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-rw-r--r--modules/bfft~.c325
1 files changed, 325 insertions, 0 deletions
diff --git a/modules/bfft~.c b/modules/bfft~.c
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+++ b/modules/bfft~.c
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+/*
+ * bfft.c - code for some fourrier transform variants and utility functions
+ * data organization is in (real, imag) pairs
+ * the first 2 components are (DC, NY)
+ * Copyright (c) 2000-2003 by Tom Schouten
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include "m_pd.h"
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define MAXORDER 64
+
+typedef struct bfftctl
+{
+ t_int c_levels;
+ char c_name[16];
+ t_int *c_clutter;
+ t_int *c_unclutter;
+ t_int c_kill_DC;
+ t_int c_kill_NY;
+} t_bfftctl;
+
+typedef struct bfft
+{
+ t_object x_obj;
+ t_float x_f;
+ t_bfftctl x_ctl;
+} t_bfft;
+
+t_class *bfft_class, *ibfft_class, *fht_class;
+
+
+static inline void bfft_perform_permutation(t_float *S, int n, t_int *f)
+{
+ t_int k,l;
+ t_float swap;
+ for(k=0; k<n; k++)
+ {
+ l = f[k];
+ while (l<k) l = f[l];
+ swap = S[k];
+ S[k] = S[l];
+ S[l] = swap;
+ }
+}
+
+static void bfft_permutation(t_bfft *x, t_int n){
+
+ t_bfftctl *ctl = &x->x_ctl;
+ int i;
+
+ if (ctl->c_clutter) free(ctl->c_clutter);
+ if (ctl->c_unclutter) free(ctl->c_unclutter);
+
+ ctl->c_clutter = (t_int *)malloc(n*sizeof(t_int));
+ ctl->c_unclutter = (t_int *)malloc(n*sizeof(t_int));
+
+
+ ctl->c_unclutter[0] = 0;
+ ctl->c_unclutter[1] = n/2;
+ for (i=1; i<n/2; i++){
+ ctl->c_unclutter[2*i] = i;
+ ctl->c_unclutter[2*i+1] = n-i;
+ }
+
+ for(i=0; i<n; i++)
+ ctl->c_clutter[ctl->c_unclutter[i]] = i;
+
+ return;
+
+ /* debug */
+ /* for(k=0; k<n; k++)
+ ** printf("clutter[%d] = %d\n", k, ctl->c_clutter[k]);
+ ** for(k=0; k<n; k++)
+ ** printf("unclutter[%d] = %d\n", k, ctl->c_unclutter[k]);
+ **
+ ** exit(1);
+ */
+}
+
+
+
+static t_int *bfft_perform(t_int *w)
+{
+
+
+ t_float *in = (float *)(w[3]);
+ t_float *out = (float *)(w[4]);
+ t_bfftctl *ctl = (t_bfftctl *)(w[1]);
+ t_int n = (t_int)(w[2]);
+ t_float scale = sqrt(1.0f / (float)(n));
+
+ mayer_fht(out, n);
+ bfft_perform_permutation(out, n, ctl->c_unclutter);
+
+ while (n--) *out++ *= scale;
+
+ return (w+5);
+}
+
+
+
+
+static t_int *ibfft_perform(t_int *w)
+{
+
+
+ t_float *in = (float *)(w[3]);
+ t_float *out = (float *)(w[4]);
+ t_bfftctl *ctl = (t_bfftctl *)(w[1]);
+ t_int n = (t_int)(w[2]);
+ t_float scale = sqrt(1.0f / (float)(n));
+
+
+ if (ctl->c_kill_DC) {out[0] = 0.0f;}
+ if (ctl->c_kill_NY) {out[1] = 0.0f;}
+
+ bfft_perform_permutation(out, n, ctl->c_clutter);
+ mayer_fht(out, n);
+
+
+ while (n--) *out++ *= scale;
+
+
+
+ return (w+5);
+}
+
+
+static t_int *fht_perform(t_int *w)
+{
+
+
+ t_float *in = (float *)(w[3]);
+ t_float *out = (float *)(w[4]);
+ t_bfftctl *ctl = (t_bfftctl *)(w[1]);
+
+
+ t_int n = (t_int)(w[2]);
+
+ mayer_fht(out, n);
+
+ return (w+5);
+}
+
+
+static void bfft_dsp(t_bfft *x, t_signal **sp)
+{
+
+ int n = sp[0]->s_n;
+ t_float *in = sp[0]->s_vec;
+ t_float *out = sp[1]->s_vec;
+
+ bfft_permutation(x, n);
+
+ if (in != out)
+ {
+ dsp_add_copy(in,out,n);
+ in = out;
+ }
+
+ dsp_add(bfft_perform, 4, &x->x_ctl, n, in, out);
+
+}
+
+static void ibfft_dsp(t_bfft *x, t_signal **sp)
+{
+
+ int n = sp[0]->s_n;
+ t_float *in = sp[0]->s_vec;
+ t_float *out = sp[1]->s_vec;
+
+ bfft_permutation(x, n);
+
+ if (in != out)
+ {
+ dsp_add_copy(in,out,n);
+ in = out;
+ }
+
+ dsp_add(ibfft_perform, 4, &x->x_ctl, n, in, out);
+
+}
+
+static void fht_dsp(t_bfft *x, t_signal **sp)
+{
+
+ int n = sp[0]->s_n;
+ t_float *in = sp[0]->s_vec;
+ t_float *out = sp[1]->s_vec;
+
+
+ if (in != out)
+ {
+ dsp_add_copy(in,out,n);
+ in = out;
+ }
+
+ dsp_add(fht_perform, 4, &x->x_ctl, n, in, out);
+
+}
+
+
+
+static void bfft_free(t_bfft *x)
+{
+
+ if (x->x_ctl.c_clutter) free(x->x_ctl.c_clutter);
+ if (x->x_ctl.c_unclutter) free(x->x_ctl.c_unclutter);
+
+}
+
+
+
+
+static void *bfft_new(void)
+{
+ t_bfft *x = (t_bfft *)pd_new(bfft_class);
+ int i;
+
+ outlet_new(&x->x_obj, gensym("signal"));
+
+
+ sprintf(x->x_ctl.c_name,"bfft");
+
+ x->x_ctl.c_clutter = NULL;
+ x->x_ctl.c_unclutter = NULL;
+
+ return (void *)x;
+
+
+}
+
+static void *ibfft_new(t_symbol *s)
+{
+ t_bfft *x = (t_bfft *)pd_new(ibfft_class);
+ int i;
+
+ outlet_new(&x->x_obj, gensym("signal"));
+
+ if (s == gensym("killDCNY")){
+ x->x_ctl.c_kill_DC = 1;
+ x->x_ctl.c_kill_NY = 1;
+ post("ibfft: removing DC and NY components.");
+ }
+ else{
+ x->x_ctl.c_kill_DC = 0;
+ x->x_ctl.c_kill_NY = 0;
+ }
+
+ x->x_ctl.c_clutter = NULL;
+ x->x_ctl.c_unclutter = NULL;
+
+ sprintf(x->x_ctl.c_name,"ibfft");
+
+ return (void *)x;
+}
+
+static void *fht_new(void)
+{
+ t_bfft *x = (t_bfft *)pd_new(fht_class);
+ int i;
+
+ outlet_new(&x->x_obj, gensym("signal"));
+
+
+ x->x_ctl.c_clutter = NULL;
+ x->x_ctl.c_unclutter = NULL;
+
+ sprintf(x->x_ctl.c_name,"fht");
+
+ return (void *)x;
+}
+
+
+
+
+void bfft_tilde_setup(void)
+{
+ //post("bfft~ v0.1");
+ bfft_class = class_new(gensym("bfft~"), (t_newmethod)bfft_new,
+ (t_method)bfft_free, sizeof(t_bfft), 0, 0);
+ CLASS_MAINSIGNALIN(bfft_class, t_bfft, x_f);
+ class_addmethod(bfft_class, (t_method)bfft_dsp, gensym("dsp"), 0);
+
+
+
+ ibfft_class = class_new(gensym("ibfft~"), (t_newmethod)ibfft_new,
+ (t_method)bfft_free, sizeof(t_bfft), 0, A_DEFSYMBOL, A_NULL);
+
+ /* add the more logical bifft~ alias */
+ class_addcreator((t_newmethod)ibfft_new,
+ gensym("bifft~"), 0, A_DEFSYMBOL, A_NULL);
+
+ CLASS_MAINSIGNALIN(ibfft_class, t_bfft, x_f);
+ class_addmethod(ibfft_class, (t_method)ibfft_dsp, gensym("dsp"), 0);
+
+
+
+ fht_class = class_new(gensym("fht~"), (t_newmethod)fht_new,
+ (t_method)bfft_free, sizeof(t_bfft), 0, 0);
+
+ CLASS_MAINSIGNALIN(fht_class, t_bfft, x_f);
+ class_addmethod(fht_class, (t_method)fht_dsp, gensym("dsp"), 0);
+
+
+
+}
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