1 files changed, 166 insertions, 0 deletions
diff --git a/shared/signal_processing.h b/shared/signal_processing.h
new file mode 100644
index 00000000..857d0b12
--- /dev/null
+++ b/shared/signal_processing.h
@@ -0,0 +1,166 @@
+// **************************************************************************
+// * This file is part of the FreeFileSync project. It is distributed under *
+// * GNU General Public License: http://www.gnu.org/licenses/gpl.html       *
+// * Copyright (C) 2008-2010 ZenJu (zhnmju123 AT gmx.de)                    *
+// **************************************************************************
+//
+#include <algorithm>
+#include <limits>
+#include <numeric>
+
+
+namespace util
+{
+template <class T>
+T abs(T value);
+
+int round(double d); //little rounding function
+
+template <class T>
+bool isNull(T number);
+
+//----------------------------------------------------------------------------------
+//       smoothen data ranges through a window around each data point              |
+//----------------------------------------------------------------------------------
+template <class InputIterator, class OutputIterator>
+void smoothen(InputIterator first, InputIterator last, OutputIterator result, size_t windowSize); //default implementation: averaging
+
+template <class InputIterator, class OutputIterator, class DataProcessor>
+void smoothen(InputIterator first, InputIterator last, OutputIterator result, size_t windowSize, DataProcessor proc);
+/*
+DataProcessor is an abstraction for data evaluation. A valid implementation needs to support three properties:
+- add data entry at window front:   operator+=(ValueType value)
+- remove data entry at window back: operator-=(ValueType value)
+- evaluate smoothed middle value:   ValueType operator()(size_t windowSize)
+*/
+//----------------------------------------------------------------------------------
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+//################# inline implementation #########################
+template <class T>
+inline
+T abs(T value)
+{
+    return value < 0 ? -value : value;
+}
+
+
+template <class T>
+inline
+bool isNull(T value)
+{
+    return abs(number) <= std::numeric_limits<T>::epsilon(); //epsilon == 0 for integer types, therefore less-equal(!)
+}
+
+
+inline
+int round(double d)
+{
+    return static_cast<int>(d < 0 ? d - .5 : d + .5);
+}
+
+
+template <class InputIterator, class OutputIterator, class DataProcessor>
+inline
+void smoothen(InputIterator first, InputIterator last, OutputIterator result, size_t windowSize, DataProcessor proc)
+{
+    windowSize = std::min(windowSize, static_cast<size_t>(last - first)); //std::distance() not used to enforce random access iterator requirement
+
+    if (windowSize <= 1)
+    {
+        std::copy(first, last, result);
+        return;
+    }
+
+    const size_t firstHalf = windowSize / 2;
+    const size_t secondHalf = windowSize - firstHalf;
+
+    //preparation
+    for (InputIterator i = first; i != first + secondHalf; ++i)
+        proc += *i;
+
+    //beginning
+    for (InputIterator i = first; i != first + firstHalf; ++i)
+    {
+        *result++ = proc(i - first + secondHalf);
+        proc += *(i + secondHalf);
+    }
+
+    //main
+    for (InputIterator i = first + firstHalf; i != last - secondHalf; ++i)
+    {
+        *result++ = proc(windowSize);
+        proc += *(i + secondHalf);
+        proc -= *(i - firstHalf);
+    }
+
+    //ending
+    for (InputIterator i = last - secondHalf; i != last; ++i)
+    {
+        *result++ = proc(windowSize - (i - last + secondHalf));
+        proc -= *(i - firstHalf);
+    }
+}
+
+
+template <class ValueType>
+class ProcessorAverage
+{
+public:
+    ProcessorAverage() : valueAcc() {}
+
+    //add front data entry
+    ProcessorAverage& operator+=(ValueType value)
+    {
+        valueAcc += value;
+        return *this;
+    }
+
+    //remove rear data entry
+    ProcessorAverage& operator-=(ValueType value)
+    {
+        valueAcc -= value;
+        return *this;
+    }
+
+    //evaluate smoothed value
+    ValueType operator()(size_t windowSize) const
+    {
+        return valueAcc / windowSize;
+    }
+
+private:
+    ValueType valueAcc; //accumulated values
+};
+
+
+
+template <class InputIterator, class OutputIterator>
+inline
+void smoothen(InputIterator first, InputIterator last, OutputIterator result, size_t windowSize)
+{
+    typedef typename std::iterator_traits<InputIterator>::value_type ValueType;
+    smoothen(first, last, result, windowSize, ProcessorAverage<ValueType>());
+}
+
+}
+\ No newline at end of file