GDI+ und AntiAliasing: mal geht' s, mal nicht

[DeddyH]

Hallöle,

ich wollte meinen runden Button um einen Style erweitern (weitere sind geplant). Leider wird der neue Style nicht rund gezeichnet. Kann mir mal jemand zeigen, wo es hakt?

Paint-Methode:

Delphi-Quellcode:

  for i := Low(TBmType) to High(TBmType) do
    begin
      FStates[i].Width := Self.Width;
      FStates[i].Height := Self.Height;
      FStates[i].Canvas.Brush.Color := FTransparentColor;
      FStates[i].Canvas.FillRect(Rect(0,0,Self.Width,Self.Height));

      graphics[i] := TGPGraphics.Create(FStates[i].Canvas.Handle);
      try
        graphics[i].SetSmoothingMode(SmoothingModeAntiAlias); //<-- explizit eingeschaltet

        case FDrawType of
          dtMembrane: DrawMembrane(i);
          dtBubble  : DrawBubble(i);
        end;
        
        DrawGDIPCaption(i);

      finally
        graphics[i].Free;
      end;

      FStates[i].TransparentColor := FStates[i].Canvas.Brush.Color;
      FStates[i].Transparent := True;

    end;  //for

DrawMembrane (AntiAliasing funktioniert):

Delphi-Quellcode:

    procedure DrawMembrane(const aState: TBmType);
    begin
      Col1 := FFirstColor;
      Col2 := AddHalfTones(FFirstColor);

      case aState of
        btUp      :  begin
                       Col1 := AddHalfTones(FFirstColor);
                       Col2 := FFirstColor;
                     end;
        btDisabled:  begin
                       Col1 := AddHalfTones(FFirstColor);
                       Col2 := FDisabledColor;
                     end;
      end;

      linGrBrush := TGPLinearGradientBrush.Create(
                         MakePoint(0, 0),
                         MakePoint(Pred(self.Width), Pred(self.Height)),
                         ColorToGPColor(Col1),
                         ColorToGPColor(Col2));

      linGrBrush.SetGammaCorrection(FGammaCorrection);

      try
        graphics[aState].FillEllipse(linGrBrush,0,0,
                                     Self.Width - 1,
                                     Self.Height - 1);
      finally
        linGrBrush.Free;
      end;
    end;

DrawBubble (AntiAliasing funktioniert nicht):

Delphi-Quellcode:

    procedure DrawBubble(const aState: TBmType);
    type TPoints = array[Boolean] of Single;
         Tcolors = array[0..1] of TGPColor;
         THighColors = array[Boolean] of TColor;
    var
      path            : TGPGraphicsPath;
      pthGrBrush      : TGPPathGradientBrush;
      count           : Integer;
      PointsX, PointsY: TPoints;
      colors          : Tcolors;
      HighColors      : THighColors;
    begin

      if aState = btDisabled then
        colors[0] := ColorToGPColor(FDisabledColor)
      else
        colors[0] := ColorToGPColor(FFirstColor);

      colors[1] := ColorToGPColor(clYellow);

      HighColors[false] := $EAEAEA;
      HighColors[true]  := AddHalfTones(FFirstColor);
      
      path:= TGPGraphicsPath.Create;
      try
        path.AddEllipse(0, 0, Self.Width - 1, Self.Height - 1);

        pthGrBrush:= TGPPathGradientBrush.Create(path);
        try

          PointsX[false] := Self.Width / 5;
          PointsY[false] := Self.Height / 5;

          PointsX[true] := Self.Width / 2;
          PointsY[true] := Self.Height / 2;

          pthGrBrush.SetCenterPoint(MakePoint(PointsX[aState = btDown],
                                              PointsY[aState = btDown]));

          pthGrBrush.SetCenterColor(ColorToGPColor(HighColors[aState = btDown]));

          count := 1;
          pthGrBrush.SetSurroundColors(@colors[0], count);
          pthGrBrush.SetGammaCorrection(FGammaCorrection);

          graphics[aState].FillPath(pthGrBrush,path);

          if aState = btDown then
            begin
              pthGrBrush.SetFocusScales(0.85,0.85);
              graphics[aState].FillPath(pthGrBrush,path);
            end;
        finally
          pthGrBrush.Free;
        end;
      finally
        path.Free;
      end;
    end;

Kann das sein, dass es an der Verwendung der Paths liegt? Ich hänge mal eine Demo an, damit man das auch mal sieht.

[edit] Ich vergaß zu sagen, dass die beiden Draw...-Prozeduren Unterprozeduren von Paint sind, die Variablen sind also bekannt. [/edit]