Как сделать так чтобы крюк поворачивался автоматически, не выходя за диапазоны угла?

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, StdCtrls, AppEvnts,Math;
 
type
  TForm1 = class(TForm)
    Timer1: TTimer;
    Image1: TImage;
    Label1: TLabel;
    ApplicationEvents1: TApplicationEvents;
    Label2: TLabel;
    procedure FormShow(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure ApplicationEvents1Message(var Msg: tagMSG;
      var Handled: Boolean);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
  THook = class
  private
    x0,y0,x,y:Integer;
    sAngle,vx,t,dt : Double;
    cAngle,vy : Double;
    color : TColor;
  public
    constructor Create(_x0, _y0: Integer; _sAngle, _cAngle: Double; _Color:TColor);
    Procedure Draw(Cs:TCanvas;H:Integer;W:Integer);
    Procedure Move; //Перемещение 
  end;
procedure rotateHook(P:TPoint);
Const
  sLen = 30;
  ds   = 30;
  dss  = 10;
  Speed_H = 40;
  
var
  Form1: TForm1;
  hook: THook;
  H1, W1 : Integer;
 
implementation
 
{$R *.dfm}
 
constructor THook.Create(_x0, _y0: Integer; _sAngle, _cAngle: Double;
_Color: TColor);
begin
  inherited Create;
  x0 := _x0;
  y0 := _y0;
  sAngle := _sAngle;
  cAngle := _cAngle;
  color := _Color;
  x:=x0;
  y:=y0;
 
end;
procedure THook.Move;
begin
  vx:=Speed_H*cAngle;
  vy:=Speed_H*sAngle;
  x:=Round(x0+vx * t);
  y:=Round(y0+vy * t);
  t := t + 0.1;
end;
procedure THook.Draw(Cs: TCanvas; H, W: Integer);
 var
  dx,dy  : Real;
  //xt,yt : Integer;
  xk,yk:Integer;
  sLength:Integer;
begin
  sLength:=sLen;
  Cs.Brush.Color := color;
  Cs.Pen.Color := color;
  Cs.Pen.Width:=1;
  dy := sLength * sAngle;
  dx := sLength * cAngle;
 
  xk:=Round(x+dx);
  yk:=Round(y+dy);
 
  H1 := H;
  W1 := W;
 
 //Cs.Pen.Width:=1;
 
 
 Cs.Polygon(
 [Point(xk,H-yk),
  Point(Round(xk-(((dx*ds)-(dy*dss))/sLength)),
  H-Round(yk-(((dy*ds)+(dx*dss))/sLength))),
  Point(Round(xk-(((dx*ds)+(dy*dss))/sLength)),
  H-Round(yk-(((dy*ds)-(dx*dss))/sLength)))]);
 
 
end;
 
procedure TForm1.FormShow(Sender: TObject);
begin
hook:=THook.Create(344,446,0,1,clBlack);
 
end;
 
procedure TForm1.Timer1Timer(Sender: TObject);
begin
  Form1.Image1.Canvas.Brush.Color:=clWhite;
  Form1.Image1.Canvas.FillRect(Form1.Image1.ClientRect);
  hook.Draw(Image1.Canvas,Image1.ClientHeight, Image1.ClientWidth);
  //hook.Move;
end;
 
procedure TForm1.ApplicationEvents1Message(var Msg: tagMSG;
  var Handled: Boolean);
var P : TPoint;
begin
 if Msg.message = WM_MOUSEMOVE then
 begin
   P:=Form1.ScreenToClient(Mouse.CursorPos);
   rotateHook(P);
 end;
end;
 
procedure rotateHook(P:TPoint);
begin
 
    hook.sAngle:=((H1-hook.y0)-P.Y)/
    Sqrt(Sqr((H1-hook.y0)-P.Y) + Sqr(P.X-(hook.x0)));
    hook.cAngle:=(P.X-(hook.x0))/
    Sqrt(Sqr((H1-hook.y0)-P.Y) + Sqr(P.X-(hook.x0)));
 
 
    // hook.sAngle:=0;
    //hook.cAngle:=-1;
 
     //hook.sAngle:=0;
     //hook.cAngle:=1;
 
    // hook.sAngle:=-1;
    // hook.cAngle:=0;
 
    //
 
   // Form1.Label1.Caption:=FloatToStr(RadToDeg(hook.sAngle));
    //Form1.Label2.Caption:=FloatToStr(RadToDeg(hook.cAngle));
 
    Form1.Label1.Caption:=FloatToStr(hook.sAngle);
    Form1.Label2.Caption:=FloatToStr(hook.cAngle);
end;
 
end.

procedure THook.Move;
begin
  vx:=Speed_H*cAngle;
  vy:=Speed_H*sAngle;
  x:=Round(x0+vx * t);
  y:=Round(y0+vy * t);
  t := t + 0.1;
end;

rotation_dir:Integer = 1;
 
procedure rotateHook(P:TPoint);
 
begin
    x:=x+rotation_dir;
    y:=y+rotation_dir;
    if ((y = 30) or (x = 315)) and ((y = 0) or (x = 605)) then
      rotation_dir:=rotation_dir*-1;
 
    hook.sAngle:=
    ((H1-hook.y0)-y)/
    Sqrt(Sqr((H1-hook.y0)-y) + Sqr(x-(hook.x0)));
    hook.cAngle:=
    (x-(hook.x0))/
    Sqrt(Sqr((H1-hook.y0)-y) + Sqr(x-(hook.x0)));
 
 
    Form1.Label1.Caption:=FloatToStr(x);
    Form1.Label2.Caption:=FloatToStr(y);
end;

if PtInRect(Rect(315,0,605,30), Point(x,y)) then rotation_dir:=rotation_dir*-1;

 rotation_dir:Integer = 1;
 rotation_dir2:Integer = 1;
....
procedure rotateHook(P:TPoint);
 
begin
    x:=x+rotation_dir2;
    y:=y+rotation_dir;
 
 
   
 
   if((x=375) or (x=315)) then rotation_dir2:=rotation_dir2*-1;
 
   if ((y = 30) or (y = 0)) then
      rotation_dir:=rotation_dir*-1;
 
    hook.sAngle:=
    ((H1-hook.y0)-y)/
    Sqrt(Sqr((H1-hook.y0)-y) + Sqr(x-(hook.x0)));
    hook.cAngle:=
    (x-(hook.x0))/
    Sqrt(Sqr((H1-hook.y0)-y) + Sqr(x-(hook.x0)));
 
 
    Form1.Label1.Caption:='X= '+FloatToStr(x);
    Form1.Label2.Caption:='Y= '+FloatToStr(y);
end;