distance := ((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1))** 0.5

if distance < 10 %if collision
then
sp2x := round(sp1x*sp1x + sp1y*sp1y)**0.5 * ((x2-x1)/(x2-x1 + y2-y1))
sp2y := round(sp1x*sp1x + sp1y*sp1y)**0.5 * ((y2-y1)/(x2-x1 + y2-y1))
end if

%-----------------------------------------------------------------------------
%  Title of Program :  Ping Pong Game
%  Purpose : It's a game with some crazy rules or let's say No rules
%  Author :  Anas Obaisi
%  Date : last edited December 19, 2002, 9:18 e
%-----------------------------------------------------------------------------

%-----------------------------------------------------------------------------
%Variable Dictionary
%-----------------------------------------------------------------------------
var b, n : int %Cordenates of the cercle centre
var chars : array char of boolean  %Arrys
var x : int % the center of the circle
var y : int % the center of the circle
var dx : int %The Change in x
var dy : int %The Change in y
var picID : int %The ball image
var picBack : int %the Background Picture
var t : array 1 .. 8 of int := init (100, 100, 135, 185, 220, 220, 185, 135) %initiling the lines of the polygon
var z : array 1 .. 8 of int := init (100, 150, 185, 185, 150, 100, 65, 65) %initiling the lines of the polygon
var distance : real
var cx : int := 5
var cy : int := 5
%-----------------------------------------------------------------------------
%Setting Values For Variables
%-----------------------------------------------------------------------------

x := 100 %assigning where the centre of the circle must be
y := 240 %assigning where the centre of the circle must be
dx := Rand.Int (10, 15) %setting the changes of x to random number
dy := Rand.Int (10, 15) %setting the changes of y to random number
b := 100 %Centre of the Circle
n := 100 %Centre of the Circle
% distance := ((b - x) * (b - x) + (n - y) * (n - y)) ** 0.5

%-----------------------------------------------------------------------------
% SET SCREEN SETTINGS
%-----------------------------------------------------------------------------

setscreen ("graphics:v16") % sets the screen for vga mode 640 x 480
setscreen ("nocursor") % Turn off cursor
setscreen ("noecho") % Do not echo keys

%----------------------------------------------------------------------------
%Drawing the intor screen
%----------------------------------------------------------------------------

Draw.FillBox (0, 0, maxx, maxy, black)
delay (1000)
Draw.FillPolygon (t, z, 8, brightblue)
Draw.Polygon (t, z, 8, cyan)
delay (1000)
var font4 : int
font4 := Font.New ("Palatino:40:bold,italic")
Font.Draw ("Welcome", 200, 300, font4, green)
delay (1000)
put "Try to prevent the bouncy ball from going behind your big circle"
delay (3000)

%----------------------------------------------------------------------------
%Play Music while the program is running
%----------------------------------------------------------------------------

process Rock
    loop
        Music.PlayFile ("Seymor.mid")
    end loop
end Rock

fork Rock


%----------------------------------------------------------------------------
%Drawing Background
%----------------------------------------------------------------------------

Draw.FillBox (0, 0, maxx, maxy, 10)
for v : 80 .. 640 by 80
    Draw.Line (v, 0, v, 480, 0)
end for

for h : 60 .. 640 by 60
    Draw.Line (0, h, 640, h, 0)
end for

drawbox (0, 0, maxx, maxy, 1)
drawbox (4, 4, maxx - 4, maxy - 4, 1)
drawfill (1, 1, 1, 1)

%---------------------------------------------------------------------------
% Capture Image as Background and Draw it
%---------------------------------------------------------------------------

picBack := Pic.New (0, 0, maxx, maxy)
Pic.Draw (picBack, 0, 0, picCopy)
cls

%---------------------------------------------------------------------------
%Drawing the Ball
%---------------------------------------------------------------------------
procedure ran
    for j : 1 .. 2
        randint (x, 200, maxx - 400)
        randint (y, 300, maxy - 200)
        randint (dx, 1, 5)
        randint (dy, 1, 5)
    end for
end ran

Draw.Oval (x, y, 10, 10, blue)
Draw.Dot (105, 240, 3)
Draw.Fill (105, 240, blue, blue)
picID := Pic.New (90, 200, 115, 250)

%---------------------------------------------------------------------------
%looping and setting the walls
%---------------------------------------------------------------------------

loop
    distance := ((b - x) * (b - x) + (n - y) * (n - y)) ** 0.5
    if distance < 10 %if collision
            then
        cx := round(dx * dx + dy * dy) ** 0.5 * ((b - x) / (b - x + n - y))
        cy := round(dx * dx + dy * dy) ** 0.5 * ((n - y) / (b - x + n - y))
    end if

    if distance < 50 then
        dx := -dx
    end if
    Pic.Draw (picBack, 0, 0, picCopy)
    Pic.Draw (picID, x, y, picMerge)
    delay (40)
    x := x + dx

    if x >= maxx - 20 or x <= 0 then
        dx := -dx
    end if

    y := y + dy
    if y >= maxy - 50 or y <= -30 then
        dy := -dy
    end if

    %-----------------------------------------------------------------------------
    %Make The Big Circle move using the Keyboared
    %-----------------------------------------------------------------------------
    Input.KeyDown (chars)

    if chars (KEY_UP_ARROW) then
        n := n + cy

    elsif chars (KEY_RIGHT_ARROW) then
        b := b + cx

    elsif chars (KEY_LEFT_ARROW) then
        b := b - cx

    elsif chars (KEY_DOWN_ARROW) then
        n := n - cy
    end if

    drawoval (b, n, 40, 40, red)
    delay (5)

end loop