Virtools脚本语言(VSL)教程 - 结构

结构定义的语法

结构类型是一种用户定义的复合类型。结构可由一些不同类型的成员组成。

struct structName
{ memberList
};

实例：

struct Person

{

String name;

int age;

float weight;

};

每个结构成员的类型可以是基本类型、其它VSL结构或C/C++结构/类。这些类型的数组成员也被支持。

struct Car

{

Entity3D entity;

Person passengers[4];

float weight;

Vector velocity;

};

要访问结构的成员，你得使用 "." 运算符。

void SetPerson(Person p, String name, int age, float weight)

{

// Set name

if (name == "")

p.name = "Unknown";

else

p.name = name;

// Set age

if (age < 0)

age = 1;

p.age = age;

// Set weight

if (weight < 0)

weight = 40;

p.weight = weight;

}

void main()

{

Car car;

car.entity = null;

car.velocity.Set(0,0,0);

car.weight = 1500;

// Set persons

for (int i = 0; i < 4; ++i)

{

String name("Passengers");

name += i;

SetPerson(car.passengers[i], name, rand()*20+20, rand()*30+60);

// Add person weight to the car weight

car.weight += car.passengers[i].weight;

}

}

在结构上使用运算符 =, == 及 !=

当在结构上使用 =, == 及 != 运算符时，VSL编译器为每个具有这种被重载运算符的成员调用合适的运算符。

对于那些没有重载运算符的成员，这个代码会产生：

Operator =

Code is generated to copy memory.

Operator == and !=

Code is generated to compare memory.

实例：

Person p1;

Person p2;

String name("john");

SetPerson(p1, name, 30, 75);

p2 = p1;

等价于：

p2.name = p1.name; // call the String operator =

p2.age = p1.age;

p2.weight = p1.weight;

p2 == p1;

等价于：

p2.name == p1.name; // call the String operator ==

p2.age == p1.age;

p2.weight == p1.weight;

p2 != p1;

等价于：

p2.name != p1.name; // call the String operator !=

p2.age != p1.age;

p2.weight != p1.weight;