Game Engine Architecture

120 3. Fundamentals of Software Engineering for Games

struct Foo // struct declaration

{

U32 mUnsignedValue;

F32 mFloatValue;

bool mBooleanValue;

};

Once a struct or class has been declared, it can be allocated (defi ned) in

any of the ways that an atomic data type can be allocated, for example,

z as an automatic variable, on the program stack;

void someFunction()

{

Foo localFoo;

// ...

}

z as a global, fi le-static or function-static;

Foo gFoo;

static Foo sFoo;

void someFunction()

{

static Foo sLocalFoo;

// ...

}

z dynamically allocated from the heap. In this case, the pointer or refer-

ence variable used to hold the address of the data can itself be allocated

as an automatic, global, static, or even dynamically.

Foo* gpFoo = NULL; // global pointer to a Foo

void someFunction()

{

// allocate a Foo instance from the heap

gpFoo = new Foo;

// ...

// allocate another Foo, assign to local

// pointer

Foo* pAnotherFoo = new Foo;

// ...

// allocate a POINTER to a Foo from the heap

Foo** ppFoo = new Foo*;

(*ppFoo) = pAnotherFoo;

}