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Diffstat (limited to 'cyclone/sickle/onepole.c')
| -rw-r--r-- | cyclone/sickle/onepole.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/cyclone/sickle/onepole.c b/cyclone/sickle/onepole.c new file mode 100644 index 0000000..f06b581 --- /dev/null +++ b/cyclone/sickle/onepole.c @@ -0,0 +1,151 @@ +/* Copyright (c) 2003 krzYszcz and others. + * For information on usage and redistribution, and for a DISCLAIMER OF ALL + * WARRANTIES, see the file, "LICENSE.txt," in this distribution. */ + +/* This is Pd's lop~ with signal-controlled cutoff. */ + +/* CHECKED scalar case: input preserved (not coefs) after changing mode */ +/* CHECKME if creation arg (or a default) restored after signal disconnection */ + +#include <math.h> +#include "m_pd.h" +#include "shared.h" +#include "sickle/sic.h" + +#if defined(NT) || defined(MACOSX) +/* cf pd/src/x_arithmetic.c */ +#define sinf sin +#endif + +#define ONEPOLE_HZ 0 +#define ONEPOLE_LINEAR 1 +#define ONEPOLE_RADIANS 2 +#define ONEPOLE_MINB0 .0001 /* CHECKED 1st term of ir for b0=0 */ +#define ONEPOLE_MAXB0 .99 /* CHECKED 1st term of ir for b0=1 */ +#define ONEPOLE_MINOMEGA 0. /* CHECKME */ +#define ONEPOLE_MAXOMEGA (SHARED_PI * .5) /* CHECKME */ + +typedef struct _onepole +{ + t_sic x_sic; + int x_mode; + float x_srcoef; + float x_ynm1; +} t_onepole; + +static t_class *onepole_class; + +static t_symbol *ps_hz; +static t_symbol *ps_linear; +static t_symbol *ps_radians; + +static void onepole_clear(t_onepole *x) +{ + x->x_ynm1 = 0.; +} + +static void onepole_hz(t_onepole *x) +{ + x->x_mode = ONEPOLE_HZ; +} + +static void onepole_linear(t_onepole *x) +{ + x->x_mode = ONEPOLE_LINEAR; +} + +static void onepole_radians(t_onepole *x) +{ + x->x_mode = ONEPOLE_RADIANS; +} + +/* LATER make ready for optional audio-rate modulation + (separate scalar case routine, use sic_makecostable(), etc.) */ +static t_int *onepole_perform(t_int *w) +{ + t_onepole *x = (t_onepole *)(w[1]); + int nblock = (int)(w[2]); + t_float *xin = (t_float *)(w[3]); + t_float fin0 = *(t_float *)(w[4]); + t_float *out = (t_float *)(w[5]); + int mode = x->x_mode; + float ynm1 = x->x_ynm1; + /* CHECKME sampled once per block */ + float b0; + if (mode == ONEPOLE_HZ) + { + float omega = fin0 * x->x_srcoef; + if (omega < ONEPOLE_MINOMEGA) + omega = ONEPOLE_MINOMEGA; + else if (omega > ONEPOLE_MAXOMEGA) + omega = ONEPOLE_MAXOMEGA; + /* The actual solution for a half-power cutoff is: + b0 = sqrt(sqr(2-cos(omega))-1) + cos(omega) - 1. + The sin(omega) below is only slightly better approximation than + Miller's b0=omega, except for the two highest octaves (or so), + where it is much better (but far from good). */ + b0 = sinf(omega); + } + else if (mode == ONEPOLE_LINEAR) + b0 = sinf(fin0 * (SHARED_PI * .5)); /* CHECKME actual range of fin0 */ + else + b0 = fin0; + if (b0 < ONEPOLE_MINB0) + b0 = ONEPOLE_MINB0; + else if (b0 > ONEPOLE_MAXB0) + b0 = ONEPOLE_MAXB0; + /* b0 is the standard 1-|a1| (where |a1| is pole's radius), + specifically: a1=b0-1 => a1 in [-.9999 .. -.01] => lowpass (stable) */ + while (nblock--) + *out++ = ynm1 = b0 * (*xin++ - ynm1) + ynm1; + x->x_ynm1 = (PD_BADFLOAT(ynm1) ? 0. : ynm1); + return (w + 6); +} + +static void onepole_dsp(t_onepole *x, t_signal **sp) +{ + x->x_srcoef = SHARED_2PI / sp[0]->s_sr; + onepole_clear(x); + dsp_add(onepole_perform, 5, x, sp[0]->s_n, + sp[0]->s_vec, sp[1]->s_vec, sp[2]->s_vec); +} + +static void *onepole_new(t_symbol *s, t_floatarg f) +{ + t_onepole *x = (t_onepole *)pd_new(onepole_class); + x->x_srcoef = SHARED_2PI / sys_getsr(); + /* CHECKED no int-to-float conversion (any int bashed to 0.) */ + sic_newinlet((t_sic *)x, f); + outlet_new((t_object *)x, &s_signal); + onepole_clear(x); + if (s == ps_linear) + x->x_mode = ONEPOLE_LINEAR; + else if (s == ps_radians) + x->x_mode = ONEPOLE_RADIANS; + else + { + x->x_mode = ONEPOLE_HZ; + if (s && s != &s_ && s != ps_hz && s != gensym("Hz")) + { + /* CHECKED no warning */ + } + } + return (x); +} + +void onepole_tilde_setup(void) +{ + ps_hz = gensym("hz"); + ps_linear = gensym("linear"); + ps_radians = gensym("radians"); + onepole_class = class_new(gensym("onepole~"), + (t_newmethod)onepole_new, 0, + sizeof(t_onepole), 0, + A_DEFFLOAT, A_DEFSYM, 0); + sic_setup(onepole_class, onepole_dsp, SIC_FLOATTOSIGNAL); + class_addmethod(onepole_class, (t_method)onepole_clear, gensym("clear"), 0); + class_addmethod(onepole_class, (t_method)onepole_hz, ps_hz, 0); + class_addmethod(onepole_class, (t_method)onepole_hz, gensym("Hz"), 0); + class_addmethod(onepole_class, (t_method)onepole_linear, ps_linear, 0); + class_addmethod(onepole_class, (t_method)onepole_radians, ps_radians, 0); +} |