Geometry Boost List: [ggl] linestring/polygon intersection with get_turns

Subject: [ggl] linestring/polygon intersection with get_turns
From: Barend Gehrels (barend)
Date: 2011-07-04 15:23:05

Hi Eddy,

> When you use get_turns for a linestring/polygon intersection, how to 
> know, with the turn_info type, which ring of the polygon the 
> linestring cross ?

The turn_info type has an array of turn operations. The turn operation 
has two segment identifiers (seg_id and other_id). These identifiers 
have a ring_index, which is -1 for the outer ring and zero-based for the 
interior rings.

Regards, Barend