[Lazarus] Slow pointer assignments

[Leonardo M. Ramé]

On 2013-04-18 12:49:07 -0300, Leonardo M. Ramé wrote:
> On 2013-04-18 08:48:11 -0700, leledumbo wrote:
> > Assign all the RGBA value in one go, that would reduce the inner loop by 4
> > times. i.e.:
> > 
> > var 
> >   PixelPtr: PLongWord; 
> >   PixelRowPtr: PByte; 
> > begin 
> >   PixelRowPtr := Fbmp.RawImage.Data; 
> >   for Y := 0 to Self.Height - 1 do 
> >   begin 
> >     PixelPtr := PLongWord(PixelRowPtr); 
> >     for X := 0 to (Self.Width - 1) div 4 do 
> >     begin 
> >       PixelPtr^ := (lRed shl 24) or (lGreen shl 16) or (lBlue shl 8) or 255; 
> >       Inc(PixelPtr); 
> >     end; 
> >     Inc(PixelRowPtr, FBmp.RawImage.Description.BytesPerLine); 
> >   end;   
> > end; 
> > 
> 
> Great!, I'll try it.
> 

Well, it's speed improved, but the image is blue... Do you know why?.

-- 
Leonardo M. Ramé
http://leonardorame.blogspot.com