Pong AI

[Blobe]

Hey, im trying to make a pong game with the second player as a computer, but i cant seem to egt the ai to work, so heres what i have and can someone please help me and give me some suggestions on how to make the paddle ahve a certian % chance to go to the ball. Thanks






var x, y, c, xinterval, yinterval, px, py, cx, cy, cinterval : int
var chars : array char of boolean
setscreen ("graphics:800,520,offscreenonly")
const INTENSITY := 300
var X : int
var hitMiss : int
X := 1
colorback (7)
cls
randint (c, 1, 15)
x := 400
y := 250
px := 50
py := 225
cx := 750
cy := 225
xinterval := 5
yinterval := 5
cinterval := 5

loop
for I : 1 .. INTENSITY
drawline (Rand.Int (0, maxx), Rand.Int (0, maxy), Rand.Int (0, maxx), Rand.Int (0, maxy), 7)
end for
drawfilloval (x, y, 10, 10, 9)
drawfilloval (x, y, 5, 5, 11)

x := x + xinterval
y := y + yinterval
if x >= maxx then
xinterval := -5
elsif x <= 0 then
xinterval := 5
end if

if y >= 490 then
yinterval := -5
elsif y <= 0 then
yinterval := 5
end if



% if cy >= 490 then
% cinterval := -5
% elsif cy <= 0 then
% cinterval := 5
% end if

if (y > py and y < py + 60) and x <= px + 15 then
xinterval := 5

end if
drawfillbox (px, py, px + 15, py + 60, black)
drawfillbox (cx, cy, cx + 15, cy + 60, black)
Input.KeyDown (chars)
if chars (KEY_DOWN_ARROW) and py > 5 then
py := py - 5
end if
if chars (KEY_UP_ARROW) and py < 435 then
py := py + 5
end if

randint (hitMiss, 1, 100)

if hitMiss <= 25 and x > 400 then
if cy > y then
cy := cy - 5
elsif cy < y then
cy := cy + 5
end if
% cy := y - 10
elsif hitMiss >=11 and x > 400 then
cy := cy + yinterval
end if

% if x > 400 then
% cy := cy - yinterval
% end if
drawfillbox (px, py, px + 15, py + 60, red)
drawfillbox (cx, cy, cx + 15, cy + 60, red)
drawfillbox (800, 520, 0, 500, 10)
drawfillbox (402, 500, 398, 0, red)

colorback (10)
locate (1, 1)
put cy
delay (5)
View.Update
X := X + 1
View.Update
end loop

[Insectoid]

Just make a Rand.Int and if it equals a certain number, the paddle goes for the ball. if you want a 1 in 3 chance,

code:

var num :=Rand.Int (1, 3) if num = 3 then     %go to ball end if

[Euphoracle]

You could give it an acceleration and increase/decrease that to a cap depending on whether it was "fast enough" to react, per say. That would make it not only look more fluid, but also allow you to give it "bad" reflexes, good reflexes, and impossible reflexes

[SNIPERDUDE]

What I did for mine was when the ball reached a certain point (halfway maybe) in the direction towards him, he would chase after it (it would move in the direction of the ball to match the Y value), but the opponent only has a certain speed in which they can move (which can be the difficulty setting)

[Blobe]

yea but insectoid where would to location of the ball be? im pretty new to programing, and i need some help

[Insectoid]

IF you've drawn the ball, you already know the location of the ball.

code:

if paddley > bally then      paddley-=1 end if

This will make the AI paddle go toward the ball.

The location of the ball is the Y value from when you drew the ball.

[Blobe]

Ok, that works, but now the AI paddle dosent run smothley, it dose not look very good, can i make it so it picks 1 number between 1,3 (or w/e) and then if it picks the number it dosent pick another and it goes to the ball, other wise it will just go a random way?

[btiffin]

This may or may not help. A friend of mine produced pongster.

http://www.digitalliquid.com/freeware.html
which leads to
http://www.pongster.com

It's heavy Flash/Director but you may be able to glean something from the sources.

Cheers

[Euphoracle]

I was fiddling with this idea; I quickly spewed out some code that happens to look like a pong game. What I did was I used a velocity to move the player's "block" as well as the computer's. However, when the player moves their block to the bottom, it resets the velocity to zero, such that they won't have to recover from a negative velocity when they overdo it. The computer, however, has to do this. By increasing/decreased the average velocity that the computer uses (by adjusting it's maximum by a "dumb" rating), I was able to make an adjustable AI that can either be super intelligent by moving very slowly and avoiding this pitfall (thus creating the "cannot be beaten" ai) and an ai that overdid it too much and had to recover based on its dumbness. This means that it is possible to animate my AI block so that it actually looks like a frantic player on the other end playing the game when it's in "dumb" mode, and like a calm, collected, professional when it is in "smart" mode.

[SNIPERDUDE]

Pretty smart. I like the "dumb" mode idea.

[Blobe]

k i like the velocity idea, but i have no idea how to use it

[S_Grimm]

velocity := 1
if input (KEY_DOWN_ARROW) then
playerx += velocity
end if

[Euphoracle]

Well here's the early stuff I was working on before I changed it up to be decent and use as an example when I peer tutor the turing class next semester. This is just the basic concept I was going on, but in UglyEdition (TM).

Turing:

%this code is ugly, please wear safety goggles setscreen ("graphics:600:600") setscreen ("offscreenonly") const PADDLE_H := 100 const PADDLE_W := 12 const PADDLE_LEFT_X := 25 const PADDLE_RIGHT_X := maxx - (25 + PADDLE_W) const PADDLE_VCAP := 16 const PADDLE_STARTY := (maxy div 2) - (PADDLE_H div 2) const PADDLE_FRIC := 1 %rate at which velocity of paddle decreases when idle const PADDLE_V_STEP := 1 %rate at which velicity increases per stroke (the ai is dumb because this puts it in the hole) const PADDLE_COLOR := green const BALL_R := 6 %this is actually the diameter; i'm too lazy to rename it const BALL_HR := BALL_R div 2 const BALL_V := 5 const BALL_COLOR := blue const K_UP := chr (200) const K_DOWN := chr (208) const DUMB_AMOUNT := 7 %10=god, 1=fence post const FPS := 1000 div 60 %millisec/sec type BALL :     record         x, y : int         vx, vy : int     end record type PADDLE : %if i was supercool and making this correctly, i wouldn't exempt the x and vx.  4 player pong anyone?     record         y : int         vy : int     end record var ball : BALL var p_paddle : PADDLE var ai_paddle : PADDLE var startpos := 0 %0=player 1=ai var done := false var chars : array char of boolean fcn get_paddle_x (left : boolean) : int     if (left) then         result PADDLE_LEFT_X     else         result PADDLE_RIGHT_X     end if end get_paddle_x proc approach (var value : int, target, step : int)     var nv : int     if (value > target) then         nv := value - step         if (nv < target) then             value := target         else             value := nv         end if     elsif (value < target) then         nv := value + step         if (nv > target) then             value := target         else             value := nv         end if     end if end approach proc reset_ball     if (startpos = 0) then         ball.x := PADDLE_LEFT_X + PADDLE_W + BALL_HR + 1         ball.y := p_paddle.y + (PADDLE_H div 2) - BALL_R     else         ball.x := PADDLE_RIGHT_X - PADDLE_W - BALL_HR - 1         ball.y := ai_paddle.y + (PADDLE_H div 2) - BALL_R     end if     ball.vx := 0     ball.vy := 0 end reset_ball proc reset_paddles     p_paddle.y := PADDLE_STARTY     p_paddle.vy := 0     ai_paddle.y := PADDLE_STARTY     ai_paddle.vy := 0 end reset_paddles proc launch_ball     var q := Rand.Int (0, 1)     if (startpos = 0) then %so it doesn't instantly bounce back         ball.vx := BALL_V     else         ball.vx := -BALL_V     end if     if (q = 0) then         ball.vy := -BALL_V     else         ball.vy := BALL_V     end if end launch_ball proc newgame     reset_paddles     reset_ball     launch_ball end newgame proc win (left : boolean)     if (left) then %player         put "player wins"         startpos := 0     else %ai         put "ai wins"         startpos := 1     end if     put "play again? (y/n) " ..     View.Update     loop         var c : string (1)         getch (c)         if (c = "y") then             newgame             exit         elsif (c = "n") then             done := true             exit         end if     end loop end win fcn collide_with_paddle (var p : PADDLE, x, y : int, left : boolean) : boolean     %vertexes     var px := get_paddle_x (left)     var x1 := px     var x2 := px + PADDLE_W     var y1 := p.y     var y2 := p.y + PADDLE_H     if (x < x2 and x > x1 and y > y1 and y < y2 and left) then         result true     elsif (x > x1 and x < x2 and y > y1 and y < y2 and (not left)) then         result true     end if     result false end collide_with_paddle fcn collide_ball : boolean %true if game is done     var new_x := ball.vx + ball.x     var new_y := ball.vy + ball.y     var changed := 0     %top & bottom walls     if (new_y < 0 or new_y > maxy) then         ball.vy := -ball.vy         changed := 1     end if     %game loser     if (new_x < 0) then         win (false)         result true     elsif (new_x > maxx) then         win (true)         result true     end if     %paddles     if (collide_with_paddle (p_paddle, new_x, new_y, true)) then         ball.vx := -ball.vx     elsif (collide_with_paddle (ai_paddle, new_x, new_y, false)) then         ball.vx := -ball.vx     end if     result false end collide_ball proc move_ball     ball.x := ball.vx + ball.x     ball.y := ball.vy + ball.y end move_ball proc do_player     Input.KeyDown (chars)     if (chars (K_UP)) then         p_paddle.vy := min (p_paddle.vy + PADDLE_V_STEP, PADDLE_VCAP)     elsif (chars (K_DOWN)) then         p_paddle.vy := max (p_paddle.vy - PADDLE_V_STEP, -PADDLE_VCAP)     else         approach (p_paddle.vy, 0, PADDLE_FRIC)     end if     if (p_paddle.vy > 1) then         p_paddle.y := min (p_paddle.y + p_paddle.vy, maxy - PADDLE_H)         if (p_paddle.y = maxy - PADDLE_H) then             p_paddle.vy := 0         end if     else         p_paddle.y := max (p_paddle.y + p_paddle.vy, 0)         if (p_paddle.y = 0) then             p_paddle.vy := 0         end if     end if end do_player proc do_ai_think     if (ball.vx < 0) then %looks more realistic if it idles when player is moving         return     end if     var projected_y := ball.y + ball.vy     var current_path := ai_paddle.y + ai_paddle.vy + (PADDLE_H div 2)     if (projected_y > current_path) then         ai_paddle.vy := min (ai_paddle.vy + PADDLE_V_STEP, round ((PADDLE_VCAP / 2) / (DUMB_AMOUNT / 10))) %makes it look dumb     elsif (projected_y < current_path) then         ai_paddle.vy := max (ai_paddle.vy - PADDLE_V_STEP, round ((-PADDLE_VCAP / 2) / (DUMB_AMOUNT / 10))) %and lose occasionally     else         approach (ai_paddle.vy, 0, PADDLE_FRIC)     end if     if (ai_paddle.vy > 1) then         ai_paddle.y := min (ai_paddle.y + ai_paddle.vy, maxy - PADDLE_H)     else         ai_paddle.y := max (ai_paddle.y + ai_paddle.vy, 0)     end if end do_ai_think proc drawball     drawfilloval (ball.x, ball.y, BALL_HR, BALL_HR, BALL_COLOR) end drawball proc drawplayer     drawfillbox (PADDLE_LEFT_X, p_paddle.y, PADDLE_LEFT_X + PADDLE_W, p_paddle.y + PADDLE_H, PADDLE_COLOR) end drawplayer proc drawai     drawfillbox (PADDLE_RIGHT_X, ai_paddle.y, PADDLE_RIGHT_X + PADDLE_W, ai_paddle.y + PADDLE_H, PADDLE_COLOR) end drawai proc drawgui     %hahahahaha end drawgui %divide by zero lol if (DUMB_AMOUNT < 1 or DUMB_AMOUNT > 10) then     put "DUMB_AMOUNT = ", DUMB_AMOUNT, "\nWHY WOULD YOU DO THIS D:<\n0 < DUMB_AMOUNT < 11\nPLEASE THANKS."     return end if loop     newgame     loop         cls         drawball         drawplayer         drawai         drawgui         View.Update         exit when (collide_ball)         move_ball         do_player         do_ai_think         Time.DelaySinceLast (FPS)     end loop     exit when done end loop

[SNIPERDUDE]

Wow pretty awesome.

Lol, UglyEdition (TM).

[S_Grimm]

good idea on the "dumb" and really ugly. ^_^