typedef struct {    SPFLOAT mode;} sp_switch; int sp_switch_create(sp_switch **p);int sp_switch_destroy(sp_switch **p);int sp_switch_init(sp_data *sp, sp_switch *p);int sp_switch_compute(sp_data *sp, sp_switch *p, SPFLOAT *trig,    SPFLOAT *in1, SPFLOAT *in2, SPFLOAT *out);