1 files changed, 72 insertions, 0 deletions
diff --git a/FTNoIR_Tracker_PT/frame_observer.h b/FTNoIR_Tracker_PT/frame_observer.h
new file mode 100644
index 00000000..4afbd72c
--- /dev/null
+++ b/FTNoIR_Tracker_PT/frame_observer.h
@@ -0,0 +1,72 @@
+/* Copyright (c) 2013 Patrick Ruoff
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+
+#ifndef FRAME_OBSERVER_H
+#define FRAME_OBSERVER_H
+
+#include <QMutex>
+#include <opencv2/opencv.hpp>
+#include <boost/shared_ptr.hpp>
+#include <set>
+
+//-----------------------------------------------------------------------------
+// Forward declarations
+class FrameObserver;
+
+//-----------------------------------------------------------------------------
+// Provides means to copy frame and point information if it has observers
+// Instantiate a FrameObserver to get the information
+class FrameProvider
+{
+	friend class FrameObserver;
+public:
+	~FrameProvider();
+
+protected:
+	virtual bool get_frame_and_points(cv::Mat& frame, boost::shared_ptr< std::vector<cv::Vec2f> >& points) = 0;
+	
+	bool has_observers() const { QMutexLocker lock(&observer_mutex); return !frame_observers.empty(); }
+
+private:
+	mutable QMutex observer_mutex;
+	void add_observer(FrameObserver* obs)    { QMutexLocker lock(&observer_mutex); frame_observers.insert(obs); }
+	void remove_observer(FrameObserver* obs) { QMutexLocker lock(&observer_mutex); frame_observers.erase(obs); }
+	std::set<FrameObserver*> frame_observers;
+};
+
+//-----------------------------------------------------------------------------
+// Used to get frame and point information from MutexedFrameProvider
+// Destroy instance if not interested anymore since a living 
+// FrameObserver instance causes MutexedFrameProvider to provide the information, 
+// potentially reducing its performance
+class FrameObserver
+{
+public:
+	FrameObserver(FrameProvider* provider) : provider(provider) { 
+		provider->add_observer(this); 
+	}
+
+	~FrameObserver() { 
+		if (provider) provider->remove_observer(this); 
+	}
+
+	bool get_frame_and_points(cv::Mat& frame, boost::shared_ptr< std::vector<cv::Vec2f> >& points) {
+		return provider ? provider->get_frame_and_points(frame, points) : false;
+	}
+
+	void on_frame_provider_destroy() { 
+		provider = NULL; 
+	}
+
+protected:
+	FrameProvider* provider;
+
+private:
+	FrameObserver(const FrameObserver&);
+};
+
+#endif //FRAME_OBSERVER_H
+\ No newline at end of file