EVOLUTION EXPLOSION

Final Year Project Presentation

Lee NorrisBSc (HONS) Computer Games Programming

Background

Story• Scientist caught in lab explosion• Needs to navigate world looking for lost vials• To obtain vials puzzles need to be completed• All vials make scientist human again• Otherwise stuck as animal

Chosen because:• Experience in the adventure-puzzle genre• Related to degree specifications

IntroductionEvolution Explosion is an adventure-puzzle game written in C++ and DirectX for the Personal Computer with a

Windows operating system. This project was designed to demonstrate the following:

A complete game that can be played from start to finish The coding structure of a complete game Multiple handling of different user inputs and selecting the appropriate handler at the beginning of the game Customisable user options Saving and Loading Selecting appropriate libraries from both C++ and DirectX to optimise, refine and refactor code In-Game sound Global Highscores Professional deployment of a game for the Windows operating system Multiple playable characters, rewards and punishments A complete game storyline outlined by a game design document Game pre-loading, pre-compiled assets, initialisation, real-time text rendering, error handling and cleanup Image manipulations such as rotation and scaling Powered by an in-house game engine Error handling Follows coding rules fully with Hungarian notation

Research and Planning Gantt Chart Methodology

• Agile Software Development Game Design Document Technical Design Document Similar Games Integrated Developer Environments Language and Application Development Interfaces Modelling

• Jackson Structured Diagram HCI

• Screen kept as simple and ‘clutter free’ as possible.• Error Handling• Consistency• Instructions

Quality Assurance

Developer Testing (Rapid Test)• Black Box Testing• Obvious bugs fixed immediately

User Testing (Stress Testing)• White Box Testing• Less visible bugs and confusions resolved

Soak Test

Front End

Five Buttons Two Sub-menus Quit confirmation Continue game button disabled if no save

game is found Checks if the front end is brought up in-game

(esc) or from starting a new game

Frontend

Levels

Five levels Graphics selection methods Character selection methods Scrolling the backgrounds• Updating (paging on level 5)• Parallax• Relative to characters velocity

Other animations• Star rotation• Door opening

Level One: Racecourse

Mini-Games Structure

Four states per mini-game• Introduction• Play• Win• Lose

Class structure• Mini-games factory• Completely independent (mini-game only knows

what it needs to know)

Pseudo Codeenum MinigameStates{

intro state = 0,play state = 1,win state = 2,lose state = 3

} eMinigameStates;

void Draw(){

switch(eMinigameStates){case intro state:draw introduction screen;break;case play state:draw play screen;break;case win state:draw win screen;break;case lose state:draw lose screen;break;}

}

Memory Game

Aim: To match all of the cards in the required timeframe.

16 Cards 2 Pairs – 8 matches Difficulty determines how much time the mini-game

runs for Win condition

• All cards have been matched Lose condition

• Timer hits zero

Memory Game

Issues Faced

Initially randomising the cards• Create a two-dimensional array with a while loop

that checks that a position on the x and y axis was free. If so, fill it. If not, look again

Crash when swapping a blank card with an image card• Changed the checking system to coordinate based

so if the clicked variables do not match the cards position then the card stays blank

Level Two: Stamping Ground

Slider Game

Aim: To rotate all of the slide into their required positions within the set timeframe.

Randomly Rotated Each click rotates 90 degrees Difficulty determines how much time the mini-game runs for Animation in the rotations Score only incremented for the first time the slides are rotated to 0

degrees Win Condition

• All slides are rotated back to 0 degrees Lose Condition

• The timer hits zero

Slider Game

Issues Faced

Rotating the slides• Create a function with a local pointer to a Sprite• Get the clicked sprite and convert rotation into

degrees• Compare the current rotation position with the

desired position• Convert position back to radians and update until

desired position is met

Level Three: Flying High

Sequence Game

Aim: To correctly follow each sequence the computer creates within the set timeframe.

Randomly generated Each new round is same as previous with one extra sequence

added Difficulty determines how many rounds there are Win Condition

• All rounds complete Lose Conditions

• Incorrect sequence• Timer hits zero

Sequence Game

Issues Faced

Constantly looping through a case invalidating it• Create a NULL case which is called once the read marker

has been validated Last lit tile remaining on in the next round• Set up a SetHotspot function that returns a boolean true• Change that boolean value to ‘false’ once the game

begins the next round Setting the timing of the game• Define a constant show frequency variable and divide it

into the round length

Level Four: Swim Gym

Lights Game

Aim: To switch on all of the lights within the set timeframe.

Lights array toggles all surrounding lights Flickering animation and SFX when user does not click

for extended period of time Difficulty determines how many lights there are Win Condition

• All lights turned on Lose Condition

• Timer hits zero

Lights Game

Issues Faced

Toggling Lights Crash• Put in checks so if light is on the edge of the grid,

do not try to toggle the light on the side of the edge that it is on

Win state check returns true if only one light is on• Move the ‘for’ loop to an external function and

assume that the win condition is false until it has checked every light and they are all on

Level Five: Vine Climb

Quiz Game

Aim: To answer all of the questions within the set timeframe.

Questions are randomly set The same question is never asked twice in one game

• Link a boolean variable to the for loops ‘i’ variable Difficulty determines how difficult the questions are

• Three structures; easy, medium, hard Timer resets itself after every question answered Win Condition

• All questions answered correctly Lose Condition

• A question is answered incorrectly• The timer hits zero

Quiz Game

Issues Faced

Same questions repeating themselves• Created a boolean variable that is set to true when

a number of an array has been chosen Comparing the answers to the correct answer• Used ‘strcmp’ to compare the string selected with

the correct string• Returned 0 = correct• Otherwise incorrect

Game Structure

Engine in separate library Each animal and mini-game completely

separate and managed by factories Everything initialised while the introduction

screen is shown so no loading times Easily editable• Levels / characters can be swapped with one line of

code Game can be restarted from anywhere

Art

Loaded in by resource• Bigger executable• No resource errors by users deleting assets

Can either be a:• Bitmap• Sprite • Static Background Layer• Scrolling Background Layer

Audio

Loaded in by resource• Bigger executable• No resource errors by users deleting assets• Played asynchronously (new sound overrides previous sound)• As opposed to synchronously (current sound needs to finish before

new sound can begin) Sound effects played by in-game events

• Card being flipped• Correct selection• Random number modularised to zero

Support for background audio with pause and rewind• Not implemented as no relevant music found

External Data Handling - Loading

Use the <sys/stat.h> header file• Call a structure from the header• Use this structure to see if a file exists• File is not opened, just checked• Boolean TRUE or FALSE is returned

If Save file exists:• Enable the ‘Continue Game’ button• If clicked, send boolean file requested to Levels• Use custom written Load function to iterate through

each byte in the file and apply it to the correct variable

Pseudo Codestructure saveTypes{

enum Level currentLevel;int difficulty;bool checkFullscreen;int score;bool miniGameWinStates[4];

} sSaveTypes;

BOOL LoadGame(){

open existing file EvoEx.dat;

Set saveTypes structure to in-game variables;

loop through each byte in the file and apply that byte to the correct variable;

close the file;}

External Data Handling - Saving

Called each time a new level begins Check if a save file exists. If not, create one Use custom written Save function to write each variable

value to the file as a byte If a variable has not been set then fill the corresponding

byte with a placeholder value Saved data includes:

• Current level• If the game should be fullscreen or windowed• The users score (written in 5 bytes)• The win states of each mini-game

Pseudo Codestructure saveTypes{

enum Level currentLevel;int difficulty;bool checkFullscreen;int score;bool miniGameWinStates[4];

} sSaveTypes;

BOOL Save(){

open existing file EvoEx.dat, if one does not exist, create it;

set in-game variables to saveTypes structure;

format each variable into bytes (e.g ‘true’ becomes ‘1’);

write the bytes to file;

close the file;}

External Data Handling – High Scores

Uses same method as saving and loading the game

Two extra functions used:• Update – Checks if the current score is higher than

a highscore and places it• Draw – Draws the scores to the screen

Debugging

Breakpoints• Show each iteration of a segment of code and

what each value contains Print to screen• Use TCHAR to format variables and print them to

screen os stream• Prints the results to the Integrated Development

Environment console

Optimisation Images

• Different Bit Depths• Main Images – 24-Bit• Secondary Images – 16-Bit• Background Images – 8-Bit

• RLE compression used – halves the image size• SetColour function used to change colour of image• Sprite sheet flipping technique used – halves animation size• Sprite class batch processes all images at once so adding extra images produces virtually no extra load time• Loaded in by resource so already compiled

Audio• Stereo sound for major sounds• Mono for less significant sounds• Looping rather than one long effect• Loaded in by resource so already compiled

Fonts• Loaded using the Sprite manager (batch processed)• Splits the image into small tiles – one for each character

Variables• Pointers to memory – less overhead• Use floating point variables as little as possible• Use a vector container to manager all of the images (entity manager)

Future Improvements

Weather System• Randomly selected when the game is opened

Sun• Use a light source for the sun

Rain• Randomly create lines that fall from the top to the bottom of the screen

Snow• Randomly create white pixels that randomly ‘sway’ left to right as they fall• Or create a small image of a snowdrop and replicate many times

Wind• Play sound effect with volume relative to the wind strength• Slow down or speed up the characters speed depending on wind direction

Future Improvements

Multiplayer

Support already implemented for multiple controllers

Instead of facing a timer, user faces another user. Winner gets the score multiplier and the next character

Future Improvements

Computer AI

Add in extra, computer controlled animals• Bird character has birds flying in opposite direction and

avoiding it• Already a distance checker so all that is required is a ‘for’ loop to

check each computer controlled characters distance from user and if the animal is to close, to move up or down to avoid it

• Elephant has baby elephant following it around• Scale the original elephant down• Check the distance from the big elephant and the facing direction

and update accordingly

Miscellaneous Improvements

Audio button in front end options so user can turn off in-game sounds

Create a resource cache to manage all game entities Add ambient lighting so transitions can be implemented Better debug support Check memory and CPU requirements Add three-dimensional engine support

• Camera class, lights class and mesh class required• Entity manager updated to check if the asset is a mesh or a

Bitmap

Conclusion Fully tested and bug free game that can be played from start to finish Five different games in one game world Demonstrates common game aspects

• Saving / Loading• Highscores• Multiple Levels• Multiple input device support• User customisable options

Industry standard Game Design Documents, Technical Design Documents and Asset Lists

On schedule with Gantt Charts Followed methodology as much as ably possible

The End

Questions?