diff options
Diffstat (limited to 'tran/congen.c')
| -rw-r--r-- | tran/congen.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/tran/congen.c b/tran/congen.c new file mode 100644 index 0000000..ed074c7 --- /dev/null +++ b/tran/congen.c @@ -0,0 +1,185 @@ +#include "stdio.h" +#ifndef mips +#include "stdlib.h" +#endif +#include "xlisp.h" +#include "sound.h" + +#include "falloc.h" +#include "cext.h" +#include "congen.h" + +void congen_free(); + + +typedef struct congen_susp_struct { + snd_susp_node susp; + long terminate_cnt; + sound_type sndin; + long sndin_cnt; + sample_block_values_type sndin_ptr; + + double value; + double rise_factor; + double fall_factor; +} congen_susp_node, *congen_susp_type; + + +void congen_s_fetch(register congen_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 value_reg; + register double rise_factor_reg; + register double fall_factor_reg; + register sample_type sndin_scale_reg = susp->sndin->scale; + register sample_block_values_type sndin_ptr_reg; + falloc_sample_block(out, "congen_s_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 the sndin input sample block: */ + susp_check_term_samples(sndin, sndin_ptr, sndin_cnt); + togo = min(togo, susp->sndin_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; + value_reg = susp->value; + rise_factor_reg = susp->rise_factor; + fall_factor_reg = susp->fall_factor; + sndin_ptr_reg = susp->sndin_ptr; + out_ptr_reg = out_ptr; + if (n) do { /* the inner sample computation loop */ + sample_type current = (sndin_scale_reg * *sndin_ptr_reg++); + if (current > value_reg) { + value_reg = current - (current - value_reg) * rise_factor_reg; + } else { + value_reg = current - (current - value_reg) * fall_factor_reg; + } + *out_ptr_reg++ = (sample_type) value_reg;; + } while (--n); /* inner loop */ + + susp->value = value_reg; + /* using sndin_ptr_reg is a bad idea on RS/6000: */ + susp->sndin_ptr += togo; + out_ptr += togo; + susp_took(sndin_cnt, 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; + } +} /* congen_s_fetch */ + + +void congen_toss_fetch(susp, snd_list) + register congen_susp_type susp; + snd_list_type snd_list; +{ + long final_count = susp->susp.toss_cnt; + time_type final_time = susp->susp.t0; + long n; + + /* fetch samples from sndin up to final_time for this block of zeros */ + while ((round((final_time - susp->sndin->t0) * susp->sndin->sr)) >= + susp->sndin->current) + susp_get_samples(sndin, sndin_ptr, sndin_cnt); + /* convert to normal processing when we hit final_count */ + /* we want each signal positioned at final_time */ + n = round((final_time - susp->sndin->t0) * susp->sndin->sr - + (susp->sndin->current - susp->sndin_cnt)); + susp->sndin_ptr += n; + susp_took(sndin_cnt, n); + susp->susp.fetch = susp->susp.keep_fetch; + (*(susp->susp.fetch))(susp, snd_list); +} + + +void congen_mark(congen_susp_type susp) +{ + sound_xlmark(susp->sndin); +} + + +void congen_free(congen_susp_type susp) +{ + sound_unref(susp->sndin); + ffree_generic(susp, sizeof(congen_susp_node), "congen_free"); +} + + +void congen_print_tree(congen_susp_type susp, int n) +{ + indent(n); + stdputstr("sndin:"); + sound_print_tree_1(susp->sndin, n); +} + + +sound_type snd_make_congen(sound_type sndin, double risetime, double falltime) +{ + register congen_susp_type susp; + rate_type sr = sndin->sr; + time_type t0 = sndin->t0; + int interp_desc = 0; + sample_type scale_factor = 1.0F; + time_type t0_min = t0; + falloc_generic(susp, congen_susp_node, "snd_make_congen"); + susp->value = 0; + susp->rise_factor = exp(log(0.5) / (sndin->sr * risetime)); + susp->fall_factor = exp(log(0.5) / (sndin->sr * falltime)); + susp->susp.fetch = congen_s_fetch; + susp->terminate_cnt = UNKNOWN; + /* handle unequal start times, if any */ + if (t0 < sndin->t0) sound_prepend_zeros(sndin, t0); + /* minimum start time over all inputs: */ + t0_min = min(sndin->t0, t0); + /* how many samples to toss before t0: */ + susp->susp.toss_cnt = (long) ((t0 - t0_min) * sr + 0.5); + if (susp->susp.toss_cnt > 0) { + susp->susp.keep_fetch = susp->susp.fetch; + susp->susp.fetch = congen_toss_fetch; + } + + /* initialize susp state */ + susp->susp.free = congen_free; + susp->susp.sr = sr; + susp->susp.t0 = t0; + susp->susp.mark = congen_mark; + susp->susp.print_tree = congen_print_tree; + susp->susp.name = "congen"; + susp->susp.log_stop_cnt = UNKNOWN; + susp->susp.current = 0; + susp->sndin = sndin; + susp->sndin_cnt = 0; + return sound_create((snd_susp_type)susp, t0, sr, scale_factor); +} + + +sound_type snd_congen(sound_type sndin, double risetime, double falltime) +{ + sound_type sndin_copy = sound_copy(sndin); + return snd_make_congen(sndin_copy, risetime, falltime); +} |