Geht das noch schneller? - Bitmap-Verrechnung

[manfred42]

Ein Versuch in Vorbereitung einer MMX-Version

Delphi-Quellcode:

procedure Draw32BitToBitmapPreMMX(const BitOben: TBitmap; BitUnten: TBitmap);
const
  Magic: UInt16 = $8081;
var
  W, x, y:      Integer;
  Stride, ORes: Integer;
  RowO,      RowU,
  RGBA_Oben, RGBA_Unten: ^TRGBQuad;
begin
  RowU := BitUnten.ScanLine[0];
  RowO := BitOben.ScanLine[0];

  W := BitUnten.Width;
  Stride := 4 * W;

  for y := 0 to BitUnten.Height - 1 do
  begin
    RGBA_Unten := RowU;
    RGBA_Oben  := RowO;
    for x := 0 to W - 1 do
    begin
      ORes := RGBA_Oben^.rgbReserved;
      with RGBA_Unten^ do
      begin
        rgbBlue := (ORes * (RGBA_Oben^.rgbBlue - rgbBlue)) *
          Magic div (1 shl 23) + rgbBlue;
        rgbGreen := (ORes * (RGBA_Oben^.rgbGreen - rgbGreen)) *
          Magic div (1 shl 23) + rgbGreen;
        rgbRed := (ORes * (RGBA_Oben^.rgbRed - rgbRed)) *
          Magic div (1 shl 23) + rgbRed;
        rgbReserved := 255;
      end;
      Inc(RGBA_Unten);   Inc(RGBA_Oben);
    end;
    Dec(Cardinal(RowU), Stride);
    Dec(Cardinal(RowO), Stride);
  end;
end;