Teardrops: fixes and enhancements:

- do not allow smoothing outlines: outlines are already optimized.
- do not allow settings incompatible with teardrop area (grid, thermal relief)
- DIALOG_COPPER_ZONE: export zone settings to similar zones only.
Fixes #11040
https://gitlab.com/kicad/code/kicad/issues/11040

pcbnew/dialogs/dialog_copper_zones.cpp

@@ -81,6 +81,7 @@ private:
     UNIT_BINDER      m_gridStyleGap;
     UNIT_BINDER      m_islandThreshold;
     bool             m_hideAutoGeneratedNets;
+    bool             m_isTeardrop;
 
     std::map<wxString, int>    m_netNameToNetCode;
     std::vector<NETINFO_ITEM*> m_netInfoItemList;
@@ -189,6 +190,26 @@ DIALOG_COPPER_ZONE::DIALOG_COPPER_ZONE( PCB_BASE_FRAME* aParent, ZONE_SETTINGS*
     m_settings.SetupLayersList( m_layers, m_Parent,
                                 LSET::AllCuMask( aParent->GetBoard()->GetCopperLayerCount() ),
                                 false );
+    m_isTeardrop = m_settings.m_TeardropType != TEARDROP_TYPE::TD_NONE;
+
+    switch( m_settings.m_TeardropType )
+    {
+    case TEARDROP_TYPE::TD_NONE:
+        // standard copper zone
+        break;
+
+    case TEARDROP_TYPE::TD_VIAPAD:
+        SetTitle( _( "Teardrop on Vias/Pads Properties" ) );
+        break;
+
+    case TEARDROP_TYPE::TD_TRACKEND:
+        SetTitle( _( "Teardrop on Tracks Properties" ) );
+        break;
+
+    default:
+        SetTitle( _( "Teardrop Properties" ) );
+        break;
+    }
 
     m_settingsExported = false;
     m_currentlySelectedNetcode = INVALID_NET_CODE;
@@ -223,6 +244,14 @@ bool DIALOG_COPPER_ZONE::TransferDataToWindow()
     m_cornerRadius.SetValue( m_settings.GetCornerRadius() );
     m_PriorityLevelCtrl->SetValue( m_settings.m_ZonePriority );
 
+    if( m_isTeardrop )  // outlines are never smoothed: they have alreay the right shape
+    {
+        m_cornerSmoothingChoice->SetSelection( 0 );
+        m_cornerSmoothingChoice->Enable( false );
+        m_cornerRadius.SetValue( 0 );
+        m_cornerRadius.Enable( false );
+    }
+
     switch( m_settings.m_ZoneBorderDisplayStyle )
     {
     case ZONE_BORDER_DISPLAY_STYLE::NO_HATCH:      m_OutlineDisplayCtrl->SetSelection( 0 ); break;
@@ -244,6 +273,12 @@ bool DIALOG_COPPER_ZONE::TransferDataToWindow()
     case ZONE_CONNECTION::FULL:        m_PadInZoneOpt->SetSelection( 0 ); break;
     }
 
+    if( m_isTeardrop )
+    {
+        m_PadInZoneOpt->SetSelection( 0 );
+        m_PadInZoneOpt->Enable( false );
+    }
+
     // Do not enable/disable antipad clearance and spoke width.  They might be needed if
     // a footprint or pad overrides the zone to specify a thermal connection.
     m_antipadClearance.SetValue( m_settings.m_ThermalReliefGap );
@@ -270,11 +305,12 @@ bool DIALOG_COPPER_ZONE::TransferDataToWindow()
     // Initialize information required to display nets list
     readNetInformation();
 
-    switch( m_settings.m_FillMode )
+    if( !m_isTeardrop && m_settings.m_FillMode == ZONE_FILL_MODE::HATCH_PATTERN )
-    {
+        m_GridStyleCtrl->SetSelection( 1 );
-    case ZONE_FILL_MODE::HATCH_PATTERN: m_GridStyleCtrl->SetSelection( 1 ); break;
+    else
-    default:                            m_GridStyleCtrl->SetSelection( 0 ); break;
+        m_GridStyleCtrl->SetSelection( 0 );
-    }
+
+    m_GridStyleCtrl->Enable( !m_isTeardrop );
 
     m_gridStyleRotation.SetUnits( EDA_UNITS::DEGREES );
     m_gridStyleRotation.SetAngleValue( m_settings.m_HatchOrientation );
@@ -655,6 +691,13 @@ void DIALOG_COPPER_ZONE::ExportSetupToOtherCopperZones( wxCommandEvent& event )
         if( zone->GetIsRuleArea() )
             continue;
 
+        // Export only to similar zones:
+        // Teardrop area -> teardrop area of same type
+        // copper zone -> copper zone
+        // Exporting current settings to a different zone type make no sense
+        if( m_settings.m_TeardropType != zone->GetTeardropAreaType() )
+            continue;
+
         m_settings.ExportSetting( *zone, false );  // false = partial export
         m_settingsExported = true;
         m_Parent->OnModify();

pcbnew/teardrop/teardrop_types.h

@@ -0,0 +1,42 @@
+/*
+ * This program source code file is part of KiCad, a free EDA CAD application.
+ *
+ * Copyright (C) 2021 Jean-Pierre Charras, jp.charras at wanadoo.fr
+ * Copyright (C) 2022 KiCad Developers, see AUTHORS.txt for contributors.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ * or you may search the http://www.gnu.org website for the version 2 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#ifndef TEARDROP_TYPES_H
+#define TEARDROP_TYPES_H
+
+/**
+ * define the type of a teardrop: on a via or pad, or a track end
+ */
+enum class TEARDROP_TYPE
+{
+    TD_NONE = 0,        // Not a teardrop: just a standard zone
+    TD_UNSPECIFIED,     // Not specified/unknown teardrop type
+    TD_VIAPAD,          // a teardrop on a via or pad
+    TD_TRACKEND         // a teardrop on a track end
+                        // (when 2 tracks having different widths have a teardrop on the
+                        // end of the largest track)
+};
+
+
+#endif  // ifndef TEARDROP_TYPES_H

pcbnew/zone.cpp

@@ -520,6 +520,8 @@ void ZONE::GetMsgPanelInfo( EDA_DRAW_FRAME* aFrame, std::vector<MSG_PANEL_ITEM>&
 
     if( GetIsRuleArea() )
         msg = _( "Rule Area" );
+    else if( IsTeardropArea() )
+        msg = _( "Teardrop Area" );
     else if( IsOnCopperLayer() )
         msg = _( "Copper Zone" );
     else
@@ -1068,6 +1070,12 @@ bool ZONE::BuildSmoothedPoly( SHAPE_POLY_SET& aSmoothedPoly, PCB_LAYER_ID aLayer
     const BOARD* board = GetBoard();
     int          maxError = ARC_HIGH_DEF;
     bool         keepExternalFillets = false;
+    bool         smooth_requested = m_cornerSmoothingType == ZONE_SETTINGS::SMOOTHING_CHAMFER
+                                    || m_cornerSmoothingType == ZONE_SETTINGS::SMOOTHING_FILLET;
+
+    if( IsTeardropArea() )  // We use teardrop shapes with no smoothing
+                            // these shapes are already optimized
+        smooth_requested = false;
 
     if( board )
     {
@@ -1079,6 +1087,10 @@ bool ZONE::BuildSmoothedPoly( SHAPE_POLY_SET& aSmoothedPoly, PCB_LAYER_ID aLayer
 
     auto smooth = [&]( SHAPE_POLY_SET& aPoly )
                   {
+
+                      if( !smooth_requested )
+                          return;
+
                       switch( m_cornerSmoothingType )
                       {
                       case ZONE_SETTINGS::SMOOTHING_CHAMFER:
@@ -1107,7 +1119,7 @@ bool ZONE::BuildSmoothedPoly( SHAPE_POLY_SET& aSmoothedPoly, PCB_LAYER_ID aLayer
     // Should external fillets (that is, those applied to concave corners) be kept?  While it
     // seems safer to never have copper extend outside the zone outline, 5.1.x and prior did
     // indeed fill them so we leave the mode available.
-    if( keepExternalFillets )
+    if( keepExternalFillets && smooth_requested )
     {
         withFillets = flattened;
         smooth( withFillets );

pcbnew/zone.h

@@ -34,6 +34,7 @@
 #include <layer_ids.h>
 #include <geometry/shape_poly_set.h>
 #include <zone_settings.h>
+#include <teardrop/teardrop_types.h>
 
 
 class EDA_RECT;
@@ -43,18 +44,6 @@ class BOARD;
 class ZONE;
 class MSG_PANEL_ITEM;
 
-/**
- * define the type of a teardrop: on a via or pad, or atrack end
- */
-enum class TEARDROP_TYPE
-{
-    TD_NONE = 0,        // Not a teardrop: just a standard zone
-    TD_UNSPECIFIED,     // Not specified/unknown teardrop type
-    TD_VIAPAD,          // a teardrop on a via or pad
-    TD_TRACKEND         // a teardrop on a track end
-                        // (when 2 tracks having different widths have a teardrop on the
-                        // end of the largest track)
-};
 
 /**
  * Handle a list of polygons defining a copper zone.

pcbnew/zone_settings.cpp

@@ -122,6 +122,11 @@ ZONE_SETTINGS& ZONE_SETTINGS::operator << ( const ZONE& aSource )
     m_removeIslands               = aSource.GetIslandRemovalMode();
     m_minIslandArea               = aSource.GetMinIslandArea();
 
+    // Currently, the teardrop area type is not really a ZONE_SETTINGS parameter,
+    // but a ZONE parameter only.
+    // However it can be used in dialogs
+    m_TeardropType                = aSource.GetTeardropAreaType();
+
     m_Layers = aSource.GetLayerSet();
 
     return *this;
@@ -155,6 +160,12 @@ void ZONE_SETTINGS::ExportSetting( ZONE& aTarget, bool aFullExport ) const
     aTarget.SetLocked( m_Locked );
     aTarget.SetIslandRemovalMode( GetIslandRemovalMode() );
     aTarget.SetMinIslandArea( GetMinIslandArea() );
+    // Currently, the teardrop area type is not imported from a ZONE_SETTINGS, because
+    // it is not really a ZONE_SETTINGS parameter, but a ZONE parameter only
+#if 0
+    aTarget.SetTeardropAreaType( m_TeardropType );
+#endif
+
 
     if( aFullExport )
     {

pcbnew/zone_settings.h

@@ -33,6 +33,7 @@
 #include <layer_ids.h>
 #include <zones.h>
 #include <geometry/eda_angle.h>
+#include <teardrop/teardrop_types.h>
 
 class wxDataViewListCtrl;
 
@@ -107,6 +108,11 @@ public:
     bool            m_Zone_45_Only;
     bool            m_Locked;
 
+    /* A zone outline can be a teardrop zone with different rules
+     * priority, smoothed corners, thermal relief...
+     */
+    TEARDROP_TYPE   m_TeardropType;
+
 private:
     int             m_cornerSmoothingType;   // Corner smoothing type
     unsigned int    m_cornerRadius;          // Corner chamfer distance / fillet radius