Mercurial > sdl-ios-xcode
annotate docs/html/sdlsemvalue.html @ 883:50f5a29c6a17
Date: Sat, 10 Apr 2004 02:25:33 -0400
From: Glenn Maynard
To: sdl@libsdl.org
Subject: [SDL] SDL_SetVideoMode() failing and not setting an error (patch)
Running an OpenGL SDL application off 1.2.7, at SDL_InitSubSystem(SDL_INIT_VIDEO) time:
Warning: Unable to initialize AAlib mouseUsing AAlib driver: Slang driver 1.0 (slang)
SDL_SetVideoMode then fails; SDL_GetError() returns "".
The installation problem is straightforward: X (the higher priority
driver) isn't running, so SDL is falling back on aalib. However,
no error is being set when aalib fails to initialize. This also
happens with the svgalib driver.
SDL_video.c line ~653 sets mode to NULL, since aalib didn't return an
OpenGL surface. Line ~711 ("failed setting a video mode") returns NULL.
The attached patch sets an error. It's a horrible, useless error
message--it should really say eg. "aalib does not support OpenGL"; this
should probably be done earlier in the individual drivers, too.
author | Sam Lantinga <slouken@libsdl.org> |
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date | Sun, 11 Apr 2004 19:54:40 +0000 |
parents | 355632dca928 |
children |
rev | line source |
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0 | 1 <HTML |
2 ><HEAD | |
3 ><TITLE | |
4 >SDL_SemValue</TITLE | |
5 ><META | |
6 NAME="GENERATOR" | |
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7 CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ |
0 | 8 "><LINK |
9 REL="HOME" | |
10 TITLE="SDL Library Documentation" | |
11 HREF="index.html"><LINK | |
12 REL="UP" | |
13 TITLE="Multi-threaded Programming" | |
14 HREF="thread.html"><LINK | |
15 REL="PREVIOUS" | |
16 TITLE="SDL_SemPost" | |
17 HREF="sdlsempost.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="SDL_CreateCond" | |
20 HREF="sdlcreatecond.html"></HEAD | |
21 ><BODY | |
22 CLASS="REFENTRY" | |
23 BGCOLOR="#FFF8DC" | |
24 TEXT="#000000" | |
25 LINK="#0000ee" | |
26 VLINK="#551a8b" | |
27 ALINK="#ff0000" | |
28 ><DIV | |
29 CLASS="NAVHEADER" | |
30 ><TABLE | |
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31 SUMMARY="Header navigation table" |
0 | 32 WIDTH="100%" |
33 BORDER="0" | |
34 CELLPADDING="0" | |
35 CELLSPACING="0" | |
36 ><TR | |
37 ><TH | |
38 COLSPAN="3" | |
39 ALIGN="center" | |
40 >SDL Library Documentation</TH | |
41 ></TR | |
42 ><TR | |
43 ><TD | |
44 WIDTH="10%" | |
45 ALIGN="left" | |
46 VALIGN="bottom" | |
47 ><A | |
48 HREF="sdlsempost.html" | |
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49 ACCESSKEY="P" |
0 | 50 >Prev</A |
51 ></TD | |
52 ><TD | |
53 WIDTH="80%" | |
54 ALIGN="center" | |
55 VALIGN="bottom" | |
56 ></TD | |
57 ><TD | |
58 WIDTH="10%" | |
59 ALIGN="right" | |
60 VALIGN="bottom" | |
61 ><A | |
62 HREF="sdlcreatecond.html" | |
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63 ACCESSKEY="N" |
0 | 64 >Next</A |
65 ></TD | |
66 ></TR | |
67 ></TABLE | |
68 ><HR | |
69 ALIGN="LEFT" | |
70 WIDTH="100%"></DIV | |
71 ><H1 | |
72 ><A | |
73 NAME="SDLSEMVALUE" | |
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74 ></A |
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75 >SDL_SemValue</H1 |
0 | 76 ><DIV |
77 CLASS="REFNAMEDIV" | |
78 ><A | |
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79 NAME="AEN8218" |
0 | 80 ></A |
81 ><H2 | |
82 >Name</H2 | |
83 >SDL_SemValue -- Return the current value of a semaphore.</DIV | |
84 ><DIV | |
85 CLASS="REFSYNOPSISDIV" | |
86 ><A | |
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87 NAME="AEN8221" |
0 | 88 ></A |
89 ><H2 | |
90 >Synopsis</H2 | |
91 ><DIV | |
92 CLASS="FUNCSYNOPSIS" | |
93 ><A | |
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94 NAME="AEN8222" |
0 | 95 ></A |
96 ><P | |
97 ></P | |
98 ><PRE | |
99 CLASS="FUNCSYNOPSISINFO" | |
100 >#include "SDL.h" | |
101 #include "SDL/SDL_thread.h"</PRE | |
102 ><P | |
103 ><CODE | |
104 ><CODE | |
105 CLASS="FUNCDEF" | |
106 >Uint32 <B | |
107 CLASS="FSFUNC" | |
108 >SDL_SemValue</B | |
109 ></CODE | |
110 >(SDL_sem *sem);</CODE | |
111 ></P | |
112 ><P | |
113 ></P | |
114 ></DIV | |
115 ></DIV | |
116 ><DIV | |
117 CLASS="REFSECT1" | |
118 ><A | |
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119 NAME="AEN8228" |
0 | 120 ></A |
121 ><H2 | |
122 >Description</H2 | |
123 ><P | |
124 ><TT | |
125 CLASS="FUNCTION" | |
126 >SDL_SemValue()</TT | |
127 > returns the current semaphore value from | |
128 the semaphore pointed to by <TT | |
129 CLASS="PARAMETER" | |
130 ><I | |
131 >sem</I | |
132 ></TT | |
133 >.</P | |
134 ></DIV | |
135 ><DIV | |
136 CLASS="REFSECT1" | |
137 ><A | |
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138 NAME="AEN8233" |
0 | 139 ></A |
140 ><H2 | |
141 >Return Value</H2 | |
142 ><P | |
143 >Returns current value of the semaphore.</P | |
144 ></DIV | |
145 ><DIV | |
146 CLASS="REFSECT1" | |
147 ><A | |
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148 NAME="AEN8236" |
0 | 149 ></A |
150 ><H2 | |
151 >Examples</H2 | |
152 ><P | |
153 ><PRE | |
154 CLASS="PROGRAMLISTING" | |
155 > sem_value = SDL_SemValue(my_sem);</PRE | |
156 ></P | |
157 ></DIV | |
158 ><DIV | |
159 CLASS="REFSECT1" | |
160 ><A | |
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161 NAME="AEN8240" |
0 | 162 ></A |
163 ><H2 | |
164 >See Also</H2 | |
165 ><P | |
166 ><A | |
167 HREF="sdlcreatesemaphore.html" | |
168 ><TT | |
169 CLASS="FUNCTION" | |
170 >SDL_CreateSemaphore</TT | |
171 ></A | |
172 >, | |
173 <A | |
174 HREF="sdldestroysemaphore.html" | |
175 ><TT | |
176 CLASS="FUNCTION" | |
177 >SDL_DestroySemaphore</TT | |
178 ></A | |
179 >, | |
180 <A | |
181 HREF="sdlsemwait.html" | |
182 ><TT | |
183 CLASS="FUNCTION" | |
184 >SDL_SemWait</TT | |
185 ></A | |
186 >, | |
187 <A | |
188 HREF="sdlsemtrywait.html" | |
189 ><TT | |
190 CLASS="FUNCTION" | |
191 >SDL_SemTryWait</TT | |
192 ></A | |
193 >, | |
194 <A | |
195 HREF="sdlsemwaittimeout.html" | |
196 ><TT | |
197 CLASS="FUNCTION" | |
198 >SDL_SemWaitTimeout</TT | |
199 ></A | |
200 >, | |
201 <A | |
202 HREF="sdlsempost.html" | |
203 ><TT | |
204 CLASS="FUNCTION" | |
205 >SDL_SemPost</TT | |
206 ></A | |
207 ></P | |
208 ></DIV | |
209 ><DIV | |
210 CLASS="NAVFOOTER" | |
211 ><HR | |
212 ALIGN="LEFT" | |
213 WIDTH="100%"><TABLE | |
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214 SUMMARY="Footer navigation table" |
0 | 215 WIDTH="100%" |
216 BORDER="0" | |
217 CELLPADDING="0" | |
218 CELLSPACING="0" | |
219 ><TR | |
220 ><TD | |
221 WIDTH="33%" | |
222 ALIGN="left" | |
223 VALIGN="top" | |
224 ><A | |
225 HREF="sdlsempost.html" | |
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226 ACCESSKEY="P" |
0 | 227 >Prev</A |
228 ></TD | |
229 ><TD | |
230 WIDTH="34%" | |
231 ALIGN="center" | |
232 VALIGN="top" | |
233 ><A | |
234 HREF="index.html" | |
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235 ACCESSKEY="H" |
0 | 236 >Home</A |
237 ></TD | |
238 ><TD | |
239 WIDTH="33%" | |
240 ALIGN="right" | |
241 VALIGN="top" | |
242 ><A | |
243 HREF="sdlcreatecond.html" | |
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244 ACCESSKEY="N" |
0 | 245 >Next</A |
246 ></TD | |
247 ></TR | |
248 ><TR | |
249 ><TD | |
250 WIDTH="33%" | |
251 ALIGN="left" | |
252 VALIGN="top" | |
253 >SDL_SemPost</TD | |
254 ><TD | |
255 WIDTH="34%" | |
256 ALIGN="center" | |
257 VALIGN="top" | |
258 ><A | |
259 HREF="thread.html" | |
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260 ACCESSKEY="U" |
0 | 261 >Up</A |
262 ></TD | |
263 ><TD | |
264 WIDTH="33%" | |
265 ALIGN="right" | |
266 VALIGN="top" | |
267 >SDL_CreateCond</TD | |
268 ></TR | |
269 ></TABLE | |
270 ></DIV | |
271 ></BODY | |
272 ></HTML | |
273 > |