#ifndef SK_PHASOR_Htypedef struct sk_phasor sk_phasor;#endif typedef struct sp_phasor{    sk_phasor *phasor;    SPFLOAT freq;} sp_phasor; int sp_phasor_create(sp_phasor **p);int sp_phasor_destroy(sp_phasor **p);int sp_phasor_init(sp_data *sp, sp_phasor *p, SPFLOAT iphs);int sp_phasor_compute(sp_data *sp, sp_phasor *p, SPFLOAT *in, SPFLOAT *out);int sp_phasor_reset(sp_data *sp, sp_phasor *p, SPFLOAT iphs);