Added main execs

1 files changed, 1191 insertions, 0 deletions

diff --git a/pcbnew/drc_clearance_test_functions.cpp b/pcbnew/drc_clearance_test_functions.cpp
new file mode 100644
index 0000000..39d1b9d
--- /dev/null
+++ b/pcbnew/drc_clearance_test_functions.cpp
@@ -0,0 +1,1191 @@
+/**
+ * @file drc_clearance_test_functions.cpp
+ */
+
+/*
+ * This program source code file is part of KiCad, a free EDA CAD application.
+ *
+ * Copyright (C) 2004-2015 Jean-Pierre Charras, jean-pierre.charras@gipsa-lab.inpg.fr
+ * Copyright (C) 2007 Dick Hollenbeck, dick@softplc.com
+ * Copyright (C) 2015 KiCad Developers, see change_log.txt for contributors.
+ *
+ * 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
+ */
+
+/****************************/
+/* DRC control				*/
+/****************************/
+
+#include <fctsys.h>
+#include <wxPcbStruct.h>
+#include <trigo.h>
+
+#include <pcbnew.h>
+#include <drc_stuff.h>
+
+#include <class_board.h>
+#include <class_module.h>
+#include <class_track.h>
+#include <class_zone.h>
+#include <class_marker_pcb.h>
+#include <math_for_graphics.h>
+#include <polygon_test_point_inside.h>
+
+
+/* compare 2 trapezoids (can be rectangle) and return true if distance > aDist
+ * i.e if for each edge of the first polygon distance from each edge of the other polygon
+ * is >= aDist
+ */
+bool trapezoid2trapezoidDRC( wxPoint aTref[4], wxPoint aTcompare[4], int aDist )
+{
+    /* Test if one polygon is contained in the other and thus the polygon overlap.
+     * This case is not covered by the following check if one polygond is
+     * completely contained in the other (because edges don't intersect)!
+     */
+    if( TestPointInsidePolygon( aTref, 4, aTcompare[0] ) )
+        return false;
+
+    if( TestPointInsidePolygon( aTcompare, 4, aTref[0] ) )
+        return false;
+
+    int ii, jj, kk, ll;
+
+    for( ii = 0, jj = 3; ii<4; jj = ii, ii++ )          // for all edges in aTref
+    {
+        for( kk = 0, ll = 3; kk < 4; ll = kk, kk++ )    // for all edges in aTcompare
+        {
+            double d;
+            int    intersect = TestForIntersectionOfStraightLineSegments( aTref[ii].x,
+                                                                          aTref[ii].y,
+                                                                          aTref[jj].x,
+                                                                          aTref[jj].y,
+                                                                          aTcompare[kk].x,
+                                                                          aTcompare[kk].y,
+                                                                          aTcompare[ll].x,
+                                                                          aTcompare[ll].y,
+                                                                          NULL, NULL, &d );
+            if( intersect || (d< aDist) )
+                return false;
+        }
+    }
+
+    return true;
+}
+
+
+/* compare a trapezoids (can be rectangle) and a segment and return true if distance > aDist
+ */
+bool trapezoid2segmentDRC( wxPoint aTref[4], wxPoint aSegStart, wxPoint aSegEnd, int aDist )
+{
+    /* Test if the segment is contained in the polygon.
+     * This case is not covered by the following check if the segment is
+     * completely contained in the polygon (because edges don't intersect)!
+     */
+    if( TestPointInsidePolygon( aTref, 4, aSegStart ) )
+        return false;
+
+    int ii, jj;
+
+    for( ii = 0, jj = 3; ii < 4; jj = ii, ii++ )  // for all edges in aTref
+    {
+        double d;
+        int    intersect = TestForIntersectionOfStraightLineSegments( aTref[ii].x,
+                                                                      aTref[ii].y,
+                                                                      aTref[jj].x,
+                                                                      aTref[jj].y,
+                                                                      aSegStart.x,
+                                                                      aSegStart.y,
+                                                                      aSegEnd.x,
+                                                                      aSegEnd.y,
+                                                                      NULL, NULL, &d );
+        if( intersect || (d< aDist) )
+            return false;
+    }
+
+    return true;
+}
+
+
+/* compare a trapezoid to a point and return true if distance > aDist
+ * do not use this function for horizontal or vertical rectangles
+ * because there is a faster an easier way to compare the distance
+ */
+bool trapezoid2pointDRC( wxPoint aTref[4], wxPoint aPcompare, int aDist )
+{
+    /* Test if aPcompare point is contained in the polygon.
+     * This case is not covered by the following check if this point is inside the polygon
+     */
+    if( TestPointInsidePolygon( aTref, 4, aPcompare ) )
+    {
+        return false;
+    }
+
+    // Test distance between aPcompare and each segment of the polygon:
+    for( int ii = 0, jj = 3; ii < 4; jj = ii, ii++ )  // for all edge in polygon
+    {
+        if( TestSegmentHit( aTref[ii], aTref[jj], aPcompare, aDist ) )
+            return false;
+    }
+
+    return true;
+}
+
+
+bool DRC::doTrackDrc( TRACK* aRefSeg, TRACK* aStart, bool testPads )
+{
+    TRACK*    track;
+    wxPoint   delta;           // lenght on X and Y axis of segments
+    LSET layerMask;
+    int       net_code_ref;
+    wxPoint   shape_pos;
+
+    NETCLASSPTR netclass = aRefSeg->GetNetClass();
+    BOARD_DESIGN_SETTINGS& dsnSettings = m_pcb->GetDesignSettings();
+
+    /* In order to make some calculations more easier or faster,
+     * pads and tracks coordinates will be made relative to the reference segment origin
+     */
+    wxPoint origin = aRefSeg->GetStart();  // origin will be the origin of other coordinates
+
+    m_segmEnd   = delta = aRefSeg->GetEnd() - origin;
+    m_segmAngle = 0;
+
+    layerMask    = aRefSeg->GetLayerSet();
+    net_code_ref = aRefSeg->GetNetCode();
+
+    // Phase 0 : Test vias
+    if( aRefSeg->Type() == PCB_VIA_T )
+    {
+        const VIA *refvia = static_cast<const VIA*>( aRefSeg );
+        // test if the via size is smaller than minimum
+        if( refvia->GetViaType() == VIA_MICROVIA )
+        {
+            if( refvia->GetWidth() < dsnSettings.m_MicroViasMinSize )
+            {
+                m_currentMarker = fillMarker( refvia, NULL,
+                                              DRCE_TOO_SMALL_MICROVIA, m_currentMarker );
+                return false;
+            }
+        }
+        else
+        {
+            if( refvia->GetWidth() < dsnSettings.m_ViasMinSize )
+            {
+                m_currentMarker = fillMarker( refvia, NULL,
+                                              DRCE_TOO_SMALL_VIA, m_currentMarker );
+                return false;
+            }
+        }
+
+        // test if via's hole is bigger than its diameter
+        // This test is necessary since the via hole size and width can be modified
+        // and a default via hole can be bigger than some vias sizes
+        if( refvia->GetDrillValue() > refvia->GetWidth() )
+        {
+            m_currentMarker = fillMarker( refvia, NULL,
+                                          DRCE_VIA_HOLE_BIGGER, m_currentMarker );
+            return false;
+        }
+
+        // For microvias: test if they are blind vias and only between 2 layers
+        // because they are used for very small drill size and are drill by laser
+        // and **only one layer** can be drilled
+        if( refvia->GetViaType() == VIA_MICROVIA )
+        {
+            LAYER_ID    layer1, layer2;
+            bool        err = true;
+
+            refvia->LayerPair( &layer1, &layer2 );
+
+            if( layer1 > layer2 )
+                std::swap( layer1, layer2 );
+
+            if( layer2 == B_Cu && layer1 == m_pcb->GetDesignSettings().GetCopperLayerCount() - 2 )
+                err = false;
+            else if( layer1 == F_Cu  &&  layer2 == In1_Cu  )
+                err = false;
+
+            if( err )
+            {
+                m_currentMarker = fillMarker( refvia, NULL,
+                                              DRCE_MICRO_VIA_INCORRECT_LAYER_PAIR, m_currentMarker );
+                return false;
+            }
+        }
+    }
+    else    // This is a track segment
+    {
+        if( aRefSeg->GetWidth() < dsnSettings.m_TrackMinWidth )
+        {
+            m_currentMarker = fillMarker( aRefSeg, NULL,
+                                          DRCE_TOO_SMALL_TRACK_WIDTH, m_currentMarker );
+            return false;
+        }
+    }
+
+    // for a non horizontal or vertical segment Compute the segment angle
+    // in tenths of degrees and its length
+    if( delta.x || delta.y )
+    {
+        // Compute the segment angle in 0,1 degrees
+        m_segmAngle = ArcTangente( delta.y, delta.x );
+
+        // Compute the segment length: we build an equivalent rotated segment,
+        // this segment is horizontal, therefore dx = length
+        RotatePoint( &delta, m_segmAngle );    // delta.x = length, delta.y = 0
+    }
+
+    m_segmLength = delta.x;
+
+    /******************************************/
+    /* Phase 1 : test DRC track to pads :     */
+    /******************************************/
+
+    /* Use a dummy pad to test DRC tracks versus holes, for pads not on all copper layers
+     * but having a hole
+     * This dummy pad has the size and shape of the hole
+     * to test tracks to pad hole DRC, using checkClearanceSegmToPad test function.
+     * Therefore, this dummy pad is a circle or an oval.
+     * A pad must have a parent because some functions expect a non null parent
+     * to find the parent board, and some other data
+     */
+    MODULE  dummymodule( m_pcb );    // Creates a dummy parent
+    D_PAD   dummypad( &dummymodule );
+
+    dummypad.SetLayerSet( LSET::AllCuMask() );     // Ensure the hole is on all layers
+
+    // Compute the min distance to pads
+    if( testPads )
+    {
+        unsigned pad_count = m_pcb->GetPadCount();
+
+        for( unsigned ii = 0;  ii<pad_count;  ++ii )
+        {
+            D_PAD* pad = m_pcb->GetPad( ii );
+
+            /* No problem if pads are on an other layer,
+             * But if a drill hole exists	(a pad on a single layer can have a hole!)
+             * we must test the hole
+             */
+            if( !( pad->GetLayerSet() & layerMask ).any() )
+            {
+                /* We must test the pad hole. In order to use the function
+                 * checkClearanceSegmToPad(),a pseudo pad is used, with a shape and a
+                 * size like the hole
+                 */
+                if( pad->GetDrillSize().x == 0 )
+                    continue;
+
+                dummypad.SetSize( pad->GetDrillSize() );
+                dummypad.SetPosition( pad->GetPosition() );
+                dummypad.SetShape( pad->GetDrillShape()  == PAD_DRILL_SHAPE_OBLONG ?
+                                   PAD_SHAPE_OVAL : PAD_SHAPE_CIRCLE );
+                dummypad.SetOrientation( pad->GetOrientation() );
+
+                m_padToTestPos = dummypad.GetPosition() - origin;
+
+                if( !checkClearanceSegmToPad( &dummypad, aRefSeg->GetWidth(),
+                                              netclass->GetClearance() ) )
+                {
+                    m_currentMarker = fillMarker( aRefSeg, pad,
+                                                  DRCE_TRACK_NEAR_THROUGH_HOLE, m_currentMarker );
+                    return false;
+                }
+
+                continue;
+            }
+
+            // The pad must be in a net (i.e pt_pad->GetNet() != 0 )
+            // but no problem if the pad netcode is the current netcode (same net)
+            if( pad->GetNetCode()                       // the pad must be connected
+               && net_code_ref == pad->GetNetCode() )   // the pad net is the same as current net -> Ok
+                continue;
+
+            // DRC for the pad
+            shape_pos = pad->ShapePos();
+            m_padToTestPos = shape_pos - origin;
+
+            if( !checkClearanceSegmToPad( pad, aRefSeg->GetWidth(), aRefSeg->GetClearance( pad ) ) )
+            {
+                m_currentMarker = fillMarker( aRefSeg, pad,
+                                              DRCE_TRACK_NEAR_PAD, m_currentMarker );
+                return false;
+            }
+        }
+    }
+
+    /***********************************************/
+    /* Phase 2: test DRC with other track segments */
+    /***********************************************/
+
+    // At this point the reference segment is the X axis
+
+    // Test the reference segment with other track segments
+    wxPoint segStartPoint;
+    wxPoint segEndPoint;
+    for( track = aStart; track; track = track->Next() )
+    {
+        // No problem if segments have the same net code:
+        if( net_code_ref == track->GetNetCode() )
+            continue;
+
+        // No problem if segment are on different layers :
+        if( !( layerMask & track->GetLayerSet() ).any() )
+            continue;
+
+        // the minimum distance = clearance plus half the reference track
+        // width plus half the other track's width
+        int w_dist = aRefSeg->GetClearance( track );
+        w_dist += (aRefSeg->GetWidth() + track->GetWidth()) / 2;
+
+        // If the reference segment is a via, we test it here
+        if( aRefSeg->Type() == PCB_VIA_T )
+        {
+            delta = track->GetEnd() - track->GetStart();
+            segStartPoint = aRefSeg->GetStart() - track->GetStart();
+
+            if( track->Type() == PCB_VIA_T )
+            {
+                // Test distance between two vias, i.e. two circles, trivial case
+                if( EuclideanNorm( segStartPoint ) < w_dist )
+                {
+                    m_currentMarker = fillMarker( aRefSeg, track,
+                                                  DRCE_VIA_NEAR_VIA, m_currentMarker );
+                    return false;
+                }
+            }
+            else    // test via to segment
+            {
+                // Compute l'angle du segment a tester;
+                double angle = ArcTangente( delta.y, delta.x );
+
+                // Compute new coordinates ( the segment become horizontal)
+                RotatePoint( &delta, angle );
+                RotatePoint( &segStartPoint, angle );
+
+                if( !checkMarginToCircle( segStartPoint, w_dist, delta.x ) )
+                {
+                    m_currentMarker = fillMarker( track, aRefSeg,
+                                                  DRCE_VIA_NEAR_TRACK, m_currentMarker );
+                    return false;
+                }
+            }
+
+            continue;
+        }
+
+        /* We compute segStartPoint, segEndPoint = starting and ending point coordinates for
+         * the segment to test in the new axis : the new X axis is the
+         * reference segment.  We must translate and rotate the segment to test
+         */
+        segStartPoint = track->GetStart() - origin;
+        segEndPoint   = track->GetEnd() - origin;
+        RotatePoint( &segStartPoint, m_segmAngle );
+        RotatePoint( &segEndPoint, m_segmAngle );
+        if( track->Type() == PCB_VIA_T )
+        {
+            if( checkMarginToCircle( segStartPoint, w_dist, m_segmLength ) )
+                continue;
+
+            m_currentMarker = fillMarker( aRefSeg, track,
+                                          DRCE_TRACK_NEAR_VIA, m_currentMarker );
+            return false;
+        }
+
+        /*	We have changed axis:
+         *  the reference segment is Horizontal.
+         *  3 cases : the segment to test can be parallel, perpendicular or have an other direction
+         */
+        if( segStartPoint.y == segEndPoint.y ) // parallel segments
+        {
+            if( abs( segStartPoint.y ) >= w_dist )
+                continue;
+
+            // Ensure segStartPoint.x <= segEndPoint.x
+            if( segStartPoint.x > segEndPoint.x )
+                std::swap( segStartPoint.x, segEndPoint.x );
+
+            if( segStartPoint.x > (-w_dist) && segStartPoint.x < (m_segmLength + w_dist) )    /* possible error drc */
+            {
+                // the start point is inside the reference range
+                //      X........
+                //    O--REF--+
+
+                // Fine test : we consider the rounded shape of each end of the track segment:
+                if( segStartPoint.x >= 0 && segStartPoint.x <= m_segmLength )
+                {
+                    m_currentMarker = fillMarker( aRefSeg, track,
+                                                  DRCE_TRACK_ENDS1, m_currentMarker );
+                    return false;
+                }
+
+                if( !checkMarginToCircle( segStartPoint, w_dist, m_segmLength ) )
+                {
+                    m_currentMarker = fillMarker( aRefSeg, track,
+                                                  DRCE_TRACK_ENDS2, m_currentMarker );
+                    return false;
+                }
+            }
+
+            if( segEndPoint.x > (-w_dist) && segEndPoint.x < (m_segmLength + w_dist) )
+            {
+                // the end point is inside the reference range
+                //  .....X
+                //    O--REF--+
+                // Fine test : we consider the rounded shape of the ends
+                if( segEndPoint.x >= 0 && segEndPoint.x <= m_segmLength )
+                {
+                    m_currentMarker = fillMarker( aRefSeg, track,
+                                                  DRCE_TRACK_ENDS3, m_currentMarker );
+                    return false;
+                }
+
+                if( !checkMarginToCircle( segEndPoint, w_dist, m_segmLength ) )
+                {
+                    m_currentMarker = fillMarker( aRefSeg, track,
+                                                  DRCE_TRACK_ENDS4, m_currentMarker );
+                    return false;
+                }
+            }
+
+            if( segStartPoint.x <=0 && segEndPoint.x >= 0 )
+            {
+            // the segment straddles the reference range (this actually only
+            // checks if it straddles the origin, because the other cases where already
+            // handled)
+            //  X.............X
+            //    O--REF--+
+                m_currentMarker = fillMarker( aRefSeg, track,
+                                              DRCE_TRACK_SEGMENTS_TOO_CLOSE, m_currentMarker );
+                return false;
+            }
+        }
+        else if( segStartPoint.x == segEndPoint.x ) // perpendicular segments
+        {
+            if( ( segStartPoint.x <= (-w_dist) ) || ( segStartPoint.x >= (m_segmLength + w_dist) ) )
+                continue;
+
+            // Test if segments are crossing
+            if( segStartPoint.y > segEndPoint.y )
+                std::swap( segStartPoint.y, segEndPoint.y );
+
+            if( (segStartPoint.y < 0) && (segEndPoint.y > 0) )
+            {
+                m_currentMarker = fillMarker( aRefSeg, track,
+                                              DRCE_TRACKS_CROSSING, m_currentMarker );
+                return false;
+            }
+
+            // At this point the drc error is due to an end near a reference segm end
+            if( !checkMarginToCircle( segStartPoint, w_dist, m_segmLength ) )
+            {
+                m_currentMarker = fillMarker( aRefSeg, track,
+                                              DRCE_ENDS_PROBLEM1, m_currentMarker );
+                return false;
+            }
+            if( !checkMarginToCircle( segEndPoint, w_dist, m_segmLength ) )
+            {
+                m_currentMarker = fillMarker( aRefSeg, track,
+                                              DRCE_ENDS_PROBLEM2, m_currentMarker );
+                return false;
+            }
+        }
+        else    // segments quelconques entre eux
+        {
+            // calcul de la "surface de securite du segment de reference
+            // First rought 'and fast) test : the track segment is like a rectangle
+
+            m_xcliplo = m_ycliplo = -w_dist;
+            m_xcliphi = m_segmLength + w_dist;
+            m_ycliphi = w_dist;
+
+            // A fine test is needed because a serment is not exactly a
+            // rectangle, it has rounded ends
+            if( !checkLine( segStartPoint, segEndPoint ) )
+            {
+                /* 2eme passe : the track has rounded ends.
+                 * we must a fine test for each rounded end and the
+                 * rectangular zone
+                 */
+
+                m_xcliplo = 0;
+                m_xcliphi = m_segmLength;
+
+                if( !checkLine( segStartPoint, segEndPoint ) )
+                {
+                    m_currentMarker = fillMarker( aRefSeg, track,
+                                                  DRCE_ENDS_PROBLEM3, m_currentMarker );
+                    return false;
+                }
+                else    // The drc error is due to the starting or the ending point of the reference segment
+                {
+                    // Test the starting and the ending point
+                    segStartPoint = track->GetStart();
+                    segEndPoint   = track->GetEnd();
+                    delta = segEndPoint - segStartPoint;
+
+                    // Compute the segment orientation (angle) en 0,1 degre
+                    double angle = ArcTangente( delta.y, delta.x );
+
+                    // Compute the segment lenght: delta.x = lenght after rotation
+                    RotatePoint( &delta, angle );
+
+                    /* Comute the reference segment coordinates relatives to a
+                     *  X axis = current tested segment
+                     */
+                    wxPoint relStartPos = aRefSeg->GetStart() - segStartPoint;
+                    wxPoint relEndPos   = aRefSeg->GetEnd() - segStartPoint;
+
+                    RotatePoint( &relStartPos, angle );
+                    RotatePoint( &relEndPos, angle );
+
+                    if( !checkMarginToCircle( relStartPos, w_dist, delta.x ) )
+                    {
+                        m_currentMarker = fillMarker( aRefSeg, track,
+                                                      DRCE_ENDS_PROBLEM4, m_currentMarker );
+                        return false;
+                    }
+
+                    if( !checkMarginToCircle( relEndPos, w_dist, delta.x ) )
+                    {
+                        m_currentMarker = fillMarker( aRefSeg, track,
+                                                      DRCE_ENDS_PROBLEM5, m_currentMarker );
+                        return false;
+                    }
+                }
+            }
+        }
+    }
+
+    return true;
+}
+
+
+/* test DRC between 2 pads.
+ * this function can be also used to test DRC between a pas and a hole,
+ * because a hole is like a round pad.
+ */
+bool DRC::checkClearancePadToPad( D_PAD* aRefPad, D_PAD* aPad )
+{
+    int     dist;
+
+    double  pad_angle;
+
+    // Get the clearance between the 2 pads. this is the min distance between aRefPad and aPad
+    int     dist_min = aRefPad->GetClearance( aPad );
+
+    // relativePadPos is the aPad shape position relative to the aRefPad shape position
+    wxPoint relativePadPos = aPad->ShapePos() - aRefPad->ShapePos();
+
+    dist = KiROUND( EuclideanNorm( relativePadPos ) );
+
+    // Quick test: Clearance is OK if the bounding circles are further away than "dist_min"
+    if( (dist - aRefPad->GetBoundingRadius() - aPad->GetBoundingRadius()) >= dist_min )
+        return true;
+
+    /* Here, pads are near and DRC depend on the pad shapes
+     * We must compare distance using a fine shape analysis
+     * Because a circle or oval shape is the easier shape to test, try to have
+     * aRefPad shape type = PAD_SHAPE_CIRCLE or PAD_SHAPE_OVAL.
+     * if aRefPad = TRAP. and aPad = RECT, also swap pads
+     * Swap aRefPad and aPad if needed
+     */
+    bool swap_pads;
+    swap_pads = false;
+
+    // swap pads to make comparisons easier
+    // priority is aRefPad = ROUND then OVAL then RECT then other
+    if( aRefPad->GetShape() != aPad->GetShape() && aRefPad->GetShape() != PAD_SHAPE_CIRCLE )
+    {
+        // pad ref shape is here oval, rect or trapezoid
+        switch( aPad->GetShape() )
+        {
+            case PAD_SHAPE_CIRCLE:
+                swap_pads = true;
+                break;
+
+            case PAD_SHAPE_OVAL:
+                swap_pads = true;
+                break;
+
+            case PAD_SHAPE_RECT:
+                if( aRefPad->GetShape() != PAD_SHAPE_OVAL )
+                    swap_pads = true;
+                break;
+
+            default:
+                break;
+        }
+    }
+
+    if( swap_pads )
+    {
+        std::swap( aRefPad, aPad );
+        relativePadPos = -relativePadPos;
+    }
+
+    /* Because pad exchange, aRefPad shape is PAD_SHAPE_CIRCLE or PAD_SHAPE_OVAL,
+     * if one of the 2 pads was a PAD_SHAPE_CIRCLE or PAD_SHAPE_OVAL.
+     * Therefore, if aRefPad is a PAD_SHAPE_SHAPE_RECT or a PAD_SHAPE_TRAPEZOID,
+     * aPad is also a PAD_SHAPE_RECT or a PAD_SHAPE_TRAPEZOID
+     */
+    bool diag = true;
+
+    switch( aRefPad->GetShape() )
+    {
+    case PAD_SHAPE_CIRCLE:
+
+        /* One can use checkClearanceSegmToPad to test clearance
+         * aRefPad is like a track segment with a null length and a witdth = GetSize().x
+         */
+        m_segmLength = 0;
+        m_segmAngle  = 0;
+
+        m_segmEnd.x = m_segmEnd.y = 0;
+
+        m_padToTestPos = relativePadPos;
+        diag = checkClearanceSegmToPad( aPad, aRefPad->GetSize().x, dist_min );
+        break;
+
+    case PAD_SHAPE_RECT:
+        // pad_angle = pad orient relative to the aRefPad orient
+        pad_angle = aRefPad->GetOrientation() + aPad->GetOrientation();
+        NORMALIZE_ANGLE_POS( pad_angle );
+
+        if( aPad->GetShape() == PAD_SHAPE_RECT )
+        {
+            wxSize size = aPad->GetSize();
+
+            // The trivial case is if both rects are rotated by multiple of 90 deg
+            // Most of time this is the case, and the test is fast
+            if( ( (aRefPad->GetOrientation() == 0) || (aRefPad->GetOrientation() == 900)
+                 || (aRefPad->GetOrientation() == 1800) || (aRefPad->GetOrientation() == 2700) )
+               && ( (aPad->GetOrientation() == 0) || (aPad->GetOrientation() == 900) || (aPad->GetOrientation() == 1800)
+                   || (aPad->GetOrientation() == 2700) ) )
+            {
+                if( (pad_angle == 900) || (pad_angle == 2700) )
+                {
+                    std::swap( size.x, size.y );
+                }
+
+                // Test DRC:
+                diag = false;
+                RotatePoint( &relativePadPos, aRefPad->GetOrientation() );
+                relativePadPos.x = std::abs( relativePadPos.x );
+                relativePadPos.y = std::abs( relativePadPos.y );
+
+                if( ( relativePadPos.x - ( (size.x + aRefPad->GetSize().x) / 2 ) ) >= dist_min )
+                    diag = true;
+
+                if( ( relativePadPos.y - ( (size.y + aRefPad->GetSize().y) / 2 ) ) >= dist_min )
+                    diag = true;
+            }
+            else    // at least one pad has any other orient. Test is more tricky
+            {   // Use the trapezoid2trapezoidDRC which also compare 2 rectangles with any orientation
+                wxPoint polyref[4];         // Shape of aRefPad
+                wxPoint polycompare[4];     // Shape of aPad
+                aRefPad->BuildPadPolygon( polyref, wxSize( 0, 0 ), aRefPad->GetOrientation() );
+                aPad->BuildPadPolygon( polycompare, wxSize( 0, 0 ), aPad->GetOrientation() );
+
+                // Move aPad shape to relativePadPos
+                for( int ii = 0; ii < 4; ii++ )
+                    polycompare[ii] += relativePadPos;
+
+                // And now test polygons:
+                if( !trapezoid2trapezoidDRC( polyref, polycompare, dist_min ) )
+                    diag = false;
+            }
+        }
+        else if( aPad->GetShape() == PAD_SHAPE_TRAPEZOID )
+        {
+            wxPoint polyref[4];         // Shape of aRefPad
+            wxPoint polycompare[4];     // Shape of aPad
+            aRefPad->BuildPadPolygon( polyref, wxSize( 0, 0 ), aRefPad->GetOrientation() );
+            aPad->BuildPadPolygon( polycompare, wxSize( 0, 0 ), aPad->GetOrientation() );
+
+            // Move aPad shape to relativePadPos
+            for( int ii = 0; ii < 4; ii++ )
+                polycompare[ii] += relativePadPos;
+
+            // And now test polygons:
+            if( !trapezoid2trapezoidDRC( polyref, polycompare, dist_min ) )
+                diag = false;
+        }
+        else
+        {
+            // Should not occur, because aPad and aRefPad are swapped
+            // to have only aPad shape RECT or TRAP and aRefPad shape TRAP or RECT.
+            wxLogDebug( wxT( "DRC::checkClearancePadToPad: unexpected pad ref RECT @ %d, %d to pad shape %d @ %d, %d"),
+                aRefPad->GetPosition().x, aRefPad->GetPosition().y,
+                aPad->GetShape(), aPad->GetPosition().x, aPad->GetPosition().y );
+        }
+        break;
+
+    case PAD_SHAPE_OVAL:     /* an oval pad is like a track segment */
+    {
+        /* Create a track segment with same dimensions as the oval aRefPad
+         * and use checkClearanceSegmToPad function to test aPad to aRefPad clearance
+         */
+        int segm_width;
+        m_segmAngle = aRefPad->GetOrientation();                // Segment orient.
+
+        if( aRefPad->GetSize().y < aRefPad->GetSize().x )     // Build an horizontal equiv segment
+        {
+            segm_width   = aRefPad->GetSize().y;
+            m_segmLength = aRefPad->GetSize().x - aRefPad->GetSize().y;
+        }
+        else        // Vertical oval: build an horizontal equiv segment and rotate 90.0 deg
+        {
+            segm_width   = aRefPad->GetSize().x;
+            m_segmLength = aRefPad->GetSize().y - aRefPad->GetSize().x;
+            m_segmAngle += 900;
+        }
+
+        /* the start point must be 0,0 and currently relativePadPos
+         * is relative the center of pad coordinate */
+        wxPoint segstart;
+        segstart.x = -m_segmLength / 2;                 // Start point coordinate of the horizontal equivalent segment
+
+        RotatePoint( &segstart, m_segmAngle );          // actual start point coordinate of the equivalent segment
+        // Calculate segment end position relative to the segment origin
+        m_segmEnd.x = -2 * segstart.x;
+        m_segmEnd.y = -2 * segstart.y;
+
+        // Recalculate the equivalent segment angle in 0,1 degrees
+        // to prepare a call to checkClearanceSegmToPad()
+        m_segmAngle = ArcTangente( m_segmEnd.y, m_segmEnd.x );
+
+        // move pad position relative to the segment origin
+        m_padToTestPos = relativePadPos - segstart;
+
+        // Use segment to pad check to test the second pad:
+        diag = checkClearanceSegmToPad( aPad, segm_width, dist_min );
+        break;
+    }
+
+    case PAD_SHAPE_TRAPEZOID:
+
+        // at this point, aPad is also a trapezoid, because all other shapes
+        // have priority, and are already tested
+        wxASSERT( aPad->GetShape() == PAD_SHAPE_TRAPEZOID );
+        {
+            wxPoint polyref[4];         // Shape of aRefPad
+            wxPoint polycompare[4];     // Shape of aPad
+            aRefPad->BuildPadPolygon( polyref, wxSize( 0, 0 ), aRefPad->GetOrientation() );
+            aPad->BuildPadPolygon( polycompare, wxSize( 0, 0 ), aPad->GetOrientation() );
+
+            // Move aPad shape to relativePadPos
+            for( int ii = 0; ii < 4; ii++ )
+                polycompare[ii] += relativePadPos;
+
+            // And now test polygons:
+            if( !trapezoid2trapezoidDRC( polyref, polycompare, dist_min ) )
+                diag = false;
+        }
+        break;
+
+    default:
+        wxLogDebug( wxT( "DRC::checkClearancePadToPad: unexpected pad shape" ) );
+        break;
+    }
+
+    return diag;
+}
+
+
+/* test if distance between a segment is > aMinDist
+ * segment start point is assumed in (0,0) and  segment start point in m_segmEnd
+ * and its orientation is m_segmAngle (m_segmAngle must be already initialized)
+ * and have aSegmentWidth.
+ */
+bool DRC::checkClearanceSegmToPad( const D_PAD* aPad, int aSegmentWidth, int aMinDist )
+{
+    wxSize  padHalfsize;            // half dimension of the pad
+    wxPoint startPoint, endPoint;
+
+    int segmHalfWidth = aSegmentWidth / 2;
+    int distToLine = segmHalfWidth + aMinDist;
+
+    padHalfsize.x = aPad->GetSize().x >> 1;
+    padHalfsize.y = aPad->GetSize().y >> 1;
+
+    if( aPad->GetShape() == PAD_SHAPE_TRAPEZOID )     // The size is bigger, due to GetDelta() extra size
+    {
+        padHalfsize.x += std::abs(aPad->GetDelta().y) / 2;   // Remember: GetDelta().y is the GetSize().x change
+        padHalfsize.y += std::abs(aPad->GetDelta().x) / 2;   // Remember: GetDelta().x is the GetSize().y change
+    }
+
+    if( aPad->GetShape() == PAD_SHAPE_CIRCLE )
+    {
+        /* Easy case: just test the distance between segment and pad centre
+         * calculate pad coordinates in the X,Y axis with X axis = segment to test
+         */
+        RotatePoint( &m_padToTestPos, m_segmAngle );
+        return checkMarginToCircle( m_padToTestPos, distToLine + padHalfsize.x, m_segmLength );
+    }
+
+    /* calculate the bounding box of the pad, including the clearance and the segment width
+     * if the line from 0 to m_segmEnd does not intersect this bounding box,
+     * the clearance is always OK
+     * But if intersect, a better analysis of the pad shape must be done.
+     */
+    m_xcliplo = m_padToTestPos.x - distToLine - padHalfsize.x;
+    m_ycliplo = m_padToTestPos.y - distToLine - padHalfsize.y;
+    m_xcliphi = m_padToTestPos.x + distToLine + padHalfsize.x;
+    m_ycliphi = m_padToTestPos.y + distToLine + padHalfsize.y;
+
+    startPoint.x = startPoint.y = 0;
+    endPoint     = m_segmEnd;
+
+    double orient = aPad->GetOrientation();
+
+    RotatePoint( &startPoint, m_padToTestPos, -orient );
+    RotatePoint( &endPoint, m_padToTestPos, -orient );
+
+    if( checkLine( startPoint, endPoint ) )
+        return true;
+
+    /* segment intersects the bounding box. But there is not always a DRC error.
+     * A fine analysis of the pad shape must be done.
+     */
+    switch( aPad->GetShape() )
+    {
+    default:
+        return false;
+
+    case PAD_SHAPE_OVAL:
+    {
+        /* an oval is a complex shape, but is a rectangle and 2 circles
+         * these 3 basic shapes are more easy to test.
+         *
+         * In calculations we are using a vertical oval shape
+         * (i.e. a vertical rounded segment)
+         * for horizontal oval shapes, swap x and y size and rotate the shape
+         */
+        if( padHalfsize.x > padHalfsize.y )
+        {
+            std::swap( padHalfsize.x, padHalfsize.y );
+            orient = AddAngles( orient, 900 );
+        }
+
+        // here, padHalfsize.x is the radius of rounded ends.
+
+        int deltay = padHalfsize.y - padHalfsize.x;
+        // here: padHalfsize.x = radius,
+        // deltay = dist between the centre pad and the centre of a rounded end
+
+        // Test the rectangular area between the two circles (the rounded ends)
+        m_xcliplo = m_padToTestPos.x - distToLine - padHalfsize.x;
+        m_ycliplo = m_padToTestPos.y - deltay;
+        m_xcliphi = m_padToTestPos.x + distToLine + padHalfsize.x;
+        m_ycliphi = m_padToTestPos.y + deltay;
+
+        if( !checkLine( startPoint, endPoint ) )
+        {
+            return false;
+        }
+
+        // test the first circle
+        startPoint.x = m_padToTestPos.x;         // startPoint = centre of the upper circle of the oval shape
+        startPoint.y = m_padToTestPos.y + deltay;
+
+        // Calculate the actual position of the circle, given the pad orientation:
+        RotatePoint( &startPoint, m_padToTestPos, orient );
+
+        // Calculate the actual position of the circle in the new X,Y axis:
+        RotatePoint( &startPoint, m_segmAngle );
+
+        if( !checkMarginToCircle( startPoint, padHalfsize.x + distToLine, m_segmLength ) )
+        {
+            return false;
+        }
+
+        // test the second circle
+        startPoint.x = m_padToTestPos.x;         // startPoint = centre of the lower circle of the oval shape
+        startPoint.y = m_padToTestPos.y - deltay;
+        RotatePoint( &startPoint, m_padToTestPos, orient );
+        RotatePoint( &startPoint, m_segmAngle );
+
+        if( !checkMarginToCircle( startPoint, padHalfsize.x + distToLine, m_segmLength ) )
+        {
+            return false;
+        }
+    }
+        break;
+
+    case PAD_SHAPE_RECT:
+        // the area to test is a rounded rectangle.
+        // this can be done by testing 2 rectangles and 4 circles (the corners)
+
+        // Testing the first rectangle dimx + distToLine, dimy:
+        m_xcliplo = m_padToTestPos.x - padHalfsize.x - distToLine;
+        m_ycliplo = m_padToTestPos.y - padHalfsize.y;
+        m_xcliphi = m_padToTestPos.x + padHalfsize.x + distToLine;
+        m_ycliphi = m_padToTestPos.y + padHalfsize.y;
+
+        if( !checkLine( startPoint, endPoint ) )
+            return false;
+
+        // Testing the second rectangle dimx , dimy + distToLine
+        m_xcliplo = m_padToTestPos.x - padHalfsize.x;
+        m_ycliplo = m_padToTestPos.y - padHalfsize.y - distToLine;
+        m_xcliphi = m_padToTestPos.x + padHalfsize.x;
+        m_ycliphi = m_padToTestPos.y + padHalfsize.y + distToLine;
+
+        if( !checkLine( startPoint, endPoint ) )
+            return false;
+
+        // testing the 4 circles which are the clearance area of each corner:
+
+        // testing the left top corner of the rectangle
+        startPoint.x = m_padToTestPos.x - padHalfsize.x;
+        startPoint.y = m_padToTestPos.y - padHalfsize.y;
+        RotatePoint( &startPoint, m_padToTestPos, orient );
+        RotatePoint( &startPoint, m_segmAngle );
+
+        if( !checkMarginToCircle( startPoint, distToLine, m_segmLength ) )
+            return false;
+
+        // testing the right top corner of the rectangle
+        startPoint.x = m_padToTestPos.x + padHalfsize.x;
+        startPoint.y = m_padToTestPos.y - padHalfsize.y;
+        RotatePoint( &startPoint, m_padToTestPos, orient );
+        RotatePoint( &startPoint, m_segmAngle );
+
+        if( !checkMarginToCircle( startPoint, distToLine, m_segmLength ) )
+            return false;
+
+        // testing the left bottom corner of the rectangle
+        startPoint.x = m_padToTestPos.x - padHalfsize.x;
+        startPoint.y = m_padToTestPos.y + padHalfsize.y;
+        RotatePoint( &startPoint, m_padToTestPos, orient );
+        RotatePoint( &startPoint, m_segmAngle );
+
+        if( !checkMarginToCircle( startPoint, distToLine, m_segmLength ) )
+            return false;
+
+        // testing the right bottom corner of the rectangle
+        startPoint.x = m_padToTestPos.x + padHalfsize.x;
+        startPoint.y = m_padToTestPos.y + padHalfsize.y;
+        RotatePoint( &startPoint, m_padToTestPos, orient );
+        RotatePoint( &startPoint, m_segmAngle );
+
+        if( !checkMarginToCircle( startPoint, distToLine, m_segmLength ) )
+            return false;
+
+        break;
+
+    case PAD_SHAPE_TRAPEZOID:
+    {
+        wxPoint poly[4];
+        aPad->BuildPadPolygon( poly, wxSize( 0, 0 ), orient );
+
+        // Move shape to m_padToTestPos
+        for( int ii = 0; ii < 4; ii++ )
+        {
+            poly[ii] += m_padToTestPos;
+            RotatePoint( &poly[ii], m_segmAngle );
+        }
+
+        if( !trapezoid2segmentDRC( poly, wxPoint( 0, 0 ), wxPoint(m_segmLength,0), distToLine ) )
+            return false;
+    }
+    break;
+    }
+
+    return true;
+}
+
+
+/**
+ * Helper function checkMarginToCircle
+ * Check the distance between a circle (round pad, via or round end of track)
+ * and a segment. the segment is expected starting at 0,0, and on the X axis
+ * return true if distance >= aRadius
+ */
+bool DRC::checkMarginToCircle( wxPoint aCentre, int aRadius, int aLength )
+{
+    if( abs( aCentre.y ) > aRadius )     // trivial case
+        return true;
+
+    // Here, distance between aCentre and X axis is < aRadius
+    if( (aCentre.x >= -aRadius ) && ( aCentre.x <= (aLength + aRadius) ) )
+    {
+        if( (aCentre.x >= 0) && (aCentre.x <= aLength) )
+            return false;           // aCentre is between the starting point and the ending point of the segm
+
+        if( aCentre.x > aLength )   // aCentre is after the ending point
+            aCentre.x -= aLength;   // move aCentre to the starting point of the segment
+
+        if( EuclideanNorm( aCentre ) < aRadius )
+            // distance between aCentre and the starting point or the ending point is < aRadius
+            return false;
+    }
+
+    return true;
+}
+
+
+// Helper function used in checkLine::
+static inline int USCALE( unsigned arg, unsigned num, unsigned den )
+{
+    int ii;
+
+    ii = KiROUND( ( (double) arg * num ) / den );
+    return ii;
+}
+
+
+/** Helper function checkLine
+ * Test if a line intersects a bounding box (a rectangle)
+ * The rectangle is defined by m_xcliplo, m_ycliplo and m_xcliphi, m_ycliphi
+ * return true if the line from aSegStart to aSegEnd is outside the bounding box
+ */
+bool DRC::checkLine( wxPoint aSegStart, wxPoint aSegEnd )
+{
+#define WHEN_OUTSIDE return true
+#define WHEN_INSIDE
+    int temp;
+
+    if( aSegStart.x > aSegEnd.x )
+        std::swap( aSegStart, aSegEnd );
+
+    if( (aSegEnd.x < m_xcliplo) || (aSegStart.x > m_xcliphi) )
+    {
+        WHEN_OUTSIDE;
+    }
+
+    if( aSegStart.y < aSegEnd.y )
+    {
+        if( (aSegEnd.y < m_ycliplo) || (aSegStart.y > m_ycliphi) )
+        {
+            WHEN_OUTSIDE;
+        }
+
+        if( aSegStart.y < m_ycliplo )
+        {
+            temp = USCALE( (aSegEnd.x - aSegStart.x), (m_ycliplo - aSegStart.y),
+                           (aSegEnd.y - aSegStart.y) );
+
+            if( (aSegStart.x += temp) > m_xcliphi )
+            {
+                WHEN_OUTSIDE;
+            }
+
+            aSegStart.y = m_ycliplo;
+            WHEN_INSIDE;
+        }
+
+        if( aSegEnd.y > m_ycliphi )
+        {
+            temp = USCALE( (aSegEnd.x - aSegStart.x), (aSegEnd.y - m_ycliphi),
+                           (aSegEnd.y - aSegStart.y) );
+
+            if( (aSegEnd.x -= temp) < m_xcliplo )
+            {
+                WHEN_OUTSIDE;
+            }
+
+            aSegEnd.y = m_ycliphi;
+            WHEN_INSIDE;
+        }
+
+        if( aSegStart.x < m_xcliplo )
+        {
+            temp = USCALE( (aSegEnd.y - aSegStart.y), (m_xcliplo - aSegStart.x),
+                           (aSegEnd.x - aSegStart.x) );
+            aSegStart.y += temp;
+            aSegStart.x  = m_xcliplo;
+            WHEN_INSIDE;
+        }
+
+        if( aSegEnd.x > m_xcliphi )
+        {
+            temp = USCALE( (aSegEnd.y - aSegStart.y), (aSegEnd.x - m_xcliphi),
+                           (aSegEnd.x - aSegStart.x) );
+            aSegEnd.y -= temp;
+            aSegEnd.x  = m_xcliphi;
+            WHEN_INSIDE;
+        }
+    }
+    else
+    {
+        if( (aSegStart.y < m_ycliplo) || (aSegEnd.y > m_ycliphi) )
+        {
+            WHEN_OUTSIDE;
+        }
+
+        if( aSegStart.y > m_ycliphi )
+        {
+            temp = USCALE( (aSegEnd.x - aSegStart.x), (aSegStart.y - m_ycliphi),
+                           (aSegStart.y - aSegEnd.y) );
+
+            if( (aSegStart.x += temp) > m_xcliphi )
+            {
+                WHEN_OUTSIDE;
+            }
+
+            aSegStart.y = m_ycliphi;
+            WHEN_INSIDE;
+        }
+
+        if( aSegEnd.y < m_ycliplo )
+        {
+            temp = USCALE( (aSegEnd.x - aSegStart.x), (m_ycliplo - aSegEnd.y),
+                           (aSegStart.y - aSegEnd.y) );
+
+            if( (aSegEnd.x -= temp) < m_xcliplo )
+            {
+                WHEN_OUTSIDE;
+            }
+
+            aSegEnd.y = m_ycliplo;
+            WHEN_INSIDE;
+        }
+
+        if( aSegStart.x < m_xcliplo )
+        {
+            temp = USCALE( (aSegStart.y - aSegEnd.y), (m_xcliplo - aSegStart.x),
+                           (aSegEnd.x - aSegStart.x) );
+            aSegStart.y -= temp;
+            aSegStart.x  = m_xcliplo;
+            WHEN_INSIDE;
+        }
+
+        if( aSegEnd.x > m_xcliphi )
+        {
+            temp = USCALE( (aSegStart.y - aSegEnd.y), (aSegEnd.x - m_xcliphi),
+                           (aSegEnd.x - aSegStart.x) );
+            aSegEnd.y += temp;
+            aSegEnd.x  = m_xcliphi;
+            WHEN_INSIDE;
+        }
+    }
+
+    if( ( (aSegEnd.x + aSegStart.x) / 2 <= m_xcliphi )
+       && ( (aSegEnd.x + aSegStart.x) / 2 >= m_xcliplo ) \
+       && ( (aSegEnd.y + aSegStart.y) / 2 <= m_ycliphi )
+       && ( (aSegEnd.y + aSegStart.y) / 2 >= m_ycliplo ) )
+    {
+        return false;
+    }
+    else
+    {
+        return true;
+    }
+}