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authorTom Schouten <doelie@users.sourceforge.net>2003-09-12 22:26:57 +0000
committerTom Schouten <doelie@users.sourceforge.net>2003-09-12 22:26:57 +0000
commit494a07a361fe4ee0e54f77468a976b1a77818770 (patch)
treeb784b32b2a29e379c6ae5947cdcdcdaadde72b5e /modules/sbosc.c
parent9f8757ccf742d984bd1c1a5d1e5906e9fd50784e (diff)
creb 0.9.0
svn path=/trunk/externals/creb/; revision=956
Diffstat (limited to 'modules/sbosc.c')
-rw-r--r--modules/sbosc.c175
1 files changed, 175 insertions, 0 deletions
diff --git a/modules/sbosc.c b/modules/sbosc.c
new file mode 100644
index 0000000..511c770
--- /dev/null
+++ b/modules/sbosc.c
@@ -0,0 +1,175 @@
+/*
+ * sbosc.c - smallband oscillator. periodic, linear interpolated frequency center.
+ * 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>
+#include <string.h>
+
+
+#define LOGTABSIZE 10
+#define TABSIZE (1<<LOGTABSIZE)
+#define MASKTABSIZE (TABSIZE-1)
+
+#define SHIFTTABSIZE ((sizeof(unsigned int) * 8) - LOGTABSIZE)
+#define FRACTABSIZE (1<<SHIFTTABSIZE)
+#define INVFRACTABSIZE (1.0f / (float)(FRACTABSIZE))
+#define MASKFRACTABSIZE (FRACTABSIZE-1)
+
+#define PITCHLIMIT 20.0f
+
+static float costable[TABSIZE];
+
+static inline void _exp_j2pi(unsigned int t, float *real, float *imag)
+{
+ unsigned int i1 = t >> SHIFTTABSIZE;
+ float f2 = (t & MASKFRACTABSIZE) * INVFRACTABSIZE;
+ unsigned int i2 = (i1+1) & MASKTABSIZE;
+ unsigned int i3 = (i1 - (TABSIZE>>2)) & MASKTABSIZE;
+ unsigned int i4 = (i2 + 1 - (TABSIZE>>2)) & MASKTABSIZE;
+ float f1 = 1.0f - f2;
+ float a1 = f1 * costable[i1];
+ float a2 = f2 * costable[i2];
+ float b1 = f1 * costable[i3];
+ float b2 = f2 * costable[i4];
+ *real = a1 + a2;
+ *imag = b1 + b2;
+}
+
+static t_class *sbosc_tilde_class;
+
+typedef struct _sbosc_tilde
+{
+ t_object x_obj;
+ float x_f;
+
+ /* state vars */
+ unsigned int x_phase; // phase of main pitch osc
+ unsigned int x_phase_inc; // frequency of main pitch osc
+ unsigned int x_harmonic; // first harmonic
+ float x_frac; // fraction of first harmonic
+
+
+} t_sbosc_tilde;
+
+static void *sbosc_tilde_new(void)
+{
+ t_sbosc_tilde *x = (t_sbosc_tilde *)pd_new(sbosc_tilde_class);
+ x->x_phase = 0;
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("signal"), gensym("signal"));
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("float"), gensym("phase"));
+ outlet_new(&x->x_obj, gensym("signal"));
+ outlet_new(&x->x_obj, gensym("signal"));
+ x->x_f = 0;
+ return (x);
+}
+
+
+static t_int *sbosc_tilde_perform(t_int *w)
+{
+ t_sbosc_tilde *x = (t_sbosc_tilde *)(w[1]);
+ t_float *pitch = (t_float *)(w[2]);
+ t_float *center= (t_float *)(w[3]);
+ t_float *out_real = (t_float *)(w[4]);
+ t_float *out_imag = (t_float *)(w[5]);
+ int n = (int)(w[6]);
+ int i;
+
+ t_float pitch_to_phase = 4294967295.0f / sys_getsr();
+
+ for (i = 0; i < n; i++)
+ {
+ float p = *pitch++;
+ float c = *center++;
+ float r1,r2,i1,i2;
+
+ /* compute harmonic mixture */
+ unsigned int h1 = x->x_phase * x->x_harmonic;
+ unsigned int h2 = h1 + x->x_phase;
+ _exp_j2pi(h1, &r1, &i1);
+ _exp_j2pi(h2, &r2, &i2);
+ r1 *= x->x_frac;
+ i1 *= x->x_frac;
+ r2 *= 1.0f - x->x_frac;
+ i2 *= 1.0f - x->x_frac;
+
+ *out_real++ = r1 + r2;
+ *out_imag++ = i1 + i2;
+
+
+ x->x_phase += x->x_phase_inc;
+
+ /* check for phase wrap & update osc */
+ if ((x->x_phase <= x->x_phase_inc))
+ {
+ float p_plus = (p < 0.0f) ? -p : p;
+ float p_limit = (p_plus < PITCHLIMIT) ? PITCHLIMIT : p_plus;
+ float c_plus = (c < 0.0f) ? -c : c;
+ float harmonic = c_plus/p_limit;
+ x->x_phase_inc = pitch_to_phase * p_limit;
+ x->x_harmonic = harmonic;
+ x->x_frac = 1.0f - (harmonic - x->x_harmonic);
+ }
+
+
+ }
+
+ return (w+7);
+}
+
+static void sbosc_tilde_dsp(t_sbosc_tilde *x, t_signal **sp)
+{
+ dsp_add(sbosc_tilde_perform, 6, x,
+ sp[0]->s_vec, sp[1]->s_vec, sp[2]->s_vec, sp[3]->s_vec, sp[0]->s_n);
+
+}
+
+static void sbosc_tilde_free(t_sbosc_tilde *x)
+{
+}
+
+static void sbosc_tilde_phase(t_sbosc_tilde *x, t_floatarg f)
+{
+ x->x_phase = f * (1.0f / 4294967295.0f);
+}
+
+void sbosc_tilde_setup(void)
+{
+ int i;
+
+ // init tables
+ for (i=0; i<TABSIZE; i++)
+ costable[i] = cos(2.0 * M_PI * (double)i / (double)TABSIZE);
+
+
+
+ // class setup
+ sbosc_tilde_class = class_new(gensym("sbosc~"),
+ (t_newmethod)sbosc_tilde_new, (t_method)sbosc_tilde_free,
+ sizeof(t_sbosc_tilde), 0, A_DEFSYM, 0);
+ CLASS_MAINSIGNALIN(sbosc_tilde_class, t_sbosc_tilde, x_f);
+ class_addmethod(sbosc_tilde_class, (t_method)sbosc_tilde_dsp,
+ gensym("dsp"), 0);
+ class_addmethod(sbosc_tilde_class, (t_method)sbosc_tilde_phase,
+ gensym("phase"), A_FLOAT, 0);
+}
+