120 lines
3.2 KiB
C
120 lines
3.2 KiB
C
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#include <m_pd.h>
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#include <m_fixed.h>
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#include "cos_table.h"
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/* ---------------- vcf~ - 2-pole bandpass filter. ----------------- */
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/* GG: complex resonator with signal frequency control
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this time using the bigger cos_table without interpolation
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really have to switch to a separate fixpoint format sometime
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*/
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typedef struct vcfctl
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{
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t_sample c_re;
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t_sample c_im;
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t_sample c_q;
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t_sample c_isr;
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} t_vcfctl;
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typedef struct sigvcf
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{
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t_object x_obj;
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t_vcfctl x_cspace;
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t_vcfctl *x_ctl;
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float x_f;
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} t_sigvcf;
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t_class *sigvcf_class;
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static void *sigvcf_new(t_floatarg q)
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{
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t_sigvcf *x = (t_sigvcf *)pd_new(sigvcf_class);
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inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_signal, &s_signal);
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inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("float"), gensym("ft1"));
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outlet_new(&x->x_obj, gensym("signal"));
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outlet_new(&x->x_obj, gensym("signal"));
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x->x_ctl = &x->x_cspace;
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x->x_cspace.c_re = 0;
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x->x_cspace.c_im = 0;
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x->x_cspace.c_q = ftofix(q);
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x->x_cspace.c_isr = 0;
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x->x_f = 0;
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return (x);
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}
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static void sigvcf_ft1(t_sigvcf *x, t_floatarg f)
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{
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x->x_ctl->c_q = (f > 0 ? ftofix(f) : 0);
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}
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static t_int *sigvcf_perform(t_int *w)
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{
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t_sample *in1 = (t_sample *)(w[1]);
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t_sample *in2 = (t_sample *)(w[2]);
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t_sample *out1 = (t_sample *)(w[3]);
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t_sample *out2 = (t_sample *)(w[4]);
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t_vcfctl *c = (t_vcfctl *)(w[5]);
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int n = (t_int)(w[6]);
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int i;
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t_sample re = c->c_re, re2;
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t_sample im = c->c_im;
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t_sample q = c->c_q;
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t_sample qinv = (q > 0 ? idiv(ftofix(1.0),q) : 0);
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t_sample ampcorrect = ftofix(2.0f) - idiv(ftofix(2.0f) , (q + ftofix(2.0f)));
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t_sample isr = c->c_isr;
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t_sample coefr, coefi;
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t_sample *tab = cos_table;
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t_sample oneminusr,cfindx,cf,r;
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for (i = 0; i < n; i++)
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{
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cf = mult(*in2++,isr);
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if (cf < 0) cf = 0;
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cfindx = mult(cf,ftofix(0.15915494))>>(fix1-ILOGCOSTABSIZE); /* 1/2*PI */
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r = (qinv > 0 ? ftofix(1.01) - mult(cf,qinv) : 0);
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if (r < 0) r = 0;
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oneminusr = ftofix(1.02f) - r; /* hand adapted */
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/* r*cos(cf) */
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coefr = mult(r,tab[cfindx]);
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/* r*sin(cf) */
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cfindx-=(ICOSTABSIZE>>2);
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cfindx += cfindx < 0 ? ICOSTABSIZE:0;
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coefi = mult(r,tab[cfindx]);
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re2 = re;
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*out1++ = re = mult(ampcorrect,mult(oneminusr,*in1++))
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+ mult(coefr,re2) - mult(coefi, im);
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*out2++ = im = mult(coefi,re2) + mult(coefr,im);
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}
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c->c_re = re;
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c->c_im = im;
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return (w+7);
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}
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static void sigvcf_dsp(t_sigvcf *x, t_signal **sp)
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{
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/* TODO sr is hardcoded */
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x->x_ctl->c_isr = ftofix(0.0001424758);
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// idiv(ftofix(6.28318),ftofix(sp[0]->s_sr));
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post("%f",fixtof(x->x_ctl->c_isr));
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dsp_add(sigvcf_perform, 6,
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sp[0]->s_vec, sp[1]->s_vec, sp[2]->s_vec, sp[3]->s_vec,
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x->x_ctl, sp[0]->s_n);
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}
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void vcf_tilde_setup(void)
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{
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sigvcf_class = class_new(gensym("vcf~"), (t_newmethod)sigvcf_new, 0,
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sizeof(t_sigvcf), 0, A_DEFFLOAT, 0);
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CLASS_MAINSIGNALIN(sigvcf_class, t_sigvcf, x_f);
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class_addmethod(sigvcf_class, (t_method)sigvcf_dsp, gensym("dsp"), 0);
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class_addmethod(sigvcf_class, (t_method)sigvcf_ft1,
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gensym("ft1"), A_FLOAT, 0);
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class_sethelpsymbol(sigvcf_class, gensym("lop~-help.pd"));
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}
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