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#include <assert.h>
#include "sig.h"
typedef struct ops_scale_ctxt_t {
sig_t *value, *min, *max;
} ops_scale_ctxt_t;
static size_t ops_scale_size(va_list ap)
{
return sizeof(ops_scale_ctxt_t);
}
/* expects three sig_t's: value, min, max.
* min is assumed to be always <= max,
* and value is assumed to always be 0-1
*/
static void ops_scale_init(void *context, va_list ap)
{
ops_scale_ctxt_t *ctxt = context;
assert(ctxt);
ctxt->value = va_arg(ap, sig_t *);
ctxt->min = va_arg(ap, sig_t *);
ctxt->max = va_arg(ap, sig_t *);
}
static void ops_scale_destroy(void *context)
{
ops_scale_ctxt_t *ctxt = context;
assert(ctxt);
sig_free(ctxt->value);
sig_free(ctxt->min);
sig_free(ctxt->max);
}
static float ops_scale_output(void *context, unsigned ticks_ms)
{
ops_scale_ctxt_t *ctxt = context;
float value, min, max;
assert(ctxt);
value = sig_output(ctxt->value, ticks_ms);
min = sig_output(ctxt->min, ticks_ms);
max = sig_output(ctxt->max, ticks_ms);
assert(max >= min);
return value * (max - min) + min;
}
sig_ops_t sig_ops_scale = {
.size = ops_scale_size,
.init = ops_scale_init,
.destroy = ops_scale_destroy,
.output = ops_scale_output,
};
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