From 3475d0cebd5a62a6627c7d2d8f46ec0ff2379bf4 Mon Sep 17 00:00:00 2001
From: Jon Evans <jon@craftyjon.com>
Date: Sun, 6 Jun 2021 14:16:31 -0400
Subject: [PATCH] PNS: Grab start item based on clearance if no direct hits
 found

Fixes annoying "routing start point violates DRC" messages when
entering the router from the hotkey and not directly over a track.
---
 pcbnew/router/pns_router.cpp    | 24 ++++++++++++++++++++++--
 pcbnew/router/pns_router.h      |  2 +-
 pcbnew/router/pns_tool_base.cpp |  3 +++
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/pcbnew/router/pns_router.cpp b/pcbnew/router/pns_router.cpp
index 1c13a2a960..d939ebbcca 100644
--- a/pcbnew/router/pns_router.cpp
+++ b/pcbnew/router/pns_router.cpp
@@ -118,10 +118,30 @@ bool ROUTER::RoutingInProgress() const
 }
 
 
-const ITEM_SET ROUTER::QueryHoverItems( const VECTOR2I& aP )
+const ITEM_SET ROUTER::QueryHoverItems( const VECTOR2I& aP, bool aUseClearance )
 {
     if( m_state == IDLE || m_placer == nullptr )
-        return m_world->HitTest( aP );
+    {
+        if( aUseClearance )
+        {
+            SEGMENT test( SEG( aP, aP ), -1 );
+            test.SetWidth( 1 );
+            test.SetLayers( LAYER_RANGE::All() );
+            NODE::OBSTACLES obs;
+            m_world->QueryColliding( &test, obs, ITEM::ANY_T, -1, false );
+
+            PNS::ITEM_SET ret;
+
+            for( OBSTACLE& obstacle : obs )
+                ret.Add( obstacle.m_item, false );
+
+            return ret;
+        }
+        else
+        {
+            return m_world->HitTest( aP );
+        }
+    }
     else
         return m_placer->CurrentNode()->HitTest( aP );
 }
diff --git a/pcbnew/router/pns_router.h b/pcbnew/router/pns_router.h
index 867a38df5c..5102bc51cf 100644
--- a/pcbnew/router/pns_router.h
+++ b/pcbnew/router/pns_router.h
@@ -173,7 +173,7 @@ public:
 
     bool IsPlacingVia() const;
 
-    const ITEM_SET QueryHoverItems( const VECTOR2I& aP );
+    const ITEM_SET QueryHoverItems( const VECTOR2I& aP, bool aUseClearance = false );
 
     bool StartDragging( const VECTOR2I& aP, ITEM* aItem, int aDragMode = DM_ANY );
     bool StartDragging( const VECTOR2I& aP, ITEM_SET aItems, int aDragMode = DM_COMPONENT );
diff --git a/pcbnew/router/pns_tool_base.cpp b/pcbnew/router/pns_tool_base.cpp
index c412e3f751..6ec92399a5 100644
--- a/pcbnew/router/pns_tool_base.cpp
+++ b/pcbnew/router/pns_tool_base.cpp
@@ -113,6 +113,9 @@ ITEM* TOOL_BASE::pickSingleItem( const VECTOR2I& aWhere, int aNet, int aLayer, b
 
     ITEM_SET candidates = m_router->QueryHoverItems( aWhere );
 
+    if( candidates.Empty() )
+        candidates = m_router->QueryHoverItems( aWhere, true );
+
     for( ITEM* item : candidates.Items() )
     {
         if( !item->IsRoutable() )