+#ifndef FILTER_H
+#define FILTER_H
+
+#include <dol.h>
+
+#define PORT_INA "inA"
+#define PORT_INB "inB"
+#define PORT_OUTA "outA"
+#define PORT_OUTB "outB"
+
+typedef struct _local_states
+{
+ int firstiteration;
+ float inA, inB, out, zero, factor;
+} Filter_State;
+
+void filter_init(DOLProcess *);
+int filter_fire(DOLProcess *);
+
+#endif