build spatialite with librttopo support

[Jeff McKenna]

• main page: ​https://strk.kbt.io/projects/rttopo/

• IRC discussion

        GlennS	Hi, I'm wondering if anyone knows of a command line tool to fix invalid geometries? Something like PostGIS's ST_MakeValid, except without having to install PostGIS.
	GlennS	I know that Spatialite can also use this via librttopo, but I'm having trouble getting that working so thought I'd see if there was an easier way before I bang my head against it any further
	EvenR	GlennS: ogr2ogr out.shp in.shp -sql "select ST_MakeValid(geometry), * FROM in" -dialect SQLite
	GlennS	EvenR: I don't thing the spatialite which ships with ogr2ogr (or is it just using my system's library?) comes with ST_MakeValid by default? I get undefined function ST_MakeValid.
	EvenR	spatialite must be built against liblwgeom : https://www.gaia-gis.it/gaia-sins/spatialite-sql-4.3.0.html
	sigq	Title: SpatiaLite SQL functions reference list (at www.gaia-gis.it)
	GlennS	yeah, as I mentioned, I'm failing to do that
	GlennS	actually that information is out of date anyway
	GlennS	they've switched from liblwgeom to librttopo

[Jeff McKenna]

Compile errors with Visual Studio 2012 & librttopo: ​https://git.osgeo.org/gogs/rttopo/librttopo/issues/24

[Jeff McKenna]

best versions:

1. librttopo-1.1.0-RC1

​https://git.osgeo.org/gitea/rttopo/librttopo/src/tag/librttopo-1.1.0-RC1

2. libspatialite-5.0.0-devel

(dowlnoaded from the Fossil Repository)

(from thread: ​https://groups.google.com/d/msg/spatialite-users/MlXsPU0ZMYw/t-ynEJ2TBQAJ)

[Jeff McKenna]

another related ticket (for 2 missing header files): ​https://git.osgeo.org/gitea/rttopo/librttopo/issues/25

[Jeff McKenna]

• added into MS4W 4.0.2 (https://ms4w.com/download.html)