Antialiasing

unit uAnalogUhr2;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls,uTUhr2, ExtCtrls;

type
  TForm2 = class(TForm)
    eH: TEdit; eMin: TEdit; eSec: TEdit; L1: TLabel; L2: TLabel;
    bSetzen: TButton; lAusgabe: TLabel; IUhr: TImage;
    procedure bAuslesenClick(Sender: TObject);
    procedure bSetzenClick(Sender: TObject);
    procedure bIncSecClick(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    b1,b2 : TBitmap;
  public
    procedure aktualisiereAusgabe;
  end;

var
  Form2: TForm2;

implementation
{$R *.DFM}

procedure zeichneUhr;
var
  mx,my,r,ax,ay,ex,ey : word;
  i,h,min,sec         : byte;
  wh,wmin,wsec        : real;
  P1,P2,P3            : PByteArray;
  x,y                 : integer;

  procedure Uhr2Winkel(h,min,sec : byte; var wh,wmin,wsec : real);
  begin
    h := h mod 12; // 24h-Anzeige --> 12h-Anzeige
    wh   := pi/2 - 2*pi/12/60*(60*h+min);
    wmin := pi/2 - 2*pi/60*min;
    wsec := pi/2 - 2*pi/60*sec;
  end;

begin
  mx := Form2.b1.Width div 2; my := Form2.b1.Height div 2;
  if mx < my then r := mx else r := my; r := r-6;
  // alles löschen
  Form2.b1.canvas.RectAngle(0,0,Form2.b1.width,Form2.b1.height);
  // Zifferblatt zeichnen
  Form2.b1.canvas.Pen.Width := 2;
  for i := 1 to 12 do
  begin
    Uhr2Winkel(i,0,0,wh,wmin,wsec);
    ax := Round(mx+r*0.8*cos(wh)); ay := Round(my-r*0.8*sin(wh));
    ex := Round(mx+r*cos(wh)); ey := Round(my-r*sin(wh));
    Form2.b1.Canvas.MoveTo(ax,ay); Form2.b1.Canvas.LineTo(ex,ey);
  end;
  // Zeit auslesen und Winkel berechnen
  h := oUhr.GetH; min := oUhr.GetMin; sec := oUhr.GetSec;
  Uhr2Winkel(h,min,sec,wh,wmin,wsec);
  // Stundenzeiger
  Form2.b1.canvas.Pen.Width := 4;
  ex := Round(mx+r*0.65*cos(wh)); ey := Round(my-r*0.65*sin(wh));
  Form2.b1.Canvas.MoveTo(mx,my); Form2.b1.Canvas.LineTo(ex,ey);
  // Minutenzeiger
  ex := Round(mx+r*0.9*cos(wmin)); ey := Round(my-r*0.9*sin(wmin));
  Form2.b1.Canvas.MoveTo(mx,my); Form2.b1.Canvas.LineTo(ex,ey);
  // Sekundenzeiger
  Form2.b1.Canvas.Pen.Width := 2;
  ex := Round(mx+r*0.98*cos(wsec)); ey := Round(my-r*0.98*sin(wsec));
  Form2.b1.Canvas.MoveTo(mx,my); Form2.b1.Canvas.LineTo(ex,ey);
  //Antialiasing
  with Form2 do
  begin
    for y := 0 to b2.Height-1 do
    begin
      P1 := b1.ScanLine[2*y];
      P2 := b1.ScanLine[2*y+1];
      P3 := b2.ScanLine[y];
      for x := 0 to b2.Width-1 do
      begin
        P3[x*3] := (P1[2*3*x]+P1[2*3*x+3]+P2[2*3*x]+P2[2*3*x+3]) div 4;
        P3[x*3+1] := (P1[2*3*x+1]+P1[2*3*x+4]+P2[2*3*x+1]+P2[2*3*x+4]) div 4;
        P3[x*3+2] := (P1[2*3*x+2]+P1[2*3*x+5]+P2[2*3*x+2]+P2[2*3*x+5]) div 4;
      end;
    end;
  end;
  //Zeichnen
  Form2.IUhr.Canvas.Draw(0,0,Form2.b2);
end;

procedure TForm2.aktualisiereAusgabe;
var
  hs,mins,secs : string;
begin
  hs := IntToStr(oUhr.GetH); if Length(hs) < 2 then hs := '0'+hs;
  mins := IntToStr(oUhr.GetMin); if Length(mins) < 2 then mins := '0'+mins;
  secs := IntToStr(oUhr.GetSec); if Length(secs) < 2 then secs := '0'+secs;
  Form2.lAusgabe.caption := hs+':'+mins+':'+secs;
  zeichneUhr;
end;

procedure TForm2.bAuslesenClick(Sender: TObject);
begin
  aktualisiereAusgabe;
end;

procedure TForm2.bSetzenClick(Sender: TObject);
var
  h,min,sec : byte;
begin
  h := StrToInt(eH.text); min := StrToInt(eMin.text); sec := StrToInt(eSec.text);
  oUhr.SetH(h); oUhr.SetMin(min); oUhr.SetSec(sec);
end;

procedure TForm2.bIncSecClick(Sender: TObject);
begin
  oUhr.IncSec; aktualisiereAusgabe;
end;

procedure TForm2.Timer1Timer(Sender: TObject);
begin
  oUhr.IncSec; aktualisiereAusgabe;
end;

procedure TForm2.FormCreate(Sender: TObject);
begin
  b1 := TBitmap.Create;  b1.PixelFormat := pf24bit;
  b1.Width := IUhr.Width*2; b1.Height := IUhr.Height*2;
  b2 := TBitmap.Create; b2.PixelFormat := pf24bit;
  b2.Width := IUhr.Width;  b2.Height := IUhr.Height;
end;

procedure TForm2.FormDestroy(Sender: TObject);
begin
  b1.Free; b2.Free;
end;

end.