[postgis-devel] SFCGAL 1.1.0 support

[Paragon Corporation]

Vincent,

Some comments about the patch

1) For the availability part of the docs.  I noticed you put ???

That should  be 2.2.0  (we won't be releasing until 2.2.0 September  so I
think you can fit it in to the 2.2.0 release)


2) It seems you have added backend switchers for ST_Difference and ST_Union.
I'm guessing that is for the same reason you override the 

ST_Intersection function too -- so that the SFCGAL implementations of those
is a true 2D and not any monkey 3D in there

And that the true 3D Difference and 3D Union functions are serviced by
ST_3DUnion and ST_3DDifference?



Overall pretty excited about these changes and can't wait to get my hammer
out to stress test them. :)

Thanks,
Regina
 

-----Original Message-----
From: postgis-devel-bounces at lists.osgeo.org
[mailto:postgis-devel-bounces at lists.osgeo.org] On Behalf Of Vincent Mora
Sent: Wednesday, January 21, 2015 1:15 PM
To: PostGIS Development Discussion
Subject: [postgis-devel] SFCGAL 1.1.0 support

Hi all,

We released SFCGAL 1.1.0 this week, and here is a patch to support it.

Spoiler: the new functions are ST_3DUnion, ST_3DDifference and ST_Volume
(and an SFCGAL backend for ST_Union, ST_Difference).

This patch is not meant to be included as is, but to provide a base for
discussion.  A summary of the modifications in the patch follows.

There are parts of the patch that are bug fixes and that do not depend on
SFCGAL 1.1.0 and can be included right away.

The points that I'd most like feedback on are:
- do we need to support older versions of SFCGAL ?
- how to make a nice section in the doc explaining the backend mechanism ?

My two cents on the first question: there is no distro provided binaries of
SFCGAL that I'm aware of, so, since you have to recompile SFCGAL, you may as
well recompile the new shiny one rather than an old dusty one.

Thanks,

V.










Summary of the modifications in the patch (the parts specific to SFCGAL
1.1.0 are tagged as such):


In liblwgeom/lwgeom_sfcgal.c
- fix bug for conversion of multisolid (caused extruded multypolygon to 
miss the solid flag)

In postgis/lwgeom_backend_api.c
- added backend switch for difference and union *SFCGAL 1.1.0*

In postgis/lwgeom_geos.h and postgis/lwgeom_geos.c
- changed the name of difference and union *SFCGAL 1.1.0*
- exposed those renamed functions *SFCGAL 1.1.0*

In postgis/lwgeom_sfcgal.c
- added difference, union, volume *SFCGAL 1.1.0*
- added makesolid and issolid

In postgis/sfcgal.sql.in
- added ST_3DDifference, ST_3DUnion and ST_Volume *SFCGAL 1.1.0*
- added ST_MakeSolid and ST_IsSolid

In regress/sfcgal/concave_hull.sql
- fixed test failure caused by insufficient tolerance *SFCGAL 1.1.0*

In regress/sfcgal/empty.sql, regress/sfcgal/empty_expected, 
regress/sfcgal/regress_ogc.sql and regress/sfcgal/regress_ogc_expected
- fixed test to avoid failure on equivalent representation of a polygon 
(different starting point for a ring) *SFCGAL 1.1.0*