昨日、MapServer5.0が正式にリリースされた。
今度のバージョンは、様々な機能が追加された、意欲的なリリースである。
特に、今まで地図のラインやフォントの描画が粗かったのだが、これはGDという描画ライブラリを利用していたからで、これとは別に、AGGライブラリが利用できるようになった。AGGライブラリはMapnikなどで利用されていたもので、アンチエイリアスの効いたきれいな表現が実現する（ただし、若干パフォーマンスがGDに比べて劣る）。
それから、以前も記したが、地図にグラフが書けるという機能とあわせて「誰にでもわかる」機能追加である。さらに、ラベル表示の優先順位がつけられるのも嬉しい。
さて、5.0であるが、実際の業務にすぐに採用するのは、まだちょっと様子を見てからの方がよい。往々にして未知のバグが潜んでいる可能性が、これまでの新バージョンリリースの状況からは予想されるからだ。多分、5.0.1や5.0.2などのメンテナンスリリースが出てきてからの方が良いと思う。
機能について詳しいことは、以下のアナウンスに記されている。
The MapServer team is proud to announce the release of MapServer 5.0!
Perhaps the most important new feature in this release is support for
map rendering using the Anti-grain Geometry (AGG) graphics library
(www.antigrain.com). AGG brings high quality 2-D rendering capabilities
to MapServer that will allow users to create maps with vastly improved
cartographic quality. Equally important is that using AGG results in a
minimal reduction in performance. All symbology supported by the default
GD (www.libgd.org) graphics library are also supported using AGG. We are
excited about the future possibilities of bringing high-end cartography
to on-demand web mapping.
This new version also includes dozens of small bug fixes, enhancements
and performance improvements. Among the new features are: style and
label attribute attribute binding; lookup table-based raster color
correction; dynamic charting (pie and bar); explicit label prioritizing;
enhanced debugging and logging; dynamic allocation for layers, classes,
styles and symbols; improved memory management and garbage collection
for MapScript; numerous improvements to OGC specification support, and
lots more. A list of RFCs related to this release is included at the end
of this message.
The source code release is available at the usual location on the
MapServer site:
http://mapserver.gis.umn.edu/download/current
This page also contains links to binary distributions that will
hopefully be updated with 5.0 binaries shortly.
Users of 4.10 and older should review the 5.0 migration guide which
documents the changes that must be made to your application when
upgrading from MapServer 4.10 to 5.0:
http://mapserver.gis.umn.edu/download/current/MIGRATION_GUIDE.TXT/
Finally, here is a summary of MapServer 5.0 feature/enhancement with the
related RFCs. For more details on a specific item, please refer to the
corresponding RFC document at http://mapserver.gis.umn.edu/development/rfc
New features:
------------
- MS RFC 19: Added Style and Label attribute binding
- MS RFC 21: Raster Color Correction via color lookup table
- MS RFC 27: Added label priority
- MS RFC 29: Added dynamic charting (pie and bar charts)
- MS RFC 31: New mechanism to load/set objects via URL using mapfile syntax
- MS RFC 32: Added support for map rendering using the AGG library for
better output quality
Long time issues resolved:
-------------------------
- MS RFC 17: Use dynamic allocation for symbols, layers, classes and styles
(got rid of the static limit on the number of instances of each in a map)
- MS RFC 24: Improved memory management and garbage collection for MapScript
- MS RFC 26: Terminology cleanup (layer transparency renamed to opacity,
scale becomes scaledenom, symbol style becomes symbol pattern)
- MS RFC 28: Enhanced the debug/logging mechanism to facilitate
troubleshooting and tuning applications. Added support for multiple
debug levels and more control on output location.
