diff options
Diffstat (limited to 'tran/fmfb.c')
| -rw-r--r-- | tran/fmfb.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/tran/fmfb.c b/tran/fmfb.c new file mode 100644 index 0000000..28ce95e --- /dev/null +++ b/tran/fmfb.c @@ -0,0 +1,139 @@ +#include "stdio.h" +#ifndef mips +#include "stdlib.h" +#endif +#include "xlisp.h" +#include "sound.h" + +#include "falloc.h" +#include "cext.h" +#include "fmfb.h" + +void fmfb_free(); + + +typedef struct fmfb_susp_struct { + snd_susp_node susp; + long terminate_cnt; + + double yy; + double sin_y; + double xx; + double x_incr; + double index; +} fmfb_susp_node, *fmfb_susp_type; + + +void fmfb__fetch(register fmfb_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 yy_reg; + register double sin_y_reg; + register double xx_reg; + register double x_incr_reg; + register double index_reg; + falloc_sample_block(out, "fmfb__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; + yy_reg = susp->yy; + sin_y_reg = susp->sin_y; + xx_reg = susp->xx; + x_incr_reg = susp->x_incr; + index_reg = susp->index; + out_ptr_reg = out_ptr; + if (n) do { /* the inner sample computation loop */ +xx_reg += x_incr_reg; + if (xx_reg > SINE_TABLE_LEN) xx_reg -= SINE_TABLE_LEN; + /* xx_reg incremented and index_reg scaled to table index_reg, and + sin_y_reg is a signal (-1 to +1) */ + yy_reg = xx_reg + index_reg * sin_y_reg; + /* so yy_reg is a table index_reg */ + while (yy_reg > SINE_TABLE_LEN) yy_reg -= SINE_TABLE_LEN; + while (yy_reg < 0) yy_reg += SINE_TABLE_LEN; + sin_y_reg = sine_table[(int) yy_reg]; /* truncation gets valid index_reg */ + /* sin_y_reg is now a signal not ready for table lookup */ + *out_ptr_reg++ = sin_y_reg;; + } while (--n); /* inner loop */ + + susp->yy = yy_reg; + susp->sin_y = sin_y_reg; + susp->xx = xx_reg; + susp->index = index_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; + } +} /* fmfb__fetch */ + + +void fmfb_free(fmfb_susp_type susp) +{ + ffree_generic(susp, sizeof(fmfb_susp_node), "fmfb_free"); +} + + +void fmfb_print_tree(fmfb_susp_type susp, int n) +{ +} + + +sound_type snd_make_fmfb(time_type t0, double hz, rate_type sr, double index, time_type d) +{ + register fmfb_susp_type susp; + /* sr specified as input parameter */ + /* t0 specified as input parameter */ + sample_type scale_factor = 1.0F; + falloc_generic(susp, fmfb_susp_node, "snd_make_fmfb"); + susp->yy = 0.0; + susp->sin_y = 0.0; + susp->xx = 0.0; + susp->x_incr = hz * SINE_TABLE_LEN / sr; + susp->index = index * SINE_TABLE_LEN / PI2; + susp->susp.fetch = fmfb__fetch; + + susp->terminate_cnt = round((d) * sr); + /* initialize susp state */ + susp->susp.free = fmfb_free; + susp->susp.sr = sr; + susp->susp.t0 = t0; + susp->susp.mark = NULL; + susp->susp.print_tree = fmfb_print_tree; + susp->susp.name = "fmfb"; + susp->susp.log_stop_cnt = UNKNOWN; + susp->susp.current = 0; + return sound_create((snd_susp_type)susp, t0, sr, scale_factor); +} + + +sound_type snd_fmfb(time_type t0, double hz, rate_type sr, double index, time_type d) +{ + return snd_make_fmfb(t0, hz, sr, index, d); +} |