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1 <HTML
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2 ><HEAD
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3 ><TITLE
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4 >SDL_SetTimer</TITLE
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5 ><META
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6 NAME="GENERATOR"
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7 CONTENT="Modular DocBook HTML Stylesheet Version 1.61
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8 "><LINK
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9 REL="HOME"
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10 TITLE="SDL Library Documentation"
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11 HREF="index.html"><LINK
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12 REL="UP"
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13 TITLE="Time"
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14 HREF="time.html"><LINK
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15 REL="PREVIOUS"
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16 TITLE="SDL_RemoveTimer"
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17 HREF="sdlremovetimer.html"></HEAD
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18 ><BODY
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19 CLASS="REFENTRY"
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20 BGCOLOR="#FFF8DC"
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21 TEXT="#000000"
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22 LINK="#0000ee"
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23 VLINK="#551a8b"
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24 ALINK="#ff0000"
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25 ><DIV
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26 CLASS="NAVHEADER"
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27 ><TABLE
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28 WIDTH="100%"
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29 BORDER="0"
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30 CELLPADDING="0"
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31 CELLSPACING="0"
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32 ><TR
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33 ><TH
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34 COLSPAN="3"
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35 ALIGN="center"
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36 >SDL Library Documentation</TH
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37 ></TR
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38 ><TR
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39 ><TD
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40 WIDTH="10%"
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41 ALIGN="left"
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42 VALIGN="bottom"
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43 ><A
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44 HREF="sdlremovetimer.html"
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45 >Prev</A
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46 ></TD
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47 ><TD
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48 WIDTH="80%"
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49 ALIGN="center"
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50 VALIGN="bottom"
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51 ></TD
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52 ><TD
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53 WIDTH="10%"
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54 ALIGN="right"
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55 VALIGN="bottom"
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56 > </TD
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57 ></TR
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58 ></TABLE
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59 ><HR
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60 ALIGN="LEFT"
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61 WIDTH="100%"></DIV
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62 ><H1
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63 ><A
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64 NAME="SDLSETTIMER"
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65 >SDL_SetTimer</A
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66 ></H1
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67 ><DIV
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68 CLASS="REFNAMEDIV"
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69 ><A
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70 NAME="AEN7926"
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71 ></A
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72 ><H2
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73 >Name</H2
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74 >SDL_SetTimer -- Set a callback to run after the specified number of milliseconds has
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75 elapsed.</DIV
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76 ><DIV
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77 CLASS="REFSYNOPSISDIV"
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78 ><A
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79 NAME="AEN7929"
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80 ></A
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81 ><H2
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82 >Synopsis</H2
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83 ><DIV
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84 CLASS="FUNCSYNOPSIS"
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85 ><A
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86 NAME="AEN7930"
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87 ></A
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88 ><P
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89 ></P
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90 ><PRE
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91 CLASS="FUNCSYNOPSISINFO"
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92 >#include "SDL.h"</PRE
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93 ><P
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94 ><CODE
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95 ><CODE
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96 CLASS="FUNCDEF"
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97 >int <B
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98 CLASS="FSFUNC"
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99 >SDL_SetTimer</B
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100 ></CODE
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101 >(Uint32 interval, SDL_TimerCallback callback);</CODE
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102 ></P
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103 ><P
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104 ></P
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105 ></DIV
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106 ></DIV
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107 ><DIV
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108 CLASS="REFSECT1"
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109 ><A
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110 NAME="SDLTIMERCALLBACK"
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111 ></A
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112 ><H2
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113 >Callback</H2
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114 ><P
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115 >/* Function prototype for the timer callback function */
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116 typedef Uint32 (*SDL_TimerCallback)(Uint32 interval);</P
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117 ></DIV
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118 ><DIV
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119 CLASS="REFSECT1"
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120 ><A
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121 NAME="AEN7939"
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122 ></A
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123 ><H2
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124 >Description</H2
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125 ><P
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126 >Set a callback to run after the specified number of milliseconds has
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127 elapsed. The callback function is passed the current timer interval
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128 and returns the next timer interval. If the returned value is the
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129 same as the one passed in, the periodic alarm continues, otherwise a
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130 new alarm is scheduled.</P
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131 ><P
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132 >To cancel a currently running timer, call
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133 <TT
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134 CLASS="FUNCTION"
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135 >SDL_SetTimer(0, NULL);</TT
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136 ></P
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137 ><P
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138 >The timer callback function may run in a different thread than your
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139 main constant, and so shouldn't call any functions from within itself.</P
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140 ><P
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141 >The maximum resolution of this timer is 10 ms, which means that if
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142 you request a 16 ms timer, your callback will run approximately 20 ms
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143 later on an unloaded system. If you wanted to set a flag signaling
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144 a frame update at 30 frames per second (every 33 ms), you might set a
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145 timer for 30 ms (see example below).</P
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146 ><P
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147 >If you use this function, you need to pass <TT
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148 CLASS="LITERAL"
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149 >SDL_INIT_TIMER</TT
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150 >
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151 to <TT
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152 CLASS="FUNCTION"
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153 >SDL_Init()</TT
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154 >.</P
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155 ><DIV
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156 CLASS="NOTE"
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157 ><BLOCKQUOTE
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158 CLASS="NOTE"
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159 ><P
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160 ><B
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161 >Note: </B
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162 >This function is kept for compatibility but has been superceeded
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163 by the new timer functions
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164 <A
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165 HREF="sdladdtimer.html"
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166 >SDL_AddTimer</A
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167 > and
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168 <A
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169 HREF="sdlremovetimer.html"
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170 >SDL_RemoveTimer</A
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171 > which support
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172 multiple timers.</P
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173 ></BLOCKQUOTE
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174 ></DIV
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175 ></DIV
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176 ><DIV
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177 CLASS="REFSECT1"
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178 ><A
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179 NAME="AEN7953"
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180 ></A
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181 ><H2
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182 >Examples</H2
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183 ><P
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184 ><PRE
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185 CLASS="PROGRAMLISTING"
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186 >SDL_SetTimer((33/10)*10, my_callback);</PRE
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187 ></P
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188 ></DIV
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189 ><DIV
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190 CLASS="REFSECT1"
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191 ><A
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192 NAME="AEN7957"
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193 ></A
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194 ><H2
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195 >See Also</H2
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196 ><P
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197 ><A
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198 HREF="sdladdtimer.html"
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199 ><TT
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200 CLASS="FUNCTION"
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201 >SDL_AddTimer</TT
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202 ></A
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203 ></P
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204 ></DIV
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205 ><DIV
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206 CLASS="NAVFOOTER"
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207 ><HR
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208 ALIGN="LEFT"
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209 WIDTH="100%"><TABLE
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210 WIDTH="100%"
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211 BORDER="0"
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212 CELLPADDING="0"
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213 CELLSPACING="0"
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214 ><TR
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215 ><TD
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216 WIDTH="33%"
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217 ALIGN="left"
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218 VALIGN="top"
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219 ><A
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220 HREF="sdlremovetimer.html"
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221 >Prev</A
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222 ></TD
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223 ><TD
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224 WIDTH="34%"
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225 ALIGN="center"
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226 VALIGN="top"
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227 ><A
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228 HREF="index.html"
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229 >Home</A
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230 ></TD
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231 ><TD
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232 WIDTH="33%"
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233 ALIGN="right"
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234 VALIGN="top"
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235 > </TD
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236 ></TR
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237 ><TR
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238 ><TD
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239 WIDTH="33%"
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240 ALIGN="left"
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241 VALIGN="top"
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242 >SDL_RemoveTimer</TD
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243 ><TD
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244 WIDTH="34%"
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245 ALIGN="center"
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246 VALIGN="top"
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247 ><A
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248 HREF="time.html"
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249 >Up</A
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250 ></TD
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251 ><TD
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252 WIDTH="33%"
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253 ALIGN="right"
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254 VALIGN="top"
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255 > </TD
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256 ></TR
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257 ></TABLE
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258 ></DIV
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259 ></BODY
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260 ></HTML
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261 > |
