Re: Drawing difference between Avaon and GDI

11-07-2006

Hello Lei,
I just wrote a blogpost on how you can get a sharp WPF line while keeping
the anti-aliased effects for diagonal/curved lines, check out the
SnapsToDevicePixels property:

http://blogs.msdn.com/seema/archive/...red-lines.aspx

Enjoy!
SeemaR
http://blogs.msdn.com/seema/

"Lei Jiang" wrote:

> I agree with you. Anti-aliasing really make lines looks smooth, but in some
> situation, I want the lines looks exactly the same width. If Avalon provide
> an option that make me could aligns the line with the center of a pixel, it
> would be great. In my situation, the precise position of a rectangle is not
> important, but a rectangle with different line width is not acceptable.
>
> "Frank Hileman" <frankhil@no.spamming.prodigesoftware.com> ÃÂ´ÃˆÃ«ÃÃ»ÃÂ¢
> news:uPhlDxlWFHA.2256@TK2MSFTNGP14.phx.gbl...
> > For the rectangular labels in green, specifically: it is clear here that
> you
> > need a rectangle positioning and width that is precisely aligns the center
> > of a pixel with the center of the rectangle lines. If Avalon does not
> > provide an easy way to do this, it should be added, as it is a common
> > requirement.
> >
> > Anti-aliasing does not solve the fractional pixel problem. As you can see,
> > it can make the problem worse.
> >
> > In VG.net you can control anti-aliasing with a RenderAppearance property.
> If
> > you turn off anti-aliasing for the rectangle you will get the correct
> > effect. This property can also be set on a composite object, so that all
> > elements within are affected. A similar property in Avalon would be very
> > helpful. It would also be helpful to have pixel-perfect control over
> > positioning and sizes.
> >
> > Another thing that would help is control over the gamma correction used
> when
> > computing the fractional pixel values for anti-aliasing. A gamma
> correction
> > that looks good over a light background generally works poorly over a dark
> > background.
> >
> > As a "fudge" in Avalon you can make line widths thicker. This will not
> > correct the true problem of pixel misalignment -- some lines will appear
> > thicker than others. Pablo's comment about the resolution of display
> devices
> > increasing is true in the long-term -- but I suspect the term is very long
> > in the real world, perhaps 10 years to be widespread, and longer for
> > industrial applications, which often use low-end display devices.
> >
> > Regards,
> > Frank Hileman
> >
> > check out VG.net: http://www.vgdotnet.com
> > Animated vector graphics system
> > Integrated Visual Studio .NET graphics editor
> >
> > "Lei Jiang" <code@263.net> wrote in message
> > news:%23$%23CLFXWFHA.3712@TK2MSFTNGP09.phx.gbl...
> > >I am porting a graphics program from GDI to Avalon and found there are
> some
> > > differences between the drawing in Avalon and that in GDI.
> > >
> > > Please see the attachment(I have compressed them to save the bandwidth),
> > > lines and texts in both picture use the same
> > > color and size, but it seems the lines and texts in Avalon are more
> > > "obscure" and "gloomy". This makes the drawing not that clear.
> > >
> > > Is there any method that could make the drawing in Avalon more "birght"
> > > and
> > > "clear", just like that in GDI?
> > >
> > > Thanks!
> > >
> > >
> > >
> > >
> >
> >
>
>
>

11-07-2006	#1 (permalink)
Seema Ramchandani [msft] Guest n/a posts	Re: Drawing difference between Avaon and GDI Hello Lei, I just wrote a blogpost on how you can get a sharp WPF line while keeping the anti-aliased effects for diagonal/curved lines, check out the SnapsToDevicePixels property: http://blogs.msdn.com/seema/archive/...red-lines.aspx Enjoy! SeemaR http://blogs.msdn.com/seema/ "Lei Jiang" wrote: > I agree with you. Anti-aliasing really make lines looks smooth, but in some > situation, I want the lines looks exactly the same width. If Avalon provide > an option that make me could aligns the line with the center of a pixel, it > would be great. In my situation, the precise position of a rectangle is not > important, but a rectangle with different line width is not acceptable. > > "Frank Hileman" <frankhil@no.spamming.prodigesoftware.com> ÃÂ´ÃˆÃ«ÃÃ»ÃÂ¢ > news:uPhlDxlWFHA.2256@TK2MSFTNGP14.phx.gbl... > > For the rectangular labels in green, specifically: it is clear here that > you > > need a rectangle positioning and width that is precisely aligns the center > > of a pixel with the center of the rectangle lines. If Avalon does not > > provide an easy way to do this, it should be added, as it is a common > > requirement. > > > > Anti-aliasing does not solve the fractional pixel problem. As you can see, > > it can make the problem worse. > > > > In VG.net you can control anti-aliasing with a RenderAppearance property. > If > > you turn off anti-aliasing for the rectangle you will get the correct > > effect. This property can also be set on a composite object, so that all > > elements within are affected. A similar property in Avalon would be very > > helpful. It would also be helpful to have pixel-perfect control over > > positioning and sizes. > > > > Another thing that would help is control over the gamma correction used > when > > computing the fractional pixel values for anti-aliasing. A gamma > correction > > that looks good over a light background generally works poorly over a dark > > background. > > > > As a "fudge" in Avalon you can make line widths thicker. This will not > > correct the true problem of pixel misalignment -- some lines will appear > > thicker than others. Pablo's comment about the resolution of display > devices > > increasing is true in the long-term -- but I suspect the term is very long > > in the real world, perhaps 10 years to be widespread, and longer for > > industrial applications, which often use low-end display devices. > > > > Regards, > > Frank Hileman > > > > check out VG.net: http://www.vgdotnet.com > > Animated vector graphics system > > Integrated Visual Studio .NET graphics editor > > > > "Lei Jiang" <code@263.net> wrote in message > > news:%23$%23CLFXWFHA.3712@TK2MSFTNGP09.phx.gbl... > > >I am porting a graphics program from GDI to Avalon and found there are > some > > > differences between the drawing in Avalon and that in GDI. > > > > > > Please see the attachment(I have compressed them to save the bandwidth), > > > lines and texts in both picture use the same > > > color and size, but it seems the lines and texts in Avalon are more > > > "obscure" and "gloomy". This makes the drawing not that clear. > > > > > > Is there any method that could make the drawing in Avalon more "birght" > > > and > > > "clear", just like that in GDI? > > > > > > Thanks! > > > > > > > > > > > > > > > > > > >
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