Looking at the code, the keyword is still in place in 8.0. It is recognized in 
the STYLE object but is silently ignored inside a LABEL object. I didn't check 
rendering code specifically to see what true vs false values affected. So, I 
think your conclusions are correct.

From: MapServer-users <mapserver-users-boun...@lists.osgeo.org> On Behalf Of 
Rahkonen Jukka via MapServer-users
Sent: Wednesday, November 15, 2023 12:59 PM
To: Mapserver-Users (mapserver-users@lists.osgeo.org) 
<mapserver-users@lists.osgeo.org>
Subject: [MapServer-users] Who remembers the truth about antialiasing?

Hi,

When Mapserver started to use AGG renderer everybody thought that antialiasing 
is not only the strength of the library but also the only way AGG can render. 
See https://mapserver.org/output/agg.html and 
https://lists.osgeo.org/pipermail/mapserver-users/2007-September/025467.html.
But then some Mapserver users noticed that AGG (and Mapnik) can also do aliased 
rendering at least for lines. Discussion on the mailing list 
https://lists.osgeo.org/pipermail/mapserver-users/2017-October/080278.html 
yielded a GitHub issue https://github.com/MapServer/MapServer/issues/5508 and a 
commit 
https://github.com/erik-h11/mapserver/commit/9ca99e763738fba7acaea6089afb5b5b7cd6e699.

However, the Mapserver documentation is unclear 
https://mapserver.org/mapfile/style.html#mapfile-style-antialias. I understand 
it so that setting antialias has not been functional since 7.0, and in 8.0 the 
whole keyword was removed.

"ANTIALIAS [true|false]
Removed in version 8.0: GD support was removed in 7.0 (and this mapfile 
parameter was removed in 8.0)
Should antialiasing be applied to the style. For line rendering only. Default 
is false."

My conclusions at the moment are:

  *   ANTIALIAS true|false does work in STYLE. It affects only lines, but 
polygon outlines are also lines. The default is TRUE.
  *   ANTIALIAS does not have an effect in other places: LABEL and SYMBOL. They 
are always antialiased.

If that is correct I may have a try with improving the documentation.

I started to experiment with antialias because I was not very satisfied with a 
very simple map that has only lines and labels. For my mind the lines on that 
map look better without antialiasing. Unfortunately I could not do anything for 
the labels. Especially dashes turn out light grey and blurry. The font is 
truetype, Vera, and the text color in the mapfile is pure black. All hints for 
making labels sharper are welcome.
[cid:image001.png@01DA17CC.42C69A10]

-Jukka Rahkonen-



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