Fixup for Altium pad/fill importer

The previous commit merged pads with copper areas.  This was appealing
but broke when the pad and the area were meant to have different
size/shape technical layers.  Small pads = Small paste.  Instead, we do
not merge the pads but we assign them to have the appropriate nets in
KiCad, allowing the same effective result but keeping the technical
layers correct

pcbnew/pcb_io/altium/altium_pcb.cpp

@@ -811,14 +811,39 @@ FOOTPRINT* ALTIUM_PCB::ParseFootprint( ALTIUM_COMPOUND_FILE& altiumLibFile,
         }
     }
 
+
+    // Loop over this multiple times to catch pads that are jumpered to each other by multiple shapes
+    for( bool changes = true; changes; )
+    {
+        changes = false;
+
+        alg::for_all_pairs( footprint->Pads().begin(), footprint->Pads().end(),
+            [&changes]( PAD* aPad1, PAD* aPad2 )
+            {
+                if( !( aPad1->GetNumber().IsEmpty() ^ aPad2->GetNumber().IsEmpty() ) )
+                    return;
+
+                for( PCB_LAYER_ID layer : aPad1->GetLayerSet().Seq() )
+                {
+                    std::shared_ptr<SHAPE> shape1 = aPad1->GetEffectiveShape( layer );
+                    std::shared_ptr<SHAPE> shape2 = aPad2->GetEffectiveShape( layer );
+
+                    if( shape1->Collide( shape2.get() ) )
+                    {
+                        if( aPad1->GetNumber().IsEmpty() )
+                            aPad1->SetNumber( aPad2->GetNumber() );
+                        else
+                            aPad2->SetNumber( aPad1->GetNumber() );
+
+                        changes = true;
+                    }
+                }
+            } );
+    }
+
     // Auto-position reference and value
     footprint->AutoPositionFields();
 
-    for( PAD* pad : footprint->Pads() )
-    {
-        pad->Recombine( false, ARC_HIGH_DEF );
-    }
-
     if( parser.HasParsingError() )
     {
         THROW_IO_ERROR( wxString::Format( wxT( "%s stream was not parsed correctly" ),
@@ -2588,6 +2613,61 @@ void ALTIUM_PCB::ConvertShapeBasedRegions6ToFootprintItemOnLayer( FOOTPRINT*
         polySet.AddHole( hole_linechain );
     }
 
+    if( aLayer == F_Cu || aLayer == B_Cu )
+    {
+        std::unique_ptr<PAD> pad = std::make_unique<PAD>( aFootprint );
+
+        LSET padLayers;
+        padLayers.set( aLayer );
+
+        pad->SetAttribute( PAD_ATTRIB::SMD );
+        pad->SetShape( PAD_SHAPE::CUSTOM );
+        pad->SetThermalSpokeAngle( ANGLE_90 );
+
+        int      anchorSize = 1;
+        VECTOR2I anchorPos = linechain.CPoint( 0 );
+
+        pad->SetShape( PAD_SHAPE::CUSTOM );
+        pad->SetAnchorPadShape( PAD_SHAPE::CIRCLE );
+        pad->SetSize( { anchorSize, anchorSize } );
+        pad->SetPosition( anchorPos );
+
+        SHAPE_POLY_SET shapePolys = polySet;
+        shapePolys.Move( -anchorPos );
+        pad->AddPrimitivePoly( shapePolys, 0, true );
+
+        auto& map = m_extendedPrimitiveInformationMaps[ALTIUM_RECORD::REGION];
+        auto  it = map.find( aPrimitiveIndex );
+
+        if( it != map.end() )
+        {
+            const AEXTENDED_PRIMITIVE_INFORMATION& info = it->second;
+
+            if( info.pastemaskexpansionmode == ALTIUM_MODE::MANUAL )
+            {
+                pad->SetLocalSolderPasteMargin(
+                        info.pastemaskexpansionmanual ? info.pastemaskexpansionmanual : 1 );
+            }
+
+            if( info.soldermaskexpansionmode == ALTIUM_MODE::MANUAL )
+            {
+                pad->SetLocalSolderMaskMargin(
+                        info.soldermaskexpansionmanual ? info.soldermaskexpansionmanual : 1 );
+            }
+
+            if( info.pastemaskexpansionmode != ALTIUM_MODE::NONE )
+                padLayers.set( aLayer == F_Cu ? F_Paste : B_Paste );
+
+            if( info.soldermaskexpansionmode != ALTIUM_MODE::NONE )
+                padLayers.set( aLayer == F_Cu ? F_Mask : B_Mask );
+        }
+
+        pad->SetLayerSet( padLayers );
+
+        aFootprint->Add( pad.release(), ADD_MODE::APPEND );
+    }
+    else
+    {
         std::unique_ptr<PCB_SHAPE> shape = std::make_unique<PCB_SHAPE>( aFootprint, SHAPE_T::POLY );
 
         shape->SetPolyShape( polySet );
@@ -2596,6 +2676,7 @@ void ALTIUM_PCB::ConvertShapeBasedRegions6ToFootprintItemOnLayer( FOOTPRINT*
         shape->SetStroke( STROKE_PARAMS( 0 ) );
 
         aFootprint->Add( shape.release(), ADD_MODE::APPEND );
+    }
 }
 
 
@@ -4368,7 +4449,55 @@ void ALTIUM_PCB::ConvertFills6ToBoardItemOnLayer( const AFILL6& aElem, PCB_LAYER
 void ALTIUM_PCB::ConvertFills6ToFootprintItemOnLayer( FOOTPRINT* aFootprint, const AFILL6& aElem,
                                                       PCB_LAYER_ID aLayer )
 {
-    std::unique_ptr<PCB_SHAPE> fill = std::make_unique<PCB_SHAPE>( aFootprint, SHAPE_T::RECTANGLE );
+    if( aLayer == F_Cu || aLayer == B_Cu )
+    {
+        std::unique_ptr<PAD> pad = std::make_unique<PAD>( aFootprint );
+
+        LSET padLayers;
+        padLayers.set( aLayer );
+
+        pad->SetAttribute( PAD_ATTRIB::SMD );
+        if( aElem.rotation == 0. )
+        {
+            pad->SetShape( PAD_SHAPE::RECTANGLE );
+            pad->SetSize( { aElem.pos2.x - aElem.pos1.x, aElem.pos2.y - aElem.pos1.y } );
+            pad->SetPosition( ( aElem.pos1 + aElem.pos2 ) / 2 );
+        }
+        else
+        {
+            pad->SetShape( PAD_SHAPE::CUSTOM );
+
+            int      anchorSize = std::min( std::abs( aElem.pos2.x - aElem.pos1.x ),
+                                            std::abs( aElem.pos2.y - aElem.pos1.y ) );
+            VECTOR2I anchorPos = aElem.pos1;
+
+            pad->SetAnchorPadShape( PAD_SHAPE::CIRCLE );
+            pad->SetSize( { anchorSize, anchorSize } );
+            pad->SetPosition( anchorPos );
+
+            SHAPE_POLY_SET shapePolys;
+            shapePolys.NewOutline();
+            shapePolys.Append( aElem.pos1.x - anchorPos.x, aElem.pos1.y - anchorPos.y );
+            shapePolys.Append( aElem.pos2.x - anchorPos.x, aElem.pos1.y - anchorPos.y );
+            shapePolys.Append( aElem.pos2.x - anchorPos.x, aElem.pos2.y - anchorPos.y );
+            shapePolys.Append( aElem.pos1.x - anchorPos.x, aElem.pos2.y - anchorPos.y );
+            shapePolys.Outline( 0 ).SetClosed( true );
+
+            VECTOR2I center( ( aElem.pos1.x + aElem.pos2.x ) / 2 - anchorPos.x,
+                             ( aElem.pos1.y + aElem.pos2.y ) / 2 - anchorPos.y );
+            shapePolys.Rotate( EDA_ANGLE( aElem.rotation, DEGREES_T ), center );
+            pad->AddPrimitivePoly( shapePolys, 0, true );
+        }
+
+        pad->SetThermalSpokeAngle( ANGLE_90 );
+        pad->SetLayerSet( padLayers );
+
+        aFootprint->Add( pad.release(), ADD_MODE::APPEND );
+    }
+    else
+    {
+        std::unique_ptr<PCB_SHAPE> fill =
+                std::make_unique<PCB_SHAPE>( aFootprint, SHAPE_T::RECTANGLE );
 
         fill->SetFilled( true );
         fill->SetLayer( aLayer );
@@ -4386,6 +4515,7 @@ void ALTIUM_PCB::ConvertFills6ToFootprintItemOnLayer( FOOTPRINT* aFootprint, con
         }
 
         aFootprint->Add( fill.release(), ADD_MODE::APPEND );
+    }
 }