[mapserver-users] Draw roads WITHOUT anti-aliasing

Eichner, Andreas - SID Andreas.Eichner at sid.sachsen.de
Mon Nov 6 00:23:52 PST 2017


Hi Erik,

just tried building a freshly pulled mapserver/master and I got strange CMake errors too. 
In my case wiping the build/ directory recreating it solved the problem.

HTH

> -----Ursprüngliche Nachricht-----
> Von: mapserver-users [mailto:mapserver-users-bounces at lists.osgeo.org] Im
> Auftrag von Erik H
> Gesendet: Freitag, 3. November 2017 21:24
> An: mapserver-users at lists.osgeo.org
> Betreff: Re: [mapserver-users] Draw roads WITHOUT anti-aliasing
> 
> I made some changes to the mapserver 7 source code that achieve what I
> want (I'm now able to switch between aliased and antialiased lines,
> based on the ANTIALIAS keyword in the STYLE section).
> 
> I tried to put up a pull request for it but I'm having problems
> compiling the code in the 'master' branch - compilation errors for
> mapmetadata.c. My code was branched off the release-7 branch and did not
> have that problem.
> 
> The cmake command I used was
> 
> cmake -DCMAKE_PREFIX_PATH=/usr/local/ WITH_GDAL=$GDAL_DIR  -
> DWITH_FRIBIDI=OFF -DWITH_WFS=OFF   -DWITH_WCS=OFF -
> DWITH_PROJ=/usr/local/lib  -DWITH_LIBXML2=OFF   WITH_POSTGIS=/usr/bin
> -DWITH_CLIENT_WFS=OFF     -DWITH_WMS=OFF    -DWITH_CLIENT_WMS=OFF
> -DWITH_CURL=OFF         -DWITH_SOS=OFF         -DWITH_PHP=OFF         -
> DWITH_PERL=OFF         -DWITH_RUBY=OFF         -DWITH_JAVA=ON         -
> DWITH_CSHARP=OFF   -DWITH_HARFBUZZ=OFF      -DWITH_PYTHON=ON     -
> DWITH_GEOS=0    -DWITH_SVGCAIRO=OFF         -DWITH_ORACLESPATIAL=OFF
> -DWITH_CAIRO=OFF -DWITH_THREAD_SAFETY=ON  -DWITH_FCGI=OFF   -DWITH_GIF=0
> ../ >../configure.out.txt
> 
> 
> Any suggestions?
> 
> Thanks
> 
> On Thu, Oct 19, 2017 at 11:04 AM, Erik H <erik.h11.01 at gmail.com> wrote:
> 
> 
> 	I just did what Andreas spelled out yesterday:
> 
> 	Simply changing the typedef in line 91 of mapagg.cpp from
> 
> 	  typedef mapserver::renderer_scanline_aa_solid<renderer_base>
> renderer_scanline;
> 
> 	to
> 
> 	  typedef mapserver::renderer_scanline_bin_solid<renderer_base>
> renderer_scanline;
> 
> 
> 
> 	However, I'd like to be able to switch between rasterizer via some
> option in the .map file, so I'd welcome any suggestion on how to do
> that.
> 
> 	On Thu, Oct 19, 2017 at 10:07 AM, Lime, Steve D (MNIT)
> <steve.lime at state.mn.us> wrote:
> 
> 
> 		Glad this was figured out! What was the code change exactly?
> ________________________________
> 
> 		From: mapserver-users <mapserver-users-
> bounces at lists.osgeo.org <mailto:mapserver-users-bounces at lists.osgeo.org>
> > on behalf of Erik H <erik.h11.01 at gmail.com>
> 		Sent: Wednesday, October 18, 2017 8:07:42 PM
> 		To: Eichner, Andreas - SID
> 		Cc: mapserver-users at lists.osgeo.org <mailto:mapserver-
> users at lists.osgeo.org>
> 		Subject: Re: [mapserver-users] Draw roads WITHOUT anti-
> aliasing
> 
> 		Andreas,
> 
> 		I made that change in mapagg.cpp and it seems to do exactly
> what I need. Wunderbar!
> 
> 		As for providing an option to switch rasterizer based on an
> option, how about reviving the FORMATOPTION 'ANTIALIAS'?
> 
> 		Thanks, Erik
> 
> 		On Wed, Oct 18, 2017 at 9:18 AM, Eichner, Andreas - SID
> <Andreas.Eichner at sid.sachsen.de <mailto:Andreas.Eichner at sid.sachsen.de>
> > wrote:
> 
> 
> 			Nope, this won't work:
> 
> 			  r->default_gamma = atof(msGetOutputFormatOption(
> format, "GAMMA", "0.75" ));
> 			  if(r->default_gamma <= 0.0 || r->default_gamma >=
> 1.0) {
> 			    r->default_gamma = 0.75;
> 			  }
> 
> 			From mapagg.cpp lines 844-847 forces 0 < GAMMA < 1
> 			Also note that MapServer uses a linear gamma function
> defined as
> 
> 			       double operator() (double x) const
> 			        {
> 			            if(x < m_start) return 0.0;
> 			            if(x > m_end) return 1.0;
> 			            return (x - m_start) / (m_end - m_start);
> 			        }
> 
> 			Where m_start is _always_ set to 0 and m_end is set to
> the GAMMA value given by you (or the default 0.75).
> 			I think someone should check this - to me it seems a
> power function was intented...
> 
> 			HTH
> 
> 			> -----Ursprüngliche Nachricht-----
> 			> Von: mapserver-users [mailto:mapserver-users-
> bounces at lists.osgeo.org <mailto:mapserver-users-bounces at lists.osgeo.org>
> ] Im
> 			> Auftrag von lars.schylberg at blixtmail.se
> 			> Gesendet: Mittwoch, 18. Oktober 2017 14:05
> 			> An: mapserver-users at lists.osgeo.org
> <mailto:mapserver-users at lists.osgeo.org>
> 			> Betreff: Re: [mapserver-users] Draw roads WITHOUT
> anti-aliasing
> 			>
> 			> Hi,
> 			>
> 			>
> 			>
> 			>
> 
> 			> I did some quick tests with :
> 			>
> 			>
> 			>
> 			>
> 			>   OUTPUTFORMAT
> 			>     NAME "png_G0"
> 			>     DRIVER AGG/PNG
> 			>     MIMETYPE "image/png"
> 			>     IMAGEMODE RGB
> 			>     EXTENSION "png"
> 			>     FORMATOPTION "GAMMA=0.0"
> 			>   END
> 			>
> 			>
> 			>
> 			>
> 			> and shp2img with options -i
> 			>
> 			>
> 			> eg: shp2img -m 01_polygon_td_poly.map -o
> 01_polygon_td_poly.png -i
> 			> png_G0
> 			>
> 			>
> 			>
> 			>
> 			>
> 			> I did some tests with both polygons, polygon outlines
> and lines and they
> 			> all seems to have anti-aliasing as far as I could
> see.
> 			>
> 			> Would this be an ok way to test it?  I also have some
> people that would
> 			> like to do lines without anti-aliasing for a strange
> reason.
> 			>
> 			>
> 			>
> 			>
> 			>
> 			> Lars Schylberg
> 			>
> 			>
> 			>
> 			>
> 			>
> 			> -----Originalmeddelande-----
> 			> > Från: "Rahkonen Jukka (MML)"
> <jukka.rahkonen at maanmittauslaitos.fi
> <mailto:jukka.rahkonen at maanmittauslaitos.fi> >
> 			> > Till: "Eichner, Andreas - SID"
> <Andreas.Eichner at sid.sachsen.de <mailto:Andreas.Eichner at sid.sachsen.de>
> >, "Erik
> 			> H" <erik.h11.01 at gmail.com>
> 			> > Kopia: mapserver-users at lists.osgeo.org
> <mailto:mapserver-users at lists.osgeo.org>
> 			> > Datum: 2017-10-18 11:13
> 			> > Ämne: Re: [mapserver-users] Draw roads WITHOUT
> anti-aliasing
> 			> >
> 			> > Hi,
> 			> >
> 			> > I suppose that the amount of antialiasing with AGG
> is set with "gamma"
> 			> parameter.  Mapserver supports that at least for
> polygons as documented
> 			> in http://www.mapserver.org/mapfile/outputformat.html
> <http://www.mapserver.org/mapfile/outputformat.html>  but you could try
> 			> if using gamma=0.0 has an effect on lines as well. It
> may be that it
> 			> does not because search
> 			> >
> 			>
> https://github.com/mapserver/mapserver/search?utf8=%E2%9C%93&q=gamma&typ
> <https://github.com/mapserver/mapserver/search?utf8=%E2%9C%93&q=gamma&ty
> p>
> 			> e=
> 			> > seems to find only something that is tied to
> polygon outlines
> 			> > https://github.com/mapserver/mapserver/blob/branch-
> 7- <https://github.com/mapserver/mapserver/blob/branch-7->
> 			> 0/renderers/agg/include/agg_renderer_outline_aa.h
> 			> >
> 			> >
> 			> > If gamma does not work for lines then it could be
> worth making a
> 			> feature request for adding a new formatoption
> "GAMMA_LINE=[].
> 			> >
> 			> > Couple of Mapnik links dealing with the same issue:
> 			> > http://gis.19327.n8.nabble.com/Turning-off-anti-
> aliasing- <http://gis.19327.n8.nabble.com/Turning-off-anti-aliasing->
> 			> td5339458.html
> 			> > http://mapnik.org/mapnik-reference/#3.0.6/line-
> gamma-method <http://mapnik.org/mapnik-reference/#3.0.6/line-gamma-
> method>
> 			> >
> 			> > -Jukka Rahkonen-
> 			> >
> 			> >
> 			> >
> 			> > -----Alkuperäinen viesti-----
> 			> > Lähettäjä: mapserver-users [mailto:mapserver-users-
> 			> bounces at lists.osgeo.org] Puolesta Eichner, Andreas -
> SID
> 			> > Lähetetty: 18. lokakuuta 2017 9:57
> 			> > Vastaanottaja: Erik H <erik.h11.01 at gmail.com>
> 			> > Kopio: mapserver-users at lists.osgeo.org
> <mailto:mapserver-users at lists.osgeo.org>
> 			> > Aihe: Re: [mapserver-users] Draw roads WITHOUT
> anti-aliasing
> 			> >
> 			> > Damn... missed attaching the images.
> 			> >
> 			> > > -----Ursprüngliche Nachricht-----
> 			> > > Von: mapserver-users [mailto:mapserver-users-
> 			> bounces at lists.osgeo.org]
> 			> > > Im Auftrag von Eichner, Andreas - SID
> 			> > > Gesendet: Mittwoch, 18. Oktober 2017 08:28
> 			> > > An: Erik H
> 			> > > Cc: mapserver-users at lists.osgeo.org
> <mailto:mapserver-users at lists.osgeo.org>
> 			> > > Betreff: Re: [mapserver-users] Draw roads WITHOUT
> anti-aliasing
> 			> > >
> 			> > > Hi,
> 			> > >
> 			> > > I just meant that it seems to be pretty easy to
> implement aliased
> 			> > > rendering with AGG.
> 			> > > Simply changing the typedef in line 91 of
> mapagg.cpp from
> 			> > >
> 			> > >   typedef
> mapserver::renderer_scanline_aa_solid<renderer_base>
> 			> > > renderer_scanline;
> 			> > >
> 			> > > to
> 			> > >
> 			> > >   typedef
> mapserver::renderer_scanline_bin_solid<renderer_base>
> 			> > > renderer_scanline;
> 			> > >
> 			> > > turns of anti-aliased rendering. I've attached
> the output of
> 			> "shp2img
> 			> > > -m line_simple.map" from the msautotests.
> 			> > > An additional member in class AGG2Renderer for
> the aliased
> 			> rasterizer
> 			> > > and conditionally passing one or the other to
> render_scanlines()
> 			> > > depending on some value of strokeStyleObj might
> be enough.
> 			> > >
> 			> > > Regards
> 			> > >
> 			> > > > -----Ursprüngliche Nachricht-----
> 			> > > > Von: Erik H [mailto:erik.h11.01 at gmail.com]
> 			> > > > Gesendet: Dienstag, 17. Oktober 2017 17:34
> 			> > > > An: Eichner, Andreas - SID
> 			> > > > Cc: Richard Greenwood; mapserver-
> users at lists.osgeo.org <mailto:mapserver-users at lists.osgeo.org>
> 			> > > > Betreff: Re: [mapserver-users] Draw roads
> WITHOUT anti-aliasing
> 			> > > >
> 			> > > > As for Andreas' remark about 'simply the use of
> another scanline
> 			> > > > rasterizer.' - I'm sorry but I'm not much of a
> C++ developer. If I
> 			> > > have
> 			> > > > to do rasterizing, I'd skip MapServer
> altogether and generate the
> 			> > > > PNG
> 			> > > in
> 			> > > > Java.
> 			> > > >
> 			> > > _______________________________________________
> 			> > > mapserver-users mailing list
> 			> > > mapserver-users at lists.osgeo.org
> <mailto:mapserver-users at lists.osgeo.org>
> 			> > >
> https://lists.osgeo.org/mailman/listinfo/mapserver-users
> <https://lists.osgeo.org/mailman/listinfo/mapserver-users>
> 			> > _______________________________________________
> 			> > mapserver-users mailing list
> 			> > mapserver-users at lists.osgeo.org <mailto:mapserver-
> users at lists.osgeo.org>
> 			> > https://lists.osgeo.org/mailman/listinfo/mapserver-
> users <https://lists.osgeo.org/mailman/listinfo/mapserver-users>
> 			>
> 			>
> 			>
> 			>
> 			>
> 			>
> 			>
> 			> --
> 			>
> 			>
> 			_______________________________________________
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> 
> 
> 
> 



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