Added creation parameter to disable highres timers. Patch submitted by tonic.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3397 dfc29bdd-3216-0410-991c-e03cc46cb475

changes.txt

@@ -1,5 +1,11 @@
 Changes in 1.8 (??.0?.2010)
 
+ - Add creation parameter which allows to disable highres timers on Windows upon device creation.
+
+ - Several transparency setup bugs fixed.
+
+ - Added a method to get real time and date in a human readable struct
+
  - Add IGUIElement::bringToBack (patch written by DtD, although I'm to blame for the function-name)
 
  - BurningVideo 

include/SIrrCreationParameters.h

@@ -38,6 +38,7 @@ namespace irr
 			WindowId(0),
 			LoggingLevel(ELL_INFORMATION),
 			DisplayAdapter(0),
+			UsePerformanceTimer(true),
 			SDK_version_do_not_use(IRRLICHT_SDK_VERSION)
 		{
 		}
@@ -66,6 +67,7 @@ namespace irr
 			WindowId = other.WindowId;
 			LoggingLevel = other.LoggingLevel;
 			DisplayAdapter = other.DisplayAdapter;
+			UsePerformanceTimer = other.UsePerformanceTimer;
 			return *this;
 		}
 
@@ -245,6 +247,13 @@ namespace irr
 		/** So far only supported on D3D */
 		u32 DisplayAdapter;
 
+		//! Enables use of high performance timers on Windows platform.
+		/** When performance timers are not used, standard GetTickCount()
+		is used instead which usually has worse resolution, but also less
+		problems with speed stepping and other techniques.
+		*/
+		bool UsePerformanceTimer;
+
 		//! Don't use or change this parameter.
 		/** Always set it to IRRLICHT_SDK_VERSION, which is done by default.
 		This is needed for sdk version checks. */

source/Irrlicht/CIrrDeviceStub.cpp

@@ -22,7 +22,7 @@ CIrrDeviceStub::CIrrDeviceStub(const SIrrlichtCreationParameters& params)
 	FileSystem(0), InputReceivingSceneManager(0), CreationParams(params),
 	Close(false)
 {
-	Timer = new CTimer();
+	Timer = new CTimer(params.UsePerformanceTimer);
 	if (os::Printer::Logger)
 	{
 		os::Printer::Logger->grab();

source/Irrlicht/CTimer.h

@@ -15,9 +15,9 @@ namespace irr
 	{
 	public:
 
-		CTimer()
+		CTimer(bool usePerformanceTimer=true)
 		{
-			os::Timer::initTimer();
+			os::Timer::initTimer(usePerformanceTimer);
 		}
 
 		//! Returns current real time in milliseconds of the system.

source/Irrlicht/os.cpp

@@ -81,7 +81,7 @@ namespace os
 	static BOOL HighPerformanceTimerSupport = FALSE;
 	static BOOL MultiCore = FALSE;
 
-	void Timer::initTimer()
+	void Timer::initTimer(bool usePerformanceTimer)
 	{
 #if !defined(_WIN32_WCE) && !defined (_IRR_XBOX_PLATFORM_)
 		// disable hires timer on multiple core systems, bios bugs result in bad hires timers.
@@ -89,7 +89,10 @@ namespace os
 		GetSystemInfo(&sysinfo);
 		MultiCore = (sysinfo.dwNumberOfProcessors > 1);
 #endif
-		HighPerformanceTimerSupport = QueryPerformanceFrequency(&HighPerformanceFreq);
+		if (usePerformanceTimer)
+			HighPerformanceTimerSupport = QueryPerformanceFrequency(&HighPerformanceFreq);
+		else
+			HighPerformanceTimerSupport = FALSE;
 		initVirtualTimer();
 	}
 

source/Irrlicht/os.h

@@ -72,7 +72,7 @@ namespace os
 		static ITimer::RealTimeDate getRealTimeAndDate();
 
 		//! initializes the real timer
-		static void initTimer();
+		static void initTimer(bool usePerformanceTimer=true);
 
 		//! sets the current virtual (game) time
 		static void setTime(u32 time);