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+/* Copyright (c) 2002 Yves Degoyon. */
+/* For information on usage and redistribution, and for a DISCLAIMER OF ALL */
+/* WARRANTIES, see the file, "COPYING" in this distribution. */
+/* */
+/* wahwah~ -- a kind of effect used in psychedelic music */
+/* the algorithm was taken from Digital Effects, */
+/* a guitar effects software for DOS which rocks, written by Alexey Smoli */
+/* ( http://st.karelia.ru/~smlalx/ ) */
+/* */
+/* 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. */
+/* */
+/* See file LICENSE for further informations on licensing terms. */
+/* */
+/* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+/* */
+/* Based on PureData by Miller Puckette and others. */
+/* */
+/* Made while listening to : */
+/* */
+/* Crass -- "Shaved Women ( Collaborators )" */
+/* Zounds -- "Can't Cheat Karma" */
+/* */
+/* Special message for the french : */
+/* "Delay all your work...and go vote against national front" */
+/* ---------------------------------------------------------------------------- */
+
+#include "m_pd.h"
+#include <stdlib.h>
+#include <math.h>
+
+#ifdef NT
+#define M_PI 3.14159265358979323846
+#endif
+
+#define BFSZ 4096 /* main delay buffer */
+#define BLOCK_DELAY 10 /* number of blocks to delay */
+#define NA 0.0 /* param not applicable */
+#define COEFFSIZE 3000 /* coefficients size */
+#define NBCOEFFS 5 /* number of coefficients */
+
+static char *wahwah_version = "wahwah~: an audio wahwah, version 0.1 (ydegoyon@free.fr)";
+
+typedef struct _wahwah
+{
+ t_object x_obj;
+ double *x_buf;
+ t_int x_samplerate;
+ t_float *x_coeffs;
+ double x_minfc; /* min frequency Hz */ /* 0< <3000 */
+ double x_maxfc; /* max frequency Hz */ /* 0< <3000 */
+ double x_sense; /* increase/decrease frequency change by one mouse movement Hz */ /* 0< <=1000 */
+ double x_maxstep; /* maximum frequency change step KHz */ /* 0< <=100 */
+ double x_dbgain; /* peaking filter gain dB */ /* -15<= <=15 */
+ double x_bandwidth; /* bandwidth in octaves (between midpoint (dBgain/2)
+ gain frequencies) or */ /* 0< <10 */
+ double x_Q; /* the EE kinda definition */ /* 0< <=1 */
+
+ /* variables for audio computation */
+ double min_coef,max_coef,cur_coef,step,maxstep;
+ t_int down;
+ /* amplitudes */
+ short x0,x1,x2;
+ t_int y0,y1,y2;
+
+ t_float x_f;
+} t_wahwah;
+
+static t_class *wahwah_class;
+
+static void wahwah_set_coeffs (t_wahwah *x)
+{
+ t_int i;
+ double omega;
+ double sn,cs;
+ double alpha = 0.0;
+ /* filter coefficients */
+ double a0,a1,a2,b0,b1,b2;
+ double A;
+
+ A = exp(x->x_dbgain/40.0)*log(10.0);
+ for (i = 0; i < COEFFSIZE; i++)
+ {
+ omega = 2.0*M_PI*(double)i/(double)x->x_samplerate;
+ sn = sin(omega);
+ cs = cos(omega);
+ if (x->x_bandwidth)
+ alpha = sn*sin(log(2.0)/2.0*x->x_bandwidth*omega/sn);
+ else
+ /* if Q is specified instead of bandwidth */
+ if (x->x_Q)
+ alpha = sn/(2.0*x->x_Q);
+
+ /* then compute the coefs for whichever filter type you want */
+ b0 = 1.0 + alpha*A;
+ b1 = -2.0*cs ;
+ b2 = 1.0 - alpha*A;
+ a0 = 1.0 + alpha/A;
+ a1 = -2.0*cs ;
+ a2 = 1.0 - alpha/A;
+
+ *(x->x_coeffs+i*NBCOEFFS) = (b0/a0);
+ *(x->x_coeffs+i*NBCOEFFS+1) = (b1/a0);
+ *(x->x_coeffs+i*NBCOEFFS+2) = (b2/a0);
+ *(x->x_coeffs+i*NBCOEFFS+3) = (a1/a0);
+ *(x->x_coeffs+i*NBCOEFFS+4) = (a2/a0);
+ // post( "wahwah~ : coeff : %f", *(x->x_coeffs+i*NBCOEFFS+4) );
+ }
+ x->min_coef = x->x_minfc;
+ x->max_coef = x->x_maxfc;
+ x->cur_coef = x->min_coef;
+ x->down = 1;
+ x->step = 0;
+ x->maxstep = x->x_maxstep/(double)x->x_samplerate*1000.0;
+}
+
+static void wahwah_bandwidth(t_wahwah *x, t_floatarg fbandwidth )
+{
+ if ( fbandwidth > 10.0 )
+ {
+ fbandwidth = 10.0;
+ }
+ if ( fbandwidth < 0.0 )
+ {
+ fbandwidth = 0.0;
+ }
+ x->x_bandwidth = fbandwidth;
+ // post( "wahwah~ : bandwidth: %f", x->x_bandwidth );
+ wahwah_set_coeffs( x );
+}
+
+static void wahwah_dbgain(t_wahwah *x, t_floatarg fdbgain )
+{
+ if ( fdbgain > 15.0 )
+ {
+ fdbgain = 15.0;
+ }
+ if ( fdbgain < -15.0 )
+ {
+ fdbgain = -15.0;
+ }
+ x->x_dbgain = fdbgain;
+ // post( "wahwah~ : dbgain: %f", x->x_dbgain );
+ wahwah_set_coeffs( x );
+}
+
+static void wahwah_maxstep(t_wahwah *x, t_floatarg fmaxstep )
+{
+ if ( fmaxstep > 100.0 )
+ {
+ fmaxstep = 100.0;
+ }
+ if ( fmaxstep < 0.0 )
+ {
+ fmaxstep = 0.0;
+ }
+ x->x_maxstep = fmaxstep;
+ // post( "wahwah~ : maxstep: %f", x->x_maxstep );
+ wahwah_set_coeffs( x );
+}
+
+static void wahwah_sensibility(t_wahwah *x, t_floatarg fsensibility )
+{
+ if ( fsensibility > 1000.0 )
+ {
+ fsensibility = 1000.0;
+ }
+ if ( fsensibility < 0.0 )
+ {
+ fsensibility = 0.0;
+ }
+ x->x_sense = fsensibility;
+ // post( "wahwah~ : sensibility: %f", x->x_sense );
+ wahwah_set_coeffs( x );
+}
+
+static void wahwah_maxfreq(t_wahwah *x, t_floatarg fmaxfreq )
+{
+ if ( fmaxfreq > 3000.0 )
+ {
+ fmaxfreq = 3000.0;
+ }
+ if ( fmaxfreq < 0.0 )
+ {
+ fmaxfreq = 0.0;
+ }
+ x->x_maxfc = fmaxfreq;
+ // post( "wahwah~ : maxfreq: %f", x->x_maxfc );
+ wahwah_set_coeffs( x );
+}
+
+static void wahwah_minfreq(t_wahwah *x, t_floatarg fminfreq )
+{
+ if ( fminfreq > 3000.0 )
+ {
+ fminfreq = 3000.0;
+ }
+ if ( fminfreq < 0.0 )
+ {
+ fminfreq = 0.0;
+ }
+ x->x_minfc = fminfreq;
+ // post( "wahwah~ : minfreq: %f", x->x_minfc );
+ wahwah_set_coeffs( x );
+}
+
+static void wahwah_step(t_wahwah *x, t_floatarg fstep )
+{
+ if ( fstep > x->x_maxstep )
+ {
+ fstep = x->x_maxstep;
+ }
+ if ( fstep < 0 )
+ {
+ fstep = 0;
+ }
+ x->step = fstep*x->x_sense/x->x_samplerate;
+}
+
+static t_int *wahwah_perform(t_int *w)
+{
+ t_float *in = (t_float *)(w[1]);
+ t_float *out = (t_float *)(w[2]);
+ t_int n = (int)(w[3]);
+ t_wahwah *x = (t_wahwah*)(w[4]);
+ t_int i;
+
+ for (i=0; i<n; i++)
+ {
+ /* read input */
+ x->x0 = (int)((*(in+i))*32768);
+
+ x->y0 = (*(x->x_coeffs+(int)x->cur_coef*NBCOEFFS))*x->x0
+ + (*(x->x_coeffs+(int)x->cur_coef*NBCOEFFS+1))*x->x1
+ + (*(x->x_coeffs+(int)x->cur_coef*NBCOEFFS+2))*x->x2
+ - (*(x->x_coeffs+(int)x->cur_coef*NBCOEFFS+3))*x->y1
+ - (*(x->x_coeffs+(int)x->cur_coef*NBCOEFFS+4))*x->y2;
+
+ x->y2 = x->y1;
+ x->y1 = x->y0;
+ x->x2 = x->x1;
+ x->x1 = x->x0;
+
+ if(x->y0 > 32767.0)
+ x->y0 = 32767.0;
+ else if(x->y0 < -32768.0)
+ x->y0 = -32768.0;
+
+ *(out+i) = (t_float)(x->y0) / 32768.0;
+
+ x->cur_coef = x->cur_coef+x->down*x->step*(abs(x->x0)/(0.5*32768.0));
+ // post ( "wahwah~ : cur coeff : %f", x->cur_coef );
+ if(x->cur_coef > x->max_coef)
+ {
+ x->cur_coef = x->max_coef;
+ x->down = -1;
+ }
+ else if(x->cur_coef < x->min_coef)
+ {
+ x->cur_coef = x->min_coef;
+ x->down = 1;
+ }
+
+ }
+
+ return (w+5);
+}
+
+static void wahwah_preset(t_wahwah *x, t_float pnumber)
+{
+ switch ( (int)pnumber )
+ {
+ /* fast change medium wah wah */
+ case 1:
+ x->x_minfc = 100.0;
+ x->x_maxfc = 1600.0;
+ x->x_sense = 100.0;
+ x->x_maxstep = 60.0;
+ x->x_dbgain = 15.0;
+ x->x_Q = 1.0;
+ break;
+
+ /* slow change medium wah wah */
+ case 2:
+ x->x_minfc = 100.0;
+ x->x_maxfc = 1600.0;
+ x->x_sense = 50.0;
+ x->x_maxstep = 36.0;
+ x->x_dbgain = 15.0;
+ x->x_Q = 1.0;
+ break;
+
+ /* fast wah wah */
+ case 3:
+ x->x_minfc = 100.0;
+ x->x_maxfc = 600.0;
+ x->x_sense = 100.0;
+ x->x_maxstep = 66.0;
+ x->x_dbgain = 15.0;
+ x->x_Q = 1.0;
+ break;
+
+ /* ranged wah wah */
+ case 4:
+ x->x_minfc = 10.0;
+ x->x_maxfc = 2900.0;
+ x->x_sense = 100.0;
+ x->x_maxstep = 66.0;
+ x->x_dbgain = 15.0;
+ x->x_Q = 1.0;
+ break;
+
+ /* wah wah 400 - 2000 */
+ case 5:
+ x->x_minfc = 400.0;
+ x->x_maxfc = 2000.0;
+ x->x_sense = 100.0;
+ x->x_maxstep = 66.0;
+ x->x_dbgain = 15.0;
+ x->x_Q = 1.0;
+ break;
+
+ default:
+ post( "wahwah~ : unknown preset requested : %d", pnumber );
+ return;
+ break;
+ }
+ wahwah_set_coeffs( x );
+}
+
+static void wahwah_dsp(t_wahwah *x, t_signal **sp)
+{
+ dsp_add(wahwah_perform, 4, sp[0]->s_vec, sp[1]->s_vec, sp[0]->s_n, x );
+}
+
+ /* clean up */
+static void wahwah_free(t_wahwah *x)
+{
+ if ( x->x_buf != NULL ) {
+ freebytes(x->x_buf, BFSZ*sizeof( double ) );
+ post( "Freed %d bytes", BFSZ*sizeof( double ) );
+ x->x_buf = NULL;
+ }
+ if ( x->x_coeffs != NULL ) {
+ freebytes(x->x_coeffs, COEFFSIZE*NBCOEFFS*sizeof( t_float ) );
+ post( "Freed %d bytes", COEFFSIZE*NBCOEFFS*sizeof( t_float ));
+ x->x_coeffs = NULL;
+ }
+}
+
+static void *wahwah_new(void)
+{
+ t_wahwah *x = (t_wahwah *)pd_new(wahwah_class);
+ outlet_new(&x->x_obj, &s_signal);
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("minfreq"));
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("maxfreq"));
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("sensibility"));
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("maxstep"));
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("dbgain"));
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("bandwidth"));
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("step"));
+
+ x->x_samplerate = (int)sys_getsr();
+
+ if ( !( x->x_buf = ( double* ) getbytes( BFSZ*sizeof( double ) ) ) )
+ {
+ post ("wahwah~ : could not allocate buffer" );
+ return NULL;
+ }
+ if ( !( x->x_coeffs = ( t_float* ) getbytes( COEFFSIZE*NBCOEFFS*sizeof( t_float ) ) ) )
+ {
+ post ("wahwah~ : could not allocate coeffs" );
+ return NULL;
+ }
+
+ // set default parameters
+ wahwah_preset( x, 1 );
+ wahwah_set_coeffs( x );
+
+ return (x);
+}
+
+void wahwah_tilde_setup(void)
+{
+ post( wahwah_version );
+ wahwah_class = class_new(gensym("wahwah~"), (t_newmethod)wahwah_new, (t_method)wahwah_free,
+ sizeof(t_wahwah), 0, 0);
+
+ CLASS_MAINSIGNALIN( wahwah_class, t_wahwah, x_f );
+ class_addmethod(wahwah_class, (t_method)wahwah_step, gensym("step"), A_FLOAT, 0);
+ class_addmethod(wahwah_class, (t_method)wahwah_minfreq, gensym("minfreq"), A_FLOAT, 0);
+ class_addmethod(wahwah_class, (t_method)wahwah_maxfreq, gensym("maxfreq"), A_FLOAT, 0);
+ class_addmethod(wahwah_class, (t_method)wahwah_sensibility, gensym("sensibility"), A_FLOAT, 0);
+ class_addmethod(wahwah_class, (t_method)wahwah_maxstep, gensym("maxstep"), A_FLOAT, 0);
+ class_addmethod(wahwah_class, (t_method)wahwah_dbgain, gensym("dbgain"), A_FLOAT, 0);
+ class_addmethod(wahwah_class, (t_method)wahwah_bandwidth, gensym("bandwidth"), A_FLOAT, 0);
+ class_addmethod(wahwah_class, (t_method)wahwah_dsp, gensym("dsp"), 0);
+ class_addmethod(wahwah_class, (t_method)wahwah_preset, gensym("preset"), A_FLOAT, 0);
+}
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-12 22:41:53 +0000