Нужно сделать так, чтобы player не мог проходить объект насквозь

unit Unit1;
 
{$mode objfpc}{$H+}
 
interface
 
uses
  Classes, SysUtils, Forms, Controls, Graphics, Dialogs, ExtCtrls, LCLType,
  StdCtrls;
 
type
 
  { TForm1 }
 
  TForm1 = class(TForm)
    background: TImage;
    block: TImage;
    Button1: TButton;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    player: TImage;
    Timer1: TTimer;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
    procedure Timer1Timer(Sender: TObject);
  private
 
  public
 
  end;
 
var
  Form1: TForm1;
  patency : Boolean; // Переменная которая отвечает за возможность прохода
  a1x,a1y , a2 : Integer;
 
implementation
 
{$R *.lfm}
 
{ TForm1 }
 
procedure TForm1.FormCreate(Sender: TObject);
begin
  Timer1.Enabled:= True;
end;
 
procedure TForm1.Button1Click(Sender: TObject);
begin
  patency:= True;
  player.left := 736;
  player.top := 288
end;
 
procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState
  );
begin
  if (Key = VK_UP) and (player.Top>5) and (patency = True) then
  begin
    player.Top:= player.Top - 7;
  end;
 
  if (Key = VK_DOWN) and  (player.Top<649) and (patency = True)  then
  begin
    player.Top:= player.Top + 7;
  end;
 
  if (Key = VK_LEFT) and (player.Left>3) and (patency = True)  then
  begin
    player.Left:= player.left - 7;
  end;
 
  if (Key = VK_RIGHT) and (player.Left<849) and (patency = True)  then
  begin
    player.left:= player.left + 7;
  end;
end;
 
procedure TForm1.Timer1Timer(Sender: TObject);
begin
  // Столкнулся ли объект player с объектом block
 if ((block.Left = player.Left) and (block.Top = player.top)) or (((block.Left + 90) = player.Left) and (player.top = (block.top + 90))) or ((block.left = (player.Left + 50)) and (block.Top =(player.top + 50)) or (((block.Left + 90) = (player.left + 50)) and ((block.top + 90) = (player.Top + 50)))) then
 
  begin
     patency:= False;
   end
  else
   begin
     patency:=True;
   end;
   Label1.Caption:= IntToStr(player.Top);
   Label2.Caption:= IntToStr(block.top);
 
end;
 
 
end.