Introduction to C++

#include 
using namespace std;

int main() {
    cout << "Game Engine Features Built with C++:" << endl;
    cout << "1. Real-time 3D rendering at 60+ FPS" << endl;
    cout << "2. Complex physics simulations" << endl;
    cout << "3. Advanced AI and pathfinding algorithms" << endl;
    return 0;
}

Why C++ for Games:

• Speed: Games need to render frames in milliseconds
• Memory control: Manage thousands of objects efficiently
• Low-level access: Direct GPU and hardware manipulation

#include 
#include   // For time measurement
using namespace std;
using namespace std::chrono;

int main() {
    auto start = high_resolution_clock::now();
    
    // Perform 1 million calculations
    long long sum = 0;
    for (int i = 0; i < 1000000; i++) {
        sum += i * i;
    }
    
    auto end = high_resolution_clock::now();
    auto duration = duration_cast(end - start);
    
    cout << "Sum: " << sum << endl;
    cout << "Time taken: " << duration.count() << " microseconds" << endl;
    cout << "\nWhy so fast?" << endl;
    cout << "- Compiled directly to machine code" << endl;
    cout << "- No interpreter overhead" << endl;
    cout << "- Optimized by compiler" << endl;
    
    return 0;
}

Performance Factors:

• This same loop in Python would take 10-50x longer
• C++ uses chrono library for precise timing
• Compiler optimizations can make code even faster

#include 
using namespace std;

// Pure procedural - no classes needed!
int add(int a, int b) {
    return a + b;
}

int multiply(int a, int b) {
    return a * b;
}

int main() {
    int x = 5, y = 10;
    
    cout << "Sum: " << add(x, y) << endl;          // 15
    cout << "Product: " << multiply(x, y) << endl; // 50
    
    return 0;
}

// This looks just like C!
// C++ is backward compatible with C
// You can mix procedural and OOP as needed

Key Point: Unlike Java which forces OOP, C++ lets you choose procedural or OOP based on your needs.

#include 
using namespace std;

void modifyByPointer(int* ptr) {
    *ptr = *ptr * 2;  // Dereference and modify
}

void modifyByReference(int& ref) {
    ref = ref * 2;    // Cleaner syntax
}

int main() {
    int num1 = 10;
    int num2 = 10;
    
    // Using pointer
    modifyByPointer(&num1);  // Pass address
    cout << "After pointer: " << num1 << endl;  // 20
    
    // Using reference (C++ only!)
    modifyByReference(num2);  // No & needed when calling
    cout << "After reference: " << num2 << endl;  // 20
    
    // Java has neither true pointers nor references
    // C has pointers but no references
    // C++ has BOTH - best of both worlds!
    
    return 0;
}

Comparison:

• C: Has pointers, manual and verbose
• C++: Has pointers AND references (safer, cleaner)
• Java: Hides pointers completely (less control)

#include 
using namespace std;

class Complex {
private:
    double real, imag;
    
public:
    Complex(double r = 0, double i = 0) : real(r), imag(i) {}
    
    // Operator overloading - C++ exclusive!
    Complex operator+(const Complex& other) {
        return Complex(real + other.real, imag + other.imag);
    }
    
    Complex operator*(const Complex& other) {
        double r = real * other.real - imag * other.imag;
        double i = real * other.imag + imag * other.real;
        return Complex(r, i);
    }
    
    void display() {
        cout << real << " + " << imag << "i" << endl;
    }
};

int main() {
    Complex c1(3, 4);   // 3 + 4i
    Complex c2(1, 2);   // 1 + 2i
    
    Complex sum = c1 + c2;      // Uses operator+
    Complex product = c1 * c2;  // Uses operator*
    
    cout << "Sum: ";
    sum.display();      // 4 + 6i
    
    cout << "Product: ";
    product.display();  // -5 + 10i
    
    // This natural syntax is ONLY possible in C++!
    // Java would need: sum = c1.add(c2) - verbose
    // C has no classes at all
    
    return 0;
}

Why This Matters:

• Operator overloading makes code more intuitive and mathematical
• STL containers use this extensively (vector[i], map[key])
• Neither C nor Java support this powerful feature

#include 
#include 
using namespace std;

class Student {
private:
    string name;
    int age;
    double gpa;
    
public:
    // Constructor
    Student(string n, int a, double g) : name(n), age(a), gpa(g) {}
    
    // Getters
    string getName() { return name; }
    int getAge() { return age; }
    double getGPA() { return gpa; }
    
    // Setter with validation
    void setGPA(double g) {
        if (g >= 0.0 && g <= 4.0)
            gpa = g;
        else
            cout << "Invalid GPA!" << endl;
    }
    
    void display() {
        cout << "Name: " << name << endl;
        cout << "Age: " << age << endl;
        cout << "GPA: " << gpa << endl;
    }
};

int main() {
    Student s1("Alice", 20, 3.8);
    s1.display();
    
    s1.setGPA(3.9);  // Valid
    s1.setGPA(5.0);  // Invalid - rejected
    
    return 0;
}

#include 
using namespace std;

class Vehicle {
protected:
    string brand;
    int year;
    
public:
    Vehicle(string b, int y) : brand(b), year(y) {}
    
    void info() {
        cout << "Brand: " << brand << ", Year: " << year << endl;
    }
};

class Car : public Vehicle {
private:
    int doors;
    
public:
    Car(string b, int y, int d) : Vehicle(b, y), doors(d) {}
    
    void display() {
        info();  // Inherited method
        cout << "Doors: " << doors << endl;
    }
};

class Bike : public Vehicle {
private:
    bool hasCarrier;
    
public:
    Bike(string b, int y, bool c) : Vehicle(b, y), hasCarrier(c) {}
    
    void display() {
        info();  // Inherited method
        cout << "Has Carrier: " << (hasCarrier ? "Yes" : "No") << endl;
    }
};

int main() {
    Car myCar("Toyota", 2024, 4);
    Bike myBike("Honda", 2023, true);
    
    cout << "Car Details:" << endl;
    myCar.display();
    
    cout << "\nBike Details:" << endl;
    myBike.display();
    
    return 0;
}

#include 
#include 
using namespace std;

int main() {
    string categories[] = {
        "Game Engines (Unreal, Unity)",
        "Web Browsers (Chrome, Firefox)",
        "Operating Systems (Windows, macOS)",
        "Databases (MySQL, MongoDB)",
        "Graphics Software (Photoshop, Blender)",
        "Machine Learning (TensorFlow, PyTorch)"
    };
    
    cout << "Major Software Categories Built with C++:" << endl << endl;
    
    for (int i = 0; i < 6; i++) {
        cout << (i + 1) << ". " << categories[i] << endl;
    }
    
    return 0;
}

#include 
#include 
using namespace std;

class GameCharacter {
private:
    string name;
    int health;
    int attackPower;
    
public:
    GameCharacter(string n, int h, int ap) 
        : name(n), health(h), attackPower(ap) {}
    
    void attack(GameCharacter& enemy) {
        cout << name << " attacks " << enemy.name << "!" << endl;
        enemy.takeDamage(attackPower);
    }
    
    void takeDamage(int damage) {
        health -= damage;
        cout << name << " takes " << damage << " damage. ";
        cout << "Health: " << health << endl;
        
        if (health <= 0) {
            cout << name << " has been defeated!" << endl;
        }
    }
    
    bool isAlive() { return health > 0; }
};

int main() {
    GameCharacter player("Hero", 100, 25);
    GameCharacter enemy("Dragon", 150, 30);
    
    cout << "=== Game Combat Simulation ===" << endl << endl;
    
    while (player.isAlive() && enemy.isAlive()) {
        player.attack(enemy);
        if (!enemy.isAlive()) break;
        
        enemy.attack(player);
        cout << endl;
    }
    
    cout << "\nWhy C++ for Games?" << endl;
    cout << "- Fast object management (thousands of characters)" << endl;
    cout << "- Low memory overhead for game objects" << endl;
    cout << "- Real-time performance (60+ FPS)" << endl;
    
    return 0;
}