PNS: Check for nearest segment anchor for initial track constraints

(Based on cherry-pick from commit c39551b032)

pcbnew/router/pns_kicad_iface.cpp

@@ -646,7 +646,7 @@ bool PNS_KICAD_IFACE_BASE::inheritTrackWidth( PNS::ITEM* aItem, int* aInheritedW
 
 
 bool PNS_KICAD_IFACE_BASE::ImportSizes( PNS::SIZES_SETTINGS& aSizes, PNS::ITEM* aStartItem,
-                                        PNS::NET_HANDLE aNet )
+                                        PNS::NET_HANDLE aNet, VECTOR2D aStartPosition )
 {
     BOARD_DESIGN_SETTINGS& bds = m_board->GetDesignSettings();
     PNS::CONSTRAINT        constraint;
@@ -658,10 +658,29 @@ bool PNS_KICAD_IFACE_BASE::ImportSizes( PNS::SIZES_SETTINGS& aSizes, PNS::ITEM*
     aSizes.SetMinClearance( bds.m_MinClearance );
     aSizes.SetClearanceSource( _( "board minimum clearance" ) );
 
+    int      startAnchor = 0;
+    VECTOR2I startPosInt( aStartPosition.x, aStartPosition.y );
+
+    if( aStartItem && aStartItem->Kind() == PNS::ITEM::SEGMENT_T )
+    {
+        // Find the start anchor which is closest to the start mouse location
+        VECTOR2I anchor0 = aStartItem->Anchor( 0 );
+        VECTOR2I anchor1 = aStartItem->Anchor( 1 );
+
+        VECTOR2<double> diff0( anchor0.x - startPosInt.x, anchor0.y - startPosInt.y );
+        VECTOR2<double> diff1( anchor1.x - startPosInt.x, anchor1.y - startPosInt.y );
+
+        double anchor0Distance = diff0.EuclideanNorm();
+        double anchor1Distance = diff1.EuclideanNorm();
+
+        if( anchor1Distance < anchor0Distance )
+            startAnchor = 1;
+    }
+
     if( aStartItem )
     {
         PNS::SEGMENT dummyTrack;
-        dummyTrack.SetEnds( aStartItem->Anchor( 0 ), aStartItem->Anchor( 0 ) );
+        dummyTrack.SetEnds( aStartItem->Anchor( startAnchor ), aStartItem->Anchor( startAnchor ) );
         dummyTrack.SetLayer( ToLAYER_ID( m_startLayer ) );
         dummyTrack.SetNet( static_cast<NETINFO_ITEM*>( aStartItem->Net() ) );
 
@@ -691,7 +710,7 @@ bool PNS_KICAD_IFACE_BASE::ImportSizes( PNS::SIZES_SETTINGS& aSizes, PNS::ITEM*
     if( !found && bds.UseNetClassTrack() && aStartItem )
     {
         PNS::SEGMENT dummyTrack;
-        dummyTrack.SetEnds( aStartItem->Anchor( 0 ), aStartItem->Anchor( 0 ) );
+        dummyTrack.SetEnds( aStartItem->Anchor( startAnchor ), aStartItem->Anchor( startAnchor ) );
         dummyTrack.SetLayer( ToLAYER_ID( m_startLayer ) );
         dummyTrack.SetNet( static_cast<NETINFO_ITEM*>( aStartItem->Net() ) );
 

pcbnew/router/pns_kicad_iface.h

@@ -70,8 +70,8 @@ public:
     void UpdateItem( PNS::ITEM* aItem ) override;
     void RemoveItem( PNS::ITEM* aItem ) override;
     void Commit() override {}
-    bool ImportSizes( PNS::SIZES_SETTINGS& aSizes, PNS::ITEM* aStartItem,
-                      PNS::NET_HANDLE aNet ) override;
+    bool ImportSizes( PNS::SIZES_SETTINGS& aSizes, PNS::ITEM* aStartItem, PNS::NET_HANDLE aNet,
+                      VECTOR2D aStartPosition ) override;
     int StackupHeight( int aFirstLayer, int aSecondLayer ) const override;
 
     int GetNetCode( PNS::NET_HANDLE aNet ) const override { return -1; }

pcbnew/router/pns_router.h

@@ -103,7 +103,8 @@ enum DRAG_MODE
     virtual void DisplayRatline( const SHAPE_LINE_CHAIN& aRatline, NET_HANDLE aNetCode ) = 0;
     virtual void HideItem( ITEM* aItem ) = 0;
     virtual void Commit() = 0;
-    virtual bool ImportSizes( SIZES_SETTINGS& aSizes, ITEM* aStartItem, NET_HANDLE aNet ) = 0;
+    virtual bool       ImportSizes( SIZES_SETTINGS& aSizes, ITEM* aStartItem, NET_HANDLE aNet,
+                                    VECTOR2D aStartPosition ) = 0;
     virtual int  StackupHeight( int aFirstLayer, int aSecondLayer ) const = 0;
     virtual void EraseView() = 0;
     virtual int GetNetCode( NET_HANDLE aNet ) const = 0;

pcbnew/router/router_tool.cpp

@@ -1208,7 +1208,7 @@ int ROUTER_TOOL::handleLayerSwitch( const TOOL_EVENT& aEvent, bool aForceVia )
 }
 
 
-bool ROUTER_TOOL::prepareInteractive()
+bool ROUTER_TOOL::prepareInteractive( VECTOR2D aStartPosition )
 {
     PCB_EDIT_FRAME* editFrame = getEditFrame<PCB_EDIT_FRAME>();
     int             routingLayer = getStartLayer( m_startItem );
@@ -1233,7 +1233,7 @@ bool ROUTER_TOOL::prepareInteractive()
     m_iface->SetStartLayer( routingLayer );
 
     frame()->GetBoard()->GetDesignSettings().m_TempOverrideTrackWidth = false;
-    m_iface->ImportSizes( sizes, m_startItem, nullptr );
+    m_iface->ImportSizes( sizes, m_startItem, nullptr, aStartPosition );
     sizes.AddLayerPair( frame()->GetScreen()->m_Route_Layer_TOP,
                         frame()->GetScreen()->m_Route_Layer_BOTTOM );
 
@@ -1301,11 +1301,11 @@ bool ROUTER_TOOL::finishInteractive()
 }
 
 
-void ROUTER_TOOL::performRouting()
+void ROUTER_TOOL::performRouting( VECTOR2D aStartPosition )
 {
     m_router->ClearViewDecorations();
 
-    if( !prepareInteractive() )
+    if( !prepareInteractive( aStartPosition ) )
         return;
 
     auto setCursor =
@@ -1711,7 +1711,7 @@ int ROUTER_TOOL::RouteSelected( const TOOL_EVENT& aEvent )
                 m_iface->SetCommitFlags( APPEND_UNDO );
 
             // Start interactive routing. Will automatically finish if possible.
-            performRouting();
+            performRouting( VECTOR2D() );
 
             // Route didn't complete automatically, need to a new undo commit
             // for the next line so those can group as far as they autoroute
@@ -1828,7 +1828,7 @@ int ROUTER_TOOL::MainLoop( const TOOL_EVENT& aEvent )
             updateStartItem( *evt );
 
             if( evt->HasPosition() )
-                performRouting();
+                performRouting( evt->Position() );
         }
         else if( evt->IsAction( &ACT_PlaceThroughVia ) )
         {
@@ -2609,7 +2609,7 @@ int ROUTER_TOOL::onTrackViaSizeChanged( const TOOL_EVENT& aEvent )
     PNS::SIZES_SETTINGS sizes( m_router->Sizes() );
 
     if( !m_router->GetCurrentNets().empty() )
-        m_iface->ImportSizes( sizes, m_startItem, m_router->GetCurrentNets()[0] );
+        m_iface->ImportSizes( sizes, m_startItem, m_router->GetCurrentNets()[0], VECTOR2D() );
 
     m_router->UpdateSizes( sizes );
 

pcbnew/router/router_tool.h

@@ -70,7 +70,7 @@ public:
     void UpdateMessagePanel();
 
 private:
-    void performRouting();
+    void performRouting( VECTOR2D aStartPosition );
     void performDragging( int aMode = PNS::DM_ANY );
     void breakTrack();
 
@@ -85,7 +85,7 @@ private:
     int onViaCommand( const TOOL_EVENT& aEvent );
     int onTrackViaSizeChanged( const TOOL_EVENT& aEvent );
 
-    bool prepareInteractive();
+    bool prepareInteractive( VECTOR2D aStartPosition );
     bool finishInteractive();
     void saveRouterDebugLog();