Hi Lars,
I had not tried that myself but did some tests now. I do not really see any
difference in the output with any values of gamma. Perhaps it is broken.
I have been thinking that one of the most common use cases is to draw adjacent
polygons with just fill but no outlines so that the whole area gets unique
color even when the fill has some transparency set in STYLE with somehow like
CLASS
NAME "polygon_test"
STYLE
COLOR 100 50 0
OPACITY 50
END
END
I am not sure if this test makes sense and I know that I can get rid of the
borders between the polygons by using COMPOSITE-OPACITY at the LAYER level.
When GD renderer was removed the support to render without anti-aliasing was
recognized as a good feature http://mapserver.org/development/rfc/ms-rfc-99.html
-Jukka Rahkonen-
Lähettäjä: mapserver-users [mailto:[email protected]]
Puolesta [email protected]
Lähetetty: 18. lokakuuta 2017 15:05
Vastaanottaja: [email protected]
Aihe: 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)"
> <[email protected]<mailto:[email protected]>>
> Till: "Eichner, Andreas - SID"
> <[email protected]<mailto:[email protected]>>,
> "Erik H" <[email protected]<mailto:[email protected]>>
> Kopia: [email protected]<mailto:[email protected]>
> 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 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&type=
> seems to find only something that is tied to polygon outlines
> 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-td5339458.html
> http://mapnik.org/mapnik-reference/#3.0.6/line-gamma-method
>
> -Jukka Rahkonen-
>
>
>
> -----Alkuperäinen viesti-----
> Lähettäjä: mapserver-users
> [mailto:[email protected]<mailto:[email protected]>]
> Puolesta Eichner, Andreas - SID
> Lähetetty: 18. lokakuuta 2017 9:57
> Vastaanottaja: Erik H <[email protected]<mailto:[email protected]>>
> Kopio: [email protected]<mailto:[email protected]>
> Aihe: Re: [mapserver-users] Draw roads WITHOUT anti-aliasing
>
> Damn... missed attaching the images.
>
> > -----Ursprüngliche Nachricht-----
> > Von: mapserver-users
> > [mailto:[email protected]<mailto:[email protected]>]
> > Im Auftrag von Eichner, Andreas - SID
> > Gesendet: Mittwoch, 18. Oktober 2017 08:28
> > An: Erik H
> > Cc: [email protected]<mailto:[email protected]>
> > 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:[email protected]<mailto:[email protected]>]
> > > Gesendet: Dienstag, 17. Oktober 2017 17:34
> > > An: Eichner, Andreas - SID
> > > Cc: Richard Greenwood;
> > > [email protected]<mailto:[email protected]>
> > > 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
> > [email protected]<mailto:[email protected]>
> > https://lists.osgeo.org/mailman/listinfo/mapserver-users
> _______________________________________________
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