aboutsummaryrefslogtreecommitdiff
path: root/modules/fdn~.c
diff options
context:
space:
mode:
Diffstat (limited to 'modules/fdn~.c')
-rw-r--r--modules/fdn~.c500
1 files changed, 500 insertions, 0 deletions
diff --git a/modules/fdn~.c b/modules/fdn~.c
new file mode 100644
index 0000000..65682b7
--- /dev/null
+++ b/modules/fdn~.c
@@ -0,0 +1,500 @@
+/*
+ * fdn.c - a feedback delay network (reverb tail)
+ * using a housholder reflection feedback matrix (In - 2/n 11T)
+ * 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.
+ */
+
+/* TODO: CLEAN UP THIS MESS
+
+add delay time generation code
+add prime calculation routine (for prime delay line lengths)
+add more diffuse feedback matrix (hadamard)
+check filtering code
+
+*/
+#include <m_pd.h>
+#include <math.h>
+#include "extlib_util.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#define FDN_MIN_DECAY_TIME .01f
+
+/*
+
+#define NBPRIMES
+int prime[NBPRIMES];
+
+static int isprime(int n)
+{
+ int i=1;
+ int d,m,p;
+ while(1){
+ p = prime[i++];
+ m = n % p;
+ if (m == 0) return 0; // it is a prime
+ d = n / p;
+ if (d < p) return 1; // it is not a prime
+ }
+}
+
+static int initprimes(void)
+{
+ int i, curprime;
+ prime[0] = 1;
+ prime[1] = 2;
+ curprime = 3;
+
+ for(i=2; i<NBPRIMES; i++){
+ while (!isprime(curprime)) curprime++;
+ prime[i] = curprime;
+ //printf("%d, ", curprime);
+ curprime++;
+ }
+ printf("\n");
+ return 0;
+}
+*/
+
+
+//static int find_nearest_prime(int n){ return n;}
+
+typedef struct fdnctl
+{
+ t_int c_order; /* veelvoud van 4 */
+ t_int c_maxorder;
+ t_float c_leak;
+ t_float c_input;
+ t_float c_output;
+ t_float *c_buf;
+ t_float *c_gain_in;
+ t_float *c_gain_state;
+ t_float c_timehigh;
+ t_float c_timelow;
+ t_int *c_tap; /* cirular feed: N+1 pointers: 1 read, (N-1)r/w, 1 write */
+ t_float *c_length; /* delay lengths in ms */
+ t_int c_bufsize;
+ t_float c_fsample;
+ t_float *c_vector[2];
+ t_float *c_vectorbuffer;
+ t_int c_curvector;
+} t_fdnctl;
+
+typedef struct fdn
+{
+ t_object x_obj;
+ t_float x_f;
+ t_fdnctl x_ctl;
+} t_fdn;
+
+
+static void fdn_order(t_fdn *x, t_int order){
+ if (order > x->x_ctl.c_maxorder) {
+ post("fdn: this should not happen (panic!) order %d is larger than maxorder %d:",
+ order, x->x_ctl.c_maxorder );
+ exit(1);
+ }
+ x->x_ctl.c_order = order;
+ x->x_ctl.c_leak = -2./ order;
+ x->x_ctl.c_input = 1./ sqrt(order); //????????????????
+
+}
+
+static void fdn_print(t_fdn *x)
+{
+ int i;
+ fprintf(stderr, "fdn: delay coefficients (ms)\n");
+ for (i=0;i<x->x_ctl.c_order;i++) {
+ fprintf(stderr, "%f ", x->x_ctl.c_length[i]);
+ }
+ fprintf(stderr, "\n");
+
+}
+
+
+static void fdn_reset(t_fdn *x)
+{
+ int i;
+ if (x->x_ctl.c_buf) memset(x->x_ctl.c_buf, 0, x->x_ctl.c_bufsize * sizeof(float));
+ if (x->x_ctl.c_vectorbuffer) memset(x->x_ctl.c_vectorbuffer, 0, x->x_ctl.c_maxorder * 2 * sizeof(float));
+}
+
+
+
+
+static t_int *fdn_perform(t_int *w)
+{
+
+
+ t_float *in = (float *)(w[3]);
+ t_float *outr = (float *)(w[4]);
+ t_float *outl = (float *)(w[5]);
+ t_fdnctl *ctl = (t_fdnctl *)(w[1]);
+ t_int n = (t_int)(w[2]);
+ t_float input = ctl->c_input;
+ t_float output = ctl->c_output;
+ t_float *gain_in = ctl->c_gain_in;
+ t_float *gain_state = ctl->c_gain_state;
+ t_int order = ctl->c_order;
+ t_int *tap = ctl->c_tap;
+ t_float *buf = ctl->c_buf;
+ t_int mask = ctl->c_bufsize - 1;
+
+ t_int i,j;
+ t_float x,y,v,left,right,z;
+ t_float filt_in, filt_last;
+
+ t_float *cvec, *lvec;
+
+ t_float save;
+
+
+ for(i=0;i<n;i++){
+
+ x = *in++;
+ y = 0;
+ left = 0;
+ right = 0;
+
+ /* get temporary vector buffers */
+ cvec = ctl->c_vector[ctl->c_curvector];
+ lvec = ctl->c_vector[ctl->c_curvector ^ 1];
+ ctl->c_curvector ^= 1;
+
+
+ /* read input vector + get sum and left/right output*/
+ for(j=0;j<order;)
+ {
+ z = buf[tap[j]];
+ cvec[j] = z;
+ y += z;
+ left += z;
+ right += z;
+ j++;
+
+ z = buf[tap[j]];
+ cvec[j] = z;
+ y += z;
+ left -= z;
+ right += z;
+ j++;
+
+ z = buf[tap[j]];
+ cvec[j] = z;
+ y += z;
+ left += z;
+ right -= z;
+ j++;
+
+ z = buf[tap[j]];
+ cvec[j] = z;
+ y += z;
+ left -= z;
+ right -= z;
+ j++;
+ }
+
+
+ /* write output */
+ *outl++ = left;
+ *outr++ = right;
+
+ /* y == leak to all inputs */
+ y *= ctl->c_leak;
+
+
+
+ /* perform feedback */
+ /* todo: decouple feedback & permutation */
+ save = cvec[0];
+ for (j=0; j<order-1; j++){
+ cvec[j] = cvec[j+1] + y + x;
+ }
+ cvec[order-1] = save + y + x;
+
+
+
+ /* apply gain + store result vector in delay lines + increment taps*/
+ tap[0] = (tap[0]+1)&mask;
+ for(j=0;j<order;j++) {
+ save = gain_in[j] * cvec[j] + gain_state[j] * lvec[j];
+ save = IS_DENORMAL(save) ? 0 : save;
+ cvec[j] = save;
+ buf[tap[j+1]] = save;
+ tap[j+1] = (tap[j+1] + 1) & mask;
+ }
+ }
+
+
+ return (w+6);
+}
+
+static void fdn_dsp(t_fdn *x, t_signal **sp)
+{
+
+ x->x_ctl.c_fsample = sp[0]->s_sr;
+ dsp_add(fdn_perform,
+ 5,
+ &x->x_ctl,
+ sp[0]->s_n,
+ sp[0]->s_vec,
+ sp[1]->s_vec,
+ sp[2]->s_vec);
+
+
+}
+static void fdn_free(t_fdn *x)
+{
+ if ( x->x_ctl.c_tap) free( x->x_ctl.c_tap);
+ if ( x->x_ctl.c_length) free( x->x_ctl.c_length);
+ if ( x->x_ctl.c_gain_in) free( x->x_ctl.c_gain_in);
+ if ( x->x_ctl.c_gain_state) free( x->x_ctl.c_gain_state);
+ if ( x->x_ctl.c_buf) free ( x->x_ctl.c_buf);
+ if ( x->x_ctl.c_vectorbuffer) free ( x->x_ctl.c_vectorbuffer );
+}
+
+
+/*
+
+each delay line is filtered with a first order iir filter:
+(gl: dc gain, gh: ny gain)
+
+H(z) = 2 gl gh / (gl + gh - z^-1 (gl - gh))
+
+this results in the difference equation
+
+yk = (2 gl gh ) / (gl + gh) x + (gl - gh) / (gl + gh) yk-1
+
+*/
+
+
+static void fdn_time(t_fdn *x, t_float timelow, t_float timehigh){
+ t_float elow, ehigh;
+ t_int i;
+ t_float gainlow, gainhigh, gainscale;
+
+ if (timelow < FDN_MIN_DECAY_TIME) timelow = FDN_MIN_DECAY_TIME;
+ if (timehigh < FDN_MIN_DECAY_TIME) timehigh = FDN_MIN_DECAY_TIME;
+
+ elow = -.003 / (timelow);
+ ehigh = -.003 / (timehigh);
+
+ /* setup gains */
+ for(i=0;i<x->x_ctl.c_order;i++){
+ gainlow = pow(10, elow * (x->x_ctl.c_length[i]));
+ gainhigh = pow(10, ehigh * (x->x_ctl.c_length[i]));
+ gainscale = 1.0f / (gainlow + gainhigh);
+ x->x_ctl.c_gain_in[i] = 2.0f * gainlow * gainhigh * gainscale;
+ x->x_ctl.c_gain_state[i] = (gainlow - gainhigh) * gainscale;
+ }
+ x->x_ctl.c_timehigh = timehigh;
+ x->x_ctl.c_timelow = timelow;
+}
+
+static void fdn_updatedamping(t_fdn *x)
+{
+ fdn_time(x, x->x_ctl.c_timelow, x->x_ctl.c_timehigh);
+}
+
+static void fdn_timelow(t_fdn *x, t_float f){
+ x->x_ctl.c_timelow = fabs(f);
+ fdn_updatedamping(x);
+}
+static void fdn_timehigh(t_fdn *x, t_float f){
+ x->x_ctl.c_timehigh = fabs(f);
+ fdn_updatedamping(x);
+}
+
+
+static void fdn_setupdelayline(t_fdn *x){
+ int sum, t, n;
+ int mask = x->x_ctl.c_bufsize - 1;
+ int start = x->x_ctl.c_tap[0];
+ t_int *tap = x->x_ctl.c_tap;
+ float *length = x->x_ctl.c_length;
+ float scale = sys_getsr() * .001f;
+
+ sum = 0;
+ tap[0] = (start & mask);
+ for (t=1; t<= x->x_ctl.c_order; t++){
+ sum += (int)(length[t-1] * scale);
+ tap[t]=(start+sum)&mask;
+ }
+
+ if (sum > mask){
+ post("fdn: warning: not enough delay memory, behaviour is undefined (this could lead to instability...)");
+ }
+
+
+}
+
+static void fdn_list (t_fdn *x, t_symbol *s, int argc, t_atom *argv){
+ int i;
+ float l;
+ int sum=0;
+
+ int order = argc & 0xfffffffc;
+
+ if (order < 4) return;
+ if (order > x->x_ctl.c_maxorder) return;
+
+
+ fdn_order(x, order);
+ for(i=0; i<order; i++)
+ if (argv[i].a_type == A_FLOAT) x->x_ctl.c_length[i] = argv[i].a_w.w_float;
+
+ fdn_setupdelayline(x);
+ fdn_updatedamping(x);
+}
+
+static void fdn_linear(t_fdn *x, t_float forder, t_float min, t_float max)
+{
+ t_int order = ((int)forder) & 0xfffffffc;
+ t_float length, inc;
+ t_int i;
+
+ if (order < 4) return;
+ if (order > x->x_ctl.c_maxorder) return;
+ if (min <= 0) return;
+ if (max <= 0) return;
+
+ inc = (max - min) / (float)(order - 1);
+ length = min;
+
+ for (i=0; i<order; i++){
+ x->x_ctl.c_length[i] = length;
+ length += inc;
+ }
+
+ fdn_order(x, order);
+ fdn_setupdelayline(x);
+ fdn_updatedamping(x);
+}
+
+
+
+static void fdn_exponential(t_fdn *x, t_float forder, t_float min, t_float max)
+{
+ t_int order = ((int)forder) & 0xfffffffc;
+ t_float length, inc;
+ t_int i;
+
+ if (order < 4) return;
+ if (order > x->x_ctl.c_maxorder) return;
+ if (min <= 0) return;
+ if (max <= 0) return;
+
+ inc = pow (max / min, 1.0f / ((float)(order - 1)));
+ length = min;
+
+ for (i=0; i<order; i++){
+ x->x_ctl.c_length[i] = length;
+ length *= inc;
+ }
+
+ fdn_order(x, order);
+ fdn_setupdelayline(x);
+ fdn_updatedamping(x);
+}
+
+
+
+
+
+t_class *fdn_class;
+
+static void *fdn_new(t_floatarg maxiorder, t_floatarg maxibufsize)
+{
+ t_int order = maxiorder;
+ t_int bufround;
+ t_fdn *x = (t_fdn *)pd_new(fdn_class);
+ t_float scale = sys_getsr() * .001f;
+ t_int bufsize = (t_int)(scale * maxibufsize);
+
+
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("float"), gensym("timelow"));
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("float"), gensym("timehigh"));
+ outlet_new(&x->x_obj, gensym("signal"));
+ outlet_new(&x->x_obj, gensym("signal"));
+
+ /* init data */
+ if (order < 4) order = 8;
+ if (bufsize < 64) bufsize = 65536;
+
+ bufround = 1;
+ while (bufround < bufsize) bufround *= 2;
+ bufsize = bufround;
+
+
+ post("fdn: maximum nb of delay lines %d, total buffer size %d samples (%f seconds)",
+ order, bufsize, ((float)bufsize) / sys_getsr());
+
+
+ x->x_ctl.c_maxorder = order;
+ x->x_ctl.c_buf = (float *)malloc(sizeof(float) * bufsize);
+ x->x_ctl.c_bufsize = bufsize;
+ x->x_ctl.c_fsample = sys_getsr();
+ x->x_ctl.c_tap = (t_int *)malloc((order + 1) * sizeof(t_int));
+ x->x_ctl.c_length = (t_float *)malloc(order * sizeof(t_int));
+ x->x_ctl.c_gain_in = (t_float *)malloc(order * sizeof(t_float));
+ x->x_ctl.c_gain_state = (t_float *)malloc(order * sizeof(t_float));
+ x->x_ctl.c_vectorbuffer = (t_float *)malloc(order * 2 * sizeof(float));
+ memset(x->x_ctl.c_vectorbuffer, 0, order * 2 * sizeof(float));
+ x->x_ctl.c_curvector = 0;
+ x->x_ctl.c_vector[0] = &x->x_ctl.c_vectorbuffer[0];
+ x->x_ctl.c_vector[1] = &x->x_ctl.c_vectorbuffer[order];
+
+ /* preset */
+ fdn_order(x,8);
+ x->x_ctl.c_length[0]= 29.0f;
+ x->x_ctl.c_length[1]= 31.0f;
+ x->x_ctl.c_length[2]= 37.0f;
+ x->x_ctl.c_length[3]= 67.0f;
+ x->x_ctl.c_length[4]= 82.0f;
+ x->x_ctl.c_length[5]= 110.0f;
+ x->x_ctl.c_length[6]= 172.0f;
+ x->x_ctl.c_length[7]= 211.0f;
+ fdn_setupdelayline(x);
+ fdn_time(x, 4, 1);
+
+ /* reset delay memory to zero */
+ fdn_reset(x);
+
+
+ return (void *)x;
+}
+
+
+void fdn_tilde_setup(void)
+{
+ //post("fdn~ v0.1");
+ fdn_class = class_new(gensym("fdn~"), (t_newmethod)fdn_new,
+ (t_method)fdn_free, sizeof(t_fdn), 0, A_DEFFLOAT, A_DEFFLOAT, 0);
+ CLASS_MAINSIGNALIN(fdn_class, t_fdn, x_f);
+ class_addmethod(fdn_class, (t_method)fdn_print, gensym("print"), 0);
+ class_addmethod(fdn_class, (t_method)fdn_reset, gensym("reset"), 0);
+ class_addmethod(fdn_class, (t_method)fdn_timehigh, gensym("timehigh"), A_DEFFLOAT, 0);
+ class_addmethod(fdn_class, (t_method)fdn_timelow, gensym("timelow"), A_DEFFLOAT, 0);
+ class_addmethod(fdn_class, (t_method)fdn_list, gensym("lines"), A_GIMME, 0);
+ class_addmethod(fdn_class, (t_method)fdn_dsp, gensym("dsp"), 0);
+ class_addmethod(fdn_class, (t_method)fdn_linear, gensym("linear"), A_FLOAT, A_FLOAT, A_FLOAT, 0);
+ class_addmethod(fdn_class, (t_method)fdn_exponential, gensym("exponential"), A_FLOAT, A_FLOAT, A_FLOAT, 0);
+
+}
+
generated by cgit v1.2.1 (git 2.18.0) at 2025-02-21 21:41:03 +0000