half_line.h

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright The KiCad Developers, see AUTHORS.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, see <https://www.gnu.org/licenses/>.
 */
 
#pragma once
 
#include <optional>
 
#include <geometry/seg.h>
#include <math/box2.h>
 
/*
 * A geometric half-line of infinite length, starting at a given point and extending infinitely.
 * A.k.a. a ray.
 *
 * In terms of geometric ops, a SEG would probably do in most cases, as it
 * has the same definition, but a separate class is more explicit and also
 * allows compile-time reasoning about the meaning of the object through
 * the type system.
 */
class HALF_LINE
{
public:
    HALF_LINE( const SEG& aSeg ) : m_seg( aSeg ) {}
 
    HALF_LINE( const VECTOR2I& aStart, const VECTOR2I& aOtherContainedPoint ) :
            m_seg( aStart, aOtherContainedPoint )
    {
    }

    const VECTOR2I& GetStart() const { return m_seg.A; }

    const VECTOR2I& GetContainedPoint() const { return m_seg.B; }
 
    bool Contains( const VECTOR2I& aPoint ) const;
 
    OPT_VECTOR2I Intersect( const SEG& aSeg ) const;
 
    OPT_VECTOR2I Intersect( const HALF_LINE& aOther ) const;

    VECTOR2I NearestPoint( const VECTOR2I& aPoint ) const;

    bool operator==( const HALF_LINE& aOther ) const { return m_seg == aOther.m_seg; }

    const SEG& GetContainedSeg() const { return m_seg; }
 
private:
    SEG m_seg;
};
 
 
std::optional<SEG> ClipHalfLineToBox( const HALF_LINE& aRay, const BOX2I& aBox );