1 files changed, 148 insertions, 0 deletions
diff --git a/apps/plugins/pdbox/PDa/extra/filters.h b/apps/plugins/pdbox/PDa/extra/filters.h
new file mode 100644
index 0000000000..72d997e425
--- /dev/null
+++ b/apps/plugins/pdbox/PDa/extra/filters.h
@@ -0,0 +1,148 @@
+/*
+ These filter coefficients computations are taken from
+ http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt  
+ written by Robert Bristow-Johnson
+*/
+#ifndef __GGEE_FILTERS_H__
+#define __GGEE_FILTERS_H__
+#ifndef M_PI
+#define M_PI 3.141593f
+#endif
+#include <math.h>
+#define LN2 0.69314718
+#define e_A(g) (pow(10,(g/40.)))
+#define e_omega(f,r) (2.0*M_PI*f/r)
+#define e_alpha(bw,omega) (sin(omega)*sinh(LN2/2. * bw * omega/sin(omega)))
+#define e_beta(a,S) (sqrt((a*a + 1)/(S) - (a-1)*(a-1)))
+typedef struct _rbjfilter
+{
+     t_object x_obj;
+     t_float  x_rate;
+     t_float  x_freq;
+     t_float  x_gain;
+     t_float  x_bw;
+} t_rbjfilter;
+static int check_stability(t_float fb1,
+                            t_float fb2, 
+                            t_float ff1,
+                            t_float ff2,
+                            t_float ff3)
+{
+    float discriminant = fb1 * fb1 + 4 * fb2;
+    if (discriminant < 0) /* imaginary roots -- resonant filter */
+    {
+            /* they're conjugates so we just check that the product
+            is less than one */
+        if (fb2 >= -1.0f) goto stable;
+    }
+    else    /* real roots */
+    {
+            /* check that the parabola 1 - fb1 x - fb2 x^2 has a
+                vertex between -1 and 1, and that it's nonnegative
+                at both ends, which implies both roots are in [1-,1]. */
+        if (fb1 <= 2.0f && fb1 >= -2.0f &&
+            1.0f - fb1 -fb2 >= 0 && 1.0f + fb1 - fb2 >= 0)
+                goto stable;
+    }
+    return 0;
+stable:
+    return 1;
+}
+#endif
+/*
+ These filter coefficients computations are taken from
+ http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt  
+ written by Robert Bristow-Johnson
+*/
+#ifndef __GGEE_FILTERS_H__
+#define __GGEE_FILTERS_H__
+#ifndef M_PI
+#define M_PI 3.141593f
+#endif
+#include <math.h>
+#define LN2 0.69314718
+#define e_A(g) (pow(10,(g/40.)))
+#define e_omega(f,r) (2.0*M_PI*f/r)
+#define e_alpha(bw,omega) (sin(omega)*sinh(LN2/2. * bw * omega/sin(omega)))
+#define e_beta(a,S) (sqrt((a*a + 1)/(S) - (a-1)*(a-1)))
+typedef struct _rbjfilter
+{
+     t_object x_obj;
+     t_float  x_rate;
+     t_float  x_freq;
+     t_float  x_gain;
+     t_float  x_bw;
+} t_rbjfilter;
+static int check_stability(t_float fb1,
+                            t_float fb2, 
+                            t_float ff1,
+                            t_float ff2,
+                            t_float ff3)
+{
+    float discriminant = fb1 * fb1 + 4 * fb2;
+    if (discriminant < 0) /* imaginary roots -- resonant filter */
+    {
+            /* they're conjugates so we just check that the product
+            is less than one */
+        if (fb2 >= -1.0f) goto stable;
+    }
+    else    /* real roots */
+    {
+            /* check that the parabola 1 - fb1 x - fb2 x^2 has a
+                vertex between -1 and 1, and that it's nonnegative
+                at both ends, which implies both roots are in [1-,1]. */
+        if (fb1 <= 2.0f && fb1 >= -2.0f &&
+            1.0f - fb1 -fb2 >= 0 && 1.0f + fb1 - fb2 >= 0)
+                goto stable;
+    }
+    return 0;
+stable:
+    return 1;
+}
+#endif

diff --git a/apps/plugins/pdbox/PDa/extra/filters.h b/apps/plugins/pdbox/PDa/extra/filters.h new file mode 100644 index 0000000000..72d997e425 --- /dev/null +++ b/apps/plugins/pdbox/PDa/extra/filters.h
@@ -0,0 +1,148 @@
	1	/*
	2
	3	These filter coefficients computations are taken from
	4	http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt
	5
	6	written by Robert Bristow-Johnson
	7
	8	*/
	9
	10
	11	#ifndef __GGEE_FILTERS_H__
	12	#define __GGEE_FILTERS_H__
	13
	14
	15
	16	#ifndef M_PI
	17	#define M_PI 3.141593f
	18	#endif
	19
	20
	21	#include <math.h>
	22	#define LN2 0.69314718
	23	#define e_A(g) (pow(10,(g/40.)))
	24	#define e_omega(f,r) (2.0M_PIf/r)
	25	#define e_alpha(bw,omega) (sin(omega)sinh(LN2/2. bw * omega/sin(omega)))
	26	#define e_beta(a,S) (sqrt((aa + 1)/(S) - (a-1)(a-1)))
	27
	28
	29
	30
	31	typedef struct _rbjfilter
	32	{
	33	t_object x_obj;
	34	t_float x_rate;
	35	t_float x_freq;
	36	t_float x_gain;
	37	t_float x_bw;
	38	} t_rbjfilter;
	39
	40
	41	static int check_stability(t_float fb1,
	42	t_float fb2,
	43	t_float ff1,
	44	t_float ff2,
	45	t_float ff3)
	46	{
	47	float discriminant = fb1 * fb1 + 4 * fb2;
	48
	49	if (discriminant < 0) /* imaginary roots -- resonant filter */
	50	{
	51	/* they're conjugates so we just check that the product
	52	is less than one */
	53	if (fb2 >= -1.0f) goto stable;
	54	}
	55	else /* real roots */
	56	{
	57	/* check that the parabola 1 - fb1 x - fb2 x^2 has a
	58	vertex between -1 and 1, and that it's nonnegative
	59	at both ends, which implies both roots are in [1-,1]. */
	60	if (fb1 <= 2.0f && fb1 >= -2.0f &&
	61	1.0f - fb1 -fb2 >= 0 && 1.0f + fb1 - fb2 >= 0)
	62	goto stable;
	63	}
	64	return 0;
	65	stable:
	66	return 1;
	67	}
	68
	69
	70
	71
	72
	73
	74	#endif
	75	/*
	76
	77	These filter coefficients computations are taken from
	78	http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt
	79
	80	written by Robert Bristow-Johnson
	81
	82	*/
	83
	84
	85	#ifndef __GGEE_FILTERS_H__
	86	#define __GGEE_FILTERS_H__
	87
	88
	89
	90	#ifndef M_PI
	91	#define M_PI 3.141593f
	92	#endif
	93
	94
	95	#include <math.h>
	96	#define LN2 0.69314718
	97	#define e_A(g) (pow(10,(g/40.)))
	98	#define e_omega(f,r) (2.0M_PIf/r)
	99	#define e_alpha(bw,omega) (sin(omega)sinh(LN2/2. bw * omega/sin(omega)))
	100	#define e_beta(a,S) (sqrt((aa + 1)/(S) - (a-1)(a-1)))
	101
	102
	103
	104
	105	typedef struct _rbjfilter
	106	{
	107	t_object x_obj;
	108	t_float x_rate;
	109	t_float x_freq;
	110	t_float x_gain;
	111	t_float x_bw;
	112	} t_rbjfilter;
	113
	114
	115	static int check_stability(t_float fb1,
	116	t_float fb2,
	117	t_float ff1,
	118	t_float ff2,
	119	t_float ff3)
	120	{
	121	float discriminant = fb1 * fb1 + 4 * fb2;
	122
	123	if (discriminant < 0) /* imaginary roots -- resonant filter */
	124	{
	125	/* they're conjugates so we just check that the product
	126	is less than one */
	127	if (fb2 >= -1.0f) goto stable;
	128	}
	129	else /* real roots */
	130	{
	131	/* check that the parabola 1 - fb1 x - fb2 x^2 has a
	132	vertex between -1 and 1, and that it's nonnegative
	133	at both ends, which implies both roots are in [1-,1]. */
	134	if (fb1 <= 2.0f && fb1 >= -2.0f &&
	135	1.0f - fb1 -fb2 >= 0 && 1.0f + fb1 - fb2 >= 0)
	136	goto stable;
	137	}
	138	return 0;
	139	stable:
	140	return 1;
	141	}
	142
	143
	144
	145
	146
	147
	148	#endif