TRACK* GetTrack( TRACK* aStartTrace, const TRACK* aEndTrace,
        const wxPoint& aPosition, LAYER_MSK aLayerMask )
{
    for( TRACK *PtSegm = aStartTrace; PtSegm != NULL; PtSegm = PtSegm->Next() )
    {
        if( PtSegm->GetState( IS_DELETED | BUSY ) == 0 )
        {
            if( aPosition == PtSegm->GetStart() )
            {
                if( aLayerMask & PtSegm->GetLayerMask() )
                    return PtSegm;
            }

            if( aPosition == PtSegm->GetEnd() )
            {
                if( aLayerMask & PtSegm->GetLayerMask() )
                    return PtSegm;
            }
        }

        if( PtSegm == aEndTrace )
            break;
    }

    return NULL;
}
TRACK* TRACK::GetTrack( TRACK* aStartTrace, TRACK* aEndTrace, ENDPOINT_T aEndPoint,
        bool aSameNetOnly, bool aSequential )
{
    const wxPoint &position = GetEndPoint( aEndPoint );
    LAYER_MSK refLayers = GetLayerMask();
    TRACK *previousSegment;
    TRACK *nextSegment;

    if( aSequential )
    {
        // Simple sequential search: from aStartTrace forward to aEndTrace
        previousSegment = NULL;
        nextSegment = aStartTrace;
    }
    else
    {
        /* Local bidirectional search: from this backward to aStartTrace
         * AND forward to aEndTrace. The idea is that nearest segments
         * are found (on average) faster in this way. In fact same-net
         * segments are almost guaranteed to be found faster, in a global
         * search, since they are grouped together in the track list */
        previousSegment = this;
        nextSegment = this;
    }

    while( nextSegment || previousSegment )
    {
        // Terminate the search in the direction if the netcode mismatches
        if( aSameNetOnly )
        {
            if( nextSegment && (nextSegment->GetNetCode() != GetNetCode()) )
                nextSegment = NULL;
            if( previousSegment && (previousSegment->GetNetCode() != GetNetCode()) )
                previousSegment = NULL;
        }

        if( nextSegment )
        {
            if ( (nextSegment != this) &&
                 !nextSegment->GetState( BUSY | IS_DELETED ) &&
                 (refLayers & nextSegment->GetLayerMask()) )
            {
                if( (position == nextSegment->m_Start) ||
                    (position == nextSegment->m_End) )
                    return nextSegment;
            }

            // Keep looking forward
            if( nextSegment == aEndTrace )
                nextSegment = NULL;
            else
                nextSegment = nextSegment->Next();
        }

        // Same as above, looking back. During sequential search this branch is inactive
        if( previousSegment )
        {
            if ( (previousSegment != this) &&
                 !previousSegment->GetState( BUSY | IS_DELETED ) &&
                 (refLayers & previousSegment->GetLayerMask()) )
            {
                if( (position == previousSegment->m_Start) ||
                    (position == previousSegment->m_End) )
                    return previousSegment;
            }

            if( previousSegment == aStartTrace )
                previousSegment = NULL;
            else
                previousSegment = previousSegment->Back();
        }
    }

    return NULL;
}
bool DRC::doTrackDrc( TRACK* aRefSeg, TRACK* aStart, bool testPads )
{
    TRACK*    track;
    wxPoint   delta;           // lenght on X and Y axis of segments
    LAYER_MSK layerMask;
    int       net_code_ref;
    wxPoint   shape_pos;

    NETCLASS* netclass = aRefSeg->GetNetClass();

    /* 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->GetLayerMask();
    net_code_ref = aRefSeg->GetNetCode();

    // Phase 0 : Test vias
    if( aRefSeg->Type() == PCB_VIA_T )
    {
        // test if the via size is smaller than minimum
        if( aRefSeg->GetShape() == VIA_MICROVIA )
        {
            if( aRefSeg->GetWidth() < netclass->GetuViaMinDiameter() )
            {
                m_currentMarker = fillMarker( aRefSeg, NULL,
                                              DRCE_TOO_SMALL_MICROVIA, m_currentMarker );
                return false;
            }
        }
        else
        {
            if( aRefSeg->GetWidth() < netclass->GetViaMinDiameter() )
            {
                m_currentMarker = fillMarker( aRefSeg, 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( aRefSeg->GetDrillValue() > aRefSeg->GetWidth() )
        {
            m_currentMarker = fillMarker( aRefSeg, 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( aRefSeg->GetShape() == VIA_MICROVIA )
        {
            LAYER_NUM layer1, layer2;
            bool err = true;

            ( (SEGVIA*) aRefSeg )->LayerPair( &layer1, &layer2 );

            if( layer1 > layer2 )
                EXCHG( layer1, layer2 );

            // test:
            if( layer1 == LAYER_N_BACK && layer2 == LAYER_N_2 )
                err = false;

            if( layer1 == (m_pcb->GetDesignSettings().GetCopperLayerCount() - 2 )
                && layer2 == LAYER_N_FRONT )
                err = false;

            if( err )
            {
                m_currentMarker = fillMarker( aRefSeg, NULL,
                                              DRCE_MICRO_VIA_INCORRECT_LAYER_PAIR, m_currentMarker );
                return false;
            }
        }
    }
    else    // This is a track segment
    {
        if( aRefSeg->GetWidth() < netclass->GetTrackMinWidth() )
        {
            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.SetLayerMask( ALL_CU_LAYERS );     // Ensure the hole is on all layers

    // Compute the min distance to pads
    if( testPads )
    {
        for( unsigned ii = 0;  ii<m_pcb->GetPadCount();  ++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->GetLayerMask() & layerMask ) == 0 )
            {
                /* 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_OBLONG ?
                                   PAD_OVAL : PAD_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->GetLayerMask() ) == 0 )
            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 )
                EXCHG( 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 )
                EXCHG( 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;
}