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1 /* |
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2 SDL - Simple DirectMedia Layer |
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3 Copyright (C) 1997-2006 Sam Lantinga |
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4 |
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5 This library is free software; you can redistribute it and/or |
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6 modify it under the terms of the GNU Lesser General Public |
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7 License as published by the Free Software Foundation; either |
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8 version 2.1 of the License, or (at your option) any later version. |
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9 |
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10 This library is distributed in the hope that it will be useful, |
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11 but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 Lesser General Public License for more details. |
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14 |
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15 You should have received a copy of the GNU Lesser General Public |
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16 License along with this library; if not, write to the Free Software |
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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18 |
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19 Sam Lantinga |
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20 slouken@libsdl.org |
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21 */ |
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22 #include "SDL_config.h" |
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23 |
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24 #ifdef SDL_TIMER_WIN32 |
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25 |
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26 #define WIN32_LEAN_AND_MEAN |
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27 #include <windows.h> |
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28 #include <mmsystem.h> |
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29 |
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30 #include "SDL_timer.h" |
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31 #include "../SDL_timer_c.h" |
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32 |
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33 #ifdef _WIN32_WCE |
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34 #error This is WinCE. Please use src/timer/wince/SDL_systimer.c instead. |
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35 #endif |
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36 |
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37 #define TIME_WRAP_VALUE (~(DWORD)0) |
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38 |
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39 /* The first (low-resolution) ticks value of the application */ |
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40 static DWORD start; |
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41 |
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42 #ifndef USE_GETTICKCOUNT |
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43 /* Store if a high-resolution performance counter exists on the system */ |
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44 static BOOL hires_timer_available; |
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45 /* The first high-resolution ticks value of the application */ |
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46 static LARGE_INTEGER hires_start_ticks; |
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47 /* The number of ticks per second of the high-resolution performance counter */ |
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48 static LARGE_INTEGER hires_ticks_per_second; |
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49 #endif |
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50 |
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51 void SDL_StartTicks(void) |
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52 { |
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53 /* Set first ticks value */ |
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54 #ifdef USE_GETTICKCOUNT |
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55 start = GetTickCount(); |
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56 #else |
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57 #if 0 /* Apparently there are problems with QPC on Win2K */ |
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58 if (QueryPerformanceFrequency(&hires_ticks_per_second) == TRUE) |
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59 { |
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60 hires_timer_available = TRUE; |
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61 QueryPerformanceCounter(&hires_start_ticks); |
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62 } |
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63 else |
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64 #endif |
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65 { |
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66 hires_timer_available = FALSE; |
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67 timeBeginPeriod(1); /* use 1 ms timer precision */ |
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68 start = timeGetTime(); |
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69 } |
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70 #endif |
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71 } |
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72 |
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73 Uint32 SDL_GetTicks(void) |
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74 { |
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75 DWORD now, ticks; |
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76 #ifndef USE_GETTICKCOUNT |
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77 LARGE_INTEGER hires_now; |
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78 #endif |
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79 |
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80 #ifdef USE_GETTICKCOUNT |
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81 now = GetTickCount(); |
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82 #else |
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83 if (hires_timer_available) |
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84 { |
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85 QueryPerformanceCounter(&hires_now); |
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86 |
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87 hires_now.QuadPart -= hires_start_ticks.QuadPart; |
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88 hires_now.QuadPart *= 1000; |
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89 hires_now.QuadPart /= hires_ticks_per_second.QuadPart; |
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90 |
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91 return (DWORD)hires_now.QuadPart; |
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92 } |
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93 else |
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94 { |
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95 now = timeGetTime(); |
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96 } |
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97 #endif |
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98 |
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99 if ( now < start ) { |
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100 ticks = (TIME_WRAP_VALUE-start) + now; |
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101 } else { |
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102 ticks = (now - start); |
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103 } |
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104 return(ticks); |
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105 } |
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106 |
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107 void SDL_Delay(Uint32 ms) |
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108 { |
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109 Sleep(ms); |
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110 } |
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111 |
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112 /* Data to handle a single periodic alarm */ |
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113 static UINT timerID = 0; |
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114 |
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115 static void CALLBACK HandleAlarm(UINT uID, UINT uMsg, DWORD_PTR dwUser, |
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116 DWORD_PTR dw1, DWORD_PTR dw2) |
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117 { |
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118 SDL_ThreadedTimerCheck(); |
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119 } |
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120 |
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121 |
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122 int SDL_SYS_TimerInit(void) |
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123 { |
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124 MMRESULT result; |
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125 |
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126 /* Set timer resolution */ |
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127 result = timeBeginPeriod(TIMER_RESOLUTION); |
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128 if ( result != TIMERR_NOERROR ) { |
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129 SDL_SetError("Warning: Can't set %d ms timer resolution", |
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130 TIMER_RESOLUTION); |
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131 } |
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132 /* Allow 10 ms of drift so we don't chew on CPU */ |
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133 timerID = timeSetEvent(TIMER_RESOLUTION,1,HandleAlarm,0,TIME_PERIODIC); |
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134 if ( ! timerID ) { |
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135 SDL_SetError("timeSetEvent() failed"); |
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136 return(-1); |
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137 } |
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138 return(SDL_SetTimerThreaded(1)); |
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139 } |
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140 |
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141 void SDL_SYS_TimerQuit(void) |
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142 { |
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143 if ( timerID ) { |
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144 timeKillEvent(timerID); |
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145 } |
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146 timeEndPeriod(TIMER_RESOLUTION); |
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147 } |
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148 |
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149 int SDL_SYS_StartTimer(void) |
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150 { |
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151 SDL_SetError("Internal logic error: Win32 uses threaded timer"); |
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152 return(-1); |
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153 } |
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154 |
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155 void SDL_SYS_StopTimer(void) |
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156 { |
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157 return; |
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158 } |
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159 |
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160 #endif /* SDL_TIMER_WIN32 */ |