nuclear@0: /************************************************************************************
nuclear@0: 
nuclear@0: PublicHeader:   OVR
nuclear@0: Filename    :   OVR_Timer.h
nuclear@0: Content     :   Provides static functions for precise timing
nuclear@0: Created     :   September 19, 2012
nuclear@0: Notes       : 
nuclear@0: 
nuclear@0: Copyright   :   Copyright 2014 Oculus VR, LLC All Rights reserved.
nuclear@0: 
nuclear@0: Licensed under the Oculus VR Rift SDK License Version 3.2 (the "License"); 
nuclear@0: you may not use the Oculus VR Rift SDK except in compliance with the License, 
nuclear@0: which is provided at the time of installation or download, or which 
nuclear@0: otherwise accompanies this software in either electronic or hard copy form.
nuclear@0: 
nuclear@0: You may obtain a copy of the License at
nuclear@0: 
nuclear@0: http://www.oculusvr.com/licenses/LICENSE-3.2 
nuclear@0: 
nuclear@0: Unless required by applicable law or agreed to in writing, the Oculus VR SDK 
nuclear@0: distributed under the License is distributed on an "AS IS" BASIS,
nuclear@0: WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
nuclear@0: See the License for the specific language governing permissions and
nuclear@0: limitations under the License.
nuclear@0: 
nuclear@0: ************************************************************************************/
nuclear@0: 
nuclear@0: #ifndef OVR_Timer_h
nuclear@0: #define OVR_Timer_h
nuclear@0: 
nuclear@0: #include "OVR_Types.h"
nuclear@0: 
nuclear@0: namespace OVR {
nuclear@0:     
nuclear@0: //-----------------------------------------------------------------------------------
nuclear@0: // ***** Timer
nuclear@0: 
nuclear@0: // Timer class defines a family of static functions used for application
nuclear@0: // timing and profiling.
nuclear@0: 
nuclear@0: class Timer
nuclear@0: {
nuclear@0: public:
nuclear@0:     enum {
nuclear@0:         MsPerSecond     = 1000,                  // Milliseconds in one second.
nuclear@0:         MksPerSecond    = 1000 * 1000,           // Microseconds in one second.
nuclear@0:         NanosPerSecond  = 1000 * 1000 * 1000,    // Nanoseconds in one second.
nuclear@0:     };
nuclear@0: 
nuclear@0:     // ***** Timing APIs for Application    
nuclear@0: 
nuclear@0:     // These APIs should be used to guide animation and other program functions
nuclear@0:     // that require precision.
nuclear@0: 
nuclear@0:     // Returns global high-resolution application timer in seconds.
nuclear@0:     static double  OVR_STDCALL GetSeconds();    
nuclear@0: 
nuclear@0:     // Returns time in Nanoseconds, using highest possible system resolution.
nuclear@0:     static uint64_t  OVR_STDCALL GetTicksNanos();
nuclear@0: 
nuclear@0:     // Kept for compatibility.
nuclear@0:     // Returns ticks in milliseconds, as a 32-bit number. May wrap around every 49.2 days.
nuclear@0:     // Use either time difference of two values of GetTicks to avoid wrap-around.
nuclear@0:     static uint32_t  OVR_STDCALL GetTicksMs()
nuclear@0:     { return  uint32_t(GetTicksNanos() / 1000000); }
nuclear@0: 
nuclear@0:     // for recorded data playback
nuclear@0:     static void SetFakeSeconds(double fakeSeconds, bool enable = true) 
nuclear@0:     { 
nuclear@0:         FakeSeconds = fakeSeconds; 
nuclear@0:         useFakeSeconds = enable; 
nuclear@0:     }
nuclear@0: 
nuclear@0: private:
nuclear@0:     friend class System;
nuclear@0:     // System called during program startup/shutdown.
nuclear@0:     static void initializeTimerSystem();
nuclear@0:     static void shutdownTimerSystem();
nuclear@0: 
nuclear@0:     // for recorded data playback
nuclear@0:     static double FakeSeconds;
nuclear@0:     static bool   useFakeSeconds;
nuclear@0:     
nuclear@0:     #if defined(OVR_OS_ANDROID)
nuclear@0:         // Android-specific data
nuclear@0:     #elif defined (OVR_OS_MS)
nuclear@0:         // Microsoft-specific data
nuclear@0:     #elif defined(OVR_OS_MAC)
nuclear@0:         static double TimeConvertFactorNanos;     // Conversion factor for GetTicksNanos
nuclear@0:         static double TimeConvertFactorSeconds;   // Conversion factor for GetSeconds.
nuclear@0:     #else
nuclear@0:         static bool MonotonicClockAvailable;      // True if clock_gettime supports CLOCK_MONOTONIC
nuclear@0:     #endif
nuclear@0: };
nuclear@0: 
nuclear@0: 
nuclear@0: } // OVR::Timer
nuclear@0: 
nuclear@0: #endif