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      1 /*
      2     SDL - Simple DirectMedia Layer
      3     Copyright (C) 1997-2006 Sam Lantinga
      4 
      5     This library is free software; you can redistribute it and/or
      6     modify it under the terms of the GNU Lesser General Public
      7     License as published by the Free Software Foundation; either
      8     version 2.1 of the License, or (at your option) any later version.
      9 
     10     This library is distributed in the hope that it will be useful,
     11     but WITHOUT ANY WARRANTY; without even the implied warranty of
     12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13     Lesser General Public License for more details.
     14 
     15     You should have received a copy of the GNU Lesser General Public
     16     License along with this library; if not, write to the Free Software
     17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
     18 
     19     Sam Lantinga
     20     slouken (at) libsdl.org
     21 */
     22 #include "SDL_config.h"
     23 
     24 #ifdef SDL_TIMER_WINCE
     25 
     26 #define WIN32_LEAN_AND_MEAN
     27 #include <windows.h>
     28 #include <mmsystem.h>
     29 
     30 #include "SDL_thread.h"
     31 #include "SDL_timer.h"
     32 #include "../SDL_timer_c.h"
     33 
     34 static Uint64 start_date;
     35 static Uint64 start_ticks;
     36 
     37 static Uint64 wce_ticks(void)
     38 {
     39   return((Uint64)GetTickCount());
     40 }
     41 
     42 static Uint64 wce_date(void)
     43 {
     44   union
     45   {
     46 	FILETIME ftime;
     47 	Uint64 itime;
     48   } ftime;
     49   SYSTEMTIME stime;
     50 
     51   GetSystemTime(&stime);
     52   SystemTimeToFileTime(&stime,&ftime.ftime);
     53   ftime.itime/=10000; // Convert 100ns intervals to 1ms intervals
     54   // Remove ms portion, which can't be relied on
     55   ftime.itime -= (ftime.itime % 1000);
     56   return(ftime.itime);
     57 }
     58 
     59 static Sint32 wce_rel_ticks(void)
     60 {
     61   return((Sint32)(wce_ticks()-start_ticks));
     62 }
     63 
     64 static Sint32 wce_rel_date(void)
     65 {
     66   return((Sint32)(wce_date()-start_date));
     67 }
     68 
     69 /* Return time in ms relative to when SDL was started */
     70 Uint32 SDL_GetTicks()
     71 {
     72   Sint32 offset=wce_rel_date()-wce_rel_ticks();
     73   if((offset < -1000) || (offset > 1000))
     74   {
     75 //    fprintf(stderr,"Time desync(%+d), resyncing\n",offset/1000);
     76 	start_ticks-=offset;
     77   }
     78 
     79   return((Uint32)wce_rel_ticks());
     80 }
     81 
     82 /* Give up approx. givem milliseconds to the OS. */
     83 void SDL_Delay(Uint32 ms)
     84 {
     85   Sleep(ms);
     86 }
     87 
     88 /* Recard start-time of application for reference */
     89 void SDL_StartTicks(void)
     90 {
     91   start_date=wce_date();
     92   start_ticks=wce_ticks();
     93 }
     94 
     95 static UINT WIN_timer;
     96 
     97 #if ( _WIN32_WCE <= 420 )
     98 
     99 static HANDLE timersThread = 0;
    100 static HANDLE timersQuitEvent = 0;
    101 
    102 DWORD TimersThreadProc(void *data)
    103 {
    104 	while(WaitForSingleObject(timersQuitEvent, 10) == WAIT_TIMEOUT)
    105 	{
    106 		SDL_ThreadedTimerCheck();
    107 	}
    108 	return 0;
    109 }
    110 
    111 int SDL_SYS_TimerInit(void)
    112 {
    113 	// create a thread to process a threaded timers
    114 	// SetTimer does not suit the needs because
    115 	// TimerCallbackProc will be called only when WM_TIMER occured
    116 
    117 	timersQuitEvent = CreateEvent(0, TRUE, FALSE, 0);
    118 	if( !timersQuitEvent )
    119 	{
    120 		SDL_SetError("Cannot create event for timers thread");
    121 		return -1;
    122 	}
    123 	timersThread = CreateThread(NULL, 0, TimersThreadProc, 0, 0, 0);
    124 	if( !timersThread )
    125 	{
    126 		SDL_SetError("Cannot create timers thread, check amount of RAM available");
    127 		return -1;
    128 	}
    129 	SetThreadPriority(timersThread, THREAD_PRIORITY_HIGHEST);
    130 
    131 	return(SDL_SetTimerThreaded(1));
    132 }
    133 
    134 void SDL_SYS_TimerQuit(void)
    135 {
    136 	SetEvent(timersQuitEvent);
    137 	if( WaitForSingleObject(timersThread, 2000) == WAIT_TIMEOUT )
    138 		TerminateThread(timersThread, 0);
    139 	CloseHandle(timersThread);
    140 	CloseHandle(timersQuitEvent);
    141 	return;
    142 }
    143 
    144 #else
    145 
    146 #pragma comment(lib, "mmtimer.lib")
    147 
    148 /* Data to handle a single periodic alarm */
    149 static UINT timerID = 0;
    150 
    151 static void CALLBACK HandleAlarm(UINT uID,  UINT uMsg, DWORD dwUser,
    152 						DWORD dw1, DWORD dw2)
    153 {
    154 	SDL_ThreadedTimerCheck();
    155 }
    156 
    157 
    158 int SDL_SYS_TimerInit(void)
    159 {
    160 	MMRESULT result;
    161 
    162 	/* Set timer resolution */
    163 	result = timeBeginPeriod(TIMER_RESOLUTION);
    164 	if ( result != TIMERR_NOERROR ) {
    165 		SDL_SetError("Warning: Can't set %d ms timer resolution",
    166 							TIMER_RESOLUTION);
    167 	}
    168 	/* Allow 10 ms of drift so we don't chew on CPU */
    169 	timerID = timeSetEvent(TIMER_RESOLUTION,1,HandleAlarm,0,TIME_PERIODIC);
    170 	if ( ! timerID ) {
    171 		SDL_SetError("timeSetEvent() failed");
    172 		return(-1);
    173 	}
    174 	return(SDL_SetTimerThreaded(1));
    175 }
    176 
    177 void SDL_SYS_TimerQuit(void)
    178 {
    179 	if ( timerID ) {
    180 		timeKillEvent(timerID);
    181 	}
    182 	timeEndPeriod(TIMER_RESOLUTION);
    183 }
    184 
    185 #endif
    186 
    187 int SDL_SYS_StartTimer(void)
    188 {
    189 	SDL_SetError("Internal logic error: WinCE uses threaded timer");
    190 	return(-1);
    191 }
    192 
    193 void SDL_SYS_StopTimer(void)
    194 {
    195 	return;
    196 }
    197 
    198 #endif /* SDL_TIMER_WINCE */
    199