Mercurial > sdl-ios-xcode
annotate docs/html/sdlsetgamma.html @ 3335:b8d313de8a65
Adam Strzelecki to SDL
Since current DirectFB implementation is incomplete for YUV surfaces (actually causes segmentation faults when trying Lock and use YUV planar textures) I decided to fix it a bit.
Here's a patch that should make DirectFB properly support YUV both packed and planar (3 planes).
(1) Removed SDL_BYTESPERPIXEL at all in favor of DFB_BYTES_PER_PIXEL(SDLToDFBPixelFormat(fmt)) which does return always proper BPP for YUVs too, coz SDL_BYTESPERPIXEL returns incorrect values for FOURCCs
(2) Fixed data->pixels allocation for planar YUVs in CreateTexture, it should allocate 150% more space
(3) Copy other planes for planar YUVs in UpdateTexture
(4) Moved checking if format is supported at all with DirectFB on CreateTexture at the beginning of the code
Waiting for comments,
--
Adam Strzelecki | nanoant.com
author | Sam Lantinga <slouken@libsdl.org> |
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date | Sun, 04 Oct 2009 04:03:37 +0000 |
parents | 355632dca928 |
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0 | 1 <HTML |
2 ><HEAD | |
3 ><TITLE | |
4 >SDL_SetGamma</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_SetPalette" | |
17 HREF="sdlsetpalette.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="SDL_GetGammaRamp" | |
20 HREF="sdlgetgammaramp.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="sdlsetpalette.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="sdlgetgammaramp.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="SDLSETGAMMA" | |
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74 ></A |
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75 >SDL_SetGamma</H1 |
0 | 76 ><DIV |
77 CLASS="REFNAMEDIV" | |
78 ><A | |
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79 NAME="AEN1569" |
0 | 80 ></A |
81 ><H2 | |
82 >Name</H2 | |
83 >SDL_SetGamma -- Sets the color gamma function for the display</DIV | |
84 ><DIV | |
85 CLASS="REFSYNOPSISDIV" | |
86 ><A | |
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87 NAME="AEN1572" |
0 | 88 ></A |
89 ><H2 | |
90 >Synopsis</H2 | |
91 ><DIV | |
92 CLASS="FUNCSYNOPSIS" | |
93 ><A | |
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94 NAME="AEN1573" |
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_SetGamma</B | |
108 ></CODE | |
109 >(float redgamma, float greengamma, float bluegamma);</CODE | |
110 ></P | |
111 ><P | |
112 ></P | |
113 ></DIV | |
114 ></DIV | |
115 ><DIV | |
116 CLASS="REFSECT1" | |
117 ><A | |
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118 NAME="AEN1579" |
0 | 119 ></A |
120 ><H2 | |
121 >Description</H2 | |
122 ><P | |
123 >Sets the "gamma function" for the display of each color component. Gamma | |
124 controls the brightness/contrast of colors displayed on the screen. | |
125 A gamma value of <TT | |
126 CLASS="CONSTANT" | |
127 >1.0</TT | |
128 > is identity (i.e., no adjustment | |
129 is made).</P | |
130 ><P | |
131 >This function adjusts the gamma based on the "gamma function" parameter, | |
132 you can directly specify lookup tables for gamma adjustment with | |
133 <A | |
134 HREF="sdlsetgammaramp.html" | |
135 >SDL_SetGammaRamp</A | |
136 >.</P | |
137 ><P | |
138 >Not all display hardware is able to change gamma.</P | |
139 ></DIV | |
140 ><DIV | |
141 CLASS="REFSECT1" | |
142 ><A | |
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143 NAME="AEN1586" |
0 | 144 ></A |
145 ><H2 | |
146 >Return Value</H2 | |
147 ><P | |
148 >Returns -1 on error (or if gamma adjustment is not supported).</P | |
149 ></DIV | |
150 ><DIV | |
151 CLASS="REFSECT1" | |
152 ><A | |
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153 NAME="AEN1589" |
0 | 154 ></A |
155 ><H2 | |
156 >See Also</H2 | |
157 ><P | |
158 ><A | |
159 HREF="sdlgetgammaramp.html" | |
160 >SDL_GetGammaRamp</A | |
161 > | |
162 <A | |
163 HREF="sdlsetgammaramp.html" | |
164 >SDL_SetGammaRamp</A | |
165 ></P | |
166 ></DIV | |
167 ><DIV | |
168 CLASS="NAVFOOTER" | |
169 ><HR | |
170 ALIGN="LEFT" | |
171 WIDTH="100%"><TABLE | |
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172 SUMMARY="Footer navigation table" |
0 | 173 WIDTH="100%" |
174 BORDER="0" | |
175 CELLPADDING="0" | |
176 CELLSPACING="0" | |
177 ><TR | |
178 ><TD | |
179 WIDTH="33%" | |
180 ALIGN="left" | |
181 VALIGN="top" | |
182 ><A | |
183 HREF="sdlsetpalette.html" | |
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184 ACCESSKEY="P" |
0 | 185 >Prev</A |
186 ></TD | |
187 ><TD | |
188 WIDTH="34%" | |
189 ALIGN="center" | |
190 VALIGN="top" | |
191 ><A | |
192 HREF="index.html" | |
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193 ACCESSKEY="H" |
0 | 194 >Home</A |
195 ></TD | |
196 ><TD | |
197 WIDTH="33%" | |
198 ALIGN="right" | |
199 VALIGN="top" | |
200 ><A | |
201 HREF="sdlgetgammaramp.html" | |
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202 ACCESSKEY="N" |
0 | 203 >Next</A |
204 ></TD | |
205 ></TR | |
206 ><TR | |
207 ><TD | |
208 WIDTH="33%" | |
209 ALIGN="left" | |
210 VALIGN="top" | |
211 >SDL_SetPalette</TD | |
212 ><TD | |
213 WIDTH="34%" | |
214 ALIGN="center" | |
215 VALIGN="top" | |
216 ><A | |
217 HREF="video.html" | |
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218 ACCESSKEY="U" |
0 | 219 >Up</A |
220 ></TD | |
221 ><TD | |
222 WIDTH="33%" | |
223 ALIGN="right" | |
224 VALIGN="top" | |
225 >SDL_GetGammaRamp</TD | |
226 ></TR | |
227 ></TABLE | |
228 ></DIV | |
229 ></BODY | |
230 ></HTML | |
231 > |