Initial source commit

minorGems/system/Time.h

@@ -0,0 +1,112 @@
+/*
+ * Modification History
+ *
+ * 2001-October-29		Jason Rohrer
+ * Created.
+ *
+ * 2004-October-14		Jason Rohrer
+ * Fixed sign bug.
+ *
+ * 2005-February-10		Jason Rohrer
+ * Added function to get time in floating point format.
+ */
+
+#include "minorGems/common.h"
+
+
+
+#ifndef TIME_INCLUDED
+#define TIME_INCLUDED 
+
+
+
+/**
+ * Interface for platform-independent, high-resolution time access.
+ *
+ * @author Jason Rohrer
+ */
+class Time {
+	public:
+
+
+		
+		/**
+		 * Gets the current time in seconds and milliseconds.
+		 *
+		 * No guarentee about when absolute 0 of this time
+		 * scale is for particular systems.
+		 *
+		 * @param outSeconds pointer to where the time in seconds
+		 *   will be returned.
+		 * @param outMilliseconds pointer to where the extra
+		 *   milliseconds will be returned.  Value returned is in [0,999].
+		 */
+		static void getCurrentTime( unsigned long *outSeconds,
+									unsigned long *outMilliseconds );
+
+        
+
+        /**
+         * Gets the current time in fractional (double) seconds.
+         *
+         * @return the current time in seconds.
+         */
+        static double getCurrentTime();
+
+        
+
+		/**
+		 * Gets the number of milliseconds that have passed
+		 * since a time in seconds and milliseconds.
+		 *
+		 * @param inSeconds the start time, in seconds.
+		 * @param inMilliseconds the start time's additional milliseconds.
+		 *
+		 * @return the number of milliseconds that have passed
+		 *   since inSeconds:inMilliseconds.  May overflow if
+		 *   more than 49 days have passed (assuming 32-bit longs).
+		 */
+		static unsigned long getMillisecondsSince(
+			unsigned long inSeconds, unsigned long inMilliseconds );
+
+
+		
+	};
+
+
+
+inline double Time::getCurrentTime() {
+    unsigned long currentTimeS;
+	unsigned long currentTimeMS;
+	getCurrentTime( &currentTimeS, &currentTimeMS );
+
+    return currentTimeS + currentTimeMS / 1000.0;
+    }
+
+
+
+inline unsigned long Time::getMillisecondsSince(
+	unsigned long inSeconds, unsigned long inMilliseconds ) {
+
+	unsigned long currentTimeS;
+	unsigned long currentTimeMS;
+	getCurrentTime( &currentTimeS, &currentTimeMS );
+
+	
+	unsigned long deltaS = ( currentTimeS - inSeconds );
+	long deltaMS = ( (long)currentTimeMS - (long)inMilliseconds );
+
+	// carry, if needed
+	if( deltaMS < 0 ) {
+		deltaS--;
+		deltaMS += 1000;
+		}
+
+	return 1000 * deltaS + deltaMS;
+	}
+
+
+
+#endif
+ 
+