diff options
Diffstat (limited to 'src/lowpass.h')
| -rw-r--r-- | src/lowpass.h | 43 |
1 files changed, 17 insertions, 26 deletions
diff --git a/src/lowpass.h b/src/lowpass.h index 6c99212..0f50683 100644 --- a/src/lowpass.h +++ b/src/lowpass.h @@ -4,43 +4,34 @@ /* FILTER INFORMATION STRUCTURE FOR FILTER ROUTINES */ -#define FILTER_SECTIONS 2 /* 2 filter sections for 24 db/oct filter */ +#define FILTER_SECTIONS 2 /* 2 filter sections for 24 db/oct filter */ typedef struct { - unsigned int length; /* size of filter */ - float history[2 * FILTER_SECTIONS]; /* history in filter */ - float *coef; /* pointer to coefficients of filter */ + unsigned int length; /* size of filter */ + float history[2 * FILTER_SECTIONS]; /* history in filter */ + float *coef; /* pointer to coefficients of filter */ } FILTER; typedef struct { - double a0, a1, a2; /* numerator coefficients */ - double b0, b1, b2; /* denominator coefficients */ + double a0, a1, a2; /* numerator coefficients */ + double b0, b1, b2; /* denominator coefficients */ } BIQUAD; static BIQUAD ProtoCoef[FILTER_SECTIONS]; /* Filter prototype coefficients, - 1 for each filter section */ + 1 for each filter section */ -void szxform( - double *a0, double *a1, double *a2, /* numerator coefficients */ - double *b0, double *b1, double *b2, /* denominator coefficients */ - double fc, /* Filter cutoff frequency */ - double fs, /* sampling rate */ - double *k, /* overall gain factor */ - float *coef); /* pointer to 4 iir coefficients */ +void szxform(double *a0, double *a1, double *a2, /* numerator coefficients */ + double *b0, double *b1, double *b2, /* denominator coefficients */ + double fc, /* Filter cutoff frequency */ + double fs, /* sampling rate */ + double *k, /* overall gain factor */ + float *coef); /* pointer to 4 iir coefficients */ +signed char lpf_init(); +void lpf_close(); +float lpf_filter(float input); +void lpf_update(float resonance, float cutoff, int samplerate); -#ifdef __cplusplus - extern "C" { -#endif - - signed char LowPass_Init(); - void LowPass_Close(); - float LowPass_Filter(float input); - void LowPass_Update(float resonance, float cutoff, int samplerate); - -#ifdef __cplusplus - } -#endif #endif |