symbian-qemu-0.9.1-12/libsdl-trunk/docs/html/sdlsettimer.html
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     4 >SDL_SetTimer</TITLE
       
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    63 WIDTH="100%"></DIV
       
    64 ><H1
       
    65 ><A
       
    66 NAME="SDLSETTIMER"
       
    67 ></A
       
    68 >SDL_SetTimer</H1
       
    69 ><DIV
       
    70 CLASS="REFNAMEDIV"
       
    71 ><A
       
    72 NAME="AEN8557"
       
    73 ></A
       
    74 ><H2
       
    75 >Name</H2
       
    76 >SDL_SetTimer&nbsp;--&nbsp;Set a callback to run after the specified number of milliseconds has
       
    77 elapsed.</DIV
       
    78 ><DIV
       
    79 CLASS="REFSYNOPSISDIV"
       
    80 ><A
       
    81 NAME="AEN8560"
       
    82 ></A
       
    83 ><H2
       
    84 >Synopsis</H2
       
    85 ><DIV
       
    86 CLASS="FUNCSYNOPSIS"
       
    87 ><A
       
    88 NAME="AEN8561"
       
    89 ></A
       
    90 ><P
       
    91 ></P
       
    92 ><PRE
       
    93 CLASS="FUNCSYNOPSISINFO"
       
    94 >#include "SDL.h"</PRE
       
    95 ><P
       
    96 ><CODE
       
    97 ><CODE
       
    98 CLASS="FUNCDEF"
       
    99 >int <B
       
   100 CLASS="FSFUNC"
       
   101 >SDL_SetTimer</B
       
   102 ></CODE
       
   103 >(Uint32 interval, SDL_TimerCallback callback);</CODE
       
   104 ></P
       
   105 ><P
       
   106 ></P
       
   107 ></DIV
       
   108 ></DIV
       
   109 ><DIV
       
   110 CLASS="REFSECT1"
       
   111 ><A
       
   112 NAME="SDLTIMERCALLBACK"
       
   113 ></A
       
   114 ><H2
       
   115 >Callback</H2
       
   116 ><P
       
   117 >/* Function prototype for the timer callback function */
       
   118 typedef Uint32 (*SDL_TimerCallback)(Uint32 interval);</P
       
   119 ></DIV
       
   120 ><DIV
       
   121 CLASS="REFSECT1"
       
   122 ><A
       
   123 NAME="AEN8570"
       
   124 ></A
       
   125 ><H2
       
   126 >Description</H2
       
   127 ><P
       
   128 >Set a callback to run after the specified number of milliseconds has
       
   129 elapsed. The callback function is passed the current timer interval
       
   130 and returns the next timer interval.  If the returned value is the
       
   131 same as the one passed in, the periodic alarm continues, otherwise a
       
   132 new alarm is scheduled.</P
       
   133 ><P
       
   134 >To cancel a currently running timer, call
       
   135 <TT
       
   136 CLASS="FUNCTION"
       
   137 >SDL_SetTimer(0, NULL);</TT
       
   138 ></P
       
   139 ><P
       
   140 >The timer callback function may run in a different thread than your
       
   141 main constant, and so shouldn't call any functions from within itself.</P
       
   142 ><P
       
   143 >The maximum resolution of this timer is 10 ms, which means that if
       
   144 you request a 16 ms timer, your callback will run approximately 20 ms
       
   145 later on an unloaded system.  If you wanted to set a flag signaling
       
   146 a frame update at 30 frames per second (every 33 ms), you might set a
       
   147 timer for 30 ms (see example below).</P
       
   148 ><P
       
   149 >If you use this function, you need to pass <TT
       
   150 CLASS="LITERAL"
       
   151 >SDL_INIT_TIMER</TT
       
   152 >
       
   153 to <TT
       
   154 CLASS="FUNCTION"
       
   155 >SDL_Init()</TT
       
   156 >.</P
       
   157 ><DIV
       
   158 CLASS="NOTE"
       
   159 ><BLOCKQUOTE
       
   160 CLASS="NOTE"
       
   161 ><P
       
   162 ><B
       
   163 >Note: </B
       
   164 >This function is kept for compatibility but has been superseded
       
   165 by the new timer functions
       
   166 <A
       
   167 HREF="sdladdtimer.html"
       
   168 >SDL_AddTimer</A
       
   169 > and
       
   170 <A
       
   171 HREF="sdlremovetimer.html"
       
   172 >SDL_RemoveTimer</A
       
   173 > which support
       
   174 multiple timers.</P
       
   175 ></BLOCKQUOTE
       
   176 ></DIV
       
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   178 ><DIV
       
   179 CLASS="REFSECT1"
       
   180 ><A
       
   181 NAME="AEN8584"
       
   182 ></A
       
   183 ><H2
       
   184 >Examples</H2
       
   185 ><P
       
   186 ><PRE
       
   187 CLASS="PROGRAMLISTING"
       
   188 >SDL_SetTimer((33/10)*10, my_callback);</PRE
       
   189 ></P
       
   190 ></DIV
       
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   192 CLASS="REFSECT1"
       
   193 ><A
       
   194 NAME="AEN8588"
       
   195 ></A
       
   196 ><H2
       
   197 >See Also</H2
       
   198 ><P
       
   199 ><A
       
   200 HREF="sdladdtimer.html"
       
   201 ><TT
       
   202 CLASS="FUNCTION"
       
   203 >SDL_AddTimer</TT
       
   204 ></A
       
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