From 184711beb46e87dfde10a77b0a69cfd9c9f88030 Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <hillbrand@ucdavis.edu>
Date: Fri, 25 Jan 2019 07:12:04 -0800
Subject: [PATCH] pcbnew: Fix via snapping to multiple tracks

Rather than selecting an arbitrary track to snap, we select the closest
track to our point, allowing the via to be placed along the full track
length.

Fixes: lp:1813324
* https://bugs.launchpad.net/kicad/+bug/1813324
---
 pcbnew/tools/drawing_tool.cpp | 20 ++++++++++++++++++--
 pcbnew/tools/grid_helper.cpp  |  4 ++--
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/pcbnew/tools/drawing_tool.cpp b/pcbnew/tools/drawing_tool.cpp
index c849b6abff..4c271ab2af 100644
--- a/pcbnew/tools/drawing_tool.cpp
+++ b/pcbnew/tools/drawing_tool.cpp
@@ -1507,6 +1507,7 @@ int DRAWING_TOOL::DrawVia( const TOOL_EVENT& aEvent )
             std::vector<KIGFX::VIEW::LAYER_ITEM_PAIR> items;
             BOX2I bbox = aVia->GetBoundingBox();
             auto view = m_frame->GetGalCanvas()->GetView();
+            std::vector<TRACK*> possible_tracks;
 
             view->Query( bbox, items );
 
@@ -1521,11 +1522,26 @@ int DRAWING_TOOL::DrawVia( const TOOL_EVENT& aEvent )
                 {
                     if( TestSegmentHit( aVia->GetPosition(), track->GetStart(), track->GetEnd(),
                                         ( track->GetWidth() + aVia->GetWidth() ) / 2 ) )
-                        return track;
+                        possible_tracks.push_back( track );
                 }
             }
 
-            return nullptr;
+            TRACK* return_track = nullptr;
+            int min_d = std::numeric_limits<int>::max();
+            for( auto track : possible_tracks )
+            {
+                SEG test( track->GetStart(), track->GetEnd() );
+                auto dist = ( test.NearestPoint( aVia->GetPosition() ) -
+                        VECTOR2I( aVia->GetPosition() ) ).EuclideanNorm();
+
+                if( dist < min_d )
+                {
+                    min_d = dist;
+                    return_track = track;
+                }
+            }
+
+            return return_track;
         }
 
 
diff --git a/pcbnew/tools/grid_helper.cpp b/pcbnew/tools/grid_helper.cpp
index f395326beb..7a4433334d 100644
--- a/pcbnew/tools/grid_helper.cpp
+++ b/pcbnew/tools/grid_helper.cpp
@@ -160,8 +160,8 @@ VECTOR2I GRID_HELPER::AlignToSegment( const VECTOR2I& aPoint, const SEG& aSeg )
 
     pts[0] = aSeg.A;
     pts[1] = aSeg.B;
-    pts[2] = aSeg.IntersectLines( SEG( nearest, nearest + VECTOR2I( 1, 0 ) ) );
-    pts[3] = aSeg.IntersectLines( SEG( nearest, nearest + VECTOR2I( 0, 1 ) ) );
+    pts[2] = aSeg.IntersectLines( SEG( nearest + VECTOR2I( -1, 1 ), nearest + VECTOR2I( 1, -1 ) ) );
+    pts[3] = aSeg.IntersectLines( SEG( nearest + VECTOR2I( -1, -1 ), nearest + VECTOR2I( 1, 1 ) ) );
 
     int min_d = std::numeric_limits<int>::max();