unit Unit1;

interface

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

type
  TWindow = class(TForm)
    Logo: TLabel;
    Start: TLabel;
    Ende: TLabel;
    S0: TShape;
    S1: TShape;
    S2: TShape;
    Update: TTimer;
    Block: TShape;

    procedure FormCreate(Sender: TObject);
    procedure StartClick(Sender: TObject);
    procedure EndeClick(Sender: TObject);
    procedure FormKeyDown(Sender: TObject; var Key: Word;
      Shift: TShiftState);
    procedure UpdateTimer(Sender: TObject);

    function GetPart(i: Integer): TShape;
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Window: TWindow;
  Richtung: Char;
  SList: TList;
  Punkte: Integer;

implementation

{$R *.DFM}

// Prozeduren

procedure TWindow.FormCreate(Sender: TObject);
begin
        Window.Color := clBlue;
        S0.Visible := false; // Kopf
        S1.Visible := false; // Mitte
        S2.Visible := false; // Schwanz
        SList := TList.Create;
        Update.Enabled := false;
        Punkte := 0;
        Block.Visible := false;
        Start.Visible := true;
        Ende.Visible := true;
        Logo.Visible := true;
        SList.Add(Pointer(S0));
        SList.Add(Pointer(S1));
        SList.Add(Pointer(S2));
        randomize;
end;

procedure TWindow.StartClick(Sender: TObject);
begin
     Start.Color := clGreen;
     S0.Visible := true;
     S1.Visible := true;
     S2.Visible := true;
     Richtung := 'u';
     Update.Enabled := true;
     S0.Left := random(ClientWidth-20);
     S0.Top := random(ClientHeight-20);
     S1.Left := S0.Left;
     S1.Top := S0.Top-20;
     S2.Left := S1.Left;
     S2.Top := S1.Top-20;
     Window.Caption := 'Resnake || Punkte: 0';
     Block.Visible := true;
     Block.Left := random(Clientwidth-20);
     Block.Top := random(ClientHeight-20);
     Start.Visible := false;
     Ende.Visible := false;
     Logo.Visible := false;
end;

procedure TWindow.EndeClick(Sender: TObject);
begin
     Ende.Color := clGreen;
     close;
end;

procedure TWindow.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
     if Key = vk_up then
     begin
          Richtung := 'u';
     end
     else if Key = vk_down then
     begin
          Richtung := 'd';
     end
     else if Key = vk_left then
     begin
          Richtung := 'l';
     end
     else if Key = vk_right then
     begin
          Richtung := 'r';
     end;
end;

procedure TWindow.UpdateTimer(Sender: TObject);
var
   i: Integer;
   Item: TShape;
   _Item: TShape;
begin
     // Körper bewegen

     For i := SList.Count-1 downto 1 do
     begin
          Item := GetPart(i);
          _Item := GetPart(i-1);
          Item.Left := _Item.Left;
          Item.Top := _Item.Top;
     end;

     // Kopf bewegen
     if Richtung = 'u' then
     begin
          S0.Top := S0.Top - 20;
     end
     else if Richtung = 'd' then
     begin
          S0.Top := S0.Top + 20;
     end
     else if Richtung = 'l' then
     begin
          S0.Left := S0.Left - 20;
     end
     else if Richtung = 'r' then
     begin
          S0.Left := S0.Left + 20;
     end;

     if S0.Left < 0 then
     begin
          S0.Left := ClientWidth - S0.Width;
     end
     else if S0.Left > ClientWidth then
     begin
          S0.Left := S0.Width;
     end
     else if S0.Top < 0 then
     begin
          S0.Top := ClientHeight-S0.Height;
     end
     else if S0.Top > ClientHeight then
     begin
          S0.Top := S0.Height;
     end;

     if (S0.Left < Block.Left+Block.Width) and
     (S0.Left > Block.Left-Block.Width) and
     (S0.Top < Block.Top+Block.Height) and
     (S0.Top > Block.Top-Block.Height) then
     begin
          Block.Left := random(Clientwidth-20);
          Block.Top := random(ClientHeight-20);
          _Item := GetPart(SList.Count-1);
          Item := TShape.Create(self);
          Item.Parent := Window;
          Item.Left := _Item.Left;
          Item.Top := _Item.Top;
          Item.Width := _Item.Width;
          Item.Height := _Item.Height;
          Item.Brush := _Item.Brush;
          Item.Pen := _Item.Pen;
          Item.Shape := _Item.Shape;
          Item.Show;
          SList.Add(Pointer(Item));
          inc(Punkte);
          Window.Caption := 'ReSnake || Punkte: '+inttostr(punkte);
     end;
end;

// Funktionen

function TWindow.GetPart(i: Integer): TShape;
begin
     Result := TShape(SList.Items[i]);
end;

procedure TWindow.FormClose(Sender: TObject; var Action: TCloseAction);
begin
     SList.Clear;
     SList.Free;
end;

end.