使用另一个 class 的变量

Question

我想用 classes.

制作某种层次结构

示例：

object.position.x

我希望能够将 Vector3 class 重新用于速度和其他方面，这就是为什么我想将其保留为 class。我那样试过。

#include"Vector3.h"

class object{
   public:
       Vector3 position;
       Vector3 velocity;
}

-------------------------------------

class Vector3{
    float x;
    float y;
    float z;
}

但它似乎没有我预期的那么好用。

当我选择 go.position.x = 0 代码块时，我要使用 ->。

request for member 'x' in 'go.GameObject::position', which is of pointer type 'Vector3*' (maybe you meant to use '->' ?)|

但是当我这样使用它们时：go.position -> x = 0，程序崩溃了。有人可以告诉我 "right" 或更好的方法是什么吗？

Answer 1

由于 class 的成员在默认情况下是私有的，因此您无法像 position.x 那样访问它们。你需要为他们写 getter 和 setter ，否则让它像 .

一样结构

structVector3{
    float x;
    float y;
    float z;
};

Answer 2

您粘贴的代码不完整，您收到的错误似乎来自不同版本的代码。下面是使用 Your 类和不带指针的示例。

#include <iostream>
using namespace std;

class Vector3{
    public:
        float x;
        float y;
        float z;
};

class Object {
   public:
       Vector3 position;
       Vector3 velocity;
};

class ObjectPointer {
   public:
       Vector3 *positionPtr;
       Vector3 *velocityPtr;

       ObjectPointer()
         : positionPtr(new Vector3()),
         velocityPtr(new Vector3())
       {
       }
};

int main() {
    // your code goes here
    Object obj;
    obj.position.x = 1;
    obj.position.y = 2;
    obj.position.z = 3;
    obj.velocity.x = 11;
    obj.velocity.y = 12;
    obj.velocity.z = 13;

    std::cout << "Object Position (" << obj.position.x
        << ", " << obj.position.y
        << ", " << obj.position.z << ")" << std::endl;
    std::cout << "Object Velocity  (" << obj.velocity.x
        << ", " << obj.velocity.y
        << ", " << obj.velocity.z << ")" << std::endl;

    ObjectPointer *objPtr = new ObjectPointer();
    objPtr->positionPtr->x = 5;
    objPtr->positionPtr->y = 6;
    objPtr->positionPtr->z = 7;
    objPtr->velocityPtr->x = 15;
    objPtr->velocityPtr->y = 16;
    objPtr->velocityPtr->z = 17;

    std::cout << "ObjectPointer Position (" << objPtr->positionPtr->x
        << ", " << objPtr->positionPtr->y
        << ", " << objPtr->positionPtr->z << ")" << std::endl;
    std::cout << "ObjectPointer Velocity  (" << objPtr->velocityPtr->x
        << ", " << objPtr->velocityPtr->y
        << ", " << objPtr->velocityPtr->z << ")" << std::endl;

    return 0;
}

使用另一个 class 的变量

Using variable of another class

c++

nested

class

vector

coordinates