#ifndef NOISE_H_INCLUDED
#define NOISE_H_INCLUDED

#if defined(__cplusplus)
extern "C"
{
#endif

/**
 * \fn  float AddNoise(float x, float amplitude, float ratio, unsigned nsamples);
 *
 * \brief   Augments a given signal by adding some random noise and a sinusoidal waveform (e.g. 50Hz from power-line).
 *
 * \param   x           The input signal.
 * \param   amplitude   The amplitude of the noise/waveform.
 * \param   ratio       The ratio between random noise and sinusoidal waveform [0,1].
 * \param   nsamples    The number of samples per period. Higher values will lower the sinusoidal frequency.
 *
 * \return  The adjusted input signal
 */
float AddNoise(float x, float amplitude, float ratio, unsigned nsamples);

/* Resets the sinusoidal phase and the LCG */
void ResetNoise();

/* Utility functions */

/* Initializes the LCG */
void slcg(unsigned seed);
/* [0,32767] Linear congruential generator (PRNG) */
unsigned lcg();
/* [0,1] LCG */
float flcg();
/* [-1,1] LCG */
float sflcg();
/* Bhaskara sine approximation (in deg) */
float fsindeg(float x);
/* Bhaskara cosine approximation (in deg) */
float fcosdeg(float x);

#if defined(__cplusplus)
};
#endif

#endif /* NOISE_H_INCLUDED */