kicad/pcbnew/router/pns_diff_pair.h

/*
 * KiRouter - a push-and-(sometimes-)shove PCB router
 *
 * Copyright (C) 2013-2015 CERN
 * Copyright (C) 2016 KiCad Developers, see AUTHORS.txt for contributors.
 * Author: Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */


#ifndef __PNS_DIFF_PAIR_H
#define __PNS_DIFF_PAIR_H

#include <vector>

#include <geometry/shape.h>
#include <geometry/shape_line_chain.h>

#include "pns_line.h"
#include "pns_via.h"
#include "pns_link_holder.h"

#include "ranged_num.h"

namespace PNS {

class DIFF_PAIR;

/**
 * DP_GATEWAY
 *
 * Defines a "gateway" for routing a differential pair - e.g. a pair of points (anchors) with certain
 * orientation, spacing and (optionally) predefined entry paths. The routing algorithm connects such
 * gateways with parallel lines, thus creating a difrerential pair.
 **/
class DP_GATEWAY {
public:
    DP_GATEWAY( const VECTOR2I& aAnchorP,
                    const VECTOR2I& aAnchorN,
                    bool aIsDiagonal,
                    int aAllowedEntryAngles = DIRECTION_45::ANG_OBTUSE,
                    int aPriority = 0 )
        : m_anchorP( aAnchorP ),
          m_anchorN( aAnchorN ),
          m_isDiagonal( aIsDiagonal ),
          m_allowedEntryAngles( aAllowedEntryAngles ),
          m_priority( aPriority )
    {
        m_hasEntryLines = false;
    }

    ~DP_GATEWAY()
    {
    }

    /**
     * Function IsDiagonal()
     *
     * @return true, if the gateway anchors lie on a diagonal line
     */
    bool IsDiagonal() const
    {
        return m_isDiagonal;
    }

    const VECTOR2I& AnchorP() const { return m_anchorP; }

    const VECTOR2I& AnchorN() const { return m_anchorN; }

    /**
     * Function AllowedAngles()
     *
     * @return a mask of 45-degree entry directoins allowed for the
     * gateway.
    */
    int AllowedAngles () const { return m_allowedEntryAngles; }

    /**
     * Function Priority()
     *
     * @return priority/score value for gateway matching
     */
    int Priority() const
    {
        return m_priority;
    }

    void SetPriority(int aPriority)
    {
        m_priority = aPriority;
    }

    void SetEntryLines( const SHAPE_LINE_CHAIN& aEntryP, const SHAPE_LINE_CHAIN& aEntryN )
    {
        m_entryP = aEntryP;
        m_entryN = aEntryN;
        m_hasEntryLines = true;
    }

    const SHAPE_LINE_CHAIN& EntryP() const { return m_entryP; }
    const SHAPE_LINE_CHAIN& EntryN() const { return m_entryN; }
    const DIFF_PAIR Entry() const ;

    void Reverse();

    bool HasEntryLines () const
    {
        return m_hasEntryLines;
    }

private:
    SHAPE_LINE_CHAIN m_entryP, m_entryN;
    bool m_hasEntryLines;
    VECTOR2I m_anchorP, m_anchorN;
    bool m_isDiagonal;
    int m_allowedEntryAngles;
    int m_priority;
};

/**
 * DP_PRIMITIVE_PAIR
 *
 * Stores staring/ending primitives (pads, vias or segments) for a differential pair.
 **/
class DP_PRIMITIVE_PAIR
{
public:
    DP_PRIMITIVE_PAIR():
        m_primP( NULL ), m_primN( NULL ) {};

    DP_PRIMITIVE_PAIR( const DP_PRIMITIVE_PAIR& aOther );
    DP_PRIMITIVE_PAIR( ITEM* aPrimP, ITEM* aPrimN );
    DP_PRIMITIVE_PAIR( const VECTOR2I& aAnchorP, const VECTOR2I& aAnchorN );

    ~DP_PRIMITIVE_PAIR();

    void SetAnchors( const VECTOR2I& aAnchorP, const VECTOR2I& aAnchorN );

    const VECTOR2I& AnchorP() const { return m_anchorP; }
    const VECTOR2I& AnchorN() const { return m_anchorN; }

    DP_PRIMITIVE_PAIR& operator=( const DP_PRIMITIVE_PAIR& aOther );

    ITEM* PrimP() const { return m_primP; }
    ITEM* PrimN() const { return m_primN; }

    bool Directional() const;

    DIRECTION_45 DirP() const;
    DIRECTION_45 DirN() const;


    void CursorOrientation( const VECTOR2I& aCursorPos, VECTOR2I& aMidpoint, VECTOR2I& aDirection ) const;

    void dump()
    {
        printf( "-- Prim-P %p anchor [%d, %d]\n", m_primP, m_anchorP.x, m_anchorP.y );
        printf( "-- Prim-N %p anchor [%d, %d]\n", m_primN, m_anchorN.x, m_anchorN.y );
    }

private:
    DIRECTION_45 anchorDirection( const ITEM* aItem, const VECTOR2I& aP ) const;

    ITEM* m_primP;
    ITEM* m_primN;
    VECTOR2I m_anchorP, m_anchorN;
};

/**
 * DP_GATEWAYS
 *
 * A set of gateways calculated for the cursor or starting/ending primitive pair.
 **/

class DP_GATEWAYS
{
    public:
        DP_GATEWAYS( int aGap ):
            m_gap( aGap ), m_viaGap( aGap )
        {
            // Do not leave unitialized members, and keep static analyser quiet:
            m_viaDiameter = 0;
            m_fitVias = true;
        }

        void SetGap( int aGap )
        {
            m_gap = aGap;
            m_viaGap = aGap;
        }

        void Clear()
        {
            m_gateways.clear();
        }

        void SetFitVias( bool aEnable, int aDiameter = 0, int aViaGap = -1 )
        {
            m_fitVias = aEnable;
            m_viaDiameter = aDiameter;
            if(aViaGap < 0)
                m_viaGap = m_gap;
            else
                m_viaGap = aViaGap;
        }


        void BuildForCursor( const VECTOR2I& aCursorPos );
        void BuildOrthoProjections( DP_GATEWAYS &aEntries, const VECTOR2I& aCursorPos, int aOrthoScore );
        void BuildGeneric( const VECTOR2I& p0_p, const VECTOR2I& p0_n, bool aBuildEntries = false, bool aViaMode = false );
        void BuildFromPrimitivePair( const DP_PRIMITIVE_PAIR& aPair, bool aPreferDiagonal );

        bool FitGateways( DP_GATEWAYS& aEntry, DP_GATEWAYS& aTarget, bool aPrefDiagonal, DIFF_PAIR& aDp );

        std::vector<DP_GATEWAY>& Gateways()
        {
            return m_gateways;
        }

        const std::vector<DP_GATEWAY>& CGateways() const
        {
            return m_gateways;
        }

        void FilterByOrientation( int aAngleMask, DIRECTION_45 aRefOrientation );

    private:
        struct DP_CANDIDATE
        {
            SHAPE_LINE_CHAIN p, n;
            VECTOR2I gw_p, gw_n;
            int score;
        };

        bool checkDiagonalAlignment( const VECTOR2I& a, const VECTOR2I& b ) const;
        void buildDpContinuation( const DP_PRIMITIVE_PAIR& aPair, bool aIsDiagonal );
        void buildEntries( const VECTOR2I& p0_p, const VECTOR2I& p0_n );

        int m_gap;
        int m_viaGap;
        int m_viaDiameter;
        bool m_fitVias;

        std::vector<DP_GATEWAY> m_gateways;
};


/**
 * DIFF_PAIR
 *
 * Basic class for a differential pair. Stores two PNS_LINEs (for positive and negative nets, respectively),
 * the gap and coupling constraints.
 **/
class DIFF_PAIR : public LINK_HOLDER {

public:
    struct COUPLED_SEGMENTS {
        COUPLED_SEGMENTS ( const SEG& aCoupledP, const SEG& aParentP, int aIndexP,
                           const SEG& aCoupledN, const SEG& aParentN, int aIndexN ) :
            coupledP( aCoupledP ),
            coupledN( aCoupledN ),
            parentP( aParentP ),
            parentN( aParentN ),
            indexP( aIndexP ),
            indexN( aIndexN )
        {}

        SEG coupledP;
        SEG coupledN;
        SEG parentP;
        SEG parentN;
        int indexP;
        int indexN;
    };

    typedef std::vector<COUPLED_SEGMENTS> COUPLED_SEGMENTS_VEC;

    DIFF_PAIR() : LINK_HOLDER( ITEM::DIFF_PAIR_T ), m_hasVias( false )
    {
        // Initialize some members, to avoid uninitialized variables.
        m_net_p = 0;
        m_net_n = 0;;
        m_width = 0;
        m_gap = 0;
        m_viaGap = 0;
        m_maxUncoupledLength = 0;
        m_chamferLimit = 0;
    }

    DIFF_PAIR( int aGap ) :
        LINK_HOLDER( ITEM::DIFF_PAIR_T ),
        m_hasVias( false )
    {
        m_gapConstraint = aGap;

        // Initialize other members, to avoid uninitialized variables.
        m_net_p = 0;
        m_net_n = 0;;
        m_width = 0;
        m_gap = 0;
        m_viaGap = 0;
        m_maxUncoupledLength = 0;
        m_chamferLimit = 0;
    }

    DIFF_PAIR( const SHAPE_LINE_CHAIN &aP, const SHAPE_LINE_CHAIN& aN, int aGap = 0 ):
        LINK_HOLDER( ITEM::DIFF_PAIR_T ),
        m_n( aN ),
        m_p( aP ),
        m_hasVias( false )
    {
        m_gapConstraint = aGap;

        // Initialize other members, to avoid uninitialized variables.
        m_net_p = 0;
        m_net_n = 0;;
        m_width = 0;
        m_gap = 0;
        m_viaGap = 0;
        m_maxUncoupledLength = 0;
        m_chamferLimit = 0;
    }

    DIFF_PAIR( const LINE &aLineP, const LINE &aLineN, int aGap = 0 ):
        LINK_HOLDER( ITEM::DIFF_PAIR_T ),
        m_line_p( aLineP ),
        m_line_n( aLineN ),
        m_hasVias( false )
    {
        m_gapConstraint = aGap;
        m_net_p = aLineP.Net();
        m_net_n = aLineN.Net();
        m_p = aLineP.CLine();
        m_n = aLineN.CLine();

        // Do not leave unitialized members, and keep static analyser quiet:
        m_width  = 0;
        m_gap  = 0;
        m_viaGap  = 0;
        m_maxUncoupledLength  = 0;
        m_chamferLimit  = 0;
    }

    static inline bool ClassOf( const ITEM* aItem )
    {
        return aItem && ITEM::DIFF_PAIR_T == aItem->Kind();
    }

    DIFF_PAIR* Clone() const override { assert( false ); return NULL; }

    virtual void ClearLinks() override
    {
        m_links.clear();
        m_line_p.ClearLinks();
        m_line_n.ClearLinks();
    }

    static DIFF_PAIR* AssembleDp( LINE *aLine );

    void SetShape( const SHAPE_LINE_CHAIN &aP, const SHAPE_LINE_CHAIN& aN, bool aSwapLanes = false )
    {
        if( aSwapLanes )
        {
            m_p = aN;
            m_n = aP;
        }
        else
        {
            m_p = aP;
            m_n = aN;
        }
    }

    void SetShape( const DIFF_PAIR& aPair )
    {
        m_p = aPair.m_p;
        m_n = aPair.m_n;
    }

    void SetNets( int aP, int aN )
    {
        m_net_p = aP;
        m_net_n = aN;
    }

    void SetWidth( int aWidth )
    {
        m_width = aWidth;
    }

    int Width() const { return m_width; }

    void SetGap( int aGap )
    {
        m_gap = aGap;
        m_gapConstraint = RANGED_NUM<int>( m_gap, 10000, 10000 );
    }

    int Gap() const
    {
        return m_gap;
    }

    void AppendVias( const VIA &aViaP, const VIA& aViaN )
    {
        m_hasVias = true;
        m_via_p = aViaP;
        m_via_n = aViaN;
    }

    void RemoveVias()
    {
        m_hasVias = false;
    }

    bool EndsWithVias() const
    {
        return m_hasVias;
    }

    int NetP() const
    {
        return m_net_p;
    }

    int NetN() const
    {
        return m_net_n;
    }

    LINE& PLine()
    {
        if( !m_line_p.IsLinked() )
            updateLine( m_line_p, m_p, m_net_p, m_via_p );

        return m_line_p;
    }

    LINE& NLine()
    {
        if( !m_line_n.IsLinked() )
            updateLine( m_line_n, m_n, m_net_n, m_via_n );

        return m_line_n;
    }

    DP_PRIMITIVE_PAIR EndingPrimitives();

    double CoupledLength() const;
    double TotalLength() const;
    double CoupledLengthFactor() const;
    double Skew() const;

    void CoupledSegmentPairs( COUPLED_SEGMENTS_VEC& aPairs ) const;

    void Clear()
    {
        m_n.Clear();
        m_p.Clear();
    }

    void Append( const DIFF_PAIR& aOther )
    {
        m_n.Append( aOther.m_n );
        m_p.Append( aOther.m_p );
    }

    bool Empty() const
    {
        return ( m_n.SegmentCount() == 0 ) || ( m_p.SegmentCount() == 0 );
    }

    const SHAPE_LINE_CHAIN& CP() const { return m_p; }
    const SHAPE_LINE_CHAIN& CN() const { return m_n; }

    bool BuildInitial( const DP_GATEWAY& aEntry, const DP_GATEWAY& aTarget, bool aPrefDiagonal );
    bool CheckConnectionAngle( const DIFF_PAIR &aOther, int allowedAngles ) const;
    int CoupledLength( const SEG& aP, const SEG& aN ) const;

    int64_t CoupledLength( const SHAPE_LINE_CHAIN& aP, const SHAPE_LINE_CHAIN& aN ) const;

    const RANGED_NUM<int> GapConstraint() const
    {
        return m_gapConstraint;
    }

private:
    void updateLine( LINE &aLine, const SHAPE_LINE_CHAIN& aShape, int aNet, const VIA& aVia )
    {
        aLine.SetShape( aShape );
        aLine.SetWidth( m_width );
        aLine.SetNet( aNet );
        aLine.SetLayer( Layers().Start() );

        if( m_hasVias )
            aLine.AppendVia( aVia );
    }

    SHAPE_LINE_CHAIN m_n, m_p;
    LINE m_line_p, m_line_n;
    VIA m_via_p, m_via_n;

    bool m_hasVias;
    int m_net_p, m_net_n;
    int m_width;
    int m_gap;
    int m_viaGap;
    int m_maxUncoupledLength;
    int m_chamferLimit;
    RANGED_NUM<int> m_gapConstraint;
};

}

#endif