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Diffstat (limited to 'modules/sbosc~.c')
| -rw-r--r-- | modules/sbosc~.c | 175 |
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); +} + |