From 2d8264124d65af3d8422d7522efdb57f381cca24 Mon Sep 17 00:00:00 2001
From: Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
Date: Thu, 27 May 2021 23:40:25 +0200
Subject: [PATCH] geometry: SHAPE_LINE_CHAIN::PathLength() now can accept the
 maximum index of the segment to calculate the length to

---
 .../kimath/include/geometry/shape_line_chain.h |  2 +-
 libs/kimath/src/geometry/shape_line_chain.cpp  | 18 ++++++++++++++++--
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/libs/kimath/include/geometry/shape_line_chain.h b/libs/kimath/include/geometry/shape_line_chain.h
index 2103cd8d41..64e6f1eb9a 100644
--- a/libs/kimath/include/geometry/shape_line_chain.h
+++ b/libs/kimath/include/geometry/shape_line_chain.h
@@ -610,7 +610,7 @@ public:
      * belonging to our line.
      * @return: path length in Euclidean metric or -1 if aP does not belong to the line chain.
      */
-    int PathLength( const VECTOR2I& aP ) const;
+    int PathLength( const VECTOR2I& aP, int aIndex = -1 ) const;
 
     /**
      * Function CheckClearance()
diff --git a/libs/kimath/src/geometry/shape_line_chain.cpp b/libs/kimath/src/geometry/shape_line_chain.cpp
index 7ef74846a7..1b96e444a3 100644
--- a/libs/kimath/src/geometry/shape_line_chain.cpp
+++ b/libs/kimath/src/geometry/shape_line_chain.cpp
@@ -842,7 +842,7 @@ int SHAPE_LINE_CHAIN::Intersect( const SHAPE_LINE_CHAIN& aChain, INTERSECTIONS&
 }
 
 
-int SHAPE_LINE_CHAIN::PathLength( const VECTOR2I& aP ) const
+int SHAPE_LINE_CHAIN::PathLength( const VECTOR2I& aP, int aIndex ) const
 {
     int sum = 0;
 
@@ -851,7 +851,21 @@ int SHAPE_LINE_CHAIN::PathLength( const VECTOR2I& aP ) const
         const SEG seg = CSegment( i );
         int d = seg.Distance( aP );
 
-        if( d <= 1 )
+        bool indexMatch = true;
+
+        if( aIndex >= 0 )
+        {
+            if( aIndex == SegmentCount() )
+            {
+                indexMatch = ( i == SegmentCount() - 1 );
+            }
+            else
+            {
+                indexMatch = ( i == aIndex );
+            }
+        }
+
+        if( indexMatch )
         {
             sum += ( aP - seg.A ).EuclideanNorm();
             return sum;