[Qgis-developer] Intersection of two lines design

Maximilian Krambach maximilian.krambach at gmx.de
Thu Mar 17 15:19:40 PDT 2016


I've frequently stumbled upon the problem that several functions (like
geomentry().intersection(geometry2), geometry().touches(geometry2) only
return something useful if BOTH geometries have a vertex at the meeting
point (which is inherited from GEOS)

My expection: they do intersect or touch if they share space.
I am Getting: Only a result if they share at least a vertex.

This results in tools like geoprocessing:intersection or clip giving
strange/unintuitive outputs.

Is it a design decision or just never discussed? It could be solved
quite easily, (see https://hub.qgis.org/issues/14504#note-2)

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