Initial source commit

minorGems/system/win32/TimeWin32.cpp

@@ -0,0 +1,77 @@
+/*
+ * Modification History
+ *
+ * 2001-November-7		Jason Rohrer
+ * Created.
+ *
+ * 2002-April-11		Jason Rohrer
+ * Added missing include, and fixed a bug.
+ *
+ * 2004-January-29		Jason Rohrer
+ * Fixed so that 0-point of time is the same as on other platforms.
+ *
+ * 2004-October-14		Jason Rohrer
+ * Fixed bug in second/millisecond callibration.
+ * Fixed bug in win32 time to ANSI time translation.
+ * Fixed daylight savings time bug.
+ */
+
+
+#include "minorGems/system/Time.h"
+
+#include <windows.h>
+#include <winbase.h>
+#include <time.h>
+#include <stdio.h>
+
+
+
+/**
+ * Windows implementation of Time.h.
+ *
+ * The 0-point should match the ANSI standard.
+ */
+
+
+
+void Time::getCurrentTime( unsigned long *outSeconds,
+						   unsigned long *outMilliseconds ) {
+    // convert from win32 broken-down time (which has msec resolution)
+    // to an ANSI time struct and then convert to an absolute time in
+    // seconds
+    // This procedure ensures that the 0-point matches the ANSI standard.
+
+    // note:
+    // we cannot simply call ANSI time() to get the seconds and then rely
+    // on GetLocalTime to get the milliseconds, since the seconds value
+    // used by GetLocalTime is (strangely enough) not calibrated to the seconds
+    // value of time().
+    // In other words, it is possible for the time() seconds to advance
+    // at a different clock cycle than the GetLocalTime seconds.
+
+    // get time using a win32 call
+    SYSTEMTIME win32TimeStruct;
+    GetLocalTime( &win32TimeStruct );
+
+    // convert this win32 structure to the ANSI standard structure
+    struct tm ansiTimeStruct;
+
+    ansiTimeStruct.tm_sec = win32TimeStruct.wSecond;
+    ansiTimeStruct.tm_min = win32TimeStruct.wMinute;
+    ansiTimeStruct.tm_hour = win32TimeStruct.wHour;
+    ansiTimeStruct.tm_mday = win32TimeStruct.wDay;
+    // ANSI time struct has month in range [0..11]
+    ansiTimeStruct.tm_mon = win32TimeStruct.wMonth - 1;
+    // ANSI time struct has year that is an offset from 1900
+    ansiTimeStruct.tm_year = win32TimeStruct.wYear - 1900;
+    // unknown daylight savings time (dst) status
+    // if we fail to init this value, we can get inconsistent results
+    ansiTimeStruct.tm_isdst = -1;
+    
+    unsigned long secondsSinceEpoch = mktime( &ansiTimeStruct );
+
+    *outSeconds = secondsSinceEpoch;
+	*outMilliseconds = (unsigned long)( win32TimeStruct.wMilliseconds );	
+	}
+
+