Pong Clone in Pascal

One of the every first graphical programs I wrote in pascal was a very basic pong clone. All the graphics were done using the Borland graphics library using vector style graphics. So you will need the bgi and chr files to build and run this program. Again I had to adjust the timing for this program as the original timing system would have only worked on the old 386 I developed this on! You’ll notice that the program made use of the goto statement in pascal which is generally frowned upon. This is because it is one of my earlier pascal programs, and I still had many bad habits from writing many programs in BASIC.

{Andrew Danson Shuffle Puck Ver. 1 1996}
{ Modified in 2012 for sanity!
 - redid indentation
 - Added more comments
 - reworked timer
}
program shuffle;

uses crt,graph,dos;
label 1,2,3,4; 
var	       
   redone				  : boolean; {does the score need to be redrawn}
   won					  : boolean; {has the player won?}
   key					  : char;    {current key press}
   keynum,ballspeed,sidespd		  : integer;
   {the ordinal version of the keypress and the ball vertical speed and horizontal speed}
   ballx,bally				  : integer; {the location of the ball}
   yourpaddlesize,comppaddlesize	  : integer; {the size of the paddles for player and computer}
   ypx,cpx				  : integer; {The location of the player paddle and computer paddle}
   name,lives,ives			  : string;
   {your name and strings for drawing the lives each player has}
   ylives				  : integer; {The players lives}
   clives				  : integer; {The computers lives}
   compspeed,maxx,ballvertdir,ballhoridir : integer;
   {The speed of the computer player, the maximum X, and direction values for the ball}
   cycles				  : integer; {cycles to wait for}
   count				  : integer; {counter for delay loop}


{ Gets the time in the same way that gwbasic timer function works }
function timer:single;
var result			: single;
   Hour, Minute, Second, Sec100	: word;
begin	   
   result:=0;
   GetTime(Hour, Minute, Second, Sec100);
   minute:=minute + (hour*60);
   second:=second + (minute*60);
   result:=second + (sec100 / 100);
   timer:=result;
end;

{initialises the game asking the player who they are and setting up everything}
procedure init;
var
   gd,gm : integer;
   nextt : single;
   c	 : single;
begin
   lowvideo;
   ballspeed:=4;
   nextt:=0;
   textcolor(lightblue);
   textbackground(blue);
   window (1,1,25,5);
   clrscr;
   writeln('	Shuffle Puck ver 1');
   writeln('by Andrew Danson 1996');
   write('what is your name ');
   readln(name);
   yourpaddlesize:=45;
   comppaddlesize:=40;
   ballx:=random(190)+10;
   bally:=random(90)+90;
   compspeed:=2;
   gd:=detect;
   gm:=9;
   initgraph(gd,gm,'');
   maxx:=getmaxx;
   ballspeed:=random(3)+1;
   if ballvertdir=1 then ballvertdir:=2 else ballvertdir:=1;
   ballhoridir:=random(3);
   sidespd:=random(2)+1;
   {work out how many delay(1) calls make up 1/200th of a second}
   c:=0;
   nextt:= timer + 1;
   while timer<nextt do
   begin
      delay(1);
      inc(c);
   end;
   c := c / 200;
   cycles := round(c);
end;

{draws the ball on screen}
procedure showball(x,y:integer);
begin
   setcolor(lightred);
   circle(x,y,3);
end;

{removes the ball from the screen}
procedure hideball(x,y:integer);
begin
   setcolor(black);
   circle(x,y,3);
end;

{draws your paddles on screen}
procedure showyourpaddle(x,size:integer);
begin
   setcolor(lightblue);
   rectangle(x,getmaxy-10,x+size,getmaxy-5);
end;

{hides your paddles on the screen}
procedure hideyourpaddle(x,size:integer);
begin
   setcolor(black);
   rectangle(x,getmaxy-10,x+size,getmaxy-5);
end;

{draws the computers paddle on screen}
procedure showcomppaddle;
begin
   setcolor(lightgreen);
   rectangle(cpx+10,5,cpx+comppaddlesize,10);
end;

{hides the computers paddle}
procedure hidecomppaddle;
begin
   setcolor(black);
   rectangle(cpx+10,5,cpx+comppaddlesize,10);
end;

{called when there is a bounce in the vertical direction}
procedure bunce;
begin
   sound(200);
   delay(2);
   nosound;
   ballspeed:=random(3)+1;
   if ballvertdir=1 then ballvertdir:=2 else ballvertdir:=1;
   ballhoridir:=random(3);
   sidespd:=random(2)+1;
end;

{checks the ball to see if it has gone of the top or bottom edge, or if it has hit a paddle
  I'm not sure what the local variable was for, looks like it is not needed.}
procedure checkball(budd:integer);
begin
   if ballygetmaxy-5 then
   begin
      sound(500);
      delay(50);
      nosound;
      ylives:=ylives-1;
      ballx:=random(190)+10;
      bally:=random(90)+90;
      redone:=true;
    end;
   if bally>getmaxy-20 then if bally<getmaxy-5 then if ypxballx-5 then
   begin
      bunce;
      bally:=bally-7
   end;
   if bally>6 then if bally<16 then if cpxballx then
   begin
      bunce;
      bally:=bally+7
   end;
   
end;

{moves the ball and deals with bouncing of the vertical walls}
procedure ballmove;
begin
   hideball(ballx,bally);
   if ballvertdir=1 then bally:=bally-ballspeed else bally:=bally+ballspeed;
   if ballhoridir=1 then ballx:=ballx-sidespd else ballx:=ballx+sidespd;
   if ballx200 then
   begin
      ballhoridir:=1;
      sound(100);
      delay(2);
      nosound;
   end;
   checkball(ballvertdir);
   showball(ballx,bally);
end;

{moves the computers paddle in a very simple way}
procedure computermove;
begin
   hidecomppaddle;
   if ballxcpx+comppaddlesize-5 then cpx:=cpx+random(compspeed-2)+2+random(2);
   showcomppaddle;
end;

{allows the player to move if they pressed a key}
procedure move;
begin
   key:=readkey;
   keynum:=ord(key);
   if keynum=75 then hideyourpaddle(ypx,yourpaddlesize);
   if keynum=77 then hideyourpaddle(ypx,yourpaddlesize);
   if upcase(key)='Q' then won:=true;
   if keynum=75 then ypx:=ypx-(yourpaddlesize-10);
   if keynum=77 then ypx:=ypx+(yourpaddlesize-10);
   if ypx205 then ypx:=205-yourpaddlesize;
   showyourpaddle(ypx,yourpaddlesize);
end;

{main program}
begin;
   randomize;
   init;
2: clearviewport;
   if sidespd=0 then sidespd:=1;
   won:=false;
   clives:=4;
   setcolor(blue);
   ylives:=4;
   rectangle(2,0,210,getmaxy);
   settextstyle(triplexfont,horizdir,3);
   cpx:=ballx-1;
   outtextxy(220,3,name+' V`s The Computer');
   outtextxy(220,100,'Press Q to quit');
   ballx:=random(190)+10;
   bally:=random(90)+60;
   while not keypressed do
   begin
      computermove;
      showyourpaddle(ypx,yourpaddlesize);
   end;
1: 
   if keypressed then move;
   if ballspeed=0 then ballspeed:=1;
   {delay(3); replaced this delay with a better timer loop}
   for count:=0 to cycles do delay(1);
   if redone then
   begin
      redone:=false;
      setcolor(black);
      outtextxy(220,30,lives);
      outtextxy(220,55,ives);
   end;
   str(clives,lives);
   str(ylives,ives);
   setcolor(green);
   outtextxy(220,30,lives);
   setcolor(blue);
   outtextxy(220,55,ives);
   ballmove;
   computermove;
   if clives<=0 then won:=true;
   if ylivesylives then
   begin
      outtextxy(200,200,'Ha Ha You Lost!');
   end
   else
   begin
      outtextxy(200,200,'Oh No You Won!');
   end;
   while not keypressed do
   begin
   end;
   outtextxy(200,220,'Do you wish to play again?');
3: 
   key:=readkey;
   if upcase(key)='N' then goto 4;
   if upcase(key)='Y' then goto 2;
   goto 3;
4: 
   closegraph;
   normvideo;
end.