unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  Menus, StdCtrls, ExtCtrls;

type
  TMain = class(TForm)
    MainMenu: TMainMenu;
    FileMenu: TMenuItem;
    Exit: TMenuItem;
    Player: TLabel;
    Bar: TShape;
    Ball: TShape;
    Timer: TTimer;
    Comp: TShape;
    AI: TTimer;
    procedure ExitClick(Sender: TObject);
    procedure FormKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure TimerTimer(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure AITimer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Main: TMain;

implementation

{$R *.DFM}

var ForwardX, ForwardY: Boolean;
var Score, Target, BallMove, BarMove, StartPos: Integer;

procedure TMain.ExitClick(Sender: TObject);
begin
Close;
end;

procedure TMain.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
const Up=38; Down=40;
begin
if (Key = Up) and ((Bar.Top - BarMove) >= StartPos) then
  Bar.Top := Bar.Top - BarMove;
if (Key = Down) and ((Bar.Top + Bar.Height + BarMove) <= Main.ClientHeight) then
  Bar.Top := Bar.Top + BarMove;
end;

procedure TMain.TimerTimer(Sender: TObject);
begin
if Comp.Top < (Target - (Comp.Height div 2)) then
  Comp.Top := Comp.Top + BarMove
else
  if Comp.Top > (Target + (Comp.Height div 2)) then
    Comp.Top := Comp.Top - BarMove;
if (Ball.Left + Ball.Width) >= Main.ClientWidth then
  ForwardX := False
else
  if Ball.Left < 0 then
  begin
    ForwardX := True;
    Score := Score - 1;
    Player.Caption := 'Player Score: ' + IntToStr(Score);
  end;
  if (Ball.Left > 0) and (Ball.Left <= Bar.Width)
  and ((Ball.Top + Ball.Height) <= (Bar.Top + Bar.Height))
  and (Ball.Top >= Bar.Top) then
  begin
    ForwardX := True;
    Score := Score + 1;
    Player.Caption := 'Player Score: ' + IntToStr(Score);
  end;
if (Ball.Top + Ball.Height) >= Main.ClientHeight then
  ForwardY := False
else
  if Ball.Top <= StartPos then
    ForwardY := True;
if ForwardX = True then
  Ball.Left := Ball.Left + BallMove
else
  if ForwardX = False then
    Ball.Left := Ball.Left - BallMove;
if ForwardY = True then
  Ball.Top := Ball.Top + BallMove
else
  if ForwardY = False then
    Ball.Top := Ball.Top - BallMove;
end;

procedure TMain.FormCreate(Sender: TObject);
begin
ForwardX := True;
ForwardY := True;
Score := 0;
BarMove := 20;
BallMove := 10;
StartPos := 40;
Target := Comp.Top;
end;

procedure TMain.AITimer(Sender: TObject);
var GapX, GapY, CrashX, CrashY: Integer;
begin
if ForwardX = False then;
if ForwardY = True then
  GapY := Main.ClientHeight - (Ball.Top + Ball.Height)
else
  GapY := Ball.Top - StartPos;
CrashX := Ball.Left + Ball.Width + GapY;
GapX := Main.ClientWidth - CrashX;
CrashY := Main.ClientHeight - GapX;
Target := CrashY
end;

end.