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#include "stdio.h"
#ifndef mips
#include "stdlib.h"
#endif
#include "xlisp.h"
#include "sound.h"
#include "falloc.h"
#include "cext.h"
#include "pwl.h"
void pwl_free();
typedef struct pwl_susp_struct {
snd_susp_node susp;
LVAL bpt_ptr;
double incr;
double lvl;
} pwl_susp_node, *pwl_susp_type;
/* IMPLEMENTATION NOTE:
* The lis argument is a list of alternating sample numbers and values
* which are taken in pairs, with an implicit (0, 0) starting point. The
* last point is a sample number only, the value being implicitly 0.
* The bpt_ptr points to the next sample number in the list.
* The incr is set to the increment per sample, and lvl is the next
* sample value.
*
* The list is assumed to be well-formed, so it should be checked by
* the caller (users should not call this directly).
*/
/* compute_lvl -- setup the susp with level, advance bpt_ptr */
/*
* returns true if it is time to terminate
*
* Note: compute_lvl gets called in the outer loop to skip over
* a breakpoint pair before starting the compute_incr loop, which
* searches for a breakpoint that is some number of samples in the
* future. This code is not embedded in compute_incr because it is
* NOT called from the initialization, where it would be wrong to
* skip over the first breakpoint.
*/
boolean compute_lvl(pwl_susp_type susp)
{
if (!cdr(susp->bpt_ptr)) return true;
susp->lvl = getflonum(car(cdr(susp->bpt_ptr)));
susp->bpt_ptr = cdr(cdr(susp->bpt_ptr));
return !susp->bpt_ptr;
}
/* compute_incr -- setup the susp with level and increment */
/*
* returns true if it is time to terminate
*/
boolean compute_incr(pwl_susp_type susp, long *n, long cur)
{
double target;
while (*n == 0) {
*n = getfixnum(car(susp->bpt_ptr)) - cur;
/* if there is a 2nd element of the pair, get the target */
if (cdr(susp->bpt_ptr))
target = getflonum(car(cdr(susp->bpt_ptr)));
else target = 0.0;
if (*n > 0) susp->incr = (target - susp->lvl) / *n;
else if (compute_lvl(susp)) return true;
}
return false;
}
void pwl__fetch(register pwl_susp_type susp, snd_list_type snd_list)
{
int cnt = 0; /* how many samples computed */
int togo;
int n;
sample_block_type out;
register sample_block_values_type out_ptr;
register sample_block_values_type out_ptr_reg;
register double incr_reg;
register double lvl_reg;
falloc_sample_block(out, "pwl__fetch");
out_ptr = out->samples;
snd_list->block = out;
while (cnt < max_sample_block_len) { /* outer loop */
/* first compute how many samples to generate in inner loop: */
/* don't overflow the output sample block: */
togo = max_sample_block_len - cnt;
if (susp->bpt_ptr == NULL) {
out: togo = 0; /* indicate termination */
break; /* we're done */
}
{ long cur = susp->susp.current + cnt;
long nn = getfixnum(car(susp->bpt_ptr)) - cur;
if (nn == 0) {
if (compute_lvl(susp) || compute_incr(susp, &nn, cur)) goto out;
}
togo = min(nn, togo);
}
n = togo;
incr_reg = susp->incr;
lvl_reg = susp->lvl;
out_ptr_reg = out_ptr;
if (n) do { /* the inner sample computation loop */
*out_ptr_reg++ = (sample_type) lvl_reg; lvl_reg += incr_reg;;
} while (--n); /* inner loop */
susp->lvl += susp->incr * togo;
out_ptr += togo;
cnt += togo;
} /* outer loop */
/* test for termination */
if (togo == 0 && cnt == 0) {
snd_list_terminate(snd_list);
} else {
snd_list->block_len = cnt;
susp->susp.current += cnt;
}
} /* pwl__fetch */
void pwl_mark(pwl_susp_type susp)
{
if (susp->bpt_ptr) mark(susp->bpt_ptr);
}
void pwl_free(pwl_susp_type susp)
{
ffree_generic(susp, sizeof(pwl_susp_node), "pwl_free");
}
void pwl_print_tree(pwl_susp_type susp, int n)
{
}
sound_type snd_make_pwl(time_type t0, rate_type sr, LVAL lis)
{
register pwl_susp_type susp;
/* sr specified as input parameter */
/* t0 specified as input parameter */
sample_type scale_factor = 1.0F;
falloc_generic(susp, pwl_susp_node, "snd_make_pwl");
susp->bpt_ptr = lis;
susp->incr = 0.0;
susp->lvl = 0.0;
{ long temp = 0; compute_incr(susp, &temp, 0); };
susp->susp.fetch = pwl__fetch;
/* initialize susp state */
susp->susp.free = pwl_free;
susp->susp.sr = sr;
susp->susp.t0 = t0;
susp->susp.mark = pwl_mark;
susp->susp.print_tree = pwl_print_tree;
susp->susp.name = "pwl";
susp->susp.log_stop_cnt = UNKNOWN;
susp->susp.current = 0;
return sound_create((snd_susp_type)susp, t0, sr, scale_factor);
}
sound_type snd_pwl(time_type t0, rate_type sr, LVAL lis)
{
return snd_make_pwl(t0, sr, lis);
}
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