Fixes two major problems: time wrapping every 42 days, and timer

resolution getting poor after a couple days of play. (for some value of "major")
2003-07-12 22:51:27 +00:00
parent cbfa6c72fc
commit fbcd804243
2 changed files with 87 additions and 59 deletions
@@ -1,29 +1,61 @@
 #ifndef RAGE_TIMER_H
 #define RAGE_TIMER_H

+/* Timer services. */
+
 /*
-----------------------------------------------------------------------------
- File: RageTimer.h
-
- Desc: Timer services.
-
- Copyright (c) 2001-2002 by the person(s) listed below.  All rights reserved.
-	Chris Danford
-----------------------------------------------------------------------------
-*/
-
+ * This can be used in two ways: as a timestamp or as a timer.
+ *
+ * As a timer,
+ * RageTimer Timer;
+ * while(1) {
+ *   printf( "Will be approximately: %f", Timer.PeekDeltaTime()) ;
+ *   float fDeltaTime = Timer.GetDeltaTime();
+ * }
+ * 
+ * or as a timestamp:
+ * void foo( RageTimer &timestamp ) {
+ *     if( timestamp.IsZero() )
+ *         printf( "The timestamp isn't set." );
+ *     else
+ *         printf( "The timestamp happened %f ago", timestamp.Ago() );
+ *     timestamp.Touch();
+ *     printf( "Near zero: %f", timestamp.Age() );
+ * }
+ */
 class RageTimer
 {
 public:
-	RageTimer();
-	unsigned int GetTicks();
-	float GetDeltaTime();	// time between last call to GetDeltaTime()
-	float PeekDeltaTime() const;
+	RageTimer() { Touch(); }
+
+	/* Time ago this RageTimer represents. */
+	float Ago() const;
+	inline void Touch();
+	inline bool IsZero() const { return m_secs == 0 && m_us == 0; }
+	inline void SetZero() { m_secs = m_us = 0; }
+
+	/* Time between last call to GetDeltaTime() (Ago() + Touch()): */
+	float GetDeltaTime();
+	/* (alias) */
+	float PeekDeltaTime() const { return Ago(); }
+
+	/* deprecated: */
 	static float GetTimeSinceStart();	// seconds since the program was started

 private:
-	static void Init();
-	int m_iLastDeltaTime;
+	static float Difference(const RageTimer &lhs, const RageTimer &rhs);
+
+	/* "float" is bad for a "time since start" RageTimer.  If the game is running for
+	 * several days, we'll lose a lot of resolution.  I don't want to use double
+	 * everywhere, since it's slow.  I'd rather not use double just for RageTimers, since
+	 * it's too easy to get a type wrong and end up with obscure resolution problems. */
+	unsigned m_secs, m_us;
 };

 #endif
+
+/*
+ * Copyright (c) 2001-2003 by the person(s) listed below.  All rights reserved.
+ *	Chris Danford
+ *	Glenn Maynard
+ */