From 577ac6e80ff4f436fbd054291ed7dddbc31bd49a Mon Sep 17 00:00:00 2001
From: Hans-Christoph Steiner <eighthave@users.sourceforge.net>
Date: Tue, 18 May 2004 21:33:33 +0000
Subject: This commit was generated by cvs2svn to compensate for changes in
 r1738, which included commits to RCS files with non-trunk default branches.

svn path=/trunk/externals/iemlib/; revision=1739
---
 src/iemlib1/sigfilter.c | 822 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 822 insertions(+)
 create mode 100644 src/iemlib1/sigfilter.c

(limited to 'src/iemlib1/sigfilter.c')

diff --git a/src/iemlib1/sigfilter.c b/src/iemlib1/sigfilter.c
new file mode 100644
index 0000000..6a05206
--- /dev/null
+++ b/src/iemlib1/sigfilter.c
@@ -0,0 +1,822 @@
+/* For information on usage and redistribution, and for a DISCLAIMER OF ALL
+* WARRANTIES, see the file, "LICENSE.txt," in this distribution.
+
+iemlib1 written by Thomas Musil, Copyright (c) IEM KUG Graz Austria 2000 - 2003 */
+
+#ifdef NT
+#pragma warning( disable : 4244 )
+#pragma warning( disable : 4305 )
+#endif
+
+
+#include "m_pd.h"
+#include "iemlib.h"
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+
+
+/* ---------- filter~ - slow dynamic filter 1. and 2. order ----------- */
+
+typedef struct sigfilter
+{
+	t_object x_obj;
+	float	wn1;
+	float	wn2;
+	float	a0;
+	float	a1;
+	float	a2;
+	float	b1;
+	float	b2;
+	float	sr;
+	float	cur_f;
+	float	cur_l;
+	float	cur_a;
+	float	cur_b;
+	float	delta_f;
+	float	delta_a;
+	float	delta_b;
+	float	end_f;
+	float	end_a;
+	float	end_b;
+	float	ticks_per_interpol_time;
+	float	rcp_ticks;
+	float	interpol_time;
+	int		ticks;
+	int		counter_f;
+	int		counter_a;
+	int		counter_b;
+	int		inv;
+	int		hp;
+	int		first_order;
+	int		event_mask;
+	void	(*calc)();
+	void	*x_debug_outlet;
+	t_atom x_at[5];
+	float	x_msi;
+} t_sigfilter;
+
+t_class *sigfilter_class;
+
+static void sigfilter_snafu(t_sigfilter *x)
+{
+
+}
+
+static void sigfilter_lp1(t_sigfilter *x)
+{
+	float al;
+
+	al = x->cur_a * x->cur_l;
+	x->a0 = 1.0f/(1.0f + al);
+	x->a1 = x->a0;
+	x->b1 = (al - 1.0f)*x->a0;
+}
+
+static void sigfilter_lp2(t_sigfilter *x)
+{
+	float l, al, bl2, rcp;
+
+	l = x->cur_l;
+	al = l*x->cur_a;
+	bl2 = l*l*x->cur_b + 1.0f;
+	rcp = 1.0f/(al + bl2);
+	x->a0 = rcp;
+	x->a1 = 2.0f*rcp;
+	x->a2 = x->a0;
+	x->b1 = rcp*2.0f*(bl2 - 2.0f);
+	x->b2 = rcp*(al - bl2);
+}
+
+static void sigfilter_hp1(t_sigfilter *x)
+{
+	float al, rcp;
+
+	al = x->cur_a * x->cur_l;
+	rcp = 1.0f/(1.0f + al);
+	x->a0 = rcp*al;
+	x->a1 = -x->a0;
+	x->b1 = rcp*(al - 1.0f);
+}
+
+static void sigfilter_hp2(t_sigfilter *x)
+{
+	float l, al, bl2, rcp;
+
+	l = x->cur_l;
+	bl2 = l*l*x->cur_b + 1.0f;
+	al = l*x->cur_a;
+	rcp = 1.0f/(al + bl2);
+	x->a0 = rcp*(bl2 - 1.0f);
+	x->a1 = -2.0f*x->a0;
+	x->a2 = x->a0;
+	x->b1 = rcp*2.0f*(bl2 - 2.0f);
+	x->b2 = rcp*(al - bl2);
+}
+
+static void sigfilter_rp2(t_sigfilter *x)
+{
+	float l, al, l2, rcp;
+
+	l = x->cur_l;
+	l2 = l*l + 1.0f;
+	al = l*x->cur_a;
+	rcp = 1.0f/(al + l2);
+	x->a0 = rcp*l;
+	x->a2 = -x->a0;
+	x->b1 = rcp*2.0f*(l2 - 2.0f);
+	x->b2 = rcp*(al - l2);
+}
+
+static void sigfilter_bp2(t_sigfilter *x)
+{
+	float l, al, l2, rcp;
+
+	l = x->cur_l;
+	l2 = l*l + 1.0f;
+	al = l*x->cur_a;
+	rcp = 1.0f/(al + l2);
+	x->a0 = rcp*al;
+	x->a2 = -x->a0;
+	x->b1 = rcp*2.0f*(l2 - 2.0f);
+	x->b2 = rcp*(al - l2);
+}
+
+static void sigfilter_bs2(t_sigfilter *x)
+{
+	float l, al, l2, rcp;
+
+	l = x->cur_l;
+	l2 = l*l + 1.0f;
+	al = l*x->cur_a;
+	rcp = 1.0f/(al + l2);
+	x->a0 = rcp*l2;
+	x->a1 = rcp*2.0f*(2.0f - l2);
+	x->a2 = x->a0;
+	x->b1 = -x->a1;
+	x->b2 = rcp*(al - l2);
+}
+
+static void sigfilter_rpw2(t_sigfilter *x)
+{
+	float l, al, l2, rcp;
+
+	l = x->cur_l;
+	l2 = l*l + 1.0f;
+	al = l*x->cur_a/x->cur_f;
+	rcp = 1.0f/(al + l2);
+	x->a0 = rcp*l;
+	x->a2 = -x->a0;
+	x->b1 = rcp*2.0f*(l2 - 2.0f);
+	x->b2 = rcp*(al - l2);
+}
+
+static void sigfilter_bpw2(t_sigfilter *x)
+{
+	float l, al, l2, rcp;
+
+	l = x->cur_l;
+	l2 = l*l + 1.0f;
+	al = l*x->cur_a/x->cur_f;
+	rcp = 1.0f/(al + l2);
+	x->a0 = rcp*al;
+	x->a2 = -x->a0;
+	x->b1 = rcp*2.0f*(l2 - 2.0f);
+	x->b2 = rcp*(al - l2);
+}
+
+static void sigfilter_bsw2(t_sigfilter *x)
+{
+	float l, al, l2, rcp;
+
+	l = x->cur_l;
+	l2 = l*l + 1.0f;
+	al = l*x->cur_a/x->cur_f;
+	rcp = 1.0f/(al + l2);
+	x->a0 = rcp*l2;
+	x->a1 = rcp*2.0f*(2.0f - l2);
+	x->a2 = x->a0;
+	x->b1 = -x->a1;
+	x->b2 = rcp*(al - l2);
+}
+
+static void sigfilter_ap1(t_sigfilter *x)
+{
+	float al;
+
+	al = x->cur_a * x->cur_l;
+	x->a0 = (1.0f - al)/(1.0f + al);
+	x->b1 = -x->a0;
+}
+
+static void sigfilter_ap2(t_sigfilter *x)
+{
+	float l, al, bl2, rcp;
+
+	l = x->cur_l;
+	bl2 = l*l*x->cur_b + 1.0f;
+	al = l*x->cur_a;
+	rcp = 1.0f/(al + bl2);
+	x->a1 = rcp*2.0f*(2.0f - bl2);
+	x->a0 = rcp*(bl2 - al);
+	x->b1 = -x->a1;
+	x->b2 = -x->a0;
+}
+
+/*static void sigfilter_bp2(t_sigfilter *x)
+{
+	float l, al, l2, rcp;
+
+	l = x->cur_l;
+	l2 = l*l + 1.0;
+	al = l*x->cur_a;
+	rcp = 1.0f/(al + l2);
+	x->a0 = rcp*al;
+	x->a2 = -x->a0;
+	x->b1 = rcp*2.0f*(2.0f - l2);
+	x->b2 = rcp*(l2 - al);
+}*/
+
+static void sigfilter_dsp_tick(t_sigfilter *x)
+{
+	if(x->event_mask)
+	{
+		if(x->counter_f)
+		{
+			float l, si, co;
+
+			if(x->counter_f <= 1)
+			{
+				x->cur_f = x->end_f;
+				x->counter_f = 0;
+				x->event_mask &= 6;/*set event_mask_bit 0 = 0*/
+			}
+			else
+			{
+				x->counter_f--;
+				x->cur_f *= x->delta_f;
+			}
+			l = x->cur_f * x->sr;
+			if(l < 1.0e-20f)
+				x->cur_l = 1.0e20f;
+			else if(l > 1.57079632f)
+				x->cur_l = 0.0f;
+			else
+			{
+				si = sin(l);
+				co = cos(l);
+				x->cur_l = co/si;
+			}
+		}
+		if(x->counter_a)
+		{
+			if(x->counter_a <= 1)
+			{
+				x->cur_a = x->end_a;
+				x->counter_a = 0;
+				x->event_mask &= 5;/*set event_mask_bit 1 = 0*/
+			}
+			else
+			{
+				x->counter_a--;
+				x->cur_a *= x->delta_a;
+			}
+		}
+		if(x->counter_b)
+		{
+			if(x->counter_b <= 1)
+			{
+				x->cur_b = x->end_b;
+				x->counter_b = 0;
+				x->event_mask &= 3;/*set event_mask_bit 2 = 0*/
+			}
+			else
+			{
+				x->counter_b--;
+				x->cur_b *= x->delta_b;
+			}
+		}
+
+		(*(x->calc))(x);
+
+		/* stability check */
+		if(x->first_order)
+		{
+			if(x->b1 <= -0.9999998f)
+				x->b1 = -0.9999998f;
+			else if(x->b1 >= 0.9999998f)
+				x->b1 = 0.9999998f;
+		}
+		else
+		{
+			float discriminant = x->b1 * x->b1 + 4.0f * x->b2;
+
+			if(x->b1 <= -1.9999996f)
+				x->b1 = -1.9999996f;
+			else if(x->b1 >= 1.9999996f)
+				x->b1 = 1.9999996f;
+
+			if(x->b2 <= -0.9999998f)
+				x->b2 = -0.9999998f;
+			else if(x->b2 >= 0.9999998f)
+				x->b2 = 0.9999998f;
+
+			if(discriminant >= 0.0f)
+			{
+				if(0.9999998f - x->b1 - x->b2 < 0.0f)
+					x->b2 = 0.9999998f - x->b1;
+				if(0.9999998f + x->b1 - x->b2 < 0.0f)
+					x->b2 = 0.9999998f + x->b1;
+			}
+		}
+	}
+}
+
+static t_int *sigfilter_perform_2o(t_int *w)
+{
+	float *in = (float *)(w[1]);
+	float *out = (float *)(w[2]);
+	t_sigfilter *x = (t_sigfilter *)(w[3]);
+	int i, n = (t_int)(w[4]);
+	float wn0, wn1=x->wn1, wn2=x->wn2;
+	float a0=x->a0, a1=x->a1, a2=x->a2;
+	float b1=x->b1, b2=x->b2;
+
+	sigfilter_dsp_tick(x);
+	for(i=0; i<n; i++)
+	{
+		wn0 = *in++ + b1*wn1 + b2*wn2;
+		*out++ = a0*wn0 + a1*wn1 + a2*wn2;
+		wn2 = wn1;
+		wn1 = wn0;
+	}
+	/* NAN protect */
+	if(PD_BADFLOAT(wn2))
+		wn2 = 0.0f;
+	if(PD_BADFLOAT(wn1))
+		wn1 = 0.0f;
+
+	x->wn1 = wn1;
+	x->wn2 = wn2;
+	return(w+5);
+}
+/*   yn0 = *out;
+	 xn0 = *in;
+	 *************
+	 yn0 = a0*xn0 + a1*xn1 + a2*xn2 + b1*yn1 + b2*yn2;
+	 yn2 = yn1;
+	 yn1 = yn0;
+	 xn2 = xn1;
+	 xn1 = xn0;
+	 *************************
+	 y/x = (a0 + a1*z-1 + a2*z-2)/(1 - b1*z-1 - b2*z-2);*/
+
+static t_int *sigfilter_perf8_2o(t_int *w)
+{
+	float *in = (float *)(w[1]);
+	float *out = (float *)(w[2]);
+	t_sigfilter *x = (t_sigfilter *)(w[3]);
+	int i, n = (t_int)(w[4]);
+	float wn[10];
+	float a0=x->a0, a1=x->a1, a2=x->a2;
+	float b1=x->b1, b2=x->b2;
+
+	sigfilter_dsp_tick(x);
+	wn[0] = x->wn2;
+	wn[1] = x->wn1;
+	for(i=0; i<n; i+=8, in+=8, out+=8)
+	{
+		wn[2] = in[0] + b1*wn[1] + b2*wn[0];
+		out[0] = a0*wn[2] + a1*wn[1] + a2*wn[0];
+		wn[3] = in[1] + b1*wn[2] + b2*wn[1];
+		out[1] = a0*wn[3] + a1*wn[2] + a2*wn[1];
+		wn[4] = in[2] + b1*wn[3] + b2*wn[2];
+		out[2] = a0*wn[4] + a1*wn[3] + a2*wn[2];
+		wn[5] = in[3] + b1*wn[4] + b2*wn[3];
+		out[3] = a0*wn[5] + a1*wn[4] + a2*wn[3];
+		wn[6] = in[4] + b1*wn[5] + b2*wn[4];
+		out[4] = a0*wn[6] + a1*wn[5] + a2*wn[4];
+		wn[7] = in[5] + b1*wn[6] + b2*wn[5];
+		out[5] = a0*wn[7] + a1*wn[6] + a2*wn[5];
+		wn[8] = in[6] + b1*wn[7] + b2*wn[6];
+		out[6] = a0*wn[8] + a1*wn[7] + a2*wn[6];
+		wn[9] = in[7] + b1*wn[8] + b2*wn[7];
+		out[7] = a0*wn[9] + a1*wn[8] + a2*wn[7];
+		wn[0] = wn[8];
+		wn[1] = wn[9];
+	}
+	/* NAN protect */
+	if(PD_BADFLOAT(wn[0]))
+		wn[0] = 0.0f;
+	if(PD_BADFLOAT(wn[1]))
+		wn[1] = 0.0f;
+
+	x->wn1 = wn[1];
+	x->wn2 = wn[0];
+	return(w+5);
+}
+
+static t_int *sigfilter_perform_1o(t_int *w)
+{
+	float *in = (float *)(w[1]);
+	float *out = (float *)(w[2]);
+	t_sigfilter *x = (t_sigfilter *)(w[3]);
+	int i, n = (t_int)(w[4]);
+	float wn0, wn1=x->wn1;
+	float a0=x->a0, a1=x->a1;
+	float b1=x->b1;
+
+	sigfilter_dsp_tick(x);
+	for(i=0; i<n; i++)
+	{
+		wn0 = *in++ + b1*wn1;
+		*out++ = a0*wn0 + a1*wn1;
+		wn1 = wn0;
+	}
+	/* NAN protect */
+	if(PD_BADFLOAT(wn1))
+		wn1 = 0.0f;
+
+	x->wn1 = wn1;
+	return(w+5);
+}
+
+static t_int *sigfilter_perf8_1o(t_int *w)
+{
+	float *in = (float *)(w[1]);
+	float *out = (float *)(w[2]);
+	t_sigfilter *x = (t_sigfilter *)(w[3]);
+	int i, n = (t_int)(w[4]);
+	float wn[9];
+	float a0=x->a0, a1=x->a1;
+	float b1=x->b1;
+
+	sigfilter_dsp_tick(x);
+	wn[0] = x->wn1;
+	for(i=0; i<n; i+=8, in+=8, out+=8)
+	{
+		wn[1] = in[0] + b1*wn[0];
+		out[0] = a0*wn[1] + a1*wn[0];
+		wn[2] = in[1] + b1*wn[1];
+		out[1] = a0*wn[2] + a1*wn[1];
+		wn[3] = in[2] + b1*wn[2];
+		out[2] = a0*wn[3] + a1*wn[2];
+		wn[4] = in[3] + b1*wn[3];
+		out[3] = a0*wn[4] + a1*wn[3];
+		wn[5] = in[4] + b1*wn[4];
+		out[4] = a0*wn[5] + a1*wn[4];
+		wn[6] = in[5] + b1*wn[5];
+		out[5] = a0*wn[6] + a1*wn[5];
+		wn[7] = in[6] + b1*wn[6];
+		out[6] = a0*wn[7] + a1*wn[6];
+		wn[8] = in[7] + b1*wn[7];
+		out[7] = a0*wn[8] + a1*wn[7];
+		wn[0] = wn[8];
+	}
+	/* NAN protect */
+	if(PD_BADFLOAT(wn[0]))
+		wn[0] = 0.0f;
+
+	x->wn1 = wn[0];
+	return(w+5);
+}
+
+static void sigfilter_ft4(t_sigfilter *x, t_floatarg t)
+{
+	int i = (int)((x->ticks_per_interpol_time)*t+0.49999f);
+
+	x->interpol_time = t;
+	if(i <= 0)
+	{
+		x->ticks = 1;
+		x->rcp_ticks = 1.0;
+	}
+	else
+	{
+		x->ticks = i;
+		x->rcp_ticks = 1.0 / (float)i;
+	}
+}
+
+static void sigfilter_ft3(t_sigfilter *x, t_floatarg b)
+{
+	if(b <= 0.0f)
+		b = 0.000001f;
+	if(x->hp)
+		b = 1.0 / b;
+	if(b != x->cur_b)
+	{
+		x->end_b = b;
+		x->counter_b = x->ticks;
+		x->delta_b = exp(log(b/x->cur_b)*x->rcp_ticks);
+		x->event_mask |= 4;/*set event_mask_bit 2 = 1*/
+	}
+}
+
+static void sigfilter_ft2(t_sigfilter *x, t_floatarg a)
+{
+	if(a <= 0.0f)
+		a = 0.000001f;
+	if(x->inv)
+		a = 1.0f / a;
+	if(x->hp)
+		a /= x->cur_b;
+	if(a != x->cur_a)
+	{
+		x->end_a = a;
+		x->counter_a = x->ticks;
+		x->delta_a = exp(log(a/x->cur_a)*x->rcp_ticks);
+		x->event_mask |= 2;/*set event_mask_bit 1 = 1*/
+	}
+}
+
+static void sigfilter_ft1(t_sigfilter *x, t_floatarg f)
+{
+	if(f <= 0.0f)
+		f = 0.000001f;
+	if(f != x->cur_f)
+	{
+		x->end_f = f;
+		x->counter_f = x->ticks;
+		x->delta_f = exp(log(f/x->cur_f)*x->rcp_ticks);
+		x->event_mask |= 1;/*set event_mask_bit 0 = 1*/
+	}
+}
+
+static void sigfilter_print(t_sigfilter *x)
+{
+//	post("fb1 = %g, fb2 = %g, ff1 = %g, ff2 = %g, ff3 = %g", x->b1, x->b2, x->a0, x->a1, x->a2);
+	x->x_at[0].a_w.w_float = x->b1;
+	x->x_at[1].a_w.w_float = x->b2;
+	x->x_at[2].a_w.w_float = x->a0;
+	x->x_at[3].a_w.w_float = x->a1;
+	x->x_at[4].a_w.w_float = x->a2;
+	outlet_list(x->x_debug_outlet, &s_list, 5, x->x_at);
+}
+
+static void sigfilter_dsp(t_sigfilter *x, t_signal **sp)
+{
+	float si, co, f;
+	int i, n=(int)sp[0]->s_n;
+
+	x->sr = 3.14159265358979323846f / (float)(sp[0]->s_sr);
+	x->ticks_per_interpol_time = 0.001f * (float)(sp[0]->s_sr) / (float)n;
+	i = (int)((x->ticks_per_interpol_time)*(x->interpol_time)+0.49999f);
+	if(i <= 0)
+	{
+		x->ticks = 1;
+		x->rcp_ticks = 1.0f;
+	}
+	else
+	{
+		x->ticks = i;
+		x->rcp_ticks = 1.0f / (float)i;
+	}
+	f = x->cur_f * x->sr;
+	if(f < 1.0e-20f)
+		x->cur_l = 1.0e20f;
+	else if(f > 1.57079632f)
+		x->cur_l = 0.0f;
+	else
+	{
+		si = sin(f);
+		co = cos(f);
+		x->cur_l = co/si;
+	}
+	if(x->first_order)
+	{
+		if(n&7)
+			dsp_add(sigfilter_perform_1o, 4, sp[0]->s_vec, sp[1]->s_vec, x, n);
+		else
+			dsp_add(sigfilter_perf8_1o, 4, sp[0]->s_vec, sp[1]->s_vec, x, n);
+	}
+	else
+	{
+		if(n&7)
+			dsp_add(sigfilter_perform_2o, 4, sp[0]->s_vec, sp[1]->s_vec, x, n);
+		else
+			dsp_add(sigfilter_perf8_2o, 4, sp[0]->s_vec, sp[1]->s_vec, x, n);
+	}
+}
+
+static void *sigfilter_new(t_symbol *s, int argc, t_atom *argv)
+{
+	t_sigfilter *x = (t_sigfilter *)pd_new(sigfilter_class);
+	char *filt_name;
+	int i;
+	float si, co, f=0.0f, a=0.0f, b=0.0f, interpol=0.0f;
+	t_symbol *filt_typ=gensym("");
+
+	inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("ft1"));
+	inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("ft2"));
+	inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("ft3"));
+	inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("ft4"));
+	outlet_new(&x->x_obj, &s_signal);
+	x->x_debug_outlet = outlet_new(&x->x_obj, &s_list);
+	x->x_msi = 0.0f;
+
+	x->x_at[0].a_type = A_FLOAT;
+	x->x_at[1].a_type = A_FLOAT;
+	x->x_at[2].a_type = A_FLOAT;
+	x->x_at[3].a_type = A_FLOAT;
+	x->x_at[4].a_type = A_FLOAT;
+
+	x->event_mask = 1;
+	x->counter_f = 1;
+	x->counter_a = 0;
+	x->counter_b = 0;
+	x->delta_f = 0.0f;
+	x->delta_a = 0.0f;
+	x->delta_b = 0.0f;
+	x->interpol_time = 0.0f;
+	x->wn1 = 0.0f;
+	x->wn2 = 0.0f;
+	x->a0 = 0.0f;
+	x->a1 = 0.0f;
+	x->a2 = 0.0f;
+	x->b1 = 0.0f;
+	x->b2 = 0.0f;
+	x->sr = 3.14159265358979323846f / 44100.0f;
+	x->calc = sigfilter_snafu;
+	x->first_order = 0;
+	if((argc == 5)&&IS_A_FLOAT(argv,4)&&IS_A_FLOAT(argv,3)&&IS_A_FLOAT(argv,2)&&IS_A_FLOAT(argv,1)&&IS_A_SYMBOL(argv,0))
+	{
+		filt_typ = atom_getsymbolarg(0, argc, argv);
+		f = (float)atom_getfloatarg(1, argc, argv);
+		a = (float)atom_getfloatarg(2, argc, argv);
+		b = (float)atom_getfloatarg(3, argc, argv);
+		interpol = (float)atom_getfloatarg(4, argc, argv);
+	}
+	filt_name = (char *)filt_typ->s_name;
+	x->cur_f = f;
+	f *= x->sr;
+	if(f < 1.0e-20f)
+		x->cur_l = 1.0e20f;
+	else if(f > 1.57079632f)
+		x->cur_l = 0.0f;
+	else
+	{
+		si = sin(f);
+		co = cos(f);
+		x->cur_l = co/si;
+	}
+	if(a <= 0.0f)
+		a = 0.000001f;
+	if(b <= 0.0f)
+		b = 0.000001f;
+	x->cur_b = b;
+
+	if(interpol <= 0.0f)
+		interpol = 0.0f;
+	x->interpol_time = interpol;
+	x->ticks_per_interpol_time = 0.001f * 44100.0f / 64.0f;
+	i = (int)((x->ticks_per_interpol_time)*(x->interpol_time)+0.49999f);
+	if(i <= 0)
+	{
+		x->ticks = 1;
+		x->rcp_ticks = 1.0f;
+	}
+	else
+	{
+		x->ticks = i;
+		x->rcp_ticks = 1.0f / (float)i;
+	}
+
+	x->calc = sigfilter_snafu;
+	
+	x->cur_a = 1.0f/a; /*a was Q*/
+	x->inv = 1;
+	x->hp = 0;
+
+	if(filt_name)
+	{
+		if(!strcmp(filt_name,"ap1"))
+		{
+			x->calc = sigfilter_ap1;
+			x->a1 = 1.0f;
+			x->first_order = 1;
+		}
+		else if(!strcmp(filt_name,"ap2"))
+		{
+			x->calc = sigfilter_ap2;
+			x->a2 = 1.0f;
+		}
+		else if(!strcmp(filt_name,"ap1c"))
+		{
+			x->calc = sigfilter_ap1;
+			x->a1 = 1.0f;
+			x->inv = 0;
+			x->cur_a = a; /*a was damping*/
+			x->first_order = 1;
+		}
+		else if(!strcmp(filt_name,"ap2c"))
+		{
+			x->calc = sigfilter_ap2;
+			x->a2 = 1.0f;
+			x->inv = 0;
+			x->cur_a = a; /*a was damping*/
+		}
+		else if(!strcmp(filt_name,"bpq2"))
+		{
+			x->calc = sigfilter_bp2;
+		}
+		else if(!strcmp(filt_name,"rbpq2"))
+		{
+			x->calc = sigfilter_rp2;
+		}
+		else if(!strcmp(filt_name,"bsq2"))
+		{
+			x->calc = sigfilter_bs2;
+		}
+		else if(!strcmp(filt_name,"bpw2"))
+		{
+			x->calc = sigfilter_bpw2;
+			x->inv = 0;
+			x->cur_a = a; /*a was bw*/
+		}
+		else if(!strcmp(filt_name,"rbpw2"))
+		{
+			x->calc = sigfilter_rpw2;
+			x->inv = 0;
+			x->cur_a = a; /*a was bw*/
+		}
+		else if(!strcmp(filt_name,"bsw2"))
+		{
+			x->calc = sigfilter_bsw2;
+			x->inv = 0;
+			x->cur_a = a; /*a was bw*/
+		}
+		else if(!strcmp(filt_name,"hp1"))
+		{
+			x->calc = sigfilter_hp1;
+			x->first_order = 1;
+		}
+		else if(!strcmp(filt_name,"hp2"))
+		{
+			x->calc = sigfilter_hp2;
+		}
+		else if(!strcmp(filt_name,"lp1"))
+		{
+			x->calc = sigfilter_lp1;
+			x->first_order = 1;
+		}
+		else if(!strcmp(filt_name,"lp2"))
+		{
+			x->calc = sigfilter_lp2;
+		}
+		else if(!strcmp(filt_name,"hp1c"))
+		{
+			x->calc = sigfilter_hp1;
+			x->cur_a = 1.0f / a;
+			x->first_order = 1;
+		}
+		else if(!strcmp(filt_name,"hp2c"))
+		{
+			x->calc = sigfilter_hp2;
+			x->inv = 0;
+			x->cur_a = a / b;
+			x->cur_b = 1.0f / b;
+			x->hp = 1;
+		}
+		else if(!strcmp(filt_name,"lp1c"))
+		{
+			x->calc = sigfilter_lp1;
+			x->inv = 0;
+			x->cur_a = a; /*a was damping*/
+			x->first_order = 1;
+		}
+		else if(!strcmp(filt_name,"lp2c"))
+		{
+			x->calc = sigfilter_lp2;
+			x->inv = 0;
+			x->cur_a = a; /*a was damping*/
+		}
+		else
+		{
+			post("filter~-Error: 1. initial-arguments: <sym> kind: \
+			 lp1, lp2, hp1, hp2, \
+			 lp1c, lp2c, hp1c, hp2c, \
+			 ap1, ap2, ap1c, ap2c, \
+			 bpq2, rbpq2, bsq2, \
+			 bpw2, rbpw2, bsw2!");
+		}
+		x->end_f = x->cur_f;
+		x->end_a = x->cur_a;
+		x->end_b = x->cur_b;
+	}
+	return (x);
+}
+
+void sigfilter_setup(void)
+{
+	sigfilter_class = class_new(gensym("filter~"), (t_newmethod)sigfilter_new,
+				0, sizeof(t_sigfilter), 0, A_GIMME, 0);
+	CLASS_MAINSIGNALIN(sigfilter_class, t_sigfilter, x_msi);
+	class_addmethod(sigfilter_class, (t_method)sigfilter_dsp, gensym("dsp"), 0);
+	class_addmethod(sigfilter_class, (t_method)sigfilter_ft1, gensym("ft1"), A_FLOAT, 0);
+	class_addmethod(sigfilter_class, (t_method)sigfilter_ft2, gensym("ft2"), A_FLOAT, 0);
+	class_addmethod(sigfilter_class, (t_method)sigfilter_ft3, gensym("ft3"), A_FLOAT, 0);
+	class_addmethod(sigfilter_class, (t_method)sigfilter_ft4, gensym("ft4"), A_FLOAT, 0);
+	class_addmethod(sigfilter_class, (t_method)sigfilter_print, gensym("print"), 0);
+	class_sethelpsymbol(sigfilter_class, gensym("iemhelp/help-filter~"));
+}
-- 
cgit v1.2.1