#ifndef _BGC_UTILITIES_H_INCLUDED_
#define _BGC_UTILITIES_H_INCLUDED_

#define BGC_FP32_EPSILON_EFFECTIVENESS_LIMIT 1.0f

#define BGC_FP32_EPSILON 4.76837E-7f
#define BGC_FP32_SQUARE_EPSILON (BGC_FP32_EPSILON * BGC_FP32_EPSILON)

#define BGC_FP32_ONE_THIRD 0.3333333333f
#define BGC_FP32_ONE_SIXTH 0.1666666667f
#define BGC_FP32_ONE_SEVENTH 0.142857142857f
#define BGC_FP32_ONE_NINETH 0.1111111111f

#define BGC_FP32_GOLDEN_RATIO_HIGH 1.618034f
#define BGC_FP32_GOLDEN_RATIO_LOW 0.618034f

#define BGC_FP64_EPSILON_EFFECTIVENESS_LIMIT 1.0

#define BGC_FP64_EPSILON 4.996003611E-14
#define BGC_FP64_SQUARE_EPSILON (BGC_FP64_EPSILON * BGC_FP64_EPSILON)

#define BGC_FP64_ONE_THIRD 0.3333333333333333333
#define BGC_FP64_ONE_SIXTH 0.1666666666666666667
#define BGC_FP64_ONE_SEVENTH 0.142857142857142857
#define BGC_FP64_ONE_NINETH 0.1111111111111111111

#define BGC_FP64_GOLDEN_RATIO_HIGH 1.61803398874989485
#define BGC_FP64_GOLDEN_RATIO_LOW 0.61803398874989485

#define BGC_SUCCESS 0
#define BGC_FAILED -1

#define BGC_ATTITUDE_ANY 0
#define BGC_ATTITUDE_ZERO 1
#define BGC_ATTITUDE_ORTHOGONAL 2
#define BGC_ATTITUDE_CO_DIRECTIONAL 3
#define BGC_ATTITUDE_COUNTER_DIRECTIONAL 4

#define BGC_AXIS_X1 1
#define BGC_AXIS_X2 2
#define BGC_AXIS_X3 3

#define BGC_AXIS_REVERSE_X1 -1
#define BGC_AXIS_REVERSE_X2 -2
#define BGC_AXIS_REVERSE_X3 -3

inline int bgc_is_correct_axis(const int axis)
{
    return axis == BGC_AXIS_X1 || axis == BGC_AXIS_REVERSE_X1
        || axis == BGC_AXIS_X2 || axis == BGC_AXIS_REVERSE_X2
        || axis == BGC_AXIS_X3 || axis == BGC_AXIS_REVERSE_X3;
}

inline int bgc_fp32_is_zero(const float value)
{
    return (-BGC_FP32_EPSILON <= value) && (value <= BGC_FP32_EPSILON);
}

inline int bgc_fp64_is_zero(const double value)
{
    return (-BGC_FP64_EPSILON <= value) && (value <= BGC_FP64_EPSILON);
}


inline int bgc_fp32_is_unit(const float value)
{
    return (1.0f - BGC_FP32_EPSILON <= value) && (value <= 1.0f + BGC_FP32_EPSILON);
}

inline int bgc_fp64_is_unit(const double value)
{
    return (1.0 - BGC_FP64_EPSILON <= value) && (value <= 1.0 + BGC_FP64_EPSILON);
}


inline int bgc_fp32_is_square_unit(const float square_value)
{
    return (1.0f - 2.0f * BGC_FP32_EPSILON <= square_value) && (square_value <= 1.0f + 2.0f * BGC_FP32_EPSILON);
}

inline int bgc_fp64_is_square_unit(const double square_value)
{
    return (1.0 - 2.0 * BGC_FP64_EPSILON <= square_value) && (square_value <= 1.0 + 2.0 * BGC_FP64_EPSILON);
}

// ================== Are Close ================= //

inline int bgc_fp32_are_close(const float value1, const float value2)
{
    const float difference = value1 - value2;
    const float square_value1 = value1 * value1;
    const float square_value2 = value2 * value2;
    const float square_difference = difference * difference;

    if (square_value1 <= BGC_FP32_EPSILON_EFFECTIVENESS_LIMIT || square_value2 <= BGC_FP32_EPSILON_EFFECTIVENESS_LIMIT) {
        return square_difference <= BGC_FP32_SQUARE_EPSILON;
    }

    return square_difference <= BGC_FP32_SQUARE_EPSILON * square_value1 && square_difference <= BGC_FP32_SQUARE_EPSILON * square_value2;
}

inline int bgc_fp64_are_close(const double value1, const double value2)
{
    const double difference = value1 - value2;
    const double square_value1 = value1 * value1;
    const double square_value2 = value2 * value2;
    const double square_difference = difference * difference;

    if (square_value1 <= BGC_FP64_EPSILON_EFFECTIVENESS_LIMIT || square_value2 <= BGC_FP64_EPSILON_EFFECTIVENESS_LIMIT) {
        return square_difference <= BGC_FP64_SQUARE_EPSILON;
    }

    return square_difference <= BGC_FP64_SQUARE_EPSILON * square_value1 && square_difference <= BGC_FP64_SQUARE_EPSILON * square_value2;
}

#endif