drc: first R-tree based test (silk to pad clearance)

pcbnew/CMakeLists.txt

@@ -249,6 +249,7 @@ set( PCBNEW_DRC_SRCS
     drc/drc_test_provider_misc.cpp
     drc/drc_test_provider_track_width.cpp
     drc/drc_test_provider_via_diameter.cpp
+    drc/drc_test_provider_silk_to_pad.cpp
     )
 
 set( PCBNEW_NETLIST_SRCS

pcbnew/drc/drc_engine.cpp

@@ -127,6 +127,10 @@ void DRC_ENGINE::loadImplicitRules()
     holeClearanceConstraint.Value().SetMin( 0 );
     rule->AddConstraint( courtyardClearanceConstraint );
 
+    DRC_CONSTRAINT silkToPadClearanceConstraint( DRC_CONSTRAINT_TYPE_SILK_TO_PAD );
+    silkToPadClearanceConstraint.Value().SetMin( 0 );
+    rule->AddConstraint( silkToPadClearanceConstraint );
+
     // 2) micro-via specific defaults (new DRC doesn't treat microvias in any special way)
 
     DRC_RULE* uViaRule = createImplicitRule( _( "board setup micro-via constraints" ));
@@ -402,7 +406,12 @@ void DRC_ENGINE::RunTests( EDA_UNITS aUnits, bool aTestTracksAgainstZones,
         int phases = 0;
 
         for( DRC_TEST_PROVIDER* provider : m_testProviders )
+        {
+            if( provider->IsEnabled() )
+            {
             phases += provider->GetNumPhases();
+            }
+        }
 
         m_progressReporter->AddPhases( phases );
     }
@@ -417,6 +426,9 @@ void DRC_ENGINE::RunTests( EDA_UNITS aUnits, bool aTestTracksAgainstZones,
 
     for( DRC_TEST_PROVIDER* provider : m_testProviders )
     {
+        if( !provider->IsEnabled() )
+            continue;
+
         drc_dbg( 0, "Running test provider: '%s'\n", provider->GetName() );
 
         ReportAux( wxString::Format( "Run DRC provider: '%s'", provider->GetName() ) );

pcbnew/drc/drc_engine.h

@@ -81,9 +81,15 @@ std::function<void( const std::shared_ptr<DRC_ITEM>& aItem, wxPoint aPos )> DRC_
 class DRC_ENGINE
 {
 public:
-    DRC_ENGINE( BOARD* aBoard, BOARD_DESIGN_SETTINGS* aSettings );
+    DRC_ENGINE( BOARD* aBoard = nullptr, BOARD_DESIGN_SETTINGS* aSettings = nullptr );
     ~DRC_ENGINE();
 
+    void SetBoard( BOARD* aBoard ) { m_board = aBoard; }
+    BOARD* GetBoard() const { return m_board; }
+
+    void SetDesignSettings( BOARD_DESIGN_SETTINGS* aSettings ) { m_designSettings = aSettings; }
+    BOARD_DESIGN_SETTINGS* GetDesignSettings() const { return m_designSettings; }
+
     void SetSchematicNetlist( NETLIST* aNetlist ) { m_schematicNetlist = aNetlist; }
     NETLIST* GetSchematicNetlist() const { return m_schematicNetlist; }
 
@@ -135,9 +141,6 @@ public:
     void RunTests( EDA_UNITS aUnits = EDA_UNITS::MILLIMETRES, bool aTestTracksAgainstZones = true,
                    bool aReportAllTrackErrors = true, bool aTestFootprints = true );
 
-    BOARD_DESIGN_SETTINGS* GetDesignSettings() const { return m_designSettings; }
-
-    BOARD* GetBoard() const { return m_board; }
 
     bool IsErrorLimitExceeded( int error_code );
 
@@ -165,6 +168,8 @@ public:
     bool QueryWorstConstraint( DRC_CONSTRAINT_TYPE_T aRuleId, DRC_CONSTRAINT& aConstraint,
                                DRC_CONSTRAINT_QUERY_T aQueryType );
 
+    std::vector<DRC_TEST_PROVIDER* > GetTestProviders() const { return m_testProviders; };
+
 private:
     void addRule( DRC_RULE* rule )
     {

pcbnew/drc/drc_item.cpp

@@ -166,6 +166,14 @@ DRC_ITEM DRC_ITEM::unresolvedVariable( DRCE_UNRESOLVED_VARIABLE,
         _( "Unresolved text variable" ),
         wxT( "unresolved_variable" ) );
 
+DRC_ITEM DRC_ITEM::silkOverPad( DRCE_SILK_OVER_PAD,
+        _( "Silkscreen overlapping component pad(s)" ),
+        wxT( "silk_over_pad" ) );
+
+DRC_ITEM DRC_ITEM::silkClearance( DRCE_SILK_CLEARANCE,
+        _( "Silkscreen clearance" ),
+        wxT( "silk_clearance" ) );
+
 
 std::vector<std::reference_wrapper<RC_ITEM>> DRC_ITEM::allItemTypes( {
             DRC_ITEM::unconnectedItems,
@@ -238,6 +246,8 @@ std::shared_ptr<DRC_ITEM> DRC_ITEM::Create( int aErrorCode )
     case DRCE_NET_CONFLICT:             return std::make_shared<DRC_ITEM>( netConflict );
     case DRCE_EXTRA_FOOTPRINT:          return std::make_shared<DRC_ITEM>( extraFootprint );
     case DRCE_UNRESOLVED_VARIABLE:      return std::make_shared<DRC_ITEM>( unresolvedVariable );
+    case DRCE_SILK_OVER_PAD:            return std::make_shared<DRC_ITEM>( silkOverPad );
+    case DRCE_SILK_CLEARANCE:           return std::make_shared<DRC_ITEM>( silkClearance );
 
     default:
         wxFAIL_MSG( "Unknown DRC error code" );

pcbnew/drc/drc_item.h

@@ -68,8 +68,10 @@ enum PCB_DRC_CODE {
     DRCE_NET_CONFLICT,                   // pad net doesn't match netlist
 
     DRCE_UNRESOLVED_VARIABLE,
+    DRCE_SILK_OVER_PAD,                  // silkscreen over component pad(s)
+    DRCE_SILK_CLEARANCE,                 // silk to silk clearance error
 
-    DRCE_LAST = DRCE_UNRESOLVED_VARIABLE
+    DRCE_LAST = DRCE_SILK_CLEARANCE
 };
 
 
@@ -144,6 +146,8 @@ private:
     static DRC_ITEM extraFootprint;
     static DRC_ITEM netConflict;
     static DRC_ITEM unresolvedVariable;
+    static DRC_ITEM silkOverPad;
+    static DRC_ITEM silkClearance;
 
 private:
     DRC_RULE*          m_violatingRule = nullptr;

pcbnew/drc/drc_rtree.h

@@ -0,0 +1,412 @@
+/*
+ * This program source code file is part of KiCad, a free EDA CAD application.
+ *
+ * Copyright (C) 2019 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2020 CERN
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 3
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-3.0.html
+ * or you may search the http://www.gnu.org website for the version 3 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#ifndef DRC_RTREE_H_
+#define DRC_RTREE_H_
+
+#include <eda_rect.h>
+#include <class_board_item.h>
+#include <class_track.h>
+#include <class_zone.h>
+#include <unordered_set>
+#include <vector>
+
+#include <geometry/rtree.h>
+#include <math/vector2d.h>
+
+/**
+ * DRC_RTREE -
+ * Implements an R-tree for fast spatial and layer indexing of connectable items.
+ * Non-owning.
+ */
+class DRC_RTREE
+{
+private:
+    struct ITEM_WITH_SHAPE
+    {
+        ITEM_WITH_SHAPE( BOARD_ITEM *aParent, SHAPE* aShape, std::shared_ptr<SHAPE> aParentShape = nullptr ) :
+            parent ( aParent ),
+            shape ( aShape ),
+            parentShape( aParentShape ) {};
+        BOARD_ITEM* parent;
+        SHAPE* shape;
+        std::shared_ptr<SHAPE> parentShape;
+    };
+
+    using drc_rtree = RTree<ITEM_WITH_SHAPE*, int, 2, double>;
+
+public:
+
+
+
+    DRC_RTREE()
+    {
+        for( int layer : LSET::AllLayersMask().Seq() )
+            m_tree[layer] = new drc_rtree();
+
+        m_count = 0;
+    }
+
+    ~DRC_RTREE()
+    {
+        for( auto tree : m_tree )
+            delete tree;
+    }
+
+    /**
+     * Function Insert()
+     * Inserts an item into the tree. Item's bounding box is taken via its GetBoundingBox() method.
+     */
+    void insert( BOARD_ITEM* aItem )
+    {
+        std::vector<SHAPE*> subshapes;
+
+        for( int layer : aItem->GetLayerSet().Seq() )
+        {
+            std::shared_ptr<SHAPE> itemShape = aItem->GetEffectiveShape( (PCB_LAYER_ID) layer );
+
+            if( itemShape->HasIndexableSubshapes() )
+            {
+                itemShape->GetIndexableSubshapes( subshapes );
+            }
+            else
+            {
+                subshapes.push_back( itemShape.get() );
+            }
+
+            for( auto subshape : subshapes )
+            {
+                const BOX2I& bbox       = subshape->BBox();
+                const int       mmin[2] = { bbox.GetX(), bbox.GetY() };
+                const int       mmax[2] = { bbox.GetRight(), bbox.GetBottom() };
+                m_tree[layer]->Insert( mmin, mmax, new ITEM_WITH_SHAPE( aItem, subshape, itemShape ) );
+                m_count++;
+            }
+        }
+    }
+
+#if 0
+    /**
+     * Function Remove()
+     * Removes an item from the tree. Removal is done by comparing pointers, attempting
+     * to remove a copy of the item will fail.
+     */
+    bool remove( BOARD_ITEM* aItem )
+    {
+        // First, attempt to remove the item using its given BBox
+        const EDA_RECT& bbox    = aItem->GetBoundingBox();
+        const int       mmin[2] = { bbox.GetX(), bbox.GetY() };
+        const int       mmax[2] = { bbox.GetRight(), bbox.GetBottom() };
+        bool            removed = false;
+
+        for( auto layer : aItem->GetLayerSet().Seq() )
+        {
+            if( ZONE_CONTAINER* zone = dyn_cast<ZONE_CONTAINER*>( aItem ) )
+            {
+                // Continue removing the zone elements from the tree until they cannot be found
+                while( !m_tree[int( layer )]->Remove( mmin, mmax, aItem ) )
+                    ;
+
+                const int mmin2[2] = { INT_MIN, INT_MIN };
+                const int mmax2[2] = { INT_MAX, INT_MAX };
+
+            // If we are not successful ( true == not found ), then we expand
+            // the search to the full tree
+                while( !m_tree[int( layer )]->Remove( mmin2, mmax2, aItem ) )
+                    ;
+
+                // Loop to the next layer
+                continue;
+            }
+
+            // The non-zone search expects only a single element in the tree with the same
+            // pointer aItem
+            if( m_tree[int( layer )]->Remove( mmin, mmax, aItem ) )
+            {
+                // N.B. We must search the whole tree for the pointer to remove
+                // because the item may have been moved before we have the chance to
+                // delete it from the tree
+                const int mmin2[2] = { INT_MIN, INT_MIN };
+                const int mmax2[2] = { INT_MAX, INT_MAX };
+
+                if( m_tree[int( layer )]->Remove( mmin2, mmax2, aItem ) )
+                    continue;
+            }
+
+            removed = true;
+        }
+
+        m_count -= int( removed );
+
+        return removed;
+    }
+
+#endif
+
+    /**
+     * Function RemoveAll()
+     * Removes all items from the RTree
+     */
+    void clear()
+    {
+        for( auto tree : m_tree )
+            tree->RemoveAll();
+
+        m_count = 0;
+    }
+
+#if 0
+    /**
+     * Determine if a given item exists in the tree.  Note that this does not search the full tree
+     * so if the item has been moved, this will return false when it should be true.
+     *
+     * @param aItem Item that may potentially exist in the tree
+     * @param aRobust If true, search the whole tree, not just the bounding box
+     * @return true if the item definitely exists, false if it does not exist within bbox
+     */
+    bool contains( BOARD_ITEM* aItem, bool aRobust = false )
+    {
+        const EDA_RECT& bbox    = aItem->GetBoundingBox();
+        const int       mmin[2] = { bbox.GetX(), bbox.GetY() };
+        const int       mmax[2] = { bbox.GetRight(), bbox.GetBottom() };
+        bool            found   = false;
+
+        auto search = [&found, &aItem]( const ITEM_WITH_SHAPE* aSearchItem ) {
+            if( aSearchItem->parent == aItem )
+            {
+                found = true;
+                return false;
+            }
+
+            return true;
+        };
+
+        for( int layer : aItem->GetLayerSet().Seq() )
+        {
+            m_tree[layer]->Search( mmin, mmax, search );
+
+            if( found )
+                break;
+        }
+
+        if( !found && aRobust )
+        {
+            for( int layer : LSET::AllCuMask().Seq() )
+            {
+                // N.B. We must search the whole tree for the pointer to remove
+                // because the item may have been moved.  We do not expand the item
+                // layer search as this should not change.
+
+                const int mmin2[2] = { INT_MIN, INT_MIN };
+                const int mmax2[2] = { INT_MAX, INT_MAX };
+
+                m_tree[layer]->Search( mmin2, mmax2, search );
+
+                if( found )
+                    break;
+            }
+        }
+
+        return found;
+    }
+
+#endif
+
+    int QueryColliding( BOARD_ITEM* aRefItem,
+                        PCB_LAYER_ID aRefLayer,
+                        PCB_LAYER_ID aTargetLayer,
+                        std::function<bool( BOARD_ITEM*)> aFilter,
+                        std::function<bool( BOARD_ITEM*, int)> aVisitor,
+                        int aClearance
+                        )
+    {
+        // keep track of BOARD_ITEMs that have been already found to collide (some items
+        // might be build of COMPOUND/triangulated shapes and a single subshape collision
+        // means we have a hit)
+        std::unordered_set<BOARD_ITEM*> collidingCompounds;
+
+        EDA_RECT box = aRefItem->GetBoundingBox();
+        box.Inflate( aClearance );
+
+        int min[2] = { box.GetX(),         box.GetY() };
+        int max[2] = { box.GetRight(),     box.GetBottom() };
+
+        std::shared_ptr<SHAPE> refShape = aRefItem->GetEffectiveShape( aRefLayer );
+
+        auto visit = [&] ( ITEM_WITH_SHAPE* aItem ) -> bool
+        {
+            if( collidingCompounds.find( aItem->parent ) != collidingCompounds.end() )
+                return true;
+
+            if( !aFilter( aItem->parent ) )
+                return true;
+
+            int actual;
+
+            bool colliding = refShape->Collide( aItem->shape, aClearance, &actual );
+
+            if( colliding )
+            {
+                collidingCompounds.insert( aItem->parent );
+                return aVisitor( aItem->parent, actual );
+            }
+
+            return true;
+        };
+
+        this->m_tree[aTargetLayer]->Search( min, max, visit );
+        return 0;
+    }
+
+#if 0
+    std::vector<std::pair<int, BOARD_ITEM*>> GetNearest( const wxPoint &aPoint,
+                                                                   PCB_LAYER_ID aLayer,
+                                                                   int aLimit )
+    {
+
+        const int point[2] = { aPoint.x, aPoint.y };
+        auto result = m_tree[int( aLayer )]->NearestNeighbors( point,
+                [aLimit]( std::size_t a_count, int a_maxDist ) -> bool
+                {
+                    return a_count >= aLimit;
+                },
+                []( BOARD_ITEM* aElement) -> bool
+                {
+                    // Don't remove any elements from the list
+                    return false;
+                },
+                [aLayer]( const int* a_point, BOARD_ITEM* a_data ) -> int
+                {
+                    switch( a_data->Type() )
+                    {
+                    case PCB_TRACE_T:
+                    {
+                        TRACK* track = static_cast<TRACK*>( a_data );
+                        SEG seg( track->GetStart(), track->GetEnd() );
+                        return seg.Distance( VECTOR2I( a_point[0], a_point[1] ) ) -
+                                           ( track->GetWidth() + 1 ) / 2;
+                    }
+                    case PCB_VIA_T:
+                    {
+                        VIA* via = static_cast<VIA*>( a_data );
+                        return ( VECTOR2I( via->GetPosition() ) -
+                                 VECTOR2I( a_point[0], a_point[1] ) ).EuclideanNorm() -
+                               ( via->GetWidth() + 1 ) / 2;
+
+                    }
+                    default:
+                    {
+                        VECTOR2I point( a_point[0], a_point[1] );
+                        int      dist = 0;
+                        auto     shape = a_data->GetEffectiveShape( aLayer );
+
+                        // Here we use a hack to get the distance by colliding with a large area
+                        // However, we can't use just MAX_INT because we will overflow the collision calculations
+                        shape->Collide( point, std::numeric_limits<int>::max() / 2, &dist);
+                        return dist;
+                    }
+                    }
+                    return 0;
+                });
+
+        return result;
+    }
+#endif
+
+    /**
+     * Returns the number of items in the tree
+     * @return number of elements in the tree;
+     */
+    size_t size()
+    {
+        return m_count;
+    }
+
+    bool empty()
+    {
+        return m_count == 0;
+    }
+
+    using iterator = typename drc_rtree::Iterator;
+
+    /**
+     * The DRC_LAYER struct provides a layer-specific auto-range iterator to the RTree.  Using
+     * this struct, one can write lines like:
+     *
+     * for( auto item : rtree.OnLayer( In1_Cu ) )
+     *
+     * and iterate over only the RTree items that are on In1
+     */
+    struct DRC_LAYER
+    {
+        DRC_LAYER( drc_rtree* aTree ) : layer_tree( aTree )
+        {
+            m_rect = { { INT_MIN, INT_MIN }, { INT_MAX, INT_MAX } };
+        };
+
+        DRC_LAYER( drc_rtree* aTree, const EDA_RECT aRect ) : layer_tree( aTree )
+        {
+            m_rect = { { aRect.GetX(), aRect.GetY() },
+                       { aRect.GetRight(), aRect.GetBottom() } };
+        };
+
+        drc_rtree::Rect m_rect;
+        drc_rtree*      layer_tree;
+
+        iterator begin()
+        {
+            return layer_tree->begin( m_rect );
+        }
+
+        iterator end()
+        {
+            return layer_tree->end( m_rect );
+        }
+    };
+
+    DRC_LAYER OnLayer( PCB_LAYER_ID aLayer )
+    {
+        return DRC_LAYER( m_tree[int( aLayer )] );
+    }
+
+    DRC_LAYER Overlapping( PCB_LAYER_ID aLayer, const wxPoint& aPoint, int aAccuracy = 0 )
+    {
+        EDA_RECT rect( aPoint, wxSize( 0, 0 ) );
+        rect.Inflate( aAccuracy );
+        return DRC_LAYER( m_tree[int( aLayer )], rect );
+    }
+
+    DRC_LAYER Overlapping( PCB_LAYER_ID aLayer, const EDA_RECT& aRect )
+    {
+        return DRC_LAYER( m_tree[int( aLayer )], aRect );
+    }
+
+
+private:
+    drc_rtree*  m_tree[PCB_LAYER_ID_COUNT];
+    size_t      m_count;
+};
+
+
+#endif /* DRC_RTREE_H_ */

pcbnew/drc/drc_test_provider.h

@@ -97,6 +97,16 @@ public:
         return m_isRuleDriven;
     }
 
+    bool IsEnabled() const
+    {
+        return m_enabled;
+    }
+
+    void Enable( bool aEnable )
+    {
+        m_enabled = aEnable;
+    }
+
 protected:
     int forEachGeometryItem( const std::vector<KICAD_T>& aTypes, LSET aLayers,
                              const std::function<bool(BOARD_ITEM*)>& aFunc );
@@ -114,6 +124,7 @@ protected:
     DRC_ENGINE* m_drcEngine;
     std::unordered_map<const DRC_RULE*, int> m_stats;
     bool        m_isRuleDriven = true;
+    bool m_enabled = true;
 
     wxString    m_msg;  // Allocating strings gets expensive enough to want to avoid it
 };

pcbnew/drc/drc_test_provider_silk_to_pad.cpp

@@ -0,0 +1,243 @@
+/*
+ * This program source code file is part of KiCad, a free EDA CAD application.
+ *
+ * Copyright (C) 2004-2020 KiCad Developers.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ * or you may search the http://www.gnu.org website for the version 2 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include <common.h>
+#include <class_board.h>
+#include <class_drawsegment.h>
+#include <class_pad.h>
+
+#include <convert_basic_shapes_to_polygon.h>
+#include <geometry/polygon_test_point_inside.h>
+#include <geometry/seg.h>
+#include <geometry/shape_poly_set.h>
+#include <geometry/shape_rect.h>
+#include <geometry/shape_segment.h>
+
+#include <drc/drc_engine.h>
+#include <drc/drc_item.h>
+#include <drc/drc_rule.h>
+#include <drc/drc_test_provider_clearance_base.h>
+
+#include <drc/drc_rtree.h>
+
+/*
+    Silk to pads clearance test. Check all pads against silkscreen (mask opening in the pad vs silkscreen)
+    Errors generated:
+    - DRCE_SILK_ON_PADS
+
+    TODO:
+    - tester only looks for edge crossings. it doesn't check if items are inside/outside the board area.
+*/
+
+namespace test {
+
+class DRC_TEST_PROVIDER_SILK_TO_PAD : public ::DRC_TEST_PROVIDER
+{
+public:
+    DRC_TEST_PROVIDER_SILK_TO_PAD ()
+    {
+    }
+
+    virtual ~DRC_TEST_PROVIDER_SILK_TO_PAD() 
+    {
+    }
+
+    virtual bool Run() override;
+
+    virtual const wxString GetName() const override 
+    {
+        return "silk_to_pad"; 
+    };
+
+    virtual const wxString GetDescription() const override
+    {
+        return "Tests for silkscreen covering components pads";
+    }
+
+    virtual int GetNumPhases() const override
+    {
+        return 1;
+    }
+
+    virtual std::set<DRC_CONSTRAINT_TYPE_T> GetConstraintTypes() const override;
+
+private:
+
+    BOARD* m_board;
+    int m_largestClearance;
+};
+
+};
+
+
+bool test::DRC_TEST_PROVIDER_SILK_TO_PAD::Run()
+{
+    m_board = m_drcEngine->GetBoard();
+
+    DRC_CONSTRAINT worstClearanceConstraint;
+    m_largestClearance = 0;
+
+    if( m_drcEngine->QueryWorstConstraint( DRC_CONSTRAINT_TYPE_SILK_TO_PAD,
+                                           worstClearanceConstraint, DRCCQ_LARGEST_MINIMUM ) )
+    {
+        m_largestClearance = worstClearanceConstraint.m_Value.Min();
+    }
+
+    reportAux( "Worst clearance : %d nm", m_largestClearance );
+    reportPhase(( "Pad to silkscreen clearances..." ));
+
+    struct SHAPE_ON_LAYER
+    {
+        SHAPE_ON_LAYER( std::shared_ptr<SHAPE> aShape, PCB_LAYER_ID aLayer )
+            : shape ( aShape ),
+              layer ( aLayer )
+        {
+        }
+        std::shared_ptr<SHAPE> shape;
+        PCB_LAYER_ID layer;
+    };
+
+    DRC_RTREE padTree;
+
+    auto addPadToTree =
+            [&padTree]( BOARD_ITEM *item ) -> bool
+            {
+                padTree.insert( item );
+                return true;
+            };
+
+
+    auto checkClearance =
+            [&] ( BOARD_ITEM* refItem ) -> bool
+            {
+                const PCB_LAYER_ID padOuterLayers[] = { F_Cu, B_Cu };
+                const PCB_LAYER_ID padSilkLayers[] = { F_SilkS, B_SilkS };
+
+
+                for( int i = 0; i < 2; i++ )
+                {
+                    padTree.QueryColliding(
+                            refItem,
+                            padSilkLayers[i],
+                            padOuterLayers[i],
+                            [&] ( BOARD_ITEM *chkItem ) -> bool
+                            {
+                                return true;
+                            },
+                            [&] ( BOARD_ITEM *collItem, int distance ) -> bool
+                            {
+                                auto constraint = m_drcEngine->EvalRulesForItems( DRC_CONSTRAINT_TYPE_SILK_TO_PAD,
+                                                  refItem, collItem );
+
+                                int  minClearance = constraint.GetValue().Min();
+
+                                if( !distance || distance < minClearance )
+                                {
+                                    std::shared_ptr<DRC_ITEM> drcItem = DRC_ITEM::Create( DRCE_SILK_OVER_PAD );
+                                    wxString msg;
+
+                                    msg.Printf( drcItem->GetErrorText() + _( " (%s clearance %s; actual %s)" ),
+                                                constraint.GetParentRule()->m_Name,
+                                                MessageTextFromValue( userUnits(), minClearance, true ),
+                                                MessageTextFromValue( userUnits(), distance, true ) );
+
+                                    drcItem->SetErrorMessage( msg );
+                                    drcItem->SetItems( refItem, collItem );
+                                    drcItem->SetViolatingRule( constraint.GetParentRule() );
+
+                                    reportViolation( drcItem, refItem->GetPosition() ); 
+                                }
+                                return true;
+                            },
+                            m_largestClearance
+                    );
+                }
+
+                return true;
+            };
+
+    int numPads = forEachGeometryItem( { PCB_PAD_T }, LSET::AllTechMask() | LSET::AllCuMask(), addPadToTree );
+
+    int numSilk = forEachGeometryItem( { PCB_LINE_T, PCB_MODULE_EDGE_T, PCB_TEXT_T, PCB_MODULE_TEXT_T },
+                         LSET( 2, F_SilkS, B_SilkS ),
+                         checkClearance
+                          );
+
+        
+    reportAux( "Tested %d pads against %d silkscreen features.", numPads, numSilk );
+
+    
+    
+#if 0
+
+
+    for( auto& silkShape : boardOutline )
+    {
+        for( auto& padShape : boardItems )
+        {
+//            printf("BoardT %d\n", boardItem->Type() );
+            
+            auto shape = boardItem->GetEffectiveShape();
+
+            auto constraint = m_drcEngine->EvalRulesForItems( DRC_CONSTRAINT_TYPE_EDGE_CLEARANCE,
+                                                              outlineItem, boardItem );
+            int  minClearance = constraint.GetValue().Min();
+            int  actual;
+
+            if( refShape->Collide( shape.get(), minClearance, &actual ) )
+            {
+                std::shared_ptr<DRC_ITEM> drcItem = DRC_ITEM::Create( DRCE_COPPER_EDGE_CLEARANCE );
+                wxString msg;
+
+                msg.Printf( drcItem->GetErrorText() + _( " (%s clearance %s; actual %s)" ),
+                            rule->GetName(),
+                            MessageTextFromValue( userUnits(), minClearance, true ),
+                            MessageTextFromValue( userUnits(), actual, true ) );
+
+                drcItem->SetErrorMessage( msg );
+                drcItem->SetItems( outlineItem, boardItem );
+                drcItem->SetViolatingRule( rule );
+
+                reportViolation( drcItem, refShape->Centre());
+            }
+        }
+    }
+
+    return true;
+
+#endif
+
+    return true;
+}
+
+
+std::set<DRC_CONSTRAINT_TYPE_T> test::DRC_TEST_PROVIDER_SILK_TO_PAD::GetConstraintTypes() const
+{
+    return { DRC_CONSTRAINT_TYPE_SILK_TO_PAD };
+}
+
+
+namespace detail
+{
+    static DRC_REGISTER_TEST_PROVIDER<test::DRC_TEST_PROVIDER_SILK_TO_PAD> dummy;
+}