PNS: Account for via stack height in diff pair length tuner

Fixes https://gitlab.com/kicad/code/kicad/-/issues/8256

pcbnew/router/pns_dp_meander_placer.cpp

@@ -141,22 +141,8 @@ void DP_MEANDER_PLACER::release()
 
 long long int DP_MEANDER_PLACER::origPathLength() const
 {
-    long long int totalP = m_padToDieLength;
+    long long int totalP = m_padToDieLength + lineLength( m_tunedPathP );
-    long long int totalN = m_padToDieLength;
+    long long int totalN = m_padToDieLength + lineLength( m_tunedPathN );
-
-    for( const ITEM* item : m_tunedPathP.CItems() )
-    {
-        if( const LINE* l = dyn_cast<const LINE*>( item ) )
-            totalP += l->CLine().Length();
-
-    }
-
-    for( const ITEM* item : m_tunedPathN.CItems() )
-    {
-        if( const LINE* l = dyn_cast<const LINE*>( item ) )
-            totalN += l->CLine().Length();
-    }
-
     return std::max( totalP, totalN );
 }
 

pcbnew/router/pns_meander_placer.cpp

@@ -97,27 +97,7 @@ bool MEANDER_PLACER::Start( const VECTOR2I& aP, ITEM* aStartItem )
 
 long long int MEANDER_PLACER::origPathLength() const
 {
-    long long int total = m_padToDieLength;
+    return m_padToDieLength + lineLength( m_tunedPath );
-
-    for( int idx = 0; idx < m_tunedPath.Size(); idx++ )
-    {
-        const ITEM* item = m_tunedPath[idx];
-
-        if( const LINE* l = dyn_cast<const LINE*>( item ) )
-        {
-            total += l->CLine().Length();
-        }
-        else if( item->OfKind( ITEM::VIA_T ) && idx > 0 && idx < m_tunedPath.Size() - 1 )
-        {
-            int layerPrev = m_tunedPath[idx - 1]->Layer();
-            int layerNext = m_tunedPath[idx + 1]->Layer();
-
-            if( layerPrev != layerNext )
-                total += m_router->GetInterface()->StackupHeight( layerPrev, layerNext );
-        }
-    }
-
-    return total;
 }
 
 

pcbnew/router/pns_meander_placer_base.cpp

@@ -260,4 +260,30 @@ VECTOR2I MEANDER_PLACER_BASE::getSnappedStartPoint( LINKED_ITEM* aStartItem, VEC
     }
 }
 
+
+long long int MEANDER_PLACER_BASE::lineLength( const ITEM_SET& aLine ) const
+{
+    long long int total = 0;
+
+    for( int idx = 0; idx < aLine.Size(); idx++ )
+    {
+        const ITEM* item = aLine[idx];
+
+        if( const LINE* l = dyn_cast<const LINE*>( item ) )
+        {
+            total += l->CLine().Length();
+        }
+        else if( item->OfKind( ITEM::VIA_T ) && idx > 0 && idx < aLine.Size() - 1 )
+        {
+            int layerPrev = aLine[idx - 1]->Layer();
+            int layerNext = aLine[idx + 1]->Layer();
+
+            if( layerPrev != layerNext )
+                total += m_router->GetInterface()->StackupHeight( layerPrev, layerNext );
+        }
+    }
+
+    return total;
+}
+
 }

pcbnew/router/pns_meander_placer_base.h

@@ -137,6 +137,13 @@ protected:
 
     VECTOR2I getSnappedStartPoint( LINKED_ITEM* aStartItem, VECTOR2I aStartPoint );
 
+    /**
+     * Calculate the total length of the line represented by an item set (tracks and vias)
+     * @param aLine
+     * @return
+     */
+    long long int lineLength( const ITEM_SET& aLine ) const;
+
     ///< Pointer to world to search colliding items.
     NODE* m_world;
 

pcbnew/router/pns_meander_skew_placer.cpp

@@ -111,12 +111,12 @@ bool MEANDER_SKEW_PLACER::Start( const VECTOR2I& aP, ITEM* aStartItem )
     if ( m_originPair.PLine().Net() == m_originLine.Net() )
     {
         m_padToDieLength = m_padToDieN;
-        m_coupledLength = itemsetLength( m_tunedPathN );
+        m_coupledLength = lineLength( m_tunedPathN );
     }
     else
     {
         m_padToDieLength = m_padToDieP;
-        m_coupledLength = itemsetLength( m_tunedPathP );
+        m_coupledLength = lineLength( m_tunedPathP );
     }
 
     return true;
@@ -125,22 +125,7 @@ bool MEANDER_SKEW_PLACER::Start( const VECTOR2I& aP, ITEM* aStartItem )
 
 long long int MEANDER_SKEW_PLACER::origPathLength() const
 {
-    return itemsetLength ( m_tunedPath );
+    return lineLength( m_tunedPath );
-}
-
-
-long long int MEANDER_SKEW_PLACER::itemsetLength( const ITEM_SET& aSet ) const
-{
-    long long int total = m_padToDieLength;
-    for( const ITEM* item : aSet.CItems() )
-    {
-        if( const LINE* l = dyn_cast<const LINE*>( item ) )
-        {
-            total += l->CLine().Length();
-        }
-    }
-
-    return total;
 }
 
 

pcbnew/router/pns_meander_skew_placer.h

@@ -53,7 +53,6 @@ public:
 
 private:
     long long int currentSkew() const;
-    long long int itemsetLength( const ITEM_SET& aSet ) const;
 
     long long int origPathLength() const override;