1 files changed, 100 insertions, 0 deletions
diff --git a/src/z_sigzero.c b/src/z_sigzero.c
new file mode 100644
index 0000000..a3f0790
--- /dev/null
+++ b/src/z_sigzero.c
@@ -0,0 +1,100 @@
+#include "zexy.h"
+#ifdef NT
+#pragma warning( disable : 4244 )
+#pragma warning( disable : 4305 )
+#endif
+
+/* ------------------------ sigzero~ ----------------------------- */
+/*
+	a very useful function, which detects, whether a signal is zeroes-only this block or not
+	this is really great together with the "switch~"-object
+*/
+
+
+
+static t_class *sigzero_class;
+
+typedef struct _sigzero
+{
+	t_object x_obj;
+	int activate;
+	int current; /* 0 == (signalblock == 0); 1==(signalblock != 0) */
+} t_sigzero;
+
+static void sigzero_activate(t_sigzero *x, t_floatarg activate)
+{
+	x->activate = (activate)?1:0;
+}
+
+static void sigzero_banged(t_sigzero *x, t_floatarg activate)
+{
+	x->activate = 1;
+}
+
+static void sigzero_off(t_sigzero *x, t_floatarg activate)
+{
+	x->activate = 0;
+}
+
+static t_int *sigzero_perform(t_int *w)
+{
+	t_float *in = (t_float *)w[1];
+	t_sigzero *x = (t_sigzero *)w[2];
+	int n = (int)w[3];
+
+	int non_zero = 0;
+
+	if (x->activate) {
+		while (n--)
+		{
+			if (*in++ != 0.) {
+				non_zero = 1;
+				break;
+			}
+		}
+		if (non_zero != x->current) {
+		    outlet_float(x->x_obj.ob_outlet, x->current = non_zero);
+		}
+//		else post("non_zero=%d\tcurrent=%d", non_zero, x->current);
+	}
+
+	return (w+4);
+}
+
+static void sigzero_dsp(t_sigzero *x, t_signal **sp)
+{
+	dsp_add(sigzero_perform, 3, sp[0]->s_vec, x, sp[0]->s_n);
+}
+
+static void helper(void)
+{
+	post("\n%c sigzero~-object :: for detecting whether a signal is currently zero or not", HEARTSYMBOL);
+	post("'bang'\t: turn the detector on\n"
+		 "'off'\t: turn it off\n"
+		 "<1/0>\t: turn it on/off\n"
+		 "'help'\t: view this\n"
+		 "signal~");
+	post("outlet :: 1/0\t: signal turned to non-zero/zero\n");
+}
+
+static void *sigzero_new(t_symbol s)
+{
+	t_sigzero *x = (t_sigzero *)pd_new(sigzero_class);
+    outlet_new(&x->x_obj, &s_float);
+	return (x);
+}
+
+void z_sigzero_setup(void)
+{
+	sigzero_class = class_new(gensym("sigzero~"), (t_newmethod)sigzero_new, 0,
+		sizeof(t_sigzero), 0, 0);
+	class_addfloat(sigzero_class, sigzero_activate);
+	class_addbang(sigzero_class, sigzero_banged);
+	class_addmethod(sigzero_class, (t_method)sigzero_off, gensym("off"), 0);
+
+	class_addmethod(sigzero_class, nullfn, gensym("signal"), 0);
+	class_addmethod(sigzero_class, (t_method)sigzero_dsp, gensym("dsp"), 0);
+
+	class_addmethod(sigzero_class, (t_method)helper, gensym("help"), 0);
+	class_sethelpsymbol(sigzero_class, gensym("zexy/sigzero~"));
+}