Mercurial > sdl-ios-xcode
annotate docs/html/sdlsetgammaramp.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_SetGammaRamp</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="Video" | |
14 HREF="video.html"><LINK | |
15 REL="PREVIOUS" | |
16 TITLE="SDL_GetGammaRamp" | |
17 HREF="sdlgetgammaramp.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="SDL_MapRGB" | |
20 HREF="sdlmaprgb.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="sdlgetgammaramp.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="sdlmaprgb.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="SDLSETGAMMARAMP" | |
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74 ></A |
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75 >SDL_SetGammaRamp</H1 |
0 | 76 ><DIV |
77 CLASS="REFNAMEDIV" | |
78 ><A | |
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79 NAME="AEN1624" |
0 | 80 ></A |
81 ><H2 | |
82 >Name</H2 | |
83 >SDL_SetGammaRamp -- Sets the color gamma lookup tables for the display</DIV | |
84 ><DIV | |
85 CLASS="REFSYNOPSISDIV" | |
86 ><A | |
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87 NAME="AEN1627" |
0 | 88 ></A |
89 ><H2 | |
90 >Synopsis</H2 | |
91 ><DIV | |
92 CLASS="FUNCSYNOPSIS" | |
93 ><A | |
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94 NAME="AEN1628" |
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 >int <B | |
106 CLASS="FSFUNC" | |
107 >SDL_SetGammaRamp</B | |
108 ></CODE | |
109 >(Uint16 *redtable, Uint16 *greentable, Uint16 *bluetable);</CODE | |
110 ></P | |
111 ><P | |
112 ></P | |
113 ></DIV | |
114 ></DIV | |
115 ><DIV | |
116 CLASS="REFSECT1" | |
117 ><A | |
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118 NAME="AEN1634" |
0 | 119 ></A |
120 ><H2 | |
121 >Description</H2 | |
122 ><P | |
123 >Sets the gamma lookup tables for the display for each color component. | |
124 Each table is an array of 256 Uint16 values, representing a mapping | |
125 between the input and output for that channel. The input is the index | |
126 into the array, and the output is the 16-bit gamma value at that index, | |
127 scaled to the output color precision. You may pass NULL to any of the | |
128 channels to leave them unchanged.</P | |
129 ><P | |
130 >This function adjusts the gamma based on lookup tables, you can also | |
131 have the gamma calculated based on a "gamma function" parameter with | |
132 <A | |
133 HREF="sdlsetgamma.html" | |
134 >SDL_SetGamma</A | |
135 >.</P | |
136 ><P | |
137 >Not all display hardware is able to change gamma.</P | |
138 ></DIV | |
139 ><DIV | |
140 CLASS="REFSECT1" | |
141 ><A | |
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142 NAME="AEN1640" |
0 | 143 ></A |
144 ><H2 | |
145 >Return Value</H2 | |
146 ><P | |
147 >Returns -1 on error (or if gamma adjustment is not supported).</P | |
148 ></DIV | |
149 ><DIV | |
150 CLASS="REFSECT1" | |
151 ><A | |
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152 NAME="AEN1643" |
0 | 153 ></A |
154 ><H2 | |
155 >See Also</H2 | |
156 ><P | |
157 ><A | |
158 HREF="sdlsetgamma.html" | |
159 >SDL_SetGamma</A | |
160 > | |
161 <A | |
162 HREF="sdlgetgammaramp.html" | |
163 >SDL_GetGammaRamp</A | |
164 ></P | |
165 ></DIV | |
166 ><DIV | |
167 CLASS="NAVFOOTER" | |
168 ><HR | |
169 ALIGN="LEFT" | |
170 WIDTH="100%"><TABLE | |
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171 SUMMARY="Footer navigation table" |
0 | 172 WIDTH="100%" |
173 BORDER="0" | |
174 CELLPADDING="0" | |
175 CELLSPACING="0" | |
176 ><TR | |
177 ><TD | |
178 WIDTH="33%" | |
179 ALIGN="left" | |
180 VALIGN="top" | |
181 ><A | |
182 HREF="sdlgetgammaramp.html" | |
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183 ACCESSKEY="P" |
0 | 184 >Prev</A |
185 ></TD | |
186 ><TD | |
187 WIDTH="34%" | |
188 ALIGN="center" | |
189 VALIGN="top" | |
190 ><A | |
191 HREF="index.html" | |
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192 ACCESSKEY="H" |
0 | 193 >Home</A |
194 ></TD | |
195 ><TD | |
196 WIDTH="33%" | |
197 ALIGN="right" | |
198 VALIGN="top" | |
199 ><A | |
200 HREF="sdlmaprgb.html" | |
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201 ACCESSKEY="N" |
0 | 202 >Next</A |
203 ></TD | |
204 ></TR | |
205 ><TR | |
206 ><TD | |
207 WIDTH="33%" | |
208 ALIGN="left" | |
209 VALIGN="top" | |
210 >SDL_GetGammaRamp</TD | |
211 ><TD | |
212 WIDTH="34%" | |
213 ALIGN="center" | |
214 VALIGN="top" | |
215 ><A | |
216 HREF="video.html" | |
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217 ACCESSKEY="U" |
0 | 218 >Up</A |
219 ></TD | |
220 ><TD | |
221 WIDTH="33%" | |
222 ALIGN="right" | |
223 VALIGN="top" | |
224 >SDL_MapRGB</TD | |
225 ></TR | |
226 ></TABLE | |
227 ></DIV | |
228 ></BODY | |
229 ></HTML | |
230 > |