PCB: Finish Route, Route From End

Adds restart routing from other ratsnest' end and automatically finish
routing.

Fixes: https://gitlab.com/kicad/code/kicad/-/issues/5051

pcbnew/router/pns_topology.cpp

@@ -93,7 +93,8 @@ const TOPOLOGY::JOINT_SET TOPOLOGY::ConnectedJoints( JOINT* aStart )
 }
 
 
-bool TOPOLOGY::LeadingRatLine( const LINE* aTrack, SHAPE_LINE_CHAIN& aRatLine )
+bool TOPOLOGY::NearestUnconnectedAnchorPoint( const LINE* aTrack, VECTOR2I& aPoint,
+                                              LAYER_RANGE& aLayers )
 {
     LINE track( *aTrack );
     VECTOR2I end;
@@ -113,6 +114,7 @@ bool TOPOLOGY::LeadingRatLine( const LINE* aTrack, SHAPE_LINE_CHAIN& aRatLine )
             || ( track.EndsWithVia() && jt->LinkCount() >= 3 ) ) // we got something connected
     {
         end = jt->Pos();
+        aLayers = jt->Layers();
     }
     else
     {
@@ -125,10 +127,25 @@ bool TOPOLOGY::LeadingRatLine( const LINE* aTrack, SHAPE_LINE_CHAIN& aRatLine )
             return false;
 
         end = it->Anchor( anchor );
+        aLayers = it->Layers();
     }
 
+    aPoint = end;
+    return true;
+}
+
+
+bool TOPOLOGY::LeadingRatLine( const LINE* aTrack, SHAPE_LINE_CHAIN& aRatLine )
+{
+    VECTOR2I end;
+    // Ratline doesn't care about the layer
+    LAYER_RANGE layers;
+
+    if( !NearestUnconnectedAnchorPoint( aTrack, end, layers ) )
+        return false;
+
     aRatLine.Clear();
-    aRatLine.Append( track.CPoint( -1 ) );
+    aRatLine.Append( aTrack->CPoint( -1 ) );
     aRatLine.Append( end );
     return true;
 }

pcbnew/router/pns_topology.h

@@ -49,6 +49,9 @@ public:
     bool SimplifyLine( LINE *aLine );
     ITEM* NearestUnconnectedItem( JOINT* aStart, int* aAnchor = nullptr,
                                   int aKindMask = ITEM::ANY_T );
+
+    bool NearestUnconnectedAnchorPoint( const LINE* aTrack, VECTOR2I& aPoint,
+                                        LAYER_RANGE& aLayers );
     bool LeadingRatLine( const LINE* aTrack, SHAPE_LINE_CHAIN& aRatLine );
 
     const JOINT_SET ConnectedJoints( JOINT* aStart );

pcbnew/router/router_tool.cpp

@@ -60,9 +60,14 @@ using namespace std::placeholders;
 #include "pns_router.h"
 #include "pns_itemset.h"
 #include "pns_logger.h"
+#include "pns_placement_algo.h"
+#include "pns_line_placer.h"
+#include "pns_topology.h"
 
 #include "pns_kicad_iface.h"
 
+#include <ratsnest/ratsnest_data.h>
+
 #include <plugins/kicad/pcb_plugin.h>
 
 using namespace KIGFX;
@@ -96,11 +101,6 @@ static const TOOL_ACTION ACT_EndTrack( "pcbnew.InteractiveRouter.EndTrack",
         _( "Finish Track" ),  _( "Stops laying the current track." ),
         BITMAPS::checked_ok );
 
-static const TOOL_ACTION ACT_AutoEndRoute( "pcbnew.InteractiveRouter.AutoEndRoute",
-        AS_CONTEXT,
-        'F', "",
-        _( "Auto-finish Track" ),  _( "Automatically finishes laying the current track." ) );
-
 static const TOOL_ACTION ACT_PlaceThroughVia( "pcbnew.InteractiveRouter.PlaceVia",
         AS_CONTEXT,
         'V', LEGACY_HK_NAME( "Add Through Via" ),
@@ -461,6 +461,13 @@ bool ROUTER_TOOL::Init()
                 return !m_router->RoutingInProgress();
             };
 
+    auto hasOtherEnd = [&]( const SELECTION& )
+            {
+                VECTOR2I    unusedEnd;
+                LAYER_RANGE unusedEndLayers;
+                return getNearestRatnestAnchor( unusedEnd, unusedEndLayers );
+            };
+
     menu.AddItem( ACTIONS::cancelInteractive,         SELECTION_CONDITIONS::ShowAlways, 1 );
     menu.AddSeparator( 1 );
 
@@ -471,12 +478,13 @@ bool ROUTER_TOOL::Init()
     menu.AddItem( PCB_ACTIONS::routeDiffPair,         notRoutingCond );
     menu.AddItem( ACT_EndTrack,                       SELECTION_CONDITIONS::ShowAlways );
     menu.AddItem( PCB_ACTIONS::routerUndoLastSegment, SELECTION_CONDITIONS::ShowAlways );
+    menu.AddItem( PCB_ACTIONS::routerContinueFromEnd, hasOtherEnd );
+    menu.AddItem( PCB_ACTIONS::routerAttemptFinish,   hasOtherEnd );
     menu.AddItem( PCB_ACTIONS::breakTrack,            notRoutingCond );
 
     menu.AddItem( PCB_ACTIONS::drag45Degree,          notRoutingCond );
     menu.AddItem( PCB_ACTIONS::dragFreeAngle,         notRoutingCond );
 
-//        Add( ACT_AutoEndRoute );  // fixme: not implemented yet. Sorry.
     menu.AddItem( ACT_PlaceThroughVia,                SELECTION_CONDITIONS::ShowAlways );
     menu.AddItem( ACT_PlaceBlindVia,                  SELECTION_CONDITIONS::ShowAlways );
     menu.AddItem( ACT_PlaceMicroVia,                  SELECTION_CONDITIONS::ShowAlways );
@@ -638,6 +646,78 @@ void ROUTER_TOOL::switchLayerOnViaPlacement()
 }
 
 
+bool ROUTER_TOOL::getNearestRatnestAnchor( VECTOR2I& aOtherEnd, LAYER_RANGE& aOtherEndLayers )
+{
+    // Can't finish something with no connections
+    if( m_router->GetCurrentNets().empty() )
+        return false;
+
+    PNS::LINE_PLACER* placer = dynamic_cast<PNS::LINE_PLACER*>( m_router->Placer() );
+
+    if( placer == nullptr )
+        return false;
+
+    PNS::LINE     current = placer->Trace();
+    PNS::NODE*    lastNode = placer->CurrentNode( true );
+    PNS::TOPOLOGY topo( lastNode );
+
+    VECTOR2I currentEndPos   = placer->CurrentEnd();
+    VECTOR2I currentStartPos = m_startSnapPoint;
+    int      currentLayer    = m_router->GetCurrentLayer();
+
+    // If we have an active line being routed, attempt finish from line front using
+    // dynamic ratnest topology
+    if( current.PointCount() > 0 )
+        return topo.NearestUnconnectedAnchorPoint( &current, aOtherEnd, aOtherEndLayers );
+
+    // No line, find nearest static ratsnest item for net
+    auto    connectivity = getEditFrame<PCB_EDIT_FRAME>()->GetBoard()->GetConnectivity();
+    RN_NET* net = connectivity->GetRatsnestForNet( m_router->GetCurrentNets()[0] );
+    auto    edges = net->GetEdges();
+
+    // Need to have something unconnected to finish to
+    if( edges.size() == 0 )
+        return false;
+
+    // Default to the first item if we don't have a position
+    std::shared_ptr<CN_ANCHOR> nearest = edges[0].GetSourceNode();
+
+    double currentDistance = DBL_MAX;
+
+    // Find nearest unconnected end
+    for( const CN_EDGE& edge : edges )
+    {
+        VECTOR2I    sourcePos = edge.GetSourcePos();
+        VECTOR2I    targetPos = edge.GetTargetPos();
+        double      sourceDistance = ( currentEndPos - sourcePos ).EuclideanNorm();
+        double      targetDistance = ( currentEndPos - targetPos ).EuclideanNorm();
+        LAYER_RANGE sourceLayers = edge.GetSourceNode()->Item()->Layers();
+        LAYER_RANGE targetLayers = edge.GetTargetNode()->Item()->Layers();
+
+        // Basically look for the closest ratnest item that isn't this item
+        // (same point, same layer)
+        if( ( sourcePos != m_startSnapPoint || !sourceLayers.Overlaps( currentLayer ) )
+            && ( sourceDistance < currentDistance ) )
+        {
+            nearest = edge.GetSourceNode();
+            currentDistance = sourceDistance;
+        }
+
+        if( ( targetPos != m_startSnapPoint || !targetLayers.Overlaps( currentLayer ) )
+            && ( targetDistance < currentDistance ) )
+        {
+            nearest = edge.GetTargetNode();
+            currentDistance = targetDistance;
+        }
+    }
+
+    aOtherEnd = nearest->Pos();
+    aOtherEndLayers = nearest->Item()->Layers();
+
+    return true;
+}
+
+
 static VIATYPE getViaTypeFromFlags( int aFlags )
 {
     switch( aFlags & VIA_ACTION_FLAGS::VIA_MASK )
@@ -1122,6 +1202,21 @@ void ROUTER_TOOL::performRouting()
                 frame()->GetCanvas()->SetCurrentCursor( KICURSOR::PENCIL );
             };
 
+    auto syncRouterAndFrameLayer =
+            [&]()
+            {
+                PCB_LAYER_ID    routingLayer = ToLAYER_ID( m_router->GetCurrentLayer() );
+                PCB_EDIT_FRAME* editFrame = getEditFrame<PCB_EDIT_FRAME>();
+
+                editFrame->SetActiveLayer( routingLayer );
+
+                if( !getView()->IsLayerVisible( routingLayer ) )
+                {
+                    editFrame->GetAppearancePanel()->SetLayerVisible( routingLayer, true );
+                    editFrame->GetCanvas()->Refresh();
+                }
+            };
+
     // Set initial cursor
     setCursor();
 
@@ -1151,6 +1246,71 @@ void ROUTER_TOOL::performRouting()
             updateEndItem( *evt );
             m_router->Move( m_endSnapPoint, m_endItem );
         }
+        else if( evt->IsAction( &PCB_ACTIONS::routerAttemptFinish )
+                 || evt->IsAction( &PCB_ACTIONS::routerContinueFromEnd ) )
+        {
+            PNS::LINE_PLACER* placer = dynamic_cast<PNS::LINE_PLACER*>( m_router->Placer() );
+
+            if( placer == nullptr )
+                break;
+
+            // Get our current line and position and nearest ratsnest to them if it exists
+            PNS::LINE   current = placer->Trace();
+            VECTOR2I    currentEnd = placer->CurrentEnd();
+            VECTOR2I    otherEnd;
+            LAYER_RANGE otherEndLayers;
+
+            if( !getNearestRatnestAnchor( otherEnd, otherEndLayers ) )
+                break;
+
+            if( evt->IsAction( &PCB_ACTIONS::routerContinueFromEnd ) )
+            {
+                // Commit routing will put the router on no layer, so save it
+                int currentLayer = m_router->GetCurrentLayer();
+
+                // Commit whatever we've fixed and restart routing from the other end
+                m_router->CommitRouting();
+
+                if( otherEndLayers.Overlaps( currentLayer ) )
+                    m_router->StartRouting( otherEnd, &current, currentLayer );
+                else
+                {
+                    m_router->StartRouting( otherEnd, &current, otherEndLayers.Start() );
+                    syncRouterAndFrameLayer();
+                }
+
+                m_startSnapPoint = otherEnd;
+
+                // Attempt to route to our current position
+                m_router->Move( currentEnd, &current );
+                VECTOR2I moveResultPoint = m_router->Placer()->CurrentEnd();
+
+                // Warp the mouse to wherever we actually ended up routing to
+                controls()->WarpMouseCursor( currentEnd, true, true );
+            }
+            else
+            {
+                VECTOR2I moveResultPoint;
+
+                // Keep moving until we don't change position
+                do
+                {
+                    moveResultPoint = m_router->Placer()->CurrentEnd();
+                    m_router->Move( otherEnd, &current );
+                } while( m_router->Placer()->CurrentEnd() != moveResultPoint );
+
+                // Fix the route and end routing if we made it to the destination
+                if( moveResultPoint == otherEnd
+                    && otherEndLayers.Overlaps( m_router->GetCurrentLayer() ) )
+                {
+                    if( m_router->FixRoute( otherEnd, &current, false ) )
+                        break;
+                }
+                // Otherwise warp the mouse so the user is at the point we managed to route to
+                else
+                    controls()->WarpMouseCursor( moveResultPoint, true, true );
+            }
+        }
         else if( evt->IsClick( BUT_LEFT ) || evt->IsDrag( BUT_LEFT ) || evt->IsAction( &PCB_ACTIONS::routeSingleTrack ) )
         {
             updateEndItem( *evt );
@@ -1166,16 +1326,7 @@ void ROUTER_TOOL::performRouting()
                 switchLayerOnViaPlacement();
 
             // Synchronize the indicated layer
-            PCB_LAYER_ID    routingLayer = ToLAYER_ID( m_router->GetCurrentLayer() );
+            syncRouterAndFrameLayer();
-            PCB_EDIT_FRAME* editFrame = getEditFrame<PCB_EDIT_FRAME>();
-
-            editFrame->SetActiveLayer( routingLayer );
-
-            if( !getView()->IsLayerVisible( routingLayer ) )
-            {
-                editFrame->GetAppearancePanel()->SetLayerVisible( routingLayer, true );
-                editFrame->GetCanvas()->Refresh();
-            }
 
             updateEndItem( *evt );
             m_router->Move( m_endSnapPoint, m_endItem );

pcbnew/router/router_tool.h

@@ -75,6 +75,7 @@ private:
 
     int getStartLayer( const PNS::ITEM* aItem );
     void switchLayerOnViaPlacement();
+    bool getNearestRatnestAnchor( VECTOR2I& aPoint, LAYER_RANGE& aLayers );
 
     int onLayerCommand( const TOOL_EVENT& aEvent );
     int onViaCommand( const TOOL_EVENT& aEvent );

pcbnew/tools/pcb_actions.cpp

@@ -1418,6 +1418,18 @@ TOOL_ACTION PCB_ACTIONS::routerUndoLastSegment( "pcbnew.InteractiveRouter.UndoLa
         WXK_BACK, "",
         _( "Undo Last Segment" ),  _( "Walks the current track back one segment." ) );
 
+TOOL_ACTION PCB_ACTIONS::routerContinueFromEnd( "pcbnew.InteractiveRouter.ContinueFromEnd",
+        AS_CONTEXT,
+        'E', "",
+        _( "Route From Other End" ),
+        _( "Commits current segments and starts next segment from nearest ratsnest end." ) );
+
+TOOL_ACTION PCB_ACTIONS::routerAttemptFinish( "pcbnew.InteractiveRouter.AttemptFinish",
+        AS_CONTEXT,
+        'F', "",
+        _( "Attempt Finish" ),
+        _( "Attempts to complete current route to nearest ratsnest end." ) );
+
 TOOL_ACTION PCB_ACTIONS::breakTrack( "pcbnew.InteractiveRouter.BreakTrack",
         AS_GLOBAL, 0, "",
         _( "Break Track" ),

pcbnew/tools/pcb_actions.h

@@ -195,6 +195,9 @@ public:
 
     static TOOL_ACTION routerUndoLastSegment;
 
+    static TOOL_ACTION routerContinueFromEnd;
+    static TOOL_ACTION routerAttemptFinish;
+
     /// Activation of the Push and Shove settings dialogs
     static TOOL_ACTION routerSettingsDialog;
     static TOOL_ACTION routerDiffPairDialog;