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#include <assert.h>
#include <math.h>
#include "sig.h"
typedef struct ops_sin_ctxt_t {
float hz;
} ops_sin_ctxt_t;
static size_t ops_sin_size(va_list ap)
{
return sizeof(ops_sin_ctxt_t);
}
static void ops_sin_init(void *context, va_list ap)
{
ops_sin_ctxt_t *ctxt = context;
assert(ctxt);
ctxt->hz = va_arg(ap, double);
assert(ctxt->hz >= .0001f);
}
static float ops_sin_output(void *context, unsigned ticks_ms)
{
ops_sin_ctxt_t *ctxt = context;
float rads_per_ms, rads;
unsigned ms_per_cycle;
assert(ctxt);
ms_per_cycle = ctxt->hz * 1000.f;
rads_per_ms = (M_PI * 2.f) * ctxt->hz * .001f;
rads = (float)(ticks_ms % ms_per_cycle) * rads_per_ms;
return sinf(rads);
}
sig_ops_t sig_ops_sin = {
.size = ops_sin_size,
.init = ops_sin_init,
.output = ops_sin_output,
};
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