diff options
| author | Brad Davis <[email protected]> | 2013-06-27 11:25:32 -0800 |
|---|---|---|
| committer | Brad Davis <[email protected]> | 2013-06-28 10:47:29 -0700 |
| commit | ebefcc885f74461cd0e3f19b5ae3622dc6cf6dbc (patch) | |
| tree | 2b16db7350fce54c2e6c1b1c4020d67419cb1164 /LibOVR/Src/Kernel/OVR_Timer.cpp | |
| parent | 0ade748e1845694c5cbe562fb823e56f09773e27 (diff) | |
SDK 0.2.2
Diffstat (limited to 'LibOVR/Src/Kernel/OVR_Timer.cpp')
| -rw-r--r-- | LibOVR/Src/Kernel/OVR_Timer.cpp | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/LibOVR/Src/Kernel/OVR_Timer.cpp b/LibOVR/Src/Kernel/OVR_Timer.cpp new file mode 100644 index 0000000..db25b8f --- /dev/null +++ b/LibOVR/Src/Kernel/OVR_Timer.cpp @@ -0,0 +1,156 @@ +/************************************************************************************
+
+Filename : OVR_Timer.cpp
+Content : Provides static functions for precise timing
+Created : September 19, 2012
+Notes :
+
+Copyright : Copyright 2012 Oculus VR, Inc. All Rights reserved.
+
+Use of this software is subject to the terms of the Oculus license
+agreement provided at the time of installation or download, or which
+otherwise accompanies this software in either electronic or hard copy form.
+
+************************************************************************************/
+
+#include "OVR_Timer.h"
+
+#if defined (OVR_OS_WIN32)
+#include <windows.h>
+
+#else
+#include <sys/time.h>
+#endif
+
+namespace OVR {
+
+//-----------------------------------------------------------------------------------
+// ***** Timer Class
+
+UInt64 Timer::GetProfileTicks()
+{
+ return (GetRawTicks() * MksPerSecond) / GetRawFrequency();
+}
+double Timer::GetProfileSeconds()
+{
+ static UInt64 StartTime = GetProfileTicks();
+ return TicksToSeconds(GetProfileTicks()-StartTime);
+}
+
+
+//------------------------------------------------------------------------
+// *** Win32 Specific Timer
+
+#if (defined (OVR_OS_WIN32))
+
+CRITICAL_SECTION WinAPI_GetTimeCS;
+volatile UInt32 WinAPI_OldTime = 0;
+volatile UInt32 WinAPI_WrapCounter = 0;
+
+
+UInt32 Timer::GetTicksMs()
+{
+ return timeGetTime();
+}
+
+UInt64 Timer::GetTicks()
+{
+ DWORD ticks = timeGetTime();
+ UInt64 result;
+
+ // On Win32 QueryPerformanceFrequency is unreliable due to SMP and
+ // performance levels, so use this logic to detect wrapping and track
+ // high bits.
+ ::EnterCriticalSection(&WinAPI_GetTimeCS);
+
+ if (WinAPI_OldTime > ticks)
+ WinAPI_WrapCounter++;
+ WinAPI_OldTime = ticks;
+
+ result = (UInt64(WinAPI_WrapCounter) << 32) | ticks;
+ ::LeaveCriticalSection(&WinAPI_GetTimeCS);
+
+ return result * MksPerMs;
+}
+
+UInt64 Timer::GetRawTicks()
+{
+ LARGE_INTEGER li;
+ QueryPerformanceCounter(&li);
+ return li.QuadPart;
+}
+
+UInt64 Timer::GetRawFrequency()
+{
+ static UInt64 perfFreq = 0;
+ if (perfFreq == 0)
+ {
+ LARGE_INTEGER freq;
+ QueryPerformanceFrequency(&freq);
+ perfFreq = freq.QuadPart;
+ }
+ return perfFreq;
+}
+
+void Timer::initializeTimerSystem()
+{
+ timeBeginPeriod(1);
+ InitializeCriticalSection(&WinAPI_GetTimeCS);
+
+}
+void Timer::shutdownTimerSystem()
+{
+ DeleteCriticalSection(&WinAPI_GetTimeCS);
+ timeEndPeriod(1);
+}
+
+#else // !OVR_OS_WIN32
+
+
+//------------------------------------------------------------------------
+// *** Standard OS Timer
+
+UInt32 Timer::GetTicksMs()
+{
+ return (UInt32)(GetProfileTicks() / 1000);
+}
+// The profile ticks implementation is just fine for a normal timer.
+UInt64 Timer::GetTicks()
+{
+ return GetProfileTicks();
+}
+
+void Timer::initializeTimerSystem()
+{
+}
+void Timer::shutdownTimerSystem()
+{
+}
+
+UInt64 Timer::GetRawTicks()
+{
+ // TODO: prefer rdtsc when available?
+
+ // Return microseconds.
+ struct timeval tv;
+ UInt64 result;
+
+ gettimeofday(&tv, 0);
+
+ result = (UInt64)tv.tv_sec * 1000000;
+ result += tv.tv_usec;
+
+ return result;
+}
+
+UInt64 Timer::GetRawFrequency()
+{
+ return MksPerSecond;
+}
+
+#endif // !OVR_OS_WIN32
+
+
+
+} // OVR
+
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