Einen Winkel errechnen!?

[sniper_w]

Ich hoffe das hilft:

Delphi-Quellcode:

type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    Label2: TLabel;
    Label1: TLabel;
    Label3: TLabel;
    procedure FormPaint(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  center : tpoint;

implementation

uses Math;

{$R *.dfm}

procedure TForm1.FormPaint(Sender: TObject);
begin
 Canvas.FillRect(ClientRect);

 Canvas.MoveTo(0, height div 2);
 Canvas.LineTo(width, height div 2);

 Canvas.MoveTo(width div 2, 0);
 Canvas.LineTo(width div 2, height);

 center := point(width div 2,height - height div 2);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
Canvas.Pen.Color := clBlack;
end;

procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
var angle,p : extended;

begin
  angle := 0;
  p := 1;
  FormPaint(self);
  Canvas.MoveTo(width div 2, height div 2);
  Canvas.LineTo(x,y);

  y := Height - y;
  Label1.Caption := 'y-center.Y  = '+inttostr(y-center.Y);

  if (x-center.X <>0) then
  begin
   Angle := ArcTan((y-center.Y)/(x-center.X)) * 180 / pi;
   Label3.Caption := 'x-center.X  = '+inttostr(x-center.X);

   if (angle<0)and(x-center.X<0) then angle := 180 + angle
        else
   if (x-center.X<0)and(y-center.Y<0) then angle := 180 + angle
        else
   if (y-center.y<0) then angle := 360 + angle;

   Label2.Caption := 'Current angle: '+Floattostr(angle)+ ' degrees.';
  end;
end;