pcbnew: Disallow new via where DRC is violated

Prior to placing the via, we check if the resulting via will pass too
close to different nets on different layers.

Fixes: lp:1718827
* https://bugs.launchpad.net/kicad/+bug/1718827

pcbnew/tools/drawing_tool.cpp

@@ -1504,20 +1504,86 @@ int DRAWING_TOOL::DrawVia( const TOOL_EVENT& aEvent )
         TRACK* findTrack( VIA* aVia )
         {
             const LSET lset = aVia->GetLayerSet();
+            std::vector<KIGFX::VIEW::LAYER_ITEM_PAIR> items;
+            BOX2I bbox = aVia->GetBoundingBox();
+            auto view = m_frame->GetGalCanvas()->GetView();
 
-            for( TRACK* track : m_board->Tracks() )
+            view->Query( bbox, items );
+
+            for( auto it : items )
             {
-                if( !(track->GetLayerSet() & lset ).any() )
+                BOARD_ITEM* item = static_cast<BOARD_ITEM*>( it.first );
+
+                if( !(item->GetLayerSet() & lset ).any() )
                     continue;
 
-                if( TestSegmentHit( aVia->GetPosition(), track->GetStart(), track->GetEnd(),
+                if( auto track = dyn_cast<TRACK*>( item ) )
-                                    ( track->GetWidth() + aVia->GetWidth() ) / 2 ) )
+                {
-                    return track;
+                    if( TestSegmentHit( aVia->GetPosition(), track->GetStart(), track->GetEnd(),
+                                        ( track->GetWidth() + aVia->GetWidth() ) / 2 ) )
+                        return track;
+                }
             }
 
             return nullptr;
         }
 
+
+        bool hasDRCViolation( VIA* aVia )
+        {
+            const LSET lset = aVia->GetLayerSet();
+            std::vector<KIGFX::VIEW::LAYER_ITEM_PAIR> items;
+            int net = 0;
+            int clearance = 0;
+            BOX2I bbox = aVia->GetBoundingBox();
+            auto view = m_frame->GetGalCanvas()->GetView();
+
+            view->Query( bbox, items );
+
+            for( auto it : items )
+            {
+                BOARD_ITEM* item = static_cast<BOARD_ITEM*>( it.first );
+
+                if( !(item->GetLayerSet() & lset ).any() )
+                    continue;
+
+                if( auto track = dyn_cast<TRACK*>( item ) )
+                {
+                    int max_clearance = std::max( clearance, track->GetClearance() );
+
+                    if( TestSegmentHit( aVia->GetPosition(), track->GetStart(), track->GetEnd(),
+                            ( track->GetWidth() + aVia->GetWidth() ) / 2  + max_clearance ) )
+                    {
+                        if( net && track->GetNetCode() != net )
+                            return true;
+
+                        net = track->GetNetCode();
+                        clearance = track->GetClearance();
+                    }
+                }
+
+                if( auto mod = dyn_cast<MODULE*>( item ) )
+                {
+                    for( auto pad : mod->Pads() )
+                    {
+                        int max_clearance = std::max( clearance, pad->GetClearance() );
+
+                        if( pad->HitTest( aVia->GetBoundingBox(), false, max_clearance ) )
+                        {
+                            if( net && pad->GetNetCode() != net )
+                                return true;
+
+                            net = pad->GetNetCode();
+                            clearance = pad->GetClearance();
+                        }
+                    }
+                }
+            }
+
+            return false;
+        }
+
+
         int findStitchedZoneNet( VIA* aVia )
         {
             const auto  pos     = aVia->GetPosition();
@@ -1572,8 +1638,6 @@ int DRAWING_TOOL::DrawVia( const TOOL_EVENT& aEvent )
             // That's not ideal, and is in fact probably worse than forcing snap in
             // this situation.
 
-//          bool do_snap = ( m_frame->Settings().m_magneticTracks == CAPTURE_CURSOR_IN_TRACK_TOOL
-//                || m_frame->Settings().m_magneticTracks == CAPTURE_ALWAYS );
             m_gridHelper.SetSnap( !( m_modifiers & MD_SHIFT ) );
             auto    via = static_cast<VIA*>( aItem );
             wxPoint pos = via->GetPosition();
@@ -1588,12 +1652,15 @@ int DRAWING_TOOL::DrawVia( const TOOL_EVENT& aEvent )
             }
         }
 
-        void PlaceItem( BOARD_ITEM* aItem, BOARD_COMMIT& aCommit ) override
+        bool PlaceItem( BOARD_ITEM* aItem, BOARD_COMMIT& aCommit ) override
         {
             auto    via = static_cast<VIA*>( aItem );
             int     newNet;
             TRACK*  track = findTrack( via );
 
+            if( hasDRCViolation( via ) )
+                return false;
+
             if( track )
             {
                 aCommit.Modify( track );
@@ -1611,6 +1678,7 @@ int DRAWING_TOOL::DrawVia( const TOOL_EVENT& aEvent )
                 via->SetNetCode( newNet );
 
             aCommit.Add( aItem );
+            return true;
         }
 
         std::unique_ptr<BOARD_ITEM> CreateItem() override

pcbnew/tools/footprint_editor_tools.cpp

@@ -109,7 +109,7 @@ int MODULE_EDITOR_TOOLS::PlacePad( const TOOL_EVENT& aEvent )
             return std::unique_ptr<BOARD_ITEM>( pad );
         }
 
-        void PlaceItem( BOARD_ITEM *aItem, BOARD_COMMIT& aCommit ) override
+        bool PlaceItem( BOARD_ITEM *aItem, BOARD_COMMIT& aCommit ) override
         {
             D_PAD* pad = dynamic_cast<D_PAD*>( aItem );
 
@@ -118,7 +118,10 @@ int MODULE_EDITOR_TOOLS::PlacePad( const TOOL_EVENT& aEvent )
                 m_frame->Export_Pad_Settings( pad );
                 pad->SetLocalCoord();
                 aCommit.Add( aItem );
+                return true;
             }
+
+            return false;
         }
     };
 

pcbnew/tools/pcb_tool.cpp

@@ -132,10 +132,16 @@ void PCB_TOOL::doInteractiveItemPlacement( INTERACTIVE_PLACER_BASE* aPlacer,
             }
             else
             {
+                auto oldFlags = newItem->GetFlags();
                 newItem->ClearFlags();
-                preview.Remove( newItem.get() );
 
-                aPlacer->PlaceItem( newItem.get(), commit );
+                if( !aPlacer->PlaceItem( newItem.get(), commit ) )
+                {
+                    newItem->SetFlags( oldFlags );
+                    continue;
+                }
+
+                preview.Remove( newItem.get() );
 
                 if( newItem->Type() == PCB_MODULE_T )
                 {
@@ -262,7 +268,8 @@ void INTERACTIVE_PLACER_BASE::SnapItem( BOARD_ITEM *aItem )
     // Base implementation performs no snapping
 }
 
-void INTERACTIVE_PLACER_BASE::PlaceItem( BOARD_ITEM *aItem, BOARD_COMMIT& aCommit )
+bool INTERACTIVE_PLACER_BASE::PlaceItem( BOARD_ITEM *aItem, BOARD_COMMIT& aCommit )
 {
     aCommit.Add( aItem );
+    return true;
 }

pcbnew/tools/pcb_tool.h

@@ -53,7 +53,7 @@ struct INTERACTIVE_PLACER_BASE
 {
     virtual std::unique_ptr<BOARD_ITEM> CreateItem() = 0;
     virtual void SnapItem( BOARD_ITEM *aItem );
-    virtual void PlaceItem( BOARD_ITEM *aItem, BOARD_COMMIT& aCommit );
+    virtual bool PlaceItem( BOARD_ITEM *aItem, BOARD_COMMIT& aCommit );
 
     PCB_EDIT_FRAME* m_frame;
     BOARD* m_board;