e14743d1 |
1 | /* |
2 | SDL - Simple DirectMedia Layer |
3 | Copyright (C) 1997-2009 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@libsdl.org |
21 | */ |
22 | #include "SDL_config.h" |
23 | |
24 | #ifdef SDL_TIMER_WIN32 |
25 | |
26 | #define WIN32_LEAN_AND_MEAN |
27 | #include <windows.h> |
28 | #include <mmsystem.h> |
29 | |
30 | #include "SDL_timer.h" |
31 | #include "../SDL_timer_c.h" |
32 | |
33 | #ifdef _WIN32_WCE |
34 | #error This is WinCE. Please use src/timer/wince/SDL_systimer.c instead. |
35 | #endif |
36 | |
37 | #define TIME_WRAP_VALUE (~(DWORD)0) |
38 | |
39 | /* The first (low-resolution) ticks value of the application */ |
40 | static DWORD start; |
41 | |
42 | #ifndef USE_GETTICKCOUNT |
43 | /* Store if a high-resolution performance counter exists on the system */ |
44 | static BOOL hires_timer_available; |
45 | /* The first high-resolution ticks value of the application */ |
46 | static LARGE_INTEGER hires_start_ticks; |
47 | /* The number of ticks per second of the high-resolution performance counter */ |
48 | static LARGE_INTEGER hires_ticks_per_second; |
49 | #endif |
50 | |
51 | void SDL_StartTicks(void) |
52 | { |
53 | /* Set first ticks value */ |
54 | #ifdef USE_GETTICKCOUNT |
55 | start = GetTickCount(); |
56 | #else |
57 | #if 0 /* Apparently there are problems with QPC on Win2K */ |
58 | if (QueryPerformanceFrequency(&hires_ticks_per_second) == TRUE) |
59 | { |
60 | hires_timer_available = TRUE; |
61 | QueryPerformanceCounter(&hires_start_ticks); |
62 | } |
63 | else |
64 | #endif |
65 | { |
66 | hires_timer_available = FALSE; |
67 | timeBeginPeriod(1); /* use 1 ms timer precision */ |
68 | start = timeGetTime(); |
69 | } |
70 | #endif |
71 | } |
72 | |
73 | Uint32 SDL_GetTicks(void) |
74 | { |
75 | DWORD now, ticks; |
76 | #ifndef USE_GETTICKCOUNT |
77 | LARGE_INTEGER hires_now; |
78 | #endif |
79 | |
80 | #ifdef USE_GETTICKCOUNT |
81 | now = GetTickCount(); |
82 | #else |
83 | if (hires_timer_available) |
84 | { |
85 | QueryPerformanceCounter(&hires_now); |
86 | |
87 | hires_now.QuadPart -= hires_start_ticks.QuadPart; |
88 | hires_now.QuadPart *= 1000; |
89 | hires_now.QuadPart /= hires_ticks_per_second.QuadPart; |
90 | |
91 | return (DWORD)hires_now.QuadPart; |
92 | } |
93 | else |
94 | { |
95 | now = timeGetTime(); |
96 | } |
97 | #endif |
98 | |
99 | if ( now < start ) { |
100 | ticks = (TIME_WRAP_VALUE-start) + now; |
101 | } else { |
102 | ticks = (now - start); |
103 | } |
104 | return(ticks); |
105 | } |
106 | |
107 | void SDL_Delay(Uint32 ms) |
108 | { |
109 | Sleep(ms); |
110 | } |
111 | |
112 | /* Data to handle a single periodic alarm */ |
113 | static UINT timerID = 0; |
114 | |
115 | static void CALLBACK HandleAlarm(UINT uID, UINT uMsg, DWORD_PTR dwUser, |
116 | DWORD_PTR dw1, DWORD_PTR dw2) |
117 | { |
118 | SDL_ThreadedTimerCheck(); |
119 | } |
120 | |
121 | |
122 | int SDL_SYS_TimerInit(void) |
123 | { |
124 | MMRESULT result; |
125 | |
126 | /* Set timer resolution */ |
127 | result = timeBeginPeriod(TIMER_RESOLUTION); |
128 | if ( result != TIMERR_NOERROR ) { |
129 | SDL_SetError("Warning: Can't set %d ms timer resolution", |
130 | TIMER_RESOLUTION); |
131 | } |
132 | /* Allow 10 ms of drift so we don't chew on CPU */ |
133 | timerID = timeSetEvent(TIMER_RESOLUTION,1,HandleAlarm,0,TIME_PERIODIC); |
134 | if ( ! timerID ) { |
135 | SDL_SetError("timeSetEvent() failed"); |
136 | return(-1); |
137 | } |
138 | return(SDL_SetTimerThreaded(1)); |
139 | } |
140 | |
141 | void SDL_SYS_TimerQuit(void) |
142 | { |
143 | if ( timerID ) { |
144 | timeKillEvent(timerID); |
145 | } |
146 | timeEndPeriod(TIMER_RESOLUTION); |
147 | } |
148 | |
149 | int SDL_SYS_StartTimer(void) |
150 | { |
151 | SDL_SetError("Internal logic error: Win32 uses threaded timer"); |
152 | return(-1); |
153 | } |
154 | |
155 | void SDL_SYS_StopTimer(void) |
156 | { |
157 | return; |
158 | } |
159 | |
160 | #endif /* SDL_TIMER_WIN32 */ |