From d67821d7714f13f72b0a507d656a31d5b553dda0 Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <hillbrand@ucdavis.edu>
Date: Tue, 8 May 2018 13:03:52 -0700
Subject: [PATCH] Add a clearance check for closed shape line chains

Also improves speed of multiple point checks by first eliminating points
outside of the BBox.
---
 common/geometry/shape_line_chain.cpp | 10 ++++++++--
 include/geometry/shape_line_chain.h  | 12 +++++++++++-
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/common/geometry/shape_line_chain.cpp b/common/geometry/shape_line_chain.cpp
index 58faf46b8e..294f77be6b 100644
--- a/common/geometry/shape_line_chain.cpp
+++ b/common/geometry/shape_line_chain.cpp
@@ -331,7 +331,7 @@ int SHAPE_LINE_CHAIN::PathLength( const VECTOR2I& aP ) const
 
 bool SHAPE_LINE_CHAIN::PointInside( const VECTOR2I& aP ) const
 {
-    if( !m_closed || SegmentCount() < 3 )
+    if( !m_closed || SegmentCount() < 3 || !BBox().Contains( aP ) )
         return false;
 
     bool inside = false;
@@ -358,6 +358,12 @@ bool SHAPE_LINE_CHAIN::PointInside( const VECTOR2I& aP ) const
 
 
 bool SHAPE_LINE_CHAIN::PointOnEdge( const VECTOR2I& aP ) const
+{
+    return CheckClearance( aP, 1 );
+}
+
+
+bool SHAPE_LINE_CHAIN::CheckClearance( const VECTOR2I& aP, const int aDist) const
 {
 	if( !PointCount() )
 		return false;
@@ -372,7 +378,7 @@ bool SHAPE_LINE_CHAIN::PointOnEdge( const VECTOR2I& aP ) const
         if( s.A == aP || s.B == aP )
             return true;
 
-        if( s.Distance( aP ) <= 1 )
+        if( s.Distance( aP ) <= aDist )
             return true;
     }
 
diff --git a/include/geometry/shape_line_chain.h b/include/geometry/shape_line_chain.h
index 6631356db9..094488c9c8 100644
--- a/include/geometry/shape_line_chain.h
+++ b/include/geometry/shape_line_chain.h
@@ -532,7 +532,7 @@ public:
     /**
      * Function PointInside()
      *
-     * Checks if point aP lies inside a convex polygon defined by the line chain. For closed
+     * Checks if point aP lies inside a polygon (any type) defined by the line chain. For closed
      * shapes only.
      * @param aP point to check
      * @return true if the point is inside the shape (edge is not treated as being inside).
@@ -548,6 +548,16 @@ public:
      */
     bool PointOnEdge( const VECTOR2I& aP ) const;
 
+    /**
+     * Function CheckClearance()
+     *
+     * Checks if point aP is closer to (or on) an edge or vertex of the line chain.
+     * @param aP point to check
+     * @param aDist distance in internal units
+     * @return true if the point is equal to or closer than aDist to the line chain.
+     */
+    bool CheckClearance( const VECTOR2I& aP, const int aDist) const;
+
     /**
      * Function SelfIntersecting()
      *