From 203c860f015eac3c2118c72d4aff47ad2cc12854 Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Thu, 19 Nov 2020 18:34:30 +0000
Subject: [PATCH] Ensure better smoothing for zones clipped by board edges.

---
 pcbnew/zone.cpp        | 10 ++++++++--
 pcbnew/zone_filler.cpp |  4 ----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/pcbnew/zone.cpp b/pcbnew/zone.cpp
index 9eb09403e8..101790dd4d 100644
--- a/pcbnew/zone.cpp
+++ b/pcbnew/zone.cpp
@@ -1177,11 +1177,13 @@ bool ZONE::BuildSmoothedPoly( SHAPE_POLY_SET& aSmoothedPoly, PCB_LAYER_ID aLayer
     }
 
     BOARD* board = GetBoard();
+    int    edgeClearance = 0;
     int    maxError = ARC_HIGH_DEF;
     bool   keepExternalFillets = false;
 
     if( board )
     {
+        edgeClearance = board->GetDesignSettings().m_CopperEdgeClearance;
         maxError = board->GetDesignSettings().m_MaxError;
         keepExternalFillets = board->GetDesignSettings().m_ZoneKeepExternalFillets;
     }
@@ -1228,14 +1230,18 @@ bool ZONE::BuildSmoothedPoly( SHAPE_POLY_SET& aSmoothedPoly, PCB_LAYER_ID aLayer
         aSmoothedPoly.BooleanAdd( *zone->Outline(), SHAPE_POLY_SET::PM_FAST );
 
     if( !GetIsRuleArea() && aBoardOutline )
-        aSmoothedPoly.BooleanIntersection( *aBoardOutline, SHAPE_POLY_SET::PM_STRICTLY_SIMPLE );
+    {
+        SHAPE_POLY_SET bufferedOutline = *aBoardOutline;
+        bufferedOutline.Deflate( std::max( m_ZoneClearance, edgeClearance ), 16 );
+        aSmoothedPoly.BooleanIntersection( bufferedOutline, SHAPE_POLY_SET::PM_STRICTLY_SIMPLE );
+    }
 
     smooth( aSmoothedPoly );
 
     if( aSmoothedPolyWithApron )
     {
         SHAPE_POLY_SET bufferedExtents = *maxExtents;
-        bufferedExtents.Inflate( m_ZoneMinThickness, 8 );
+        bufferedExtents.Inflate( m_ZoneMinThickness, 16 );
         *aSmoothedPolyWithApron = aSmoothedPoly;
         aSmoothedPolyWithApron->BooleanIntersection( bufferedExtents, SHAPE_POLY_SET::PM_FAST );
     }
diff --git a/pcbnew/zone_filler.cpp b/pcbnew/zone_filler.cpp
index 3e3ab04253..8a1dbea2fc 100644
--- a/pcbnew/zone_filler.cpp
+++ b/pcbnew/zone_filler.cpp
@@ -664,10 +664,6 @@ void ZONE_FILLER::buildCopperItemClearances( const ZONE* aZone, PCB_LAYER_ID aLa
                 return aReporter && ( ticker++ % 50 ) == 0 && aReporter->IsCancelled();
             };
 
-    static PCB_SHAPE dummyEdge;
-    dummyEdge.SetParent( m_board );
-    dummyEdge.SetLayer( Edge_Cuts );
-
     // A small extra clearance to be sure actual track clearances are not smaller than
     // requested clearance due to many approximations in calculations, like arc to segment
     // approx, rounding issues, etc.