std::vector 的 Box2D 怪异行为

Question

最近我开始玩 box2d 并尝试将其抽象为 class

RigidBody::RigidBody() {

}

RigidBody::RigidBody(const RigidBody& other) {
    m_fixture = other.m_fixture;

    b2BodyDef bodyDef;
    bodyDef.position = other.m_body->GetPosition();
    bodyDef.type = other.m_body->GetType();

    m_body = Runtime::PhysicsWorld.CreateBody(&bodyDef);

    b2FixtureDef fixtureDef;
    fixtureDef.shape                = m_fixture->GetShape();
    fixtureDef.density              = m_fixture->GetDensity();
    fixtureDef.friction             = m_fixture->GetFriction();
    fixtureDef.restitution          = m_fixture->GetRestitution();
    fixtureDef.restitutionThreshold = m_fixture->GetRestitutionThreshold();

    m_fixture = m_body->CreateFixture(&fixtureDef);
}

RigidBody::RigidBody(sf::Vector2f pos, BodyType type) {
    pos /= Constants::PPM;

    b2BodyDef bodyDef;
    bodyDef.position = pos;
    bodyDef.type = (b2BodyType)type;

    m_body = Runtime::PhysicsWorld.CreateBody(&bodyDef);

    sf::Vector2f size(50.0f, 50.0f);

    size /= 2.0f;
    size /= Constants::PPM;

    b2PolygonShape shape;
    shape.SetAsBox(size.x, size.y);

    b2FixtureDef fixtureDef;

    fixtureDef.shape                = &shape;
    fixtureDef.density              = 1.0f;
    fixtureDef.friction             = 0.5f;
    fixtureDef.restitution          = 0.0f;
    fixtureDef.restitutionThreshold = 0.5f;

    m_body->CreateFixture(&fixtureDef);
}

RigidBody::~RigidBody() {
    Runtime::PhysicsWorld.DestroyBody(m_body);
}

但是 vector 的行为真的很奇怪，我知道这可能是因为复制构造函数或析构函数，但我想不通

std::vector<hv::RigidBody> m_Bodies;

当我调用 m_Bodies.erase(m_Bodies.begin()) 时，问题出在矢量擦除上，由于某种原因它删除了最后一个对象

m_Bodies.erase(m_Bodies.begin());

在我第二次调用 m_Bodies.erase(m_Bodies.begin()) 之后，我得到了这个

此外，如果我调用 m_Bodies.erase(m_Bodies.begin() + 3)，向量中有多少对象并不重要，它总是会删除最后一个对象

*编辑更正的问题

Answer 1

问题是我没有定义运算符=

解决了

RigidBody* RigidBody::operator=(const RigidBody& other) {
    if(m_body)
        Runtime::PhysicsWorld.DestroyBody(m_body);

    m_fixture = other.m_fixture;

    b2BodyDef bodyDef;
    bodyDef.position = other.m_body->GetPosition();
    bodyDef.type = other.m_body->GetType();

    m_body = Runtime::PhysicsWorld.CreateBody(&bodyDef);

    b2FixtureDef fixtureDef;
    fixtureDef.shape = m_fixture->GetShape();
    fixtureDef.density = m_fixture->GetDensity();
    fixtureDef.friction = m_fixture->GetFriction();
    fixtureDef.restitution = m_fixture->GetRestitution();
    fixtureDef.restitutionThreshold = m_fixture->GetRestitutionThreshold();

    m_fixture = m_body->CreateFixture(&fixtureDef);

    return this;
}

std::vector 的 Box2D 怪异行为

Box2D weird behavior with std::vector

c++

vector

box2d

sfml

rigid-bodies

最近我开始玩 box2d 并尝试将其抽象为 class