240-492 games programming with java

240-492 Games Programming with Java ::: Introduction :::

1

-240492

Games Programming with Java

Montri Karnjanadecha Andrew Davison

2 240-492 Games Programming with Java

::: Introduction :::

Chapter 1

Introduction to Game Programming


3

Outline

• What is a game?• Why do people play games?• Taxonomy of computer games• The computer as a game technology• The game design sequence• Design techniques and ideas• The future of computer games

Reference: http://www.erasmatazz.com/free/AoCGD.pdf


4

What is a Game?

• Board games• Card games• Athletic games• Children’s games• Computer games


5

Board Games

• Consists of playing surface divided into sectors populated by a set of movable pieces

• The pieces are directly related to players• Playing surface represents an environment• Players maneuver their pieces across the playing

surface to:– capture other player’s pieces– reach an objective– gain control of territory– etc.


6

Card Games

• Utilize a set of 52 symbols generated from 2 factors:– Rank (13 values)

– Suit (4 values)

• Revolve around combinations built from these two factors

• Each legal combination is assigned a victory value

• The player’s primary concern is the analysis of combinations


7

Athletic Games

• Emphasize physical more than mental prowess• Skillful use of the body is the primary concern• Athletic games vs athletic competitions• A race is a competition• An athletic game is a competition with interacti

on between players.


8

Children’s Games

• Group activities emphasizing simple physical play

• The player’s primary concern is the use of social skills

• Examples– Hide and Seek

– Red Rover

– Tag

– Kick the Can


9

Computer Games

• Played on 5 types of computers– expensive dedicated machines (arcade)

– inexpensive dedicated machines (handheld)

– multi program home games (Nintendo, Play Station)

– persona; computers

– large mainframe computers

• Computer acts as opponent and referee• Skill & Action (emphasizing hand eye

coordination)


10

Computer Games (cont’d)

• These S&A games are frequently violent in nature

• Areas of computer games:– adventure games

– fantasy role playing games

– war games


11

Games’ Common Elements

• Representation– A game subjectively represents a subset of reality

• Interaction– Games provide interactive elements.

• Conflict– Arises naturally from the interaction in a game

– Game agent attempts to block the player to reach his goal

• Safty– Games provide save way to experience reality


12

Games vs Simulations

• Simulation– serious attempt to accurately represent a real phenomen

on

– created for evaluative purposes

• Game– artistically simplified representation of a phenomenon

– created for entertainment purposes

– small simulation lacking the degree of detail

• Flight Simulator vs RED BARON


13

Games vs Puzzles

• Cube puzzle vs Tic Tac Toe• High jumping vs Basket ball• Cube puzzle does not respond to the moves• High jump pole does not react to the jumper’s e

ffort• Basket ball & Tic Tac Toe: opposing player ack

nowledge and respond to the player’s action


14

Games vs Toys vs Stories

• Games– allow player to manipulate facts but rules remain fixed

– indirect contact of audience experience

– to be experienced many times

• Toys– user is free to manipulate the toy

– no control to user experience

• Stories– audiences don’t have control of facts presented

– to be experienced once


15

Why do People Play Games?

• To learn (need not be conscious)• Fantasy/Exploration (example of Disney Land)• Nose-Thumbing (violent, socially unacceptable)• Proving oneself (high score)• Social lubrication (card games, board games)• exercise (mental and/or physical)• need for acknowledgement


16

Enjoyment Factors

• Game play• Graphics• Color• Animation• Sound

} Reality


17

A Taxonomy of Computer Games

Skill&Action Games(emphasize motor skills)

– Combat games

– Maze games

– Sport games

– Paddle games

– Race games

– Miscellaneous games

Strategy Games(emphasize cognition skills)

– Adventures

– D&D games

– War games

– Games of chance

– Educational games

– Children’s games

– Interpersonal games


18

Combat Games

• Present a direct and violent confrontation• The player must destroy the bad guys• The player must avoid being hit• Examples

– Start Raiders

– Spacewar

– Asteroids

– Missile Command

– Space Invaders

– Battlezone


19

Maze Games

• Maze of paths through which the player must move

• Avoiding or destroying the bad guys• The player may make his way to an exit• Example

– Pac-Man


20

Sport Games

• Model popular sport games• Examples

– football

– basket ball

– snooker


21

Paddle Games

• Intercepting a projectile with a paddle-controlled piece

• Easy to develop• Examples

– Pong

– Breakout

– Warlords

– Chicken


22

Race Games

• Examples– Downhill

– Match Racer

– Night Driver

– Test Drive

– Dog Daze


23

Adventures

• Closer to puzzles than games• moving through a complex world• collecting tools• finding treasure or goal• Examples

– Adventure

– The Wizard and the Princes

– Time Zone

– Deadline


24

Game of Chance

• Easy to Program• Example

– Blackjack


25

Educational and Children’s Games

• Designed with explicit educational goals• Examples

– Hang Man

– Mammurabi

– Lunar Lander

– Rockey’s Boots


26

The Computer as Game Technology

• responding to the human player• acting as game referee• providing Real-time play• providing intelligent opponent• limiting information to the player• utilizing data transfer over communication line• Limited I/O capability and single-user

orientation are major weaknesses


27

Design Concepts

• Go with the grain– Don’t force the machine to do perform tasks for which i

t is not well-suited

– Recgrids vs Hexgrids

• Don’t transplant– A game that succeeds in one technology may not succe

ed in other technologies

• Design around the I/O– carefully consider what can and cannot be display and

what can and cannot be inputted


28

Design Concepts (cont’d)

• Keep it clean– Sticking close to the theme and eschewing distracting

detail

• Store less and process more– Main role of a computer is to process information not

store information

– Fill your program with active bytes not lazy bytes

– Games with information-rich and process-poor are close to stories


29

Design Concepts (cont’d)

• Maintain unity of design effort– Game must be designed, but computer must be

programmed

– Conflicts between artists and programmer


30

Game Design Sequence

• Choose a goal and a topic• Research and preparation• Design phase

– I/O structure– Game structure– Program structure– Evaluation of the design

• Pre-programming phase• Programming phase• Playtesting phase


31

Choose a Goal and a Topic

• A game must have a clearly defined goal expressed in terms of the effect on the player

• Choose a goal in which you believe

• The goal of STAR RAIDERS concerns the violent resolution of anger through skillful planning and dexterity. The topic is combat is space


32

Choose a Goal and a Topic

• The goal of EASTERN FRONT 1941 concerns the nature of modern war, the different between fire power and effectiveness. The topic is the war between Russian and Germany


33

Research and Preparation

• Read everything you can on the topic

• Your game must give the authentic feel

• Concentrate on goal and topic

• Write NO CODE!


34

Design Phase

• Primary objective is to create the outlines of three interdependent structures:– the I/O structure

– the game structure

– the program structure

• All 3 structures must be created simultaneously


35

I/O Structure

• Communicating information between computer and player

• the most constraining structure• I/O composed of input (keyboard, joystick,

mouse,etc.) and output (display and sound)• Devote special care to the input structure• How can a player control the game with a

joystick?• Choice of input devices


36

Game Structure

• Internal architecture of causal relationships tha

t define the obstacles the player must overcome

• Main problem is with realizing possibilities

• How to distill the fantasy of the goal and topic i

nto a workable system

• The designed must identify some “key” element

from the topic (eg. movement)


37

Program Structure

• Translate I/O structure and game structure into

product

• Organization of mainline code, subroutines,

interrupts and data that make up the entire

program

• Important elements

– Memory map

– variables and subroutines definitions

– document


38

Evaluation of the Design

• Does this design satisfy my design goal?

• Does it do what I want it to do?

• Will the player really experience what I want him to experience?

• Examine the stability of the game structure– Are there any circumstances in which the game could get

out of control?

• Insure that shortcuts to victory are blocked

• Don’t hesitate to abort the game


39

Pre-programming Phase

• To prepare complete game document

• The tone of the document should emphasize the player’s experience rather that technical considerations

• Compare first set of document to program structure notes


40

Programming Phase

• Easiest phase

• Requires attention to detail

• Game failed to live up to their potential because the programmer:– did not expend enough effort

– rushed the job

– didn’t bother to write in assembly language


41

Playtesting Phase

• To check for some design and programming pr

oblems

• Have courage to trash a fatal-flawed game

• test the game yourself to find programming bu

gs, then let other playtesters to check for bugs i

n game structure

• polish the game

• write the game manual


42

Design Techniques and Ideas

• Balancing solitaire games– human vs computer

• Relationships between opponents

• Smooth learning curve

• The illusion of winnability


43

Balancing Solitaire Games

• Vast resources– widely used– the computer is provided with immense resources that it

uses stupidly– easy to implement

• Artificial smarts– ad-hoc artificial intelligent routines– produce reasonable behavior

• the computer should not drive its tanks over a cliff or crash spaceships into each other

– unpredictability (human should not be able to guess)


44

Limited Information

• To limit the amount of information available to the human player


45

Pace

• Make the game fast so that the human player does not have much time to think


46

Relationships between Opponents

• Symmetric relationships– both sides have equals capability

– easy to program

• Asymmetric games– almost all solitaire games

• Triangularity– rock-scissors-paper game

• Actors and Indirect Relationships– not a very successful approach


47

Smooth Learning Curve

• Flat curve => hard to learn

• Steep curve => easy to learn

• A sharp jump => has one trick

• Many sharp jumps => has many tricks

• Falling curve => something wrong with the game

• Upward smoothly => goo game

• Games without smooth curve frustrates players


48

The Illusion of Winnability

• PAC-MAN appears winnable to most players, yet is never quite winnable

• Clean games encourage all players

• Careful analysis of the sources of player failure:– what trips up the player: game flaws or unwinnable or

player mistake?

240-492 games programming with java

Documents