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Diffstat (limited to 'modules/ead~.c')
| -rw-r--r-- | modules/ead~.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/modules/ead~.c b/modules/ead~.c new file mode 100644 index 0000000..1fe09b7 --- /dev/null +++ b/modules/ead~.c @@ -0,0 +1,158 @@ +/* + * ead.c - exponential attack decay envelope + * 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 "extlib_util.h" + +/* pointer to */ +t_class *ead_class; + + +/* state data fpr attack/decay dsp plugin */ +typedef struct eadctl +{ + t_float c_attack; + t_float c_decay; + t_float c_state; + t_int c_target; +} t_eadctl; + + +/* object data structure */ +typedef struct ead +{ + t_object x_obj; + t_eadctl x_ctl; +} t_ead; + + + +static void ead_attack(t_ead *x, t_floatarg f) +{ + x->x_ctl.c_attack = milliseconds_2_one_minus_realpole(f); +} + +static void ead_decay(t_ead *x, t_floatarg f) +{ + x->x_ctl.c_decay = milliseconds_2_one_minus_realpole(f); +} + +static void ead_start(t_ead *x) +{ + /* reset state if necessary to prevent skipping */ + + // always reset, seems to be safest + //if (x->x_ctl.c_target == 1) + + x->x_ctl.c_state = 0.0f; + x->x_ctl.c_target = 1; +} + + +/* dsp callback function, not a method */ +static t_int *ead_perform(t_int *w) +{ + + /* interprete arguments */ + t_float *out = (float *)(w[3]); + t_eadctl *ctl = (t_eadctl *)(w[1]); + t_float attack = ctl->c_attack; + t_float decay = ctl->c_decay; + t_float state = ctl->c_state; + t_int n = (t_int)(w[2]); + + t_int i; + + + /* A/D code */ + + for (i = 0; i < n; i++){ + switch(ctl->c_target){ + case 1: + /* attack phase */ + *out++ = state; + state += attack*(1 - state); + ctl->c_target = (state <= ENVELOPE_MAX); + break; + default: + /* decay phase */ + *out++ = state; + state -= decay*state; + break; + } + + } + + /* save state */ + ctl->c_state = IS_DENORMAL(state) ? 0 : state; + + return (w+4); +} + + +static void ead_dsp(t_ead *x, t_signal **sp) +{ + dsp_add(ead_perform, 3, &x->x_ctl, sp[0]->s_n, sp[0]->s_vec); +} + +/* destructor */ +static void ead_free(void) +{ + +} + + + +/* constructor */ +static void *ead_new(t_floatarg attack, t_floatarg decay, t_floatarg sustain, t_floatarg release) +{ + /* create instance */ + t_ead *x = (t_ead *)pd_new(ead_class); + /* create new inlets, convert incoming message float to attack/decay */ + inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("float"), gensym("attack")); + inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("float"), gensym("decay")); + /* create a dsp outlet */ + outlet_new(&x->x_obj, gensym("signal")); + + /* initialize */ + x->x_ctl.c_state = 0; + x->x_ctl.c_target = 0; + ead_attack(x, attack); + ead_decay(x, decay); + + /* return instance */ + return (void *)x; +} + +void ead_tilde_setup(void) +{ + //post("ead~ v0.1"); + + ead_class = class_new(gensym("ead~"), (t_newmethod)ead_new, + (t_method)ead_free, sizeof(t_ead), 0, A_DEFFLOAT, A_DEFFLOAT, 0); + + + class_addmethod(ead_class, (t_method)ead_start, gensym("start"), 0); + class_addmethod(ead_class, (t_method)ead_start, gensym("bang"), 0); + class_addmethod(ead_class, (t_method)ead_dsp, gensym("dsp"), 0); + class_addmethod(ead_class, (t_method)ead_attack, gensym("attack"), A_FLOAT, 0); + class_addmethod(ead_class, (t_method)ead_decay, gensym("decay"), A_FLOAT, 0); +} + |