constants.h

/*
 * Copyright (c) 2015 Thomas Roell.  All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal with the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimers.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimers in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of Thomas Roell, nor the names of its contributors
 *     may be used to endorse or promote products derived from this Software
 *     without specific prior written permission.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 * CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * WITH THE SOFTWARE.
 */

#if !defined(_CONSTANTS_H)
#define _CONSTANTS_H

#define GRAVITY     9.80665f /* m/s^2 */
#define PI          3.14159265358979323846f
#define DEG2RAD     (PI / 180.0f)
#define RAD2DEG     (180.0f / PI)
#define KNOTS2MPS   0.514444444f
#define GAUSS2TESLA (0.0001f)


static inline float angle_difference(float a, float b)
{
    float out = a - b;
    while (out < -PI) { out += (2 * PI); }
    while (out >  PI) { out -= (2 * PI); }
    return out;
}

static inline float angle_normalize(float a)
{
    float out = a;
    while (out < 0.0)      { out += (2 * PI); }
    while (out > (2 * PI)) { out -= (2 * PI); }
    return out;
}

#endif /* _CONSTANTS_H */