Mercurial > sdl-ios-xcode
annotate docs/html/sdljoystickgetaxis.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 |
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rev | line source |
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0 | 1 <HTML |
2 ><HEAD | |
3 ><TITLE | |
4 >SDL_JoystickGetAxis</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="Joystick" | |
14 HREF="joystick.html"><LINK | |
15 REL="PREVIOUS" | |
16 TITLE="SDL_JoystickUpdate" | |
17 HREF="sdljoystickupdate.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="SDL_JoystickGetHat" | |
20 HREF="sdljoystickgethat.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="sdljoystickupdate.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="sdljoystickgethat.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="SDLJOYSTICKGETAXIS" | |
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74 ></A |
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75 >SDL_JoystickGetAxis</H1 |
0 | 76 ><DIV |
77 CLASS="REFNAMEDIV" | |
78 ><A | |
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79 NAME="AEN6320" |
0 | 80 ></A |
81 ><H2 | |
82 >Name</H2 | |
83 >SDL_JoystickGetAxis -- Get the current state of an axis</DIV | |
84 ><DIV | |
85 CLASS="REFSYNOPSISDIV" | |
86 ><A | |
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87 NAME="AEN6323" |
0 | 88 ></A |
89 ><H2 | |
90 >Synopsis</H2 | |
91 ><DIV | |
92 CLASS="FUNCSYNOPSIS" | |
93 ><A | |
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94 NAME="AEN6324" |
0 | 95 ></A |
96 ><P | |
97 ></P | |
98 ><PRE | |
99 CLASS="FUNCSYNOPSISINFO" | |
100 >#include "SDL.h"</PRE | |
101 ><P | |
102 ><CODE | |
103 ><CODE | |
104 CLASS="FUNCDEF" | |
105 >Sint16 <B | |
106 CLASS="FSFUNC" | |
107 >SDL_JoystickGetAxis</B | |
108 ></CODE | |
109 >(SDL_Joystick *joystick, int axis);</CODE | |
110 ></P | |
111 ><P | |
112 ></P | |
113 ></DIV | |
114 ></DIV | |
115 ><DIV | |
116 CLASS="REFSECT1" | |
117 ><A | |
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118 NAME="AEN6330" |
0 | 119 ></A |
120 ><H2 | |
121 >Description</H2 | |
122 ><P | |
123 ><TT | |
124 CLASS="FUNCTION" | |
125 >SDL_JoystickGetAxis</TT | |
126 > returns the current state of the given <TT | |
127 CLASS="PARAMETER" | |
128 ><I | |
129 >axis</I | |
130 ></TT | |
131 > on the given <TT | |
132 CLASS="PARAMETER" | |
133 ><I | |
134 >joystick</I | |
135 ></TT | |
136 >.</P | |
137 ><P | |
138 >On most modern joysticks the X axis is usually represented by <TT | |
139 CLASS="PARAMETER" | |
140 ><I | |
141 >axis</I | |
142 ></TT | |
143 > 0 and the Y axis by <TT | |
144 CLASS="PARAMETER" | |
145 ><I | |
146 >axis</I | |
147 ></TT | |
148 > 1. The value returned by <TT | |
149 CLASS="FUNCTION" | |
150 >SDL_JoystickGetAxis</TT | |
151 > is a signed integer (-32768 to 32768) representing the current position of the <TT | |
152 CLASS="PARAMETER" | |
153 ><I | |
154 >axis</I | |
155 ></TT | |
156 >, it maybe necessary to impose certain tolerances on these values to account for jitter. It is worth noting that some joysticks use axes 2 and 3 for extra buttons.</P | |
157 ></DIV | |
158 ><DIV | |
159 CLASS="REFSECT1" | |
160 ><A | |
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161 NAME="AEN6341" |
0 | 162 ></A |
163 ><H2 | |
164 >Return Value</H2 | |
165 ><P | |
166 >Returns a 16-bit signed integer representing the current position of the <TT | |
167 CLASS="PARAMETER" | |
168 ><I | |
169 >axis</I | |
170 ></TT | |
171 >.</P | |
172 ></DIV | |
173 ><DIV | |
174 CLASS="REFSECT1" | |
175 ><A | |
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176 NAME="AEN6345" |
0 | 177 ></A |
178 ><H2 | |
179 >Examples</H2 | |
180 ><P | |
181 ><PRE | |
182 CLASS="PROGRAMLISTING" | |
183 >Sint16 x_move, y_move; | |
184 SDL_Joystick *joy1; | |
185 . | |
186 . | |
187 x_move=SDL_JoystickGetAxis(joy1, 0); | |
188 y_move=SDL_JoystickGetAxis(joy1, 1);</PRE | |
189 ></P | |
190 ></DIV | |
191 ><DIV | |
192 CLASS="REFSECT1" | |
193 ><A | |
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194 NAME="AEN6349" |
0 | 195 ></A |
196 ><H2 | |
197 >See Also</H2 | |
198 ><P | |
199 ><A | |
200 HREF="sdljoysticknumaxes.html" | |
201 ><TT | |
202 CLASS="FUNCTION" | |
203 >SDL_JoystickNumAxes</TT | |
204 ></A | |
205 ></P | |
206 ></DIV | |
207 ><DIV | |
208 CLASS="NAVFOOTER" | |
209 ><HR | |
210 ALIGN="LEFT" | |
211 WIDTH="100%"><TABLE | |
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212 SUMMARY="Footer navigation table" |
0 | 213 WIDTH="100%" |
214 BORDER="0" | |
215 CELLPADDING="0" | |
216 CELLSPACING="0" | |
217 ><TR | |
218 ><TD | |
219 WIDTH="33%" | |
220 ALIGN="left" | |
221 VALIGN="top" | |
222 ><A | |
223 HREF="sdljoystickupdate.html" | |
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224 ACCESSKEY="P" |
0 | 225 >Prev</A |
226 ></TD | |
227 ><TD | |
228 WIDTH="34%" | |
229 ALIGN="center" | |
230 VALIGN="top" | |
231 ><A | |
232 HREF="index.html" | |
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233 ACCESSKEY="H" |
0 | 234 >Home</A |
235 ></TD | |
236 ><TD | |
237 WIDTH="33%" | |
238 ALIGN="right" | |
239 VALIGN="top" | |
240 ><A | |
241 HREF="sdljoystickgethat.html" | |
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242 ACCESSKEY="N" |
0 | 243 >Next</A |
244 ></TD | |
245 ></TR | |
246 ><TR | |
247 ><TD | |
248 WIDTH="33%" | |
249 ALIGN="left" | |
250 VALIGN="top" | |
251 >SDL_JoystickUpdate</TD | |
252 ><TD | |
253 WIDTH="34%" | |
254 ALIGN="center" | |
255 VALIGN="top" | |
256 ><A | |
257 HREF="joystick.html" | |
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258 ACCESSKEY="U" |
0 | 259 >Up</A |
260 ></TD | |
261 ><TD | |
262 WIDTH="33%" | |
263 ALIGN="right" | |
264 VALIGN="top" | |
265 >SDL_JoystickGetHat</TD | |
266 ></TR | |
267 ></TABLE | |
268 ></DIV | |
269 ></BODY | |
270 ></HTML | |
271 > |