29 The Power of Inheritance and Polymorphism

Implementation: class Dungeon 1053}}}return fPlayer->Alive();(Note the need for type casts when getting members of the collections; the functionDynamicArray::Nth() returns a void* pointer.)The CreateWindow() function creates a Window object and sets its backgroundfrom the map.void Dungeon::CreateWindow(){fDWindow = new Window(1, 1, fWidth, fHeight);for(int row = 1; row PrepareContent();fDWindow->ShowAll();}Class Dungeon has several trivial access functions:int Dungeon::Accessible(Pt p) const{return (' ' == fDRep[p.Y()-1][p.X()-1]);}Window *Dungeon::Display() { return fDWindow; }Player *Dungeon::Human() { return fPlayer; }int Dungeon::ValidPoint(Pt p) const{int x = p.X();int y = p.Y();// check x rangeif((x = fWidth)) return 0;// check y rangeif((y = fHeight)) return 0;// and accessibilityreturn Accessible(p);}There are similar pairs of functions M_at_Pt() and PI_at_Pt(), andRemoveM() and RemoveProp() that work with the fInhabitants list of Monstersand the fProps list of Collectables. Examples of the implementations areCollectable *Dungeon::PI_at_Pt(Pt p){int n = fProps.Length();for(int i=1; iWhere();if(w.Equals(p)) return pi;