[mapserver-commits] r12533 - trunk/docs/en/development/rfc

[svn at osgeo.org]

Author: assefa
Date: 2011-09-09 07:55:28 -0700 (Fri, 09 Sep 2011)
New Revision: 12533

Modified:
   trunk/docs/en/development/rfc/ms-rfc-73.txt
Log:
update rfc base on comments

Modified: trunk/docs/en/development/rfc/ms-rfc-73.txt
===================================================================
--- trunk/docs/en/development/rfc/ms-rfc-73.txt	2011-09-09 09:00:27 UTC (rev 12532)
+++ trunk/docs/en/development/rfc/ms-rfc-73.txt	2011-09-09 14:55:28 UTC (rev 12533)
@@ -1,84 +1,98 @@
-.. _rfc73:
-
-==============================================================================
-MS RFC 73: Improved SVG symbols support
-==============================================================================
-
-:Date: 2011/05/19
-:Authors: Zak James (zjames at dmsolutions.ca)
-:Authors: Yewondwossen Assefa (yassefa at dmsolutions.ca)
-:Last Edited: 2011/05/19
-:Status:  Proposed
-:Version: MapServer 6.2
-:Id: $Id:$
-
-Overview
-------------------------------------------------------------------------------
-
-The SVG format offers several advantages over existing mapserver symbol types
-but existing support is limited. We propose the implementation of complete
-support using the libsvg-cairo library, part of the cairo project.
-
-
-Technical Solution
-------------------------------------------------------------------------------
-
-All renderers will be extended with an added supports_svg flag, set to 0 for
-all but the cairo renderer. When an SVG symbol is requested, other renderers
-will trigger a call to msRenderSVGToPixmap which will parse the referenced svg
-file (using libsvg-cairo) and render the svg into the symbol's pixmapbuffer
-using cairo. After this operation, normal pixmap symbol handling will be used.
-
-For the cairo renderer, the renderSVGSymbolCairo function will use libsvg-cairo
-to parse the symbol, but will then use the cairo api to render the symbol
-directly.
-
-Configure.in will be modified to detect the --with-libsvg-cairo configure
-option and define USE_LIBSVG_CAIRO.
-
-Usage example
-------------------------------------------------------------------------------
-
-::
-
-  SYMBOL
-    NAME "svgsymbol"
-    TYPE SVG
-    IMAGE "/path/to/symbol.svg"
-  END
-
-
-
-... once defined, the symbol is used within the mapfile like any other.
-
-Backwards Compatibility Issues
-------------------------------------------------------------------------------
-
-There are no compatibility issues with existing mapfiles. The SVG symbol type
-is already allowed within a SYMBOLSET. SVG Symbol support will be disabled by
-default. Enabling it will require installation of the libsvg-cairo library
-available from 
-* http://cairographics.org/snapshots/libsvg-cairo-0.1.6.tar.gz
-
-Affected Files
-------------------------------------------------------------------------------
-
-* mapserver.h
-* mapdraw.c
-* mapdummyrenderer.c
-* maprendering.c
-* mapsymbol.c
-* mapsymbol.h
-* mapcairo.c
-* mapagg.cpp
-* configure.in
-
-Ticket Id
-------------------------------------------------------------------------------
-
-* http://trac.osgeo.org/mapserver/ticket/3671
-
-
-
-Voting History
-------------------------------------------------------------------------------
+.. _rfc73:
+
+==============================================================================
+MS RFC 73: Improved SVG symbols support
+==============================================================================
+
+:Date: 2011/05/19
+:Authors: Zak James (zjames at dmsolutions.ca)
+:Authors: Yewondwossen Assefa (yassefa at dmsolutions.ca)
+:Last Edited: 2011/05/19
+:Status:  Proposed
+:Version: MapServer 6.2
+:Id: $Id:$
+
+Overview
+------------------------------------------------------------------------------
+
+The SVG format offers several advantages over existing mapserver symbol types
+but existing support is limited. We propose the implementation of complete
+support using the libsvg-cairo library, part of the cairo project.
+
+
+Technical Solution
+------------------------------------------------------------------------------
+
+All renderers will be extended with an added supports_svg flag, set to 0 for
+all but the cairo renderer. When an SVG symbol is requested, other renderers
+will trigger a call to msRenderSVGToPixmap which will parse the referenced svg
+file (using libsvg-cairo) and render the svg into the symbol's pixmapbuffer
+using cairo. After this operation, normal pixmap symbol handling will be used.
+
+For the cairo renderer, the renderSVGSymbolCairo function will use libsvg-cairo
+to parse the symbol, but will then use the cairo api to render the symbol
+directly.
+
+Configure.in will be modified to detect the --with-libsvg-cairo configure
+option and define USE_LIBSVG_CAIRO.
+
+Existing Partial Implementation
+------------------------------------------------------------------------------
+If this rfc is adopted the existing SVG symbol code
+(see http://trac.osgeo.org/mapserver/ticket/3343) would be superceeded
+and would be removed.
+
+The proposed implementation will reuse the existing changes to the parser
+but the approach for reading and rendering the symbols would be different.
+It will use an existing SVG parser which includes a more complete SVG
+implementation and will pass through the SVG instructions directly in
+the case of a cairo (pdf or postscript) outputformat to improve
+quality. Additionally, this version will pre-scale and rotate the SVG before
+rasterizing with agg to avoid bitmap artifacts.
+
+Usage example
+------------------------------------------------------------------------------
+
+::
+
+  SYMBOL
+    NAME "svgsymbol"
+    TYPE SVG
+    IMAGE "/path/to/symbol.svg"
+  END
+
+
+
+... once defined, the symbol is used within the mapfile like any other.
+
+Backwards Compatibility Issues
+------------------------------------------------------------------------------
+
+There are no compatibility issues with existing mapfiles. The SVG symbol type
+is already allowed within a SYMBOLSET. SVG Symbol support will be disabled by
+default. Enabling it will require installation of the libsvg-cairo library
+available from 
+* http://cairographics.org/snapshots/libsvg-cairo-0.1.6.tar.gz
+
+Affected Files
+------------------------------------------------------------------------------
+
+* mapserver.h
+* mapdraw.c
+* mapdummyrenderer.c
+* maprendering.c
+* mapsymbol.c
+* mapsymbol.h
+* mapcairo.c
+* mapagg.cpp
+* configure.in
+
+Ticket Id
+------------------------------------------------------------------------------
+
+* http://trac.osgeo.org/mapserver/ticket/3671
+
+
+
+Voting History
+------------------------------------------------------------------------------