Question

好的，我正在制作我自己的简单引擎，我已经成功实现了ECS，现在我正在尝试用物理实现Box2D而且我在做某些事情上遇到了麻烦所以我有一个类型的组件：＆＃34; RigidBody2D＆＃34;它做了一些物理计算，它看起来像这样（注意我使用Unity3D就像保存Start，Awake和Update功能的组件一样，我不使用系统）：

'RigidBody.h'
    #pragma once
    #include "Component.h"      

class RigidBody2D : public Component
{
private:
    float Density = 1.f;
    float Friction = 1.f;
    b2BodyDef bodyDef;
    b2FixtureDef fixtureDef;
    b2PolygonShape dynamicBox;
public:
    Transfrm* Trans;
    b2Body* Body;

    RigidBody2D() : Component("RigidBody2D") {
        Trans = new Transfrm(b2Vec2(0.f, 0.f), 0.f, b2Vec2(1.f, 1.f));
        bodyDef.type = b2_dynamicBody;
        bodyDef.position.Set(Trans->Position.x, Trans->Position.y);
        Body = CurrentPhysicsWorld->CreateBody(&bodyDef);
        dynamicBox.SetAsBox(1.0f, 1.0f);
        fixtureDef.shape = &dynamicBox;
        fixtureDef.density = GetDensity();
        fixtureDef.friction = GetFriction();
        Body->CreateFixture(&fixtureDef); // The Line That Causes trouble
    };

    ~RigidBody2D();
};

好吧所以一切都很好，我基本上复制了Box2D示例中的例子：＆＃34; HelloWorld.cpp＆＃34;并将它们实现到一个类中，在我的控制台中运行后，我得到了这样的消息：

"Assertion failed: m_nodeCount == m_nodeCapacity, file ..\..\Box2D\Collision\b2DynamicTree.cpp, line 58"

经过一些测试后我发现造成这个问题的一行是：

Body->CreateFixture(&fixtureDef);

当我评论此行时，程序运行，然后Visual Studio 2015向我显示一条消息："Wntdll.pdb Not Loaded, wntdll.pdb contains the debug information required to find the source for the module ntdll.dll" 我不确定导致此问题的原因或原因，因为这是我第一次使用Box2D。

编辑： MVCE必须是这个，你需要在项目中设置Box2D才能运行这段代码：

#include <Box2D.h>

b2World CurrentWorld;

class World {
public:
    b2World physicsWorld;
    World() { CurrentWorld = this->physicsWorld; };
    ~World() {};
};

class RigidBody2D
{
public:
    b2Body* Body;
    b2BodyDef bodyDef;
    b2FixtureDef fixtureDef;
    b2PolygonShape dynamicBox;

    RigidBody2D() {
        bodyDef.type = b2_dynamicBody;
        bodyDef.position.Set(Trans->Position.x, Trans->Position.y);
        Body = CurrentWorld->CreateBody(&bodyDef);
        dynamicBox.SetAsBox(1.0f, 1.0f);
        fixtureDef.shape = &dynamicBox;
        Body->CreateFixture(&fixtureDef);
    }
    ~RigidBody2D() {};
};

int main() {
    World wrld = World();
    RigidBody2D body = RigidBody2D();
    return 0;
}

Answer 1

好吧，看起来你没有创造世界。 b2World结构未在任何地方初始化。以下代码适用于我没有问题：

static b2World *CurrentWorld = nullptr;

class RigidBody2D
{
public:
    b2Body* Body;
    b2BodyDef bodyDef;
    b2FixtureDef fixtureDef;
    b2PolygonShape dynamicBox;

    RigidBody2D() {
        bodyDef.type = b2_dynamicBody;
        bodyDef.position.Set(1.0, 1.0);
        Body = CurrentWorld->CreateBody(&bodyDef);
        dynamicBox.SetAsBox(1.0f, 1.0f);
        fixtureDef.shape = &dynamicBox;
        Body->CreateFixture(&fixtureDef);
    }
    ~RigidBody2D() {}
};

int main(int argc, char** argv)
{
    b2Vec2 gravity(0.0f, -10.0f);
    CurrentWorld = new b2World(gravity); // <- you missed that

    RigidBody2D *body = new RigidBody2D();

    float32 timeStep = 1.0f / 60.0f;
    int32 velocityIterations = 6;
    int32 positionIterations = 2;
    for (int32 i = 0; i < 60; ++i)
    {
        CurrentWorld->Step(timeStep, velocityIterations, positionIterations);
        b2Vec2 position = body->Body->GetPosition();
        float32 angle = body->Body->GetAngle();
        printf("%4.2f %4.2f %4.2f\n", position.x, position.y, angle);
    }

    return 0;
}

Box2D：断言失败并且Wntdll.pdb未加载

1 个答案: