On Wed, 17 Feb 2010 06:52:25 -0300 Luiz Americo Pereira Camara <luiz...@oi.com.br> wrote:
> Mattias Gaertner escreveu: > > On Wed, 17 Feb 2010 04:39:26 -0300 > > Luiz Americo Pereira Camara <luiz...@oi.com.br> wrote: > > > > > >> Mattias Gaertner escreveu: > >> > >>> On Tue, 16 Feb 2010 17:15:37 -0300 > >>> Luiz Americo Pereira Camara <luiz...@oi.com.br> wrote: > >>> > >>> > >>> > >>>> or > >>>> > >>>> colGray be redefined as colGray : TFPColor = (Red: $8080; Green: > >>>> $8080; Blue: $8080; Alpha: alphaOpaque) ?? > >>>> > >>>> > >>> Yes, although this rarely makes a difference. > >>> > >>> > >> It does. > >> See below. > >> > >> > >>> > >>> > >>> > >>>> This info will help to fix http://bugs.freepascal.org/view.php?id=15793 > >>>> > >>>> > >>> IMO the bug report is misleading. Converting a TFPColor to RGB looses > >>> bits. > >>> > >> The bug is not about converting to RGB. See the attached example in > >> bugreport. > >> > >> SetCol := colGray; > >> Img.Colors[0,0] := SetCol; > >> GetCol := Img.Colors[0,0]; > >> > >> SetCol <> GetCol > >> > > > > That's exactly what my long response explained. > > Why do you expect that the 48bit color constants can be assigned to > > 24bit images without loss? Is this somewhere wrongly documented? > > > > fpimage is not documented at all AFAIK. > > It's not loosing bits if your information, in previous mail, about > TFPColor format is correct. > > Defining colGray, and related, as TFPColor = (Red: $8080; Green: $8080; > Blue: $8080; Alpha: alphaOpaque) would make it work. ... would make it work with a 24bit color image that uses one pixel color conversion *$101, div $100. It won't work on a 24bit color image that uses color conversion *$100, div $100 or on any other format. > The point is that the TFPColor constants are inconsistently defined. $8000 is exactly the middle. It is the right value for gray. Your comparison is wrong. It is as wrong as: ASingle := ADouble; if ASingle<>ADouble then ... Mattias _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
