This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
SDL_systimer.c
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
11
12
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
13
Lesser General Public License for more details.
15
16
17
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
18
19
Sam Lantinga
20
slouken@libsdl.org
21
*/
22
#include "SDL_config.h"
24
25
#ifdef SDL_TIMER_WIN32
26
27
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
28
29
30
#include <mmsystem.h>
#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
36
37
38
#endif
#define TIME_WRAP_VALUE (~(DWORD)0)
39
/* The first (low-resolution) ticks value of the application */
40
41
static DWORD start;
42
43
44
45
46
47
48
49
50
#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
51
52
void
SDL_StartTicks(void)
54
/* Set first ticks value */
55
#ifdef USE_GETTICKCOUNT
56
start = GetTickCount();
57
#else
58
59
60
61
62
#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
64
65
66
67
68
{
hires_timer_available = FALSE;
timeBeginPeriod(1); /* use 1 ms timer precision */
start = timeGetTime();
}
69
70
71
#endif
}
72
73
Uint32
SDL_GetTicks(void)
75
DWORD now, ticks;
76
#ifndef USE_GETTICKCOUNT
77
LARGE_INTEGER hires_now;
79
80
#ifdef USE_GETTICKCOUNT
81
now = GetTickCount();
82
#else
83
84
85
86
87
88
89
90
91
92
93
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();
}
94
#endif
96
97
98
99
100
101
if (now < start) {
ticks = (TIME_WRAP_VALUE - start) + now;
} else {
ticks = (now - start);
}
return (ticks);
102
103
}
104
105
void
SDL_Delay(Uint32 ms)
106
{
108
109
110
111
112
}
/* Data to handle a single periodic alarm */
static UINT timerID = 0;
113
114
115
static void CALLBACK
HandleAlarm(UINT uID, UINT uMsg, DWORD_PTR dwUser,
DWORD_PTR dw1, DWORD_PTR dw2)
116
{
117
SDL_ThreadedTimerCheck();
118
119
120
}
121
122
int
SDL_SYS_TimerInit(void)
123
{
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
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));
140
141
}
142
143
void
SDL_SYS_TimerQuit(void)
144
{
145
146
147
148
if (timerID) {
timeKillEvent(timerID);
}
timeEndPeriod(TIMER_RESOLUTION);
149
150
}
151
152
int
SDL_SYS_StartTimer(void)
153
{
154
155
SDL_SetError("Internal logic error: Win32 uses threaded timer");
return (-1);
156
157
}
158
159
void
SDL_SYS_StopTimer(void)
160
{
162
163
}
164
#endif /* SDL_TIMER_WIN32 */
165
/* vi: set ts=4 sw=4 expandtab: */