From f87ae66f2d43fffd257dfe7c8b723e597c2609ef Mon Sep 17 00:00:00 2001
From: Thomas Fischer <thomas.fischer@ufz.de>
Date: Thu, 7 Apr 2016 21:02:32 +0200
Subject: [PATCH] [GL] Impl. of GeoLib::sortSegments().
---
GeoLib/AnalyticalGeometry.cpp | 47 +++++++++++++++++++++++++++++++++++
GeoLib/AnalyticalGeometry.h | 9 +++++++
2 files changed, 56 insertions(+)
diff --git a/GeoLib/AnalyticalGeometry.cpp b/GeoLib/AnalyticalGeometry.cpp
index 4422f56d6f5..bf1a4f86264 100644
--- a/GeoLib/AnalyticalGeometry.cpp
+++ b/GeoLib/AnalyticalGeometry.cpp
@@ -706,4 +706,51 @@ lineSegmentIntersect2d(MathLib::Point3d const& a, MathLib::Point3d const& b,
}
}
+void sortSegments(
+ MathLib::Point3d const& seg_beg_pnt,
+ std::vector<GeoLib::LineSegment>& sub_segments)
+{
+ double const eps(std::numeric_limits<double>::epsilon());
+
+ auto findNextSegment = [&eps](
+ MathLib::Point3d const& seg_beg_pnt,
+ std::vector<GeoLib::LineSegment>& sub_segments,
+ std::vector<GeoLib::LineSegment>::iterator& sub_seg_it)
+ {
+ if (sub_seg_it == sub_segments.end())
+ return;
+ // find appropriate segment for the given segment begin point
+ auto act_beg_seg_it = std::find_if(
+ sub_seg_it, sub_segments.end(),
+ [&seg_beg_pnt, &eps](GeoLib::LineSegment const& seg)
+ {
+ return MathLib::sqrDist(seg_beg_pnt, seg.getBeginPoint()) < eps ||
+ MathLib::sqrDist(seg_beg_pnt, seg.getEndPoint()) < eps;
+ });
+ if (act_beg_seg_it == sub_segments.end())
+ return;
+ // if necessary correct orientation of segment, i.e. swap beg and end
+ if (MathLib::sqrDist(seg_beg_pnt, act_beg_seg_it->getEndPoint()) <
+ MathLib::sqrDist(seg_beg_pnt, act_beg_seg_it->getBeginPoint()))
+ std::swap(act_beg_seg_it->getBeginPoint(),
+ act_beg_seg_it->getEndPoint());
+ assert(sub_seg_it != sub_segments.end());
+ // exchange segments within the container
+ if (sub_seg_it != act_beg_seg_it)
+ std::swap(*sub_seg_it, *act_beg_seg_it);
+ };
+
+ // find start segment
+ auto seg_it = sub_segments.begin();
+ findNextSegment(seg_beg_pnt, sub_segments, seg_it);
+
+ while (seg_it != sub_segments.end())
+ {
+ MathLib::Point3d & new_seg_beg_pnt(seg_it->getEndPoint());
+ seg_it++;
+ if (seg_it != sub_segments.end())
+ findNextSegment(new_seg_beg_pnt, sub_segments, seg_it);
+ }
+}
+
} // end namespace GeoLib
diff --git a/GeoLib/AnalyticalGeometry.h b/GeoLib/AnalyticalGeometry.h
index ae7af19a7d9..a952d7f502c 100644
--- a/GeoLib/AnalyticalGeometry.h
+++ b/GeoLib/AnalyticalGeometry.h
@@ -384,6 +384,15 @@ void computeAndInsertAllIntersectionPoints(GeoLib::PointVec &pnt_vec,
GeoLib::Polygon rotatePolygonToXY(GeoLib::Polygon const& polygon_in,
MathLib::Vector3 & plane_normal);
+/// Sorts the vector of segments such that the \f$i\f$-th segment is connected
+/// with the \f$i+1\f$st segment, i.e. the end point of the \f$i\f$-th segment
+/// is the start point of the \f$i+1\f$st segment.
+/// The current implementation requires that all segments have to be
+/// connectable. In order to obtain a unique result the segments are sorted such
+/// that the begin point of the first segment is \c seg_beg_pnt.
+void sortSegments(MathLib::Point3d const& seg_beg_pnt,
+ std::vector<GeoLib::LineSegment>& sub_segments);
+
} // end namespace GeoLib
#include "AnalyticalGeometry-impl.h"
--
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