Angle.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2009-2011  Sandro Santilli <strk@kbt.io>
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU Lesser General Public Licence as published
 * by the Free Software Foundation.
 * See the COPYING file for more information.
 *
 **********************************************************************
 *
 * Last port: algorithm/Angle.java r378 (JTS-1.12)
 *
 **********************************************************************/
 
#pragma once
 
#include <geos/export.h>
#include <geos/algorithm/Orientation.h> // for constants
 
// Forward declarations
namespace geos {
namespace geom {
class Coordinate;
}
}
 
namespace geos {
namespace algorithm { // geos::algorithm
 
//
class GEOS_DLL Angle {
public:
 
    static constexpr double PI_TIMES_2 = 2.0 * MATH_PI;
    static constexpr double PI_OVER_2 = MATH_PI / 2.0;
    static constexpr double PI_OVER_4 = MATH_PI / 4.0;
 
    static const int COUNTERCLOCKWISE = Orientation::COUNTERCLOCKWISE;
 
    static const int CLOCKWISE = Orientation::CLOCKWISE;
 
    static const int NONE = Orientation::COLLINEAR;
 
    static double toDegrees(double radians);
 
    static double toRadians(double angleDegrees);
 
    static double angle(const geom::CoordinateXY& p0,
                        const geom::CoordinateXY& p1);
 
    //
    static double angle(const geom::CoordinateXY& p);
 
    static bool isAcute(const geom::CoordinateXY& p0,
                        const geom::CoordinateXY& p1,
                        const geom::CoordinateXY& p2);
 
    static bool isObtuse(const geom::CoordinateXY& p0,
                         const geom::CoordinateXY& p1,
                         const geom::CoordinateXY& p2);
 
    static double angleBetween(const geom::CoordinateXY& tip1,
                               const geom::CoordinateXY& tail,
                               const geom::CoordinateXY& tip2);
 
    static double angleBetweenOriented(const geom::CoordinateXY& tip1,
                                       const geom::CoordinateXY& tail,
                                       const geom::CoordinateXY& tip2);
 
    static double interiorAngle(const geom::CoordinateXY& p0,
                                const geom::CoordinateXY& p1,
                                const geom::CoordinateXY& p2);
 
    static int getTurn(double ang1, double ang2);
 
    static double normalize(double angle);
 
    static double normalizePositive(double angle);
 
 
    static double diff(double ang1, double ang2);
 
    static inline void sinCosSnap(const double ang, double& rSin, double& rCos) {
        // calculate both; may be optimized with FSINCOS instruction
        rSin = std::sin(ang);
        rCos = std::cos(ang);
        // snap near-zero values
        if (std::fabs(rSin) < 5e-16) rSin = 0.0;
        if (std::fabs(rCos) < 5e-16) rCos = 0.0;
    }
 
};
 
 
} // namespace geos::algorithm
} // namespace geos