////  AngleUtil.h//  libraries/shared/src////  Created by Tobias Schwinger on 3/23/13.//  Copyright 2013 High Fidelity, Inc.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html// #ifndef hifi_AngleUtil_h#define hifi_AngleUtil_h #include <math.h> struct Degrees {     static float pi() { return 180.0f; }    static float twicePi() { return 360.0f; }    static float halfPi()  { return 90.0f; }}; struct Radians {     static float pi() { return 3.141592653589793f; }    static float twicePi() { return 6.283185307179586f; }    static float halfPi()  { return 1.5707963267948966f; }}; struct Rotations {     static float pi() { return 0.5f; }    static float twicePi() { return 1.0f; }    static float halfPi()  { return 0.25f; }}; // // Converts an angle from one unit to another.// template< class UnitFrom, class UnitTo >float angleConvert(float a) {     return a * (UnitTo::halfPi() / UnitFrom::halfPi());}  // // Clamps an angle to the range of [-180; 180) degrees.// template< class Unit >float angleSignedNormal(float a) {     // result is remainder(a, Unit::twicePi());    float result = fmod(a, Unit::twicePi());    if (result >= Unit::pi()) {         result -= Unit::twicePi();     } else if (result < -Unit::pi()) {         result += Unit::twicePi();    }     return result;} // // Clamps an angle to the range of [0; 360) degrees.// template< class Unit >float angleUnsignedNormal(float a) {     return angleSignedNormal<Unit>(a - Unit::pi()) + Unit::pi();}  //  // Clamps a polar direction so that azimuth is in the range of [0; 360)// degrees and altitude is in the range of [-90; 90] degrees.//// The so normalized angle still contains ambiguity due to gimbal lock:// Both poles can be reached from any azimuthal direction.// template< class Unit >void angleHorizontalPolar(float& azimuth, float& altitude) {     altitude = angleSignedNormal<Unit>(altitude);    if (altitude > Unit::halfPi()) {         altitude = Unit::pi() - altitude;        azimuth += Unit::pi();     } else if (altitude < -Unit::halfPi()) {         altitude = -Unit::pi() - altitude;        azimuth += Unit::pi();    }    azimuth = angleUnsignedNormal<Unit>(azimuth);} #endif // hifi_AngleUtil_h