kicad/pcbnew/router/pns_line.h

/*
 * KiRouter - a push-and-(sometimes-)shove PCB router
 *
 * Copyright (C) 2013-2017 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_LINE_H
#define __PNS_LINE_H

#include <math/box2.h>
#include <math/vector2d.h>

#include <geometry/direction45.h>
#include <geometry/seg.h>
#include <geometry/shape.h>
#include <geometry/shape_line_chain.h>

#include "pns_item.h"
#include "pns_via.h"
#include "pns_link_holder.h"

namespace PNS {

class LINKED_ITEM;
class NODE;
class VIA;

/**
 * LINE
 *
 * Represents a track on a PCB, connecting two non-trivial joints (that is,
 * vias, pads, junctions between multiple traces or two traces different widths
 * and combinations of these). PNS_LINEs are NOT stored in the model (NODE).
 * Instead, they are assembled on-the-fly, based on a via/pad/segment that
 * belongs to/starts/ends them.
 *
 * PNS_LINEs can be either loose (consisting of segments that do not belong to
 * any NODE) or owned (with segments taken from a NODE) - these are
 * returned by NODE::AssembleLine and friends.
 *
 * A LINE may have a VIA attached at its end (i.e. the last point) - this is used by via
 * dragging/force propagation stuff.
 */

#define PNS_HULL_MARGIN 10

class LINE : public LINK_HOLDER
{
public:

    /**
     * Constructor
     * Makes an empty line.
     */
    LINE() : LINK_HOLDER( LINE_T )
    {
        m_hasVia = false;
        m_width = 1;        // Dummy value
        m_snapThreshhold = 0;
    }

    LINE( const LINE& aOther );

    /**
     * Constructor
     * Copies properties (net, layers, etc.) from a base line and replaces the shape
     * by another
     **/
    LINE( const LINE& aBase, const SHAPE_LINE_CHAIN& aLine )
            : LINK_HOLDER( aBase ),
              m_line( aLine ),
              m_width( aBase.m_width ),
              m_snapThreshhold( aBase.m_snapThreshhold )
    {
        m_net = aBase.m_net;
        m_layers = aBase.m_layers;
        m_hasVia = false;
    }

    /**
     * Constructor
     * Constructs a LINE for a lone VIA (ie a stitching via).
     * @param aVia
     */
    LINE( const VIA& aVia ) :
        LINK_HOLDER( LINE_T )
    {
        m_hasVia = true;
        m_via = aVia;
        m_width = aVia.Diameter();
        m_net = aVia.Net();
        m_layers = aVia.Layers();
        m_rank = aVia.Rank();
        m_snapThreshhold = 0;
    }

    ~LINE();

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

    /// @copydoc ITEM::Clone()
    virtual LINE* Clone() const override;

    LINE& operator=( const LINE& aOther );

    bool IsLinkedChecked() const
    {
        return IsLinked() && LinkCount() == SegmentCount();
    }

    ///> Assigns a shape to the line (a polyline/line chain)
    void SetShape( const SHAPE_LINE_CHAIN& aLine )
    {
        m_line = aLine;
        m_line.SetWidth( m_width );
    }

    ///> Returns the shape of the line
    const SHAPE* Shape() const override
    {
        return &m_line;
    }

    ///> Modifiable accessor to the underlying shape
    SHAPE_LINE_CHAIN& Line()
    {
        return m_line;
    }

    ///> Const accessor to the underlying shape
    const SHAPE_LINE_CHAIN& CLine() const
    {
        return m_line;
    }

    ///> Returns the number of segments in the line
    int SegmentCount() const
    {
        return m_line.SegmentCount();
    }

    ///> Returns the number of points in the line
    int PointCount() const
    {
        return m_line.PointCount();
    }

    ///> Returns the number of arcs in the line
    int ArcCount() const
    {
        return m_line.ArcCount();
    }

    ///> Returns the aIdx-th point of the line
    const VECTOR2I& CPoint( int aIdx ) const
    {
        return m_line.CPoint( aIdx );
    }

    ///> Returns the aIdx-th segment of the line
    const SEG CSegment( int aIdx ) const
    {
        return m_line.CSegment( aIdx );
    }

    ///> Sets line width
    void SetWidth( int aWidth )
    {
        m_width = aWidth;
        m_line.SetWidth( aWidth );
    }

    ///> Returns line width
    int Width() const
    {
        return m_width;
    }

    ///> Returns true if the line is geometrically identical as line aOther
    bool CompareGeometry( const LINE& aOther );

    ///> Reverses the point/vertex order
    void Reverse();

    ///> Clips the line to the nearest obstacle, traversing from the line's start vertex (0).
    ///> Returns the clipped line.
    const LINE ClipToNearestObstacle( NODE* aNode ) const;

    ///> Clips the line to a given range of vertices.
    void ClipVertexRange ( int aStart, int aEnd );

    ///> Returns the number of corners of angles specified by mask aAngles.
    int CountCorners( int aAngles ) const;

    ///> Calculates a line thightly wrapping a convex hull
    ///> of an obstacle object (aObstacle).
    ///> aPrePath = path from origin to the obstacle
    ///> aWalkaroundPath = path around the obstacle
    ///> aPostPath = past from obstacle till the end
    ///> aCW = whether to walk around in clockwise or counter-clockwise direction.
    bool Walkaround( SHAPE_LINE_CHAIN aObstacle,
            SHAPE_LINE_CHAIN& aPre,
            SHAPE_LINE_CHAIN& aWalk,
            SHAPE_LINE_CHAIN& aPost,
            bool aCw ) const;

    bool Walkaround( const SHAPE_LINE_CHAIN& aObstacle,
            SHAPE_LINE_CHAIN& aPath,
            bool aCw ) const;

    bool Is45Degree() const;

    ///> Prints out all linked segments
    void ShowLinks() const;

    bool EndsWithVia() const { return m_hasVia; }

    void AppendVia( const VIA& aVia );
    void RemoveVia() { m_hasVia = false; }

    const VIA& Via() const { return m_via; }

    virtual void Mark( int aMarker ) const override;
    virtual void Unmark( int aMarker = -1 ) const override;
    virtual int Marker() const override;

    void DragSegment( const VECTOR2I& aP, int aIndex, bool aFreeAngle = false );
    void DragCorner( const VECTOR2I& aP, int aIndex, bool aFreeAngle = false );

    void SetRank( int aRank ) override;
    int Rank() const override;

    bool HasLoops() const;
    bool HasLockedSegments() const;

    void Clear();
    void Merge ( const LINE& aOther );

    OPT_BOX2I ChangedArea( const LINE* aOther ) const;

    void SetSnapThreshhold( int aThreshhold )
    {
        m_snapThreshhold = aThreshhold;
    }

    int GetSnapThreshhold() const
    {
        return m_snapThreshhold;
    }

private:
    void dragSegment45( const VECTOR2I& aP, int aIndex );
    void dragCorner45( const VECTOR2I& aP, int aIndex );
    void dragSegmentFree( const VECTOR2I& aP, int aIndex );
    void dragCornerFree( const VECTOR2I& aP, int aIndex );

    VECTOR2I snapToNeighbourSegments(
            const SHAPE_LINE_CHAIN& aPath, const VECTOR2I& aP, int aIndex ) const;

    VECTOR2I snapDraggedCorner(
            const SHAPE_LINE_CHAIN& aPath, const VECTOR2I& aP, int aIndex ) const;

    ///> The actual shape of the line
    SHAPE_LINE_CHAIN m_line;

    ///> our width
    int m_width;

    ///> If true, the line ends with a via
    bool m_hasVia;

    ///> Width to smooth out jagged segments
    int m_snapThreshhold;

    ///> Via at the end point, if m_hasVia == true
    VIA m_via;
};

}

#endif    // __PNS_LINE_H