            cpShapeSetFriction(shape, 1.0f);
            addShape(shape);
        }
        CC_SAFE_DELETE_ARRAY(vec);
        
        CC_BREAK_IF(i < count);
        
        _mass = PHYSICS_INFINITY;
        _moment = PHYSICS_INFINITY;
        
        setMaterial(material);
        
        return true;
    } while (false);
    
    CC_SAFE_DELETE_ARRAY(vec);
    
    return false;
}

Vec2 PhysicsShapeEdgePolygon::getCenter()
{
    int count = (int)_cpShapes.size();
    cpVect* points = new (std::nothrow) cpVect[count];
    int i = 0;
    for(auto shape : _cpShapes)
    {
        points[i++] = ((cpSegmentShape*)shape)->a;
    }
    
    Vec2 center = PhysicsHelper::cpv2point(cpCentroidForPoly(count, points));
    delete[] points;
    
    return center;
}

void PhysicsShapeEdgePolygon::getPoints(cocos2d::Vec2 *outPoints) const
{
    int i = 0;
    for(auto shape : _cpShapes)
    {
        outPoints[i++] = PhysicsHelper::cpv2point(((cpSegmentShape*)shape)->a);
    }
}

int PhysicsShapeEdgePolygon::getPointsCount() const
{
    return static_cast<int>(_cpShapes.size());
}

// PhysicsShapeEdgeChain
PhysicsShapeEdgeChain* PhysicsShapeEdgeChain::create(const Vec2* points, int count, const PhysicsMaterial& material/* = MaterialDefault*/, float border/* = 1*/)
{
    PhysicsShapeEdgeChain* shape = new (std::nothrow) PhysicsShapeEdgeChain();
    if (shape && shape->init(points, count, material, border))
    {
        shape->autorelease();
        return shape;
    }
    
    CC_SAFE_DELETE(shape);
    return nullptr;
}

void PhysicsShapeEdgePolygon::updateScale()
{
    cpFloat factorX = _newScaleX / _scaleX;
    cpFloat factorY = _newScaleY / _scaleY;

    for (auto shape : _cpShapes)
    {
        cpVect a = cpSegmentShapeGetA(shape);
        a.x *= factorX;
        a.y *= factorY;
        cpVect b = cpSegmentShapeGetB(shape);
        b.x *= factorX;
        b.y *= factorY;
        cpSegmentShapeSetEndpoints(shape, a, b);
    }
    
    PhysicsShape::updateScale();
}

bool PhysicsShapeEdgeChain::init(const Vec2* points, int count, const PhysicsMaterial& material/* = MaterialDefault*/, float border/* = 1*/)
{
    cpVect* vec = nullptr;
    do
    {
        _type = Type::EDGECHAIN;
        
        vec = new (std::nothrow) cpVect[count];
        PhysicsHelper::points2cpvs(points, vec, count);
        
        int i = 0;
        for (; i < count - 1; ++i)
        {
            auto shape = cpSegmentShapeNew(s_sharedBody, vec[i], vec[i + 1], border);
            CC_BREAK_IF(shape == nullptr);
            cpShapeSetElasticity(shape, 1.0f);
            cpShapeSetFriction(shape, 1.0f);
            addShape(shape);
        }
        CC_SAFE_DELETE_ARRAY(vec);
        CC_BREAK_IF(i < count - 1);
        
        _mass = PHYSICS_INFINITY;
        _moment = PHYSICS_INFINITY;
        
        setMaterial(material);
        
        return true;
    } while (false);
    
    CC_SAFE_DELETE_ARRAY(vec);
    
    return false;
}

Vec2 PhysicsShapeEdgeChain::getCenter()
{
    int count = (int)_cpShapes.size() + 1;
    cpVect* points = new (std::nothrow) cpVect[count];
    int i = 0;
    for(auto shape : _cpShapes)
    {
        points[i++] = ((cpSegmentShape*)shape)->a;
    }
    
    points[i++] = ((cpSegmentShape*)_cpShapes.back())->b;
    
    Vec2 center = PhysicsHelper::cpv2point(cpCentroidForPoly(count, points));
    delete[] points;
    
    return center;
}

void PhysicsShapeEdgeChain::getPoints(Vec2* outPoints) const
{
    int i = 0;
    for(auto shape : _cpShapes)
    {
        outPoints[i++] = PhysicsHelper::cpv2point(((cpSegmentShape*)shape)->a);
    }
    
    outPoints[i++] = PhysicsHelper::cpv2point(((cpSegmentShape*)_cpShapes.back())->b);
}

int PhysicsShapeEdgeChain::getPointsCount() const
{
    return static_cast<int>(_cpShapes.size() + 1);
}

void PhysicsShapeEdgeChain::updateScale()
{
    cpFloat factorX = _newScaleX / _scaleX;
    cpFloat factorY = _newScaleY / _scaleY;

    for (auto shape : _cpShapes)
    {
        cpVect a = cpSegmentShapeGetA(shape);
        a.x *= factorX;
        a.y *= factorY;
        cpVect b = cpSegmentShapeGetB(shape);
        b.x *= factorX;
        b.y *= factorY;
        cpSegmentShapeSetEndpoints(shape, a, b);
    }
    
    PhysicsShape::updateScale();
}

void PhysicsShape::setGroup(int group)
{
    if (group < 0)
    {
        for (auto shape : _cpShapes)
        {
            cpShapeSetGroup(shape, (cpGroup)group);
        }
    }
    
    _group = group;
}

bool PhysicsShape::containsPoint(const Vec2& point) const
{
    for (auto shape : _cpShapes)
    {
        if (cpShapePointQuery(shape, PhysicsHelper::point2cpv(point)))
        {
            return true;
        }
    }
    
    return false;
}

NS_CC_END

#endif // CC_USE_PHYSICS