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Geometry building and C++ UDF library
Posted by: Sebastien Thomas
Date: June 29, 2009 08:08AM

I'm using mysql-5.1.23-beta-GIS to develop some function in C++ (the goal is to get something faster than stored procedures)

Everything seems to be alright as long as i'm using POINT parameters, but i got into trouble with more complex Geometries. Being given a polygon, i want to access its "exterior_ring". I'm using something like this :

Geometry *g, *g2;
GeometryBuffer buffer;
String s, s_tmp;
uint32 n_points;
g2 = Geometry::create_from_wkb(&buffer, s.ptr(), s.length(), &s_tmp);
Log(n_points : %d", n_points);

g2 seems to be created, but n_points returns 39314552 whereas calling : "select numpoints(exteriorring(geom))" in sql returns 2504 points, which is much more correct.

Is there anything i do wrong creating g2 ? I couldn't find any information on how to use the string i got from g->exterior_ring(&s);

Edited 2 time(s). Last edit at 06/29/2009 08:17AM by Sebastien Thomas.

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Geometry building and C++ UDF library
June 29, 2009 08:08AM

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