gmath.h

/*
 * File: gmath.h
 * -------------
 * This file exports several functions for working with graphical
 * geometry along with the mathematical constants <code>PI</code>
 * and <code>E</code>.
 *
 * @version 2021/04/09
 * - added sgl::math namespace
 * @version 2018/11/22
 * - added headless mode support
 * - alphabetized methods
 * @version 2018/09/25
 * - added doc comments for new documentation generation
 * @version 2017/12/12
 * - added floatingPointEqual(a, b, tolerance)
 * @version 2016/10/14
 * - added floatingPointEqual method for comparing floats and doubles
 */


#ifndef _gmath_h
#define _gmath_h

#include <cmath>
#include <limits>

namespace sgl {

struct GPoint;

namespace math {

extern const double PI;

extern const double E;

double cosDegrees(double angle);


int countDigits(int n, int base = 10);

template<typename T>
bool floatingPointEqual(T f1, T f2, T tolerance) {
    return (std::fabs(f1 - f2) <= tolerance);
}

template<typename T>
bool floatingPointEqual(T f1, T f2) {
    return floatingPointEqual(f1, f2, /* tolerance */ (T) std::numeric_limits<T>::epsilon() * std::fmax(fabs(f1), fabs(f2)));
}

template<typename T>
bool floatingPointEqual(T f1, int f2) {
    return floatingPointEqual(f1, (T) f2);
}

template<typename T>
bool floatingPointEqual(int f1, T f2) {
    return floatingPointEqual((T) f1, f2);
}

template<typename T>
bool floatingPointEqual(T f1, long int f2) {
    return floatingPointEqual(f1, (T) f2);
}

template<typename T>
bool floatingPointEqual(long int f1, T f2) {
    return floatingPointEqual((T) f1, f2);
}

double sinDegrees(double angle);

double tanDegrees(double angle);

double toDegrees(double radians);

double toRadians(double degrees);

double vectorAngle(double x, double y);

double vectorAngle(const ::sgl::GPoint& pt);

double vectorDistance(double x, double y);

double vectorDistance(const ::sgl::GPoint& pt);

} // namespace math
} // namespace sgl

#endif // _gmath_h