first Csound opcode

jakesine.c

#include "csdl.h"
#include "jakesine.h"

int jakesine_init (CSOUND *csound, JAKESINE *p)
{
    p->inc = *p->freq_in * csound->tpidsr;
    p->phase = *p->phase_in * TWOPI;
    return OK;
}

int jakesine_perf (CSOUND *csound, JAKESINE *p)
{
    int n = csound->ksmps;
    MYFLT *audio = p->audio_out;
    MYFLT amp = *p->amp_in;
    MYFLT *phase = &p->phase;
    MYFLT inc = p->inc;

    do {
        *audio++ = amp * sin(*phase);
        *phase += inc;
    } while (--n);

    return OK;
}

static OENTRY localops[] = {
    {"jakesine", sizeof(JAKESINE), 5, "a", "iii", (SUBR)jakesine_init, (SUBR)NULL, (SUBR)jakesine_perf},
};

LINKAGE

jakesine.h

#include "csdl.h"

typedef struct
{
    OPDS h;
    MYFLT *audio_out, *amp_in, *freq_in, *phase_in;
    MYFLT inc, phase;
} JAKESINE;