Mercurial > sdl-ios-xcode
view src/timer/win32/SDL_systimer.c @ 1701:442248d4e738 SDL-1.3
Merged DirectSound dropout fix from SDL 1.2
author | Sam Lantinga <slouken@libsdl.org> |
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date | Fri, 23 Jun 2006 08:48:24 +0000 |
parents | 4da1ee79c9af |
children |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" #ifdef SDL_TIMER_WIN32 #define WIN32_LEAN_AND_MEAN #include <windows.h> #include <mmsystem.h> #include "SDL_timer.h" #include "../SDL_timer_c.h" #ifdef _WIN32_WCE #error This is WinCE. Please use src/timer/wince/SDL_systimer.c instead. #endif #define TIME_WRAP_VALUE (~(DWORD)0) /* The first (low-resolution) ticks value of the application */ static DWORD start; #ifndef USE_GETTICKCOUNT /* Store if a high-resolution performance counter exists on the system */ static BOOL hires_timer_available; /* The first high-resolution ticks value of the application */ static LARGE_INTEGER hires_start_ticks; /* The number of ticks per second of the high-resolution performance counter */ static LARGE_INTEGER hires_ticks_per_second; #endif void SDL_StartTicks(void) { /* Set first ticks value */ #ifdef USE_GETTICKCOUNT start = GetTickCount(); #else #if 0 /* Apparently there are problems with QPC on Win2K */ if (QueryPerformanceFrequency(&hires_ticks_per_second) == TRUE) { hires_timer_available = TRUE; QueryPerformanceCounter(&hires_start_ticks); } else #endif { hires_timer_available = FALSE; timeBeginPeriod(1); /* use 1 ms timer precision */ start = timeGetTime(); } #endif } Uint32 SDL_GetTicks(void) { DWORD now, ticks; #ifndef USE_GETTICKCOUNT LARGE_INTEGER hires_now; #endif #ifdef USE_GETTICKCOUNT now = GetTickCount(); #else if (hires_timer_available) { QueryPerformanceCounter(&hires_now); hires_now.QuadPart -= hires_start_ticks.QuadPart; hires_now.QuadPart *= 1000; hires_now.QuadPart /= hires_ticks_per_second.QuadPart; return (DWORD) hires_now.QuadPart; } else { now = timeGetTime(); } #endif if (now < start) { ticks = (TIME_WRAP_VALUE - start) + now; } else { ticks = (now - start); } return (ticks); } void SDL_Delay(Uint32 ms) { Sleep(ms); } /* Data to handle a single periodic alarm */ static UINT timerID = 0; static void CALLBACK HandleAlarm(UINT uID, UINT uMsg, DWORD_PTR dwUser, DWORD_PTR dw1, DWORD_PTR dw2) { SDL_ThreadedTimerCheck(); } int SDL_SYS_TimerInit(void) { MMRESULT result; /* Set timer resolution */ result = timeBeginPeriod(TIMER_RESOLUTION); if (result != TIMERR_NOERROR) { SDL_SetError("Warning: Can't set %d ms timer resolution", TIMER_RESOLUTION); } /* Allow 10 ms of drift so we don't chew on CPU */ timerID = timeSetEvent(TIMER_RESOLUTION, 1, HandleAlarm, 0, TIME_PERIODIC); if (!timerID) { SDL_SetError("timeSetEvent() failed"); return (-1); } return (SDL_SetTimerThreaded(1)); } void SDL_SYS_TimerQuit(void) { if (timerID) { timeKillEvent(timerID); } timeEndPeriod(TIMER_RESOLUTION); } int SDL_SYS_StartTimer(void) { SDL_SetError("Internal logic error: Win32 uses threaded timer"); return (-1); } void SDL_SYS_StopTimer(void) { return; } #endif /* SDL_TIMER_WIN32 */ /* vi: set ts=4 sw=4 expandtab: */