Support custom padstacks in footprint checker

pcbnew/footprint.cpp

@@ -3142,12 +3142,15 @@ void FOOTPRINT::CheckShortingPads( const std::function<void( const PAD*, const P
                 if( pad->GetBoundingBox().Intersects( other->GetBoundingBox() ) )
                 {
                     VECTOR2I pos;
-                    // TODO(JE) padstacks - need to check complex against complex
-                    SHAPE*   padShape = pad->GetEffectiveShape( PADSTACK::ALL_LAYERS ).get();
-                    SHAPE*   otherShape = other->GetEffectiveShape( PADSTACK::ALL_LAYERS ).get();
 
-                    if( padShape->Collide( otherShape, 0, nullptr, &pos ) )
-                        aErrorHandler( pad, other, DRCE_SHORTING_ITEMS, pos );
+                    for( PCB_LAYER_ID l : pad->Padstack().RelevantShapeLayers( other->Padstack() ) )
+                    {
+                        SHAPE*   padShape = pad->GetEffectiveShape( l ).get();
+                        SHAPE*   otherShape = other->GetEffectiveShape( l ).get();
+
+                        if( padShape->Collide( otherShape, 0, nullptr, &pos ) )
+                            aErrorHandler( pad, other, DRCE_SHORTING_ITEMS, pos );
+                    }
                 }
             }
         }

pcbnew/padstack.cpp

@@ -922,6 +922,26 @@ PCB_LAYER_ID PADSTACK::EffectiveLayerFor( PCB_LAYER_ID aLayer ) const
 }
 
 
+LSET PADSTACK::RelevantShapeLayers( const PADSTACK& aOther ) const
+{
+    LSET ret;
+
+#ifdef DEBUG
+    if( m_parent && aOther.m_parent
+        && ( m_mode == MODE::CUSTOM || aOther.m_mode == MODE::CUSTOM ) )
+    {
+        wxASSERT_MSG( m_parent->BoardCopperLayerCount() == aOther.m_parent->BoardCopperLayerCount(),
+                      wxT( "Expected both padstacks to have the same board copper layer count" ) );
+    }
+#endif
+
+    ForEachUniqueLayer( [&]( PCB_LAYER_ID aLayer ) { ret.set( aLayer ); } );
+    aOther.ForEachUniqueLayer( [&]( PCB_LAYER_ID aLayer ) { ret.set( aLayer ); } );
+
+    return ret;
+}
+
+
 PADSTACK::COPPER_LAYER_PROPS& PADSTACK::CopperLayer( PCB_LAYER_ID aLayer )
 {
     PCB_LAYER_ID layer = EffectiveLayerFor( aLayer );

pcbnew/padstack.h

@@ -345,6 +345,13 @@ public:
      */
     PCB_LAYER_ID EffectiveLayerFor( PCB_LAYER_ID aLayer ) const;
 
+    /**
+     * Returns the set of layers that must be considered if checking one padstack against another.
+     * For example, two normal padstacks will just return a set with ALL_LAYERS, but if one of them
+     * is FRONT_INNER_BACK, there are three layers to check.
+     */
+    LSET RelevantShapeLayers( const PADSTACK& aOther ) const;
+
     // The following section has convenience getters for the padstack properties on a given layer.
 
     PAD_SHAPE Shape( PCB_LAYER_ID aLayer ) const;