triangle2D.H

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/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | www.openfoam.com
     \\/     M anipulation  |
-------------------------------------------------------------------------------
    Copyright (C) 2020-2021 OpenCFD Ltd.
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.
 
    OpenFOAM 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.
 
    OpenFOAM 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 OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
Class
    Foam::triangle2D
 
Description
    2-D triangle and queries
 
SourceFiles
    triangle2DI.H
    triangle2D.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef triangle2D_H
#define triangle2D_H
 
#include "vector.H"
#include "vector2D.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                         Class triangle2D Declaration
\*---------------------------------------------------------------------------*/
 
class triangle2D
:
    public FixedList<vector2D, 3>
{
    // Private Data
 
        //- Area
        scalar area_;
 
        //- Helper for intersections
        static FixedList<vector2D, 7> work_;
 
 
public:
 
    static int debug;
 
    //- Relative tolerance
    static scalar relTol;
 
    //- Absolute tolerance
    static scalar absTol;
 
    //- Construct from 3 2-D points
    triangle2D
    (
        const vector2D& a,
        const vector2D& b,
        const vector2D& c,
        const bool orient = false
    );
 
    //- Construct from 3 3-D points and axes
    triangle2D
    (
        const vector& a3d,
        const vector& b3d,
        const vector& c3d,
        const vector& axis1,
        const vector& axis2,
        const bool orient = false
    );
 
 
    // Member Functions
 
        //- Returns:
        //-   1 if points are ordered in anti-clockwise direction
        //-  -1 if points are ordered in clockwise direction
        //-   0 if the triangle  has collapsed to a line
        inline label order() const;
 
        //- Write the triangle in OBJ format
        inline static void writeOBJ
        (
            Ostream& os,
            const triangle2D& tri,
            label offset
        );
 
        //- Return the number of similar points between two triangles
        inline static label nClosePoints
        (
            const triangle2D& triA,
            const triangle2D& triB
        );
 
        //- Return the signed area
        inline static scalar area
        (
            const vector2D& a,
            const vector2D& b,
            const vector2D& c
        );
 
        //- Set the intersection between a line and segment
        //- Return true if lines intersect
        inline static bool lineSegmentIntersectionPoint
        (
            const vector2D& lp1,
            const vector2D& lp2,
            const vector2D& sp1,
            const vector2D& sp2,
            vector2D& intersection
        );
 
        //- Set the intersection between two lines
        //- Return true if lines intersect
        inline static bool lineIntersectionPoint
        (
            const vector2D& a,
            const vector2D& b,
            const vector2D& c,
            const vector2D& d,
            vector2D& intersection
        );
 
        //- Return true if lines ab and cd intersect
        inline static bool lineIntersects
        (
            const vector2D& a,
            const vector2D& b,
            const vector2D& c,
            const vector2D& d
        );
 
        //- Snap [this] triangle's points to those of triB if they are within
        //- absTol
        //  Returns the number of snapped points
        label snapClosePoints(const triangle2D& triB);
 
        //- Return the intersection centre and area
        void interArea
        (
            const triangle2D& triB,
            vector2D& centre,
            scalar& area
        ) const;
 
        //- Return the intersection area
        scalar interArea(const triangle2D& triB) const;
 
        //- Return true if triB overlaps
        bool overlaps(const triangle2D& triB) const;
 
        //- Return the triangle area
        inline scalar area() const noexcept;
 
        //- Return the triangle centre
        inline vector2D centre() const;
 
        //- Return true if tri is within this triangle
        inline bool contains(const triangle2D& tri) const;
 
        //- Return true if triB is the same as this triangle
        inline bool isSame(const triangle2D& triB) const;
 
        //- Return true if t point p is inside this triangle
        inline bool pointInside(const vector2D& p) const;
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#include "triangle2DI.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //