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

2. ‫کتاب‬ ‫معرفی‬
‫های‬ ‫مکانیزم‬Abstraction
‫های‬ ‫کالس‬Concrete

3. ‫منبع‬:‫کتاب‬The C++ programming language‫نوشته‬
‫آقای‬Bjarne Stroustrup

4. ‫ها‬ ‫کالس‬
Concrete Class
Abstract Class
Classes in hierarchies

5. ‫مشابه‬ ‫عملکرد‬Built-in type‫ها‬
‫یا‬ ‫نمایش‬Representation‫از‬ ‫بخشی‬ ‫آنها‬Definition
‫آنهاست‬
‫در‬ ‫داری‬ ‫نگه‬stack‫صورت‬ ‫به‬ ‫حافظه‬ ‫تخصیص‬ ‫و‬static‫است‬.
‫گیرد‬ ‫می‬ ‫صورت‬ ‫مستقیم‬ ‫صورت‬ ‫به‬ ‫اجاع‬ ‫و‬ ‫دسترسی‬.
‫با‬ ‫و‬ ‫کامل‬ ‫صورت‬ ‫به‬ ‫اولیه‬ ‫دهی‬ ‫مقدار‬constructor‫گیرد‬ ‫می‬ ‫صورت‬.
‫قابلیت‬copy‫دارند‬ ‫کردن‬.

6. 01. class complex {
02. double re, im; // Representation: two doubles
03. public:
04. // Construct complex from two scalars
05. complex(double r, double i) : re(r), im(i) {}
06. complex(double r) : re(r), im(0) {}// Construct complrex from one scalar
07. complex() : re(0), im(0) {} // Default complex: {0,0}
08.
09. double real() const { return re; }
10. void real(double d) { re = d; }
11. double image() const { return im; }
12. void image(double d) { im = d; }
13.
14. // Add to re and im and return the result
15. complex& operator+=(complex& z) { re+=z.re; im+=z.im; return *this; }
16. complex& operator-=(complex& z) { re-=z.re; im-=z.im; return *this; }
17. complex& operator*=(complex& z); // Defined out-of-class somewhere
18. complex& operator/=(complex& z); // Defined out-of-class somewhere
19. };

7. 01. complex operator+(complex a, complex b) { return a += b; }
02. complex operator-(complex a, complex b) { return a -= b; }
03. // Unary minus
04. complex operator-(complex a) { return complex(-a.real(), -a.image()); }
05. complex operator*(complex a, complex b) { return a *= b; }
06. complex operator/(complex a, complex b) { return a /= b; }
07.
08. bool operator==(complex a, complex b) // Equal
09. {
10. return a.real() == b.real() && a.image() == b.image();
11. }
12.
13. bool operator!=(complex a, complex b) // Not equal
14. {
15. return !(a == b);
16. }
17.
18. complex sqrt(complex);

8. 01. void f(complex z)
02. {
03. // Construct {2.3, 0.0} from 2.3
04. complex a(2.3);
05. complex b(1/a);
06. complex c(a + z * complex(1, 2.3));
07.
08. // ...
09.
10. if (c != b)
11. c = -(b / a) + 2 * b;
12. }

9. 01. class Vector {
02. private:
03. double* elem; // Elem points to an array of sz doubles
04. int sz;
05. public:
06. // Constructor: acquire resources
07. Vector(int s) : elem(new double[s]), sz(s)
08. {
09. // Initialize elements
10. for (int i=0; i!=s; ++i) elem[i] = 0;
11. }
12.
13. // Destructor: release resources
14. ~Vector() { delete[] elem; }
15.
16. double& operator[](int i);
17. int size() const;
18. }

10. 01. void fct(int n)
02. {
03. Vector v(n);
04.
05. // ... use v ...
06.
07. {
08. Vector v2(2 * n);
09.
10. // ... use v and v2 ...
11.
12. } // v2 is destroyed here
13.
14. // ... use v ...
15.
16. } // v is destroyed here

11. Initializer list
push_back

12. 01. class Vector {
02. public:
03. Vector(std::initializer_lsit<double> lst);
04. void push_back(double d);
05. }
06.
07. Vector::Vector(std::initializer_list<double> lst)
08. : elem(new double[lst.size()], sz(lst.size)
09. {
10. copy(lst.begin(), lst.end(), elem);
11. }
12.
13. Vector v1 = {1,2,3,4,5};
14. Vector v2 = {1.23, 3.45, 6.7, 8};

13. 01. Vector read(istream& is)
02. {
03. // Read floating-point values into d
04. Vector v;
05. for (double d; is >> d;)
06. v.push_back(d); // Add d to v
07. return v;
08. }