Super Pong

Andrew Dunsmore

CSC436

Overview

• Purpose

• Design Specification

• Software Engineering

Purpose

• Waste Time

• Kill Twenty Minutes

• Something to do besides homework

Super Pong

• Video ping pong• Players move paddle

to intercept ping (ball)• If the ping is missed,

opponent scores a point

• Played until a player scores a set number of points

But what makes it SUPER?

• User level options

• Sound Effects

• Multi-Player

• Physics Models

• Ping Motion

• Boards (pre-defined and user-created)

Sounds

• Default or user-defined

• Categories can be set independently– External/Internal Wall Impacts– Own/Opponent Paddle

• User-defined sounds limited to digital (wav) of a set length

Single/Multi-Player

• Single player games can be played at 3 levels of difficulty

• Multi-player options– Direct connect using IP addresses– Connection to server program

• Multi-Player communication using Windows Sockets

Artificial Intelligence Model

• AI model not yet determined• 2 possible Models

• Random Intelligence• Instead of AI, the

computer player randomly chooses not to try to hit the ping

• Time-deferred guessing• Computer calculates

expected position using pings current position and dx and dy

• Data can not be acted upon for dt, then must wait to gain more data

AI Model (continued)

• The choice of AI Model will be based on 2 metrics– Realism: the user should not be aware when the

computer chose not to hit the ping– Difficulty rating: algorithm must ensure that

Amateur games are easy and Expert games are hard

Multi-Player Issues

• Utilizes Windows Sockets• At a minimum the game must communicate:

– Both paddle positions

– Ping position

• Issue:– User’s screen resolution is based on their desktop

settings

– Points will need to be translated between different resolutions

Physics Models

• User can choose from 3 different models

• True– Angle of reflection = -Angle of

incident• Pool

– Angle of reflection is based on angle of incident, speed of ping, and firmness of bumper

– Bumper firmness can be set by user as a percentage – 100% firmness will behave like True model

• Crazy– Angle of reflection is random

Ping Motion (or Physics II)

• Ping motion can be set by user

• Motion can be static, free rotate, or incident rotate

• Ping will begin rotating if:– Paddle is in motion at time

of collision– Low incident angle with a

wall

• A ping’s rotation will affect its reflection angle

Boards

• User can pick from 6 pre-defined boards

• User-created boards also possible with included sub-program

Board Customization

• Included board creation sub-program will be similar to MS Paint Brush

• Differences:– Area will be defined by fixed grid– A cell in grid is either filled or blank– Only half of board needs to be designed – other half of board is a mirror

image• Details:

– Mirror image used to ensure equality for both players– Grids used to ease board recognition by program– For diagonal filled boxes, user can hit a button and computer will half fill

adjacent boxes• For multi-player games, if other player doesn’t have the board, the

program will automatically send it

SE – Finite State Machine

• Game Init: Setting variables when game is loaded into memory

• Game Menu: Resting point for the game – executes menu commands

• Game Starting: Scores, Timers, etc. reset Resources acquired for Game Run

• Game Run: Handles the bulk of the game’s instructions, physics, video, etc. (typically ran every 1/30 second)

• Game Restart: Displays winner, releases resources used in Game Run

• Game Exit: Releases all resources and returns control to the OS

The FSM and OO C++

• The Finite State Machine smoothly translates to Object Oriented languages

• The states become C++ functions• Game Init = game_init• Game Menu = handled in WinMain• Game Starting = handled in game_main• Game Run = game_main• Game Restart = handled in game_main• Game Exit = game_shutdown

Pseudo Codeconst int GAME_STATE_START = 0const int …int state;

game_init() { // initiate run-time variables: state = GAME_STATE_START;}game_main() { // note: this function is called on each frame // typically every 1/30 seconds switch (state) { case (GAME_STATE_START) // set variables for a new game // and set up the new board state = GAME_STATE_RUN; break; …}

game_shutdown() { // this function releases all resources // and returns control to the OS SendMessage(…);}WinMain() { // set up window CreateWindowEx(…); // get resources and set initial variables game(init); // enter the main game loop while(1) { if(WM_CLOSE) { // if exit msg received game_shutdown() // end the game return(0); } // end if game_main() // else call the main game

// function } // end while()}

Super Pong

Drew Dunsmore

CSC436

?Questions?