OSDev.org

Code: Select all

void Game::GameLoop () {
  set<GameEntity*>::iterator i = gameEntities->begin();
  while (*i) {
    (*i)->doUpdate();
    i++;
  }
  this->drawScreen();
}

Code: Select all

void Gun::Fire() {
  Bullet &newBullet;
  Shell &newShell;

  if (bullets == 0) return;
  bullets--;

  newShell = new Shell("up",12, this); // shell goes up from the point of the gun, with speed 12
  newBullet = new Bullet("forward", 300, this); // bullet goes forward from the gun, speed 300. The this-pointer is passed as a reference so the bullet knows from what gun it came

  GlobalWorld::add(newShell);
  GlobalWorld::add(newBullet);
}

Code: Select all

bool Person::intersectWith(GameObject *object) {
  // function entered when something enters the person
  if (dynamic_cast<Bullet *>(object)) {
    // hit by a bullet, die
    this->die();
  } else if (dynamic_case<Vehicle *>(object)) {
    // hit by a vehicle, fly
    this->setDirection(object->getDirection());
    this->setSpeed(0.9 * object->getSpeed());
    object->setSpeed(0.85 * object->getSpeed());
  }
}

Code: Select all

// Vehicle.h

class Vehicle
{
private:
   int mass; // approx. mass of vehicle in kilograms
   imt height, width, length;  // approx. maximum dimensions of the vehicle in cm
   Motion_Vector velocity; // assumes the existence of a class Motion_Vector for describing direction and speed
   int carrying_cap;  //  # of passengers it can carry
   int passengers;

public:
   // constructor function - sets all the starting values
   Vehicle(intm ms, int hght, int wght, int len, Motion_Vector starting_velocity, int capacity, int psgnrs);
 
   // destructor - cleans up after a variable is finished
   ~Vehicle();

   // access functions - return the value of the instance variables
   // Since these are defined in the header, they are inline functions
   int Mass() {return mass};
   int Height() {return height};
   int Width() {return width);
   int Length() {retun length};
   Motion_Vector Velocity() {return velocity};

   // change functions - functions for altering the instance variables
   void Enter(int new_passengers) throw (TooManyException);
   void Exit(int leaving_passengers) throw (DangerousExitException); 

   Motion_Vector Accelerate(int acceleration);
   Motion_Vector Turn(Motion_Vector heading);
   Motion_Vector Impact(int opposing_mass, Motion_Vector delta_v);
}

Code: Select all

void Vehicle::Exit(int leaving_passengers) throw (DangerousExitException)
    { 
        passengers = (leaving_passengers >= passengers) ? 0 : passengers - leaving_passengers;
        if(velocity.Speed() != 0) 
          throw DangerousExitException();
    }

Code: Select all

class Car::Vehicle 
{
private:
  int horsepower;  // maximum engine power

public:
   Car(int ms, int hght, int wght, int len, Motion_Vector starting_velocity, int capacity, int psgnrs, int hp);
}

Code: Select all

#include <car.h>

main()
{
Motion_Vector tmp_vect;
Car kitt(1000, 150, 180, 220, PARKED_NORTH, 2, 600);
Car karr(1000, 150, 180, 220, PARKED_SOUTH, 2, 600);

kitt.Enter(1);            // Michael Knight gets into driver's seat
kitt.Accelerate(88); 
kitt.Turn(SHARP_LEFT);
kitt.Turn(SHARP_LEFT);
kitt.Turn(SHARP_LEFT);
kitt.Turn(SHARP_LEFT);   // back at our starting point, going 88KPH

karr.Accelerate(88);  // uh-oh, collision course
tmp_vect = kitt.Velocity();   // need to keep velocity from before impact

kitt.Impact(karr.Velocity(), 1000);
karr.Impact(tmp_vect, 1000);

kitt.Exit(1);  // a very stunned and woozy Michael gets out
}

Code: Select all

class Basic {
  public:
    Basic(int i);
    ~Basic();
  private:
    int i;
};

Code: Select all

Basic *object = new Basic(123);

Code: Select all

class X
{
public:
    X() { y = 5; }
private:
    int y;
};

Code: Select all

X x;
X* px = new X;