Как заставить точки двигаться по нажатию клавиш? - Turbo Pascal

Uses Crt,Graph;
const Path_of_driver='F:\BGI';
   
Type
 TPoint = object
 x,y:integer;
 color:word;
 procedure Init(InitX,InitY:integer;col:word);
 procedure Hide;
 procedure Draw;
 procedure SetX(NewX:integer);
 procedure SetY(NewY:integer);
 function  GetX:integer;
 function  GetY:integer;
 procedure Move(NewX,NewY:integer);
 Procedure Coords(a:char; var NewX,NewY:integer; h:integer);
end;
 
Procedure TPoint.Init(InitX,InitY:integer; col:word);
begin
  x:=InitX;
  y:=InitY;
  color:=col;
end;
 
Procedure TPoint.Hide;
begin
 PutPixel(x,y,GetBkColor);
end;
 
Procedure TPoint.Draw;
begin
 PutPixel(x,y,color);
end;
 
Function TPoint.GetX:integer;
begin
  GetX:=x;
end;
 
Function TPoint.GetY:integer;
begin
  GetY:=y;
end;
 
Procedure TPoint.SetX(NewX:integer);
begin
  x:=NewX;
end;
 
Procedure TPoint.SetY(NewY:integer);
begin
  y:=NewY;
end;
 
procedure TPoint.Move(NewX,NewY:integer);
begin
  Hide;
  x:=NewX;
  y:=NewY;
  Draw;
end;
 
Procedure TPoint.Coords(a:char; var NewX,NewY:integer; h:integer);
begin
    if a=#0 then begin
      a:=readkey;
      case a of
           #80: begin Inc(NewY,h); if NewY>GetMaxY-20 then NewY:=20;
                end;
           #75: begin dec(NewX,h); if NewX<10 then NewX:=GetMaxX-10;
                end;
           #77: begin inc(NewX,h); if NewX>GetMaxX-10 then NewX:=10;
                end;
           #72: begin dec(NewY,h); if NewY<20 then NewY:=GetMaxY-20;
                end;
       end;
     end
end;
VAR gd,gm,NewX,NewY,h,x,y,vh,i: integer;
    color: word;
    Q,a:char;
    str:string;
    tp:TPoint;
    mas:array[1..100] of TPoint;
BEGIN
     Randomize;
     gd:=Detect;
     InitGraph(gd,gm,Path_of_driver);
     if GraphResult<>grok then begin
         write('error:',GraphErrorMsg(GraphResult));
         halt;
     end;
 
     tp.Init(GetMaxX div 2,GetMaxY div 2,10);
 
     NewX:=GetMaxX div 2;
     NewY:=GetMaxY div 2;
     h:=2;
  RestoreCrtMode;
     Q:='y';
  While  Q<>'n' do begin
  write('Chtoby dvigat tochki vvedite: p ');
  readln(str);
  writeln('Nazhmite: Enter');
  writeln('Chtoby dvigat tochki ispolzujte strelki');
  readln;
  SetGraphMode(gm);
  repeat
    a:=readkey;
    tp.Coords(a,NewX,NewY,h);
    if str='p'   then begin
                   for vh:=1 to 100 do with mas[vh] do begin
                   tp.SetX(Random(640));
                   tp.SetY(Random(480));
           Hide;                                  
                   Init(tp.GetX,tp.GetY,3);
                   Draw;
                   Move(tp.GetX,tp.GetY);                   
                 end;
                 end;       
    
  until a=#27;
 
  RestoreCrtMode;
 
  write('Continue? (y/n) ');
  readln(Q);
  end;
 
  closegraph;
  clrscr;
END.