bmp drehen

[arukas]

Ich hab jetzt alles so geändert wie ich es glaube verstanden zu haben, aber das Bild dreht sich immer noch nicht.

Delphi-Quellcode:

procedure TForm1.Button1Click(Sender: TObject);
begin
bmp:=image1.Picture.Bitmap;
bmp:=rotate(bmp,67,34,5);
  image1.picture.bitmap.assign(bmp);
  bmp.free; //das free ist wichtig, sonst hast du ein speicherleck

end;
FUNCTION Tform1.rotate(CONST BitmapOriginal: TBitmap;
  CONST iRotationAxis, jRotationAxis: INTEGER;
  CONST AngleOfRotation: DOUBLE  {radians} ): TBitmap;

  VAR 
    cosTheta   : EXTENDED;
    i          : INTEGER; 
    iOriginal  : INTEGER;
    iPrime     : INTEGER;
    j          : INTEGER;
    jOriginal  : INTEGER;
    jPrime     : INTEGER;
    RowOriginal: pRGBTripleArray;
    RowRotated : pRGBTRipleArray;
    sinTheta   : EXTENDED;
BEGIN
  RESULT := BitmapOriginal;
  RESULT.Width  := BitmapOriginal.Width;
  RESULT.Height := BitmapOriginal.Height;
  RESULT.PixelFormat := pf24bit;

  cosTheta := COS(AngleOfRotation);

  FOR j := RESULT.Height-1 DOWNTO 0 DO 
  BEGIN
    RowRotated := RESULT.Scanline[j]; 
    jPrime := j - jRotationAxis; 

    FOR i := RESULT.Width-1 DOWNTO 0 DO 
    BEGIN
      iPrime := i - iRotationAxis;
      iOriginal := iRotationAxis + ROUND(iPrime * CosTheta - jPrime * sinTheta);
      jOriginal := jRotationAxis + ROUND(iPrime * sinTheta + jPrime * cosTheta);

      IF (iOriginal >= 0) AND (iOriginal <= BitmapOriginal.Width-1) AND
          (jOriginal >= 0) AND (jOriginal <= BitmapOriginal.Height-1) 
      THEN BEGIN
        RowOriginal := BitmapOriginal.Scanline[jOriginal]; 
        RowRotated[i] := RowOriginal[iOriginal] 
      END 
      ELSE BEGIN 
        RowRotated[i].rgbtBlue := 255;
        RowRotated[i].rgbtGreen := 0;
        RowRotated[i].rgbtRed := 0;
     END

    END 
  END 
END;

euer arukas