Mercurial > sdl-ios-xcode

comparison docs/html/sdlsettimer.html @ 0:74212992fb08

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Initial revision
author Sam Lantinga <slouken@lokigames.com>
date Thu, 26 Apr 2001 16:45:43 +0000
parents
children 55f1f1b3e27d
comparison
equal deleted inserted replaced
-1:000000000000 0:74212992fb08
1 <HTML
2 ><HEAD
3 ><TITLE
4 >SDL_SetTimer</TITLE
5 ><META
6 NAME="GENERATOR"
7 CONTENT="Modular DocBook HTML Stylesheet Version 1.61
8 "><LINK
9 REL="HOME"
10 TITLE="SDL Library Documentation"
11 HREF="index.html"><LINK
12 REL="UP"
13 TITLE="Time"
14 HREF="time.html"><LINK
15 REL="PREVIOUS"
16 TITLE="SDL_RemoveTimer"
17 HREF="sdlremovetimer.html"></HEAD
18 ><BODY
19 CLASS="REFENTRY"
20 BGCOLOR="#FFF8DC"
21 TEXT="#000000"
22 LINK="#0000ee"
23 VLINK="#551a8b"
24 ALINK="#ff0000"
25 ><DIV
26 CLASS="NAVHEADER"
27 ><TABLE
28 WIDTH="100%"
29 BORDER="0"
30 CELLPADDING="0"
31 CELLSPACING="0"
32 ><TR
33 ><TH
34 COLSPAN="3"
35 ALIGN="center"
36 >SDL Library Documentation</TH
37 ></TR
38 ><TR
39 ><TD
40 WIDTH="10%"
41 ALIGN="left"
42 VALIGN="bottom"
43 ><A
44 HREF="sdlremovetimer.html"
45 >Prev</A
46 ></TD
47 ><TD
48 WIDTH="80%"
49 ALIGN="center"
50 VALIGN="bottom"
51 ></TD
52 ><TD
53 WIDTH="10%"
54 ALIGN="right"
55 VALIGN="bottom"
56 >&nbsp;</TD
57 ></TR
58 ></TABLE
59 ><HR
60 ALIGN="LEFT"
61 WIDTH="100%"></DIV
62 ><H1
63 ><A
64 NAME="SDLSETTIMER"
65 >SDL_SetTimer</A
66 ></H1
67 ><DIV
68 CLASS="REFNAMEDIV"
69 ><A
70 NAME="AEN7926"
71 ></A
72 ><H2
73 >Name</H2
74 >SDL_SetTimer&nbsp;--&nbsp;Set a callback to run after the specified number of milliseconds has
75 elapsed.</DIV
76 ><DIV
77 CLASS="REFSYNOPSISDIV"
78 ><A
79 NAME="AEN7929"
80 ></A
81 ><H2
82 >Synopsis</H2
83 ><DIV
84 CLASS="FUNCSYNOPSIS"
85 ><A
86 NAME="AEN7930"
87 ></A
88 ><P
89 ></P
90 ><PRE
91 CLASS="FUNCSYNOPSISINFO"
92 >#include "SDL.h"</PRE
93 ><P
94 ><CODE
95 ><CODE
96 CLASS="FUNCDEF"
97 >int <B
98 CLASS="FSFUNC"
99 >SDL_SetTimer</B
100 ></CODE
101 >(Uint32 interval, SDL_TimerCallback callback);</CODE
102 ></P
103 ><P
104 ></P
105 ></DIV
106 ></DIV
107 ><DIV
108 CLASS="REFSECT1"
109 ><A
110 NAME="SDLTIMERCALLBACK"
111 ></A
112 ><H2
113 >Callback</H2
114 ><P
115 >/* Function prototype for the timer callback function */
116 typedef Uint32 (*SDL_TimerCallback)(Uint32 interval);</P
117 ></DIV
118 ><DIV
119 CLASS="REFSECT1"
120 ><A
121 NAME="AEN7939"
122 ></A
123 ><H2
124 >Description</H2
125 ><P
126 >Set a callback to run after the specified number of milliseconds has
127 elapsed. The callback function is passed the current timer interval
128 and returns the next timer interval. If the returned value is the
129 same as the one passed in, the periodic alarm continues, otherwise a
130 new alarm is scheduled.</P
131 ><P
132 >To cancel a currently running timer, call
133 <TT
134 CLASS="FUNCTION"
135 >SDL_SetTimer(0, NULL);</TT
136 ></P
137 ><P
138 >The timer callback function may run in a different thread than your
139 main constant, and so shouldn't call any functions from within itself.</P
140 ><P
141 >The maximum resolution of this timer is 10 ms, which means that if
142 you request a 16 ms timer, your callback will run approximately 20 ms
143 later on an unloaded system. If you wanted to set a flag signaling
144 a frame update at 30 frames per second (every 33 ms), you might set a
145 timer for 30 ms (see example below).</P
146 ><P
147 >If you use this function, you need to pass <TT
148 CLASS="LITERAL"
149 >SDL_INIT_TIMER</TT
150 >
151 to <TT
152 CLASS="FUNCTION"
153 >SDL_Init()</TT
154 >.</P
155 ><DIV
156 CLASS="NOTE"
157 ><BLOCKQUOTE
158 CLASS="NOTE"
159 ><P
160 ><B
161 >Note: </B
162 >This function is kept for compatibility but has been superceeded
163 by the new timer functions
164 <A
165 HREF="sdladdtimer.html"
166 >SDL_AddTimer</A
167 > and
168 <A
169 HREF="sdlremovetimer.html"
170 >SDL_RemoveTimer</A
171 > which support
172 multiple timers.</P
173 ></BLOCKQUOTE
174 ></DIV
175 ></DIV
176 ><DIV
177 CLASS="REFSECT1"
178 ><A
179 NAME="AEN7953"
180 ></A
181 ><H2
182 >Examples</H2
183 ><P
184 ><PRE
185 CLASS="PROGRAMLISTING"
186 >SDL_SetTimer((33/10)*10, my_callback);</PRE
187 ></P
188 ></DIV
189 ><DIV
190 CLASS="REFSECT1"
191 ><A
192 NAME="AEN7957"
193 ></A
194 ><H2
195 >See Also</H2
196 ><P
197 ><A
198 HREF="sdladdtimer.html"
199 ><TT
200 CLASS="FUNCTION"
201 >SDL_AddTimer</TT
202 ></A
203 ></P
204 ></DIV
205 ><DIV
206 CLASS="NAVFOOTER"
207 ><HR
208 ALIGN="LEFT"
209 WIDTH="100%"><TABLE
210 WIDTH="100%"
211 BORDER="0"
212 CELLPADDING="0"
213 CELLSPACING="0"
214 ><TR
215 ><TD
216 WIDTH="33%"
217 ALIGN="left"
218 VALIGN="top"
219 ><A
220 HREF="sdlremovetimer.html"
221 >Prev</A
222 ></TD
223 ><TD
224 WIDTH="34%"
225 ALIGN="center"
226 VALIGN="top"
227 ><A
228 HREF="index.html"
229 >Home</A
230 ></TD
231 ><TD
232 WIDTH="33%"
233 ALIGN="right"
234 VALIGN="top"
235 >&nbsp;</TD
236 ></TR
237 ><TR
238 ><TD
239 WIDTH="33%"
240 ALIGN="left"
241 VALIGN="top"
242 >SDL_RemoveTimer</TD
243 ><TD
244 WIDTH="34%"
245 ALIGN="center"
246 VALIGN="top"
247 ><A
248 HREF="time.html"
249 >Up</A
250 ></TD
251 ><TD
252 WIDTH="33%"
253 ALIGN="right"
254 VALIGN="top"
255 >&nbsp;</TD
256 ></TR
257 ></TABLE
258 ></DIV
259 ></BODY
260 ></HTML
261 >