initial commit

samples/wp8/OcvRotatingCube/PhoneXamlDirect3DApp1/PhoneXamlDirect3DApp1Comp/BasicTimer.h

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+#pragma once
+
+#include <wrl.h>
+
+// Helper class for basic timing.
+ref class BasicTimer sealed
+{
+public:
+    // Initializes internal timer values.
+    BasicTimer()
+    {
+        if (!QueryPerformanceFrequency(&m_frequency))
+        {
+            throw ref new Platform::FailureException();
+        }
+        Reset();
+    }
+
+    // Reset the timer to initial values.
+    void Reset()
+    {
+        Update();
+        m_startTime = m_currentTime;
+        m_total = 0.0f;
+        m_delta = 1.0f / 60.0f;
+    }
+
+    // Update the timer's internal values.
+    void Update()
+    {
+        if (!QueryPerformanceCounter(&m_currentTime))
+        {
+            throw ref new Platform::FailureException();
+        }
+
+        m_total = static_cast<float>(
+            static_cast<double>(m_currentTime.QuadPart - m_startTime.QuadPart) /
+            static_cast<double>(m_frequency.QuadPart)
+            );
+
+        if (m_lastTime.QuadPart == m_startTime.QuadPart)
+        {
+            // If the timer was just reset, report a time delta equivalent to 60Hz frame time.
+            m_delta = 1.0f / 60.0f;
+        }
+        else
+        {
+            m_delta = static_cast<float>(
+                static_cast<double>(m_currentTime.QuadPart - m_lastTime.QuadPart) /
+                static_cast<double>(m_frequency.QuadPart)
+                );
+        }
+
+        m_lastTime = m_currentTime;
+    }
+
+    // Duration in seconds between the last call to Reset() and the last call to Update().
+    property float Total
+    {
+        float get() { return m_total; }
+    }
+
+    // Duration in seconds between the previous two calls to Update().
+    property float Delta
+    {
+        float get() { return m_delta; }
+    }
+
+private:
+    LARGE_INTEGER m_frequency;
+    LARGE_INTEGER m_currentTime;
+    LARGE_INTEGER m_startTime;
+    LARGE_INTEGER m_lastTime;
+    float m_total;
+    float m_delta;
+};