seg.h

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2013 CERN
 * Copyright (C) 2021 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * @author Tomasz Wlostowski <[email protected]>
 *
 * 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
 */
 
#ifndef __SEG_H
#define __SEG_H
 
#include <math.h>                       // for sqrt
#include <stdlib.h>                     // for abs
#include <optional>
#include <ostream>                      // for operator<<, ostream, basic_os...
#include <type_traits>                  // for swap
 
#include <math/vector2d.h>
#include <geometry/eda_angle.h>
 
typedef std::optional<VECTOR2I> OPT_VECTOR2I;
 
class SEG
{
public:
    using ecoord = VECTOR2I::extended_type;
    friend inline std::ostream& operator<<( std::ostream& aStream, const SEG& aSeg );
 
    /* Start and the of the segment. Public, to make access simpler.
     */
    VECTOR2I A;
    VECTOR2I B;
 
    SEG()
    {
        m_index = -1;
    }
 
    SEG( int aX1, int aY1, int aX2, int aY2 ) :
        A( VECTOR2I( aX1, aY1 ) ),
        B( VECTOR2I( aX2, aY2 ) )
    {
        m_index = -1;
    }
 
    SEG( const VECTOR2I& aA, const VECTOR2I& aB ) :
        A( aA ),
        B( aB )
    {
        m_index = -1;
    }
 
    SEG( const VECTOR2I& aA, const VECTOR2I& aB, int aIndex ) :
        A( aA ),
        B( aB )
    {
        m_index = aIndex;
    }
 
    SEG( const SEG& aSeg ) :
        A( aSeg.A ),
        B( aSeg.B ),
        m_index( aSeg.m_index )
    {
    }
 
    SEG& operator=( const SEG& aSeg )
    {
        A = aSeg.A;
        B = aSeg.B;
        m_index = aSeg.m_index;
 
        return *this;
    }
 
    bool operator==( const SEG& aSeg ) const
    {
        return (A == aSeg.A && B == aSeg.B) ;
    }
 
    bool operator!=( const SEG& aSeg ) const
    {
        return (A != aSeg.A || B != aSeg.B);
    }
 
    static SEG::ecoord Square( int a )
    {
        return ecoord( a ) * a;
    }
 
    VECTOR2I LineProject( const VECTOR2I& aP ) const;
 
    int Side( const VECTOR2I& aP ) const
    {
        const ecoord det = ( B - A ).Cross( aP - A );
 
        return det < 0 ? -1 : ( det > 0 ? 1 : 0 );
    }
 
    int LineDistance( const VECTOR2I& aP, bool aDetermineSide = false ) const;
 
    EDA_ANGLE Angle( const SEG& aOther ) const;
 
    const VECTOR2I NearestPoint( const VECTOR2I& aP ) const;
 
    const VECTOR2I NearestPoint( const SEG &aSeg ) const;
 
    bool NearestPoints( const SEG& aSeg, VECTOR2I& aPtA, VECTOR2I& aPtB, int64_t& aDistSq ) const;
 
    const VECTOR2I ReflectPoint( const VECTOR2I& aP ) const;
 
    OPT_VECTOR2I Intersect( const SEG& aSeg, bool aIgnoreEndpoints = false,
                            bool aLines = false ) const;
 
    bool Intersects( const SEG& aSeg ) const;
 
    OPT_VECTOR2I IntersectLines( const SEG& aSeg ) const
    {
        return Intersect( aSeg, false, true );
    }
 
    SEG PerpendicularSeg( const VECTOR2I& aP ) const;
 
    SEG ParallelSeg( const VECTOR2I& aP ) const;
 
    bool Collide( const SEG& aSeg, int aClearance, int* aActual = nullptr ) const;
 
    ecoord SquaredDistance( const SEG& aSeg ) const;
 
    int Distance( const SEG& aSeg ) const;
 
    ecoord SquaredDistance( const VECTOR2I& aP ) const;
 
    int Distance( const VECTOR2I& aP ) const;
 
    void CanonicalCoefs( ecoord& qA, ecoord& qB, ecoord& qC ) const
    {
        qA = ecoord{ A.y } - B.y;
        qB = ecoord{ B.x } - A.x;
        qC = -qA * A.x - qB * A.y;
    }
 
    bool Collinear( const SEG& aSeg ) const
    {
        ecoord qa, qb, qc;
        CanonicalCoefs( qa, qb, qc );
 
        ecoord d1 = std::abs( aSeg.A.x * qa + aSeg.A.y * qb + qc );
        ecoord d2 = std::abs( aSeg.B.x * qa + aSeg.B.y * qb + qc );
 
        return ( d1 <= 1 && d2 <= 1 );
    }
 
    bool ApproxCollinear( const SEG& aSeg, int aDistanceThreshold = 1 ) const;
    bool ApproxParallel( const SEG& aSeg, int aDistanceThreshold = 1 ) const;
    bool ApproxPerpendicular( const SEG& aSeg ) const;
 
    bool Overlaps( const SEG& aSeg ) const
    {
        if( aSeg.A == aSeg.B ) // single point corner case
        {
            if( A == aSeg.A || B == aSeg.A )
                return false;
 
            return Contains( aSeg.A );
        }
 
        if( !Collinear( aSeg ) )
            return false;
 
        if( Contains( aSeg.A ) || Contains( aSeg.B ) )
            return true;
 
        if( aSeg.Contains( A ) || aSeg.Contains( B ) )
            return true;
 
        return false;
    }
 
 
    bool Contains( const SEG& aSeg ) const
    {
        if( aSeg.A == aSeg.B ) // single point corner case
            return Contains( aSeg.A );
 
        if( !Collinear( aSeg ) )
            return false;
 
        if( Contains( aSeg.A ) && Contains( aSeg.B ) )
            return true;
 
        return false;
    }
 
    int Length() const
    {
        return ( A - B ).EuclideanNorm();
    }
 
    ecoord SquaredLength() const
    {
        return ( A - B ).SquaredEuclideanNorm();
    }
 
    ecoord TCoef( const VECTOR2I& aP ) const;
 
    int Index() const
    {
        return m_index;
    }
 
    bool Contains( const VECTOR2I& aP ) const;
 
    void Reverse()
    {
        std::swap( A, B );
    }
 
    SEG Reversed() const
    {
        return SEG( B, A );
    }
 
    VECTOR2I Center() const
    {
        return A + ( B - A ) / 2;
    }
 
    bool operator<( const SEG& aSeg ) const
    {
        if( A == aSeg.A )
            return B < aSeg.B;
 
        return A < aSeg.A;
    }
 
private:
    bool ccw( const VECTOR2I& aA, const VECTOR2I& aB, const VECTOR2I &aC ) const;
 
    bool intersects( const SEG& aSeg, bool aIgnoreEndpoints = false, bool aLines = false,
                     VECTOR2I* aPt = nullptr ) const;
 
    bool mutualDistanceSquared( const SEG& aSeg, ecoord& aD1, ecoord& aD2 ) const;
 
private:
    int m_index;
};
 
inline SEG::ecoord SEG::TCoef( const VECTOR2I& aP ) const
{
    VECTOR2I d = B - A;
    return d.Dot( aP - A);
}
 
inline std::ostream& operator<<( std::ostream& aStream, const SEG& aSeg )
{
    aStream << "[ " << aSeg.A << " - " << aSeg.B << " ]";
 
    return aStream;
}
 
#endif // __SEG_H