diff options
Diffstat (limited to 'source/bp.c')
| -rw-r--r-- | source/bp.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/source/bp.c b/source/bp.c new file mode 100644 index 0000000..d21bc19 --- /dev/null +++ b/source/bp.c @@ -0,0 +1,123 @@ +#include "defines.h"
+
+/*--------------- bp ---------------*/
+
+typedef struct bpctl
+{
+ float c_x1;
+ float c_x2;
+ float c_coef1;
+ float c_coef2;
+ float c_gain;
+} t_bpctl;
+
+typedef struct bp
+{
+ t_object x_obj;
+ float x_freq;
+ float x_q;
+ t_bpctl x_cspace;
+ t_bpctl *x_ctl;
+ float x_f;
+} t_bp;
+
+t_class *bp_class;
+
+static void bp_docoef(t_bp *x, t_floatarg f, t_floatarg q);
+
+static void *bp_new(t_floatarg f, t_floatarg q)
+{
+ t_bp *x = (t_bp *)pd_new(bp_class);
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("float"), gensym("ft1"));
+ inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("float"), gensym("ft2"));
+ outlet_new(&x->x_obj, gensym("float"));
+ x->x_ctl = &x->x_cspace;
+ x->x_cspace.c_x1 = 0;
+ x->x_cspace.c_x2 = 0;
+ bp_docoef(x, f, q);
+ x->x_f = 0;
+ return (x);
+}
+
+static float bp_qcos(float f)
+{
+ if (f >= -(0.5f*3.14159f) && f <= 0.5f*3.14159f)
+ {
+ float g = f*f;
+ return (((g*g*g * (-1.0f/720.0f) + g*g*(1.0f/24.0f)) - g*0.5f) + 1);
+ }
+ else return (0);
+}
+
+static void bp_docoef(t_bp *x, t_floatarg f, t_floatarg q)
+{
+ float r, oneminusr, omega;
+ if (f < 0.0001f) f = 0.0001f;
+ if (q < 0) q = 0;
+ x->x_freq = f;
+ x->x_q = q;
+ omega = f * (2.0f * 3.14159f);
+ if (q < 0.001) oneminusr = 1.0f;
+ else oneminusr = omega/q;
+ if (oneminusr > 1.0f) oneminusr = 1.0f;
+ r = 1.0f - oneminusr;
+ x->x_ctl->c_coef1 = 2.0f * bp_qcos(omega) * r;
+ x->x_ctl->c_coef2 = - r * r;
+ x->x_ctl->c_gain = 2 * oneminusr * (oneminusr + r * omega);
+ /* post("r %f, omega %f, coef1 %f, coef2 %f",
+ r, omega, x->x_ctl->c_coef1, x->x_ctl->c_coef2); */
+}
+
+static void bp_ft1(t_bp *x, t_floatarg f)
+{
+ bp_docoef(x, f, x->x_q);
+}
+
+static void bp_ft2(t_bp *x, t_floatarg q)
+{
+ bp_docoef(x, x->x_freq, q);
+}
+
+static void bp_clear(t_bp *x, t_floatarg q)
+{
+ x->x_ctl->c_x1 = x->x_ctl->c_x2 = 0;
+}
+
+static void bp_perform(t_bp *x, t_float in)
+{
+ float out;
+ t_bpctl *c = x->x_ctl;
+ float last = c->c_x1;
+ float prev = c->c_x2;
+ float coef1 = c->c_coef1;
+ float coef2 = c->c_coef2;
+ float gain = c->c_gain;
+
+ float output = in + coef1 * last + coef2 * prev;
+ out = gain * output;
+
+ prev = last;
+ last = output;
+
+ /* NAN protect */
+ if (!((last <= 0) || (last >= 0)))
+ last = 0;
+ if (!((prev <= 0) || (prev >= 0)))
+ prev = 0;
+ c->c_x1 = last;
+ c->c_x2 = prev;
+
+ outlet_float(x->x_obj.ob_outlet, out);
+}
+
+void bp_setup(void)
+{
+ bp_class = class_new(gensym("bp"), (t_newmethod)bp_new, 0,
+ sizeof(t_bp), 0, A_DEFFLOAT, A_DEFFLOAT, 0);
+ class_addfloat(bp_class, (t_method)bp_perform);
+ class_addmethod(bp_class, (t_method)bp_ft1,
+ gensym("ft1"), A_FLOAT, 0);
+ class_addmethod(bp_class, (t_method)bp_ft2,
+ gensym("ft2"), A_FLOAT, 0);
+ class_addmethod(bp_class, (t_method)bp_clear, gensym("clear"), 0);
+}
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