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mirror of https://github.com/cookiengineer/audacity synced 2025-05-05 22:28:57 +02:00
2010-01-24 09:19:39 +00:00

134 lines
3.5 KiB
C

#include "stdio.h"
#ifndef mips
#include "stdlib.h"
#endif
#include "xlisp.h"
#include "sound.h"
#include "falloc.h"
#include "cext.h"
#include "osc.h"
void osc_free();
typedef struct osc_susp_struct {
snd_susp_node susp;
long terminate_cnt;
double ph_incr;
table_type the_table;
sample_type *table_ptr;
double table_len;
double phase;
} osc_susp_node, *osc_susp_type;
void osc__fetch(register osc_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 ph_incr_reg;
register sample_type * table_ptr_reg;
register double table_len_reg;
register double phase_reg;
falloc_sample_block(out, "osc__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;
/* don't run past terminate time */
if (susp->terminate_cnt != UNKNOWN &&
susp->terminate_cnt <= susp->susp.current + cnt + togo) {
togo = susp->terminate_cnt - (susp->susp.current + cnt);
if (togo == 0) break;
}
n = togo;
ph_incr_reg = susp->ph_incr;
table_ptr_reg = susp->table_ptr;
table_len_reg = susp->table_len;
phase_reg = susp->phase;
out_ptr_reg = out_ptr;
if (n) do { /* the inner sample computation loop */
long table_index = (long) phase_reg;
double x1 = table_ptr_reg[table_index];
*out_ptr_reg++ = (sample_type) (x1 + (phase_reg - table_index) *
(table_ptr_reg[table_index + 1] - x1));
phase_reg += ph_incr_reg;
while (phase_reg >= table_len_reg) phase_reg -= table_len_reg;
;
} while (--n); /* inner loop */
susp->phase = phase_reg;
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;
}
} /* osc__fetch */
void osc_free(osc_susp_type susp)
{
table_unref(susp->the_table);
ffree_generic(susp, sizeof(osc_susp_node), "osc_free");
}
void osc_print_tree(osc_susp_type susp, int n)
{
}
sound_type snd_make_osc(sound_type input, double step, rate_type sr, double hz, time_type t0, time_type d, double phase)
{
register osc_susp_type susp;
/* sr specified as input parameter */
/* t0 specified as input parameter */
sample_type scale_factor = 1.0F;
falloc_generic(susp, osc_susp_node, "snd_make_osc");
susp->ph_incr = 0;
susp->the_table = sound_to_table(input);
susp->table_ptr = susp->the_table->samples;
susp->table_len = susp->the_table->length;
susp->phase = compute_phase(phase, step, (long) susp->table_len,
input->sr, sr, hz, &susp->ph_incr);
susp->susp.fetch = osc__fetch;
susp->terminate_cnt = round((d) * sr);
/* initialize susp state */
susp->susp.free = osc_free;
susp->susp.sr = sr;
susp->susp.t0 = t0;
susp->susp.mark = NULL;
susp->susp.print_tree = osc_print_tree;
susp->susp.name = "osc";
susp->susp.log_stop_cnt = UNKNOWN;
susp->susp.current = 0;
return sound_create((snd_susp_type)susp, t0, sr, scale_factor);
}
sound_type snd_osc(sound_type input, double step, rate_type sr, double hz, time_type t0, time_type d, double phase)
{
return snd_make_osc(input, step, sr, hz, t0, d, phase);
}