An introduction to C++ programming language for game engine development

2.  User-Defined Types
 Structures
 Classes
 Enumerations

3.  Fundamental Types
 short, int, long
 char
 bool
 float, double
 User-defined types
 Structure
 Class
 Enumerator

4. 1. struct Vector
2. {
3. int sz; // Number of elements
4. double* elem; // Pointer to elements
5. };

5. 1. void f(Vector v, Vector& rv, Vector* pv)
2. {
3. int i1 = v.sz; // Access through name
4. int i2 = rv.sz; // Access through reference
5. int i4 = pv->sz; // Access through pointer
6. }

6. 1. void vector_init(Vector& v, int s)
2. {
3. v.elem = new double[s];
4. v.sz = s;
5. }

7. 1. // Read s integers from cin and return their
2. // sum; s is assumed to be positive.
3. double read_and_sum(int s)
4. {
5. Vector v;
6. vector_init(v, s); // Allocate s elements for v
7. for (int i=0; i!=s; ++i)
8. cin >> v.elem[i];
9.
10. double sum = 0;
11. for (int i=0; i!=s; ++i)
12. sum += v.elem[i];// Take the sum of the elements
13.
14. return sum;
15. }

8. 1. class Vector
2. {
3. public:
4. Vector(int s) : elem(new double[s]), sz(s) {}
5. double& operator[](int i) { return elem[i]; }
6. int size() { return sz; }
7.
8. private:
9. double* elem; // Pointer to the elements
10. int sz; // The number of elements
11. };

9. 1. class Vector
2. {
3. public:
4. Vector(int s) : elem(new double[s]), sz(s) {}
5. double& operator[](int i) { return elem[i]; }
6. int size() { return sz; }
7.
8. private:
9. double* elem; // Pointer to the elements
10. int sz; // The number of elements
11. };

10. 1. enum Color { red, blue, green };
2. enum Traffic_light { green, yellow, red };
3.
4. Color col = Color::red;
5. Traffic_light light = Traffic_light::red;

11. 1. // Prefix increment: ++
2. Traffic_light& operator++(Traffic_light& t)
3. {
4. switch (t)
5. {
6. case Traffic_light::green: return t=Traffic_light::yellow;
7. case Traffic_light::yellow: return t=Traffic_light::red;
8. case Traffic_light::red: return t=Traffic_light::green;
9. }
10. }
11.
12. Traffic_light next = ++light; // next becomes green