29 The Power of Inheritance and Polymorphism

EXERCISES1 Complete and run the dungeon game program.2 This one is only for users of Borland's system.Why should the monsters wait while the user thinks? If they know what they want to do,they should be able to continue!The current program requires user input in each cycle of the game. If there is no input,the program stops and waits. The game is much more interesting if this wait is limited.If the user doesn't type any command within a second or so, the monsters should gettheir chance to run anyway.This is not too hard to arrange.First, the main while() loop in Dungeon::Run() should have a call WindowRep::Instance()->Delay(1). This results in a 1 second pause in each cycle.The Player::Run() function only gets called if there have been some keystrokes. If thereare no keystrokes waiting to be processed, the Dungeon::Run() function skips to the loopthat lets each monster have a chance to run.All that is required is a system function, in the "console" library package, that allows aprogram to check whether input data are available (without "blocking" like a normal readfunction). The Borland conio library includes such a function.Using the on-line help system in the Borland environment, and other printeddocumentation, find how to check for input. Use this function in a reorganized versionof the dungeon program.(You can achieve the same result in the Symantec system but only by utilisingspecialized system calls to the "Toolbox" component of the Macintosh operating system.It is all a little obscure and clumsy.)3 Add multiple levels to the dungeon.(There are various ways that this might be done. The easiest is probably to define a newclass DungeonLevel . The Dungeon object owns the main window, the Player, and a listof DungeonLevel objects. Each DungeonLevel object owns a map, a list of collectables,and a list of monsters. You will need some way of allowing a user to go up or downlevels. When you change level, the new DungeonLevel resets the background map inthe main window and arranges for all data to be redrawn.)4 Add more challenging Monsters and "traps".(Use your own imagination.)