From f615b026d9b0416ef2dd796062345980205ebaf6 Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <seth@kipro-pcb.com>
Date: Fri, 7 Aug 2020 15:57:59 -0700
Subject: [PATCH] pcbnew: Account for zone expansion in conn

Connecting zone-to-zone, we need to allow for the stroke-width in
old-style polygons.

Also, speed up the calculation by skipping zone points that do not fall
inside the matching BBox

Fixes https://gitlab.com/kicad/code/kicad/issues/5043
---
 pcbnew/connectivity/connectivity_algo.cpp | 35 ++++++++++++++++-------
 pcbnew/connectivity/connectivity_items.h  | 10 +++++--
 2 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/pcbnew/connectivity/connectivity_algo.cpp b/pcbnew/connectivity/connectivity_algo.cpp
index 21d6053ca3..62d26fc72e 100644
--- a/pcbnew/connectivity/connectivity_algo.cpp
+++ b/pcbnew/connectivity/connectivity_algo.cpp
@@ -655,13 +655,10 @@ void CN_VISITOR::checkZoneItemConnection( CN_ZONE* aZone, CN_ITEM* aItem )
 
 void CN_VISITOR::checkZoneZoneConnection( CN_ZONE* aZoneA, CN_ZONE* aZoneB )
 {
-    const auto refParent = static_cast<const ZONE_CONTAINER*>( aZoneA->Parent() );
-    const auto testedParent = static_cast<const ZONE_CONTAINER*>( aZoneB->Parent() );
+    const auto parentA = static_cast<const ZONE_CONTAINER*>( aZoneA->Parent() );
+    const auto parentB = static_cast<const ZONE_CONTAINER*>( aZoneB->Parent() );
 
-    if( testedParent->Type () != PCB_ZONE_AREA_T )
-        return;
-
-    if( aZoneB == aZoneA  || refParent == testedParent )
+    if( aZoneB == aZoneA  || parentA == parentB )
         return;
 
     if( aZoneA->Layer() != aZoneB->Layer() )
@@ -670,13 +667,28 @@ void CN_VISITOR::checkZoneZoneConnection( CN_ZONE* aZoneA, CN_ZONE* aZoneB )
     if( aZoneB->Net() != aZoneA->Net() )
         return; // we only test zones belonging to the same net
 
+    const BOX2I& boxA = aZoneA->BBox();
+    const BOX2I& boxB = aZoneB->BBox();
+
+    int radiusA = 0;
+    int radiusB = 0;
+
+    if( parentA->GetFilledPolysUseThickness() )
+        radiusA = ( parentA->GetMinThickness() + 1 ) / 2;
+
+    if( parentB->GetFilledPolysUseThickness() )
+        radiusB = ( parentB->GetMinThickness() + 1 ) / 2;
+
     PCB_LAYER_ID layer = static_cast<PCB_LAYER_ID>( aZoneA->Layer() );
 
-    const auto& outline = refParent->GetFilledPolysList( layer ).COutline( aZoneA->SubpolyIndex() );
+    const auto& outline = parentA->GetFilledPolysList( layer ).COutline( aZoneA->SubpolyIndex() );
 
     for( int i = 0; i < outline.PointCount(); i++ )
     {
-        if( aZoneB->ContainsPoint( outline.CPoint( i ), 0 ) )
+        if( !boxB.Contains( outline.CPoint( i ) ) )
+            continue;
+
+        if( aZoneB->ContainsPoint( outline.CPoint( i ), radiusA ) )
         {
             aZoneA->Connect( aZoneB );
             aZoneB->Connect( aZoneA );
@@ -685,11 +697,14 @@ void CN_VISITOR::checkZoneZoneConnection( CN_ZONE* aZoneA, CN_ZONE* aZoneB )
     }
 
     const auto& outline2 =
-            testedParent->GetFilledPolysList( layer ).COutline( aZoneB->SubpolyIndex() );
+            parentB->GetFilledPolysList( layer ).COutline( aZoneB->SubpolyIndex() );
 
     for( int i = 0; i < outline2.PointCount(); i++ )
     {
-        if( aZoneA->ContainsPoint( outline2.CPoint( i ), 0 ) )
+        if( !boxA.Contains( outline2.CPoint( i ) ) )
+            continue;
+
+        if( aZoneA->ContainsPoint( outline2.CPoint( i ), radiusB ) )
         {
             aZoneA->Connect( aZoneB );
             aZoneB->Connect( aZoneA );
diff --git a/pcbnew/connectivity/connectivity_items.h b/pcbnew/connectivity/connectivity_items.h
index 058759bfff..75990c2bdc 100644
--- a/pcbnew/connectivity/connectivity_items.h
+++ b/pcbnew/connectivity/connectivity_items.h
@@ -375,11 +375,15 @@ public:
         return ContainsPoint( anchor->Pos(), 0 );
     }
 
-    bool ContainsPoint( const VECTOR2I p, int aAccuracy ) const
+    bool ContainsPoint( const VECTOR2I p, int aAccuracy = 0 ) const
     {
         auto zone = static_cast<ZONE_CONTAINER*> ( Parent() );
-        int clearance = zone->GetFilledPolysUseThickness() ? zone->GetMinThickness() / 2 : 0;
-        return m_cachedPoly->ContainsPoint( p, clearance + aAccuracy );
+        int clearance = ( aAccuracy + 1 ) / 2;
+
+        if( zone->GetFilledPolysUseThickness() )
+            clearance += ( zone->GetMinThickness() + 1 ) / 2;
+
+        return m_cachedPoly->ContainsPoint( p, clearance );
     }
 
     const BOX2I& BBox()