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Challenge #15 - Table Tennis / Pong AI

Started by kevin, November 12, 2008, 08:41:27 PM

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kevin





Challenge #15 - Table Tennis / Pong  AI


    When learning to write Video Games,  it's commonly suggested that new programmers have a go a creating their version of classic retro games such as Pong / Tennis style game initially.  The theory being, that even though this is a retro challenge,  in order to build our own version of Pong, our program will need to cover many of the initial problems facing game programmers.    Such as, display principals (drawing the screen),  controls (getting input from the player), collisions  and computer controls characters,   Other wise known as  AI.   To be honest,  not too many retro games have 'smart' characters.  There are some exceptions to this of course, but generally speaking most old games have very simplistic AI algorithms. 

 
    In this challenge, your goal is to create your own Table Tennis/Pong styled game where the human controlled player hits the ball with the computer controlled player.  The player should control the bat (keys, joypad or mouse), with the aim of keeping the ball in play.  The ball is considered out of play, once it passed the players bat and leaves the screen/play area (behind the bat)    The visuals/physics are not important,  the challenge here is that you'll need to create the logic for the computer controlled player.



Reference Materials

  2 Player Pong


Submission

* Submissions can be written in any version of PlayBasic

* Submission can only be accepted in Source Code form only.

* Authors can use external Media (images/music) provided you created the media/and or have permission to distribute the includes media or the Media is in the public domain.

* Zip up your Submissions and please try to keep it smaller than 500K !

* Authors automatically give consent for their submission(s) to distributed and used for promotional purposes via UnderwareDesign.com, PlayBasic code tank.

* Authors can submit as many times as they like.

* To make a submission, zip up your projects source code + media and either post it in this thread, or create your own thread in either the Source Codes or Show Case forums and post a link bellow.



Dead Line

Anytime before the next ice age




slayer93

#1
My quick try at this. Not the most advance ai or pong game.

Up/Down Arrowkeys to move.

PlayBASIC Code: [Select]
; PROJECT : Pong!
; AUTHOR : Christian Ang
; CREATED : 11/12/2008
; ---------------------------------------------------------------------

;
; Setup
SetFPS 0
CreateCamera 1
RenderToScreen

;
; Create Bats
Box 0, 0, 10, 100, 1
GetImage 1, 0, 0, 10, 100
PrepareFXImage 1

Player=NewSprite(20, GetScreenHeight()/2, 1)
CenterSpriteHandle Player
SpriteCollision Player,True
SpriteCollisionMode Player,0

Computer=NewSprite(GetScreenWidth()-20, GetScreenHeight()/2, 1)
CenterSpriteHandle Computer
SpriteCollision Computer,True
SpriteCollisionMode Computer,0
Cls(0)

;
; Create Ball
Circle 10, 10, 10, 0
GetImage 2, 0, 0, 20, 20
PrepareFXImage 2
Ball=NewSprite(GetScreenWidth()/2, GetScreenHeight()/2, 2)
CenterSpriteHandle Ball
SpriteCollision Ball,True
SpriteCollisionMode Ball,2

;
; Set Ball Direction
Ballx=rnd(1)
Bally=rnd(1)
if Ballx=0 then Ballx=-1
if Bally=0 then Bally=-1

;
; Timer System Vars
msPerFrame#=1000/60
oldTime=Timer()

compTime=Timer()
compDecisionTime=rnd(100)+100
compDecision=rnd(3)

;
; Loop
Do

;
; Draw to Scene Buffer
CaptureToScene
ClsScene

;
; Show Score
Text 0,0,"Player Score: "+str$(pScore)+" | Computer Score: "+str$(cScore)

;
; Update Timer System
framesPast# = (Timer()-oldTime)/msPerFrame#
oldTime=Timer()

;
; Controls
If Upkey()=1 then MoveSprite Player,0.0,-5.0*framesPast#
If Downkey()=1 then MoveSprite Player,0.0,5.0*framesPast#

;
; Computer Ai
; Make a decision every so often
If Timer()-compTime => compDecisionTime
; Don't make it super smart by making 1 out of 10 moves go the wrong way
; and 1 out of 10 stay still
compDecision=rnd(9)
compDecisionTime=rnd(100)+200
compTime=Timer()
Endif

; Act on decision
If compDecision=0
;
; Idle
Else
If compDecision=1
;
; Wrong Way
If GetSpriteY(Ball) < GetSpriteY(Computer)
MoveSprite Computer,0.0,5.0*framesPast#
Else
MoveSprite Computer,0.0,-5.0*framesPast#
Endif
Else
;
; Right Way
If GetSpriteY(Ball) < GetSpriteY(Computer)
MoveSprite Computer,0.0,-5.0*framesPast#
Else
MoveSprite Computer,0.0,5.0*framesPast#
Endif
Endif
Endif

;
; Move Ball
If Ballx=1
MoveSprite Ball,-6.0*framesPast#,0.0
Else
MoveSprite Ball,6.0*framesPast#,0.0
Endif

If Bally=1
MoveSprite Ball,0.0,-2.0*framesPast#
Else
MoveSprite Ball,0.0,2.0*framesPast#
Endif

;
; Collision
If SpriteHit(Ball,2,1) > 0
Ballx=-Ballx
Endif
If GetSpriteY(Ball) < 0 or GetSpriteY(Ball) > GetScreenHeight() then Bally=-Bally

If GetSpriteY(Player)-50 < 0 then PositionSprite Player,20,50
If GetSpriteY(Player)+50 > GetScreenHeight() then PositionSprite Player,20,GetScreenHeight()-50
If GetSpriteY(Computer)-50 < 0 then PositionSprite Computer,GetScreenWidth()-20,50
If GetSpriteY(Computer)+50 > GetScreenHeight() then PositionSprite Computer,GetScreenWidth()-20,GetScreenHeight()-50

;
; Score
If GetSpriteX(Ball) < 0
inc cScore
reset=1
Endif
If GetSpriteX(Ball) > GetScreenWidth()
inc pScore
reset=1
Endif

Login required to view complete source code



markel422

#2
I've decided to take Kevin's advice and to not jump too far ahead of myself when it comes to making a big projected game.

I actually really did needed to start small because I had no idea how complicated this programming actually was and Kevin's predictions on how long it takes for a new programmer to create a Pong Game was right on. Compared to only a few hours for very Experienced people to create this...It actually took me a few weeks to get this right (As seen on my Code File on top, the start date and end date) and to understand the concepts of this. I was even able to successfully create the AI for the Computer which is an absolute first for me.:)

I really like how much I've improved on this Game Programming. When I first started, My mind was already blown away just by seeing one line of code :o, but now look at my Progress. :)

At the same time I wonder what my next level of Game Programming will be? After the Pong Game Now.

Here's the Code:

PlayBASIC Code: [Select]
; PROJECT : FirstGamePong
; AUTHOR : Michael
; CREATED : 10/17/2009
; EDITED : 10/30/2009
; ---------------------------------------------------------------------

openscreen 800,600,32,1

setfps 60

loadfont "Arial",1,24,0

gosub Ball_Restart

ballsize=8

player1x=40
player1y=300
player2x=750
player2y=300
playerspeed=4
Width=10
Height=80
p2width=10
p2height=50

sw=getscreenwidth()/2
sh=getscreenheight()/2

Dim PlayerScore(2)
PlayerScore(1)=0
PlayerScore(2)=0

do
cls 0

Compstate=false

//Create Movement of Ball
Ballx=ballx+ballspeedx

//Add Collision Code for X Screen
;if ballx+ballsize > getscreenwidth()
;ballx = getscreenwidth() - ballsize
;ballspeedx=ballspeedx * -1
;endif

;if ballx-ballsize < 0
;ballx = 0 + ballsize
;ballspeedx=ballspeedx * -1
;endif

//Add Collision Code for Y Screen
if bally+ballsize > getscreenheight()
bally = getscreenheight() - ballsize
ballspeedy=ballspeedy * -1
endif

if Bally-ballsize < 0
bally = 0 + ballsize
ballspeedy=ballspeedy * -1
endif

bally=bally+ballspeedy

//Create Ball Collision for Player
if player1y+height>Bally-ballsize and player1y<Bally+ballsize
if player1x+width>ballx-ballsize and player1x<Ballx+ballsize
Ballspeedx=ballspeedx * -1
endif
endif

//Create Ball Collision for AI
if player2y+height>Bally-ballsize and player2y<Bally+ballsize
if player2x+width>ballx-ballsize and player2x<Ballx+ballsize
Ballspeedx=ballspeedx * -1
endif
endif


//Create Movement of Player 1
if upkey()=true
player1y=player1y-playerspeed
endif

if downkey()=true
player1y=player1y+playerspeed
endif

//Create AI for Player 2

compball=bally-40

;Handle logic if ball is more than white line of AI space make AI move
if compstate=false
if ballx > sw
Compstate=true
if player2y > compball
player2y = player2y - 3
else if player2y < compball
player2y = player2y + 3
endif
endif
endif
endif

;Handle logic if ball is less than white line of AI space make AI get in center
if compstate=false
if ballx < sw
compstate=true
if player2y > sh-40
player2y = player2y - 3
else if player2y < sh-40
player2y = player2y + 3
endif
endif
endif
endif

if player2y = sh-40
compstate=false
endif

//Box Screen Collision for Player
if player1y < 0
player1y = 0
endif

if player1y+height > getscreenheight()
player1y = getscreenheight() - height
endif

//Box Screen Collision for AI
if player2y < 0
player2y = 0
endif

if player2y+height > getscreenheight()
player2y = getscreenheight() - height
endif

//Create Ball
Circle ballx,bally,ballsize,1


//Create Human Player 1
Box player1x,player1y,player1x+width,player1y+height,1

//Create AI Player 2
Login required to view complete source code


kevin

#3
      Well I'm impressed, you've done really well with this and it even seems to play fairly also ! - So a  big  congratulations are in order !   

     
QuoteAt the same time I wonder what my next level of Game Programming will be? After the Pong Game Now.

         Well, you could expand this further.   Multi Ball perhaps ?   yes, cruel I know :)

         What Pong represents is a hand of concepts that are fairly universal in 2D (and 3D) game programming,  stuff like  object management,   handling  user input, object collisions,  motion and ultimately the visual representations of the in game characters (the bat and ball).     What you're about to find out,  is that these concepts are in virtually every game ever written..  So concepts you've learnt here overlap between different game genres.

          As for what's next,  well something along the lines of Snake game is a common one,  or for the little more adventure perhaps a Space Invaders game might be a good healthy challenge next.    Alternatively  most of the major 1980's  arcade games a worth tackling.   Pac Man,  Frogger, Donkey Kong,   Asteroids,  Centipede,  Boulder Dash..   etc -  The down side of knocking up one of those,  is that you generally require at least some mock up artwork.    Atm, the more time you spend focusing upon the programming, the better..                   

        Snake Game
        Shoot the Alien
         

    Edit:  Another option might be an BreakOut / Arkanoid style game.  Which is basically Pong up against a wall.