Adding input callback

source/quickerNES/core/core.hpp

@@ -26,6 +26,10 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
 #include <stdexcept>
 #include <string>
 
+#ifdef QUICKERNES_ENABLE_INPUT_CALLBACK
+extern void (*input_callback_cb)(void);
+#endif
+
 namespace quickerNES
 {
 
@@ -844,6 +848,10 @@ class Core : private Cpu
         input_state.arkanoid_latch = current_arkanoid_latch;
         input_state.arkanoid_fire = current_arkanoid_fire;
         #endif
+
+		#ifdef QUICKERNES_ENABLE_INPUT_CALLBACK
+        input_callback_cb();
+		#endif
       }
       input_state.w4016 = data;
       return;