/* * 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 #include #include #include /** * 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 ); }