Mercurial > sdl-ios-xcode
annotate docs/html/sdlmaprgba.html @ 773:da0a2ad35bf4
Date: Sun, 4 Jan 2004 23:48:19 +0100
From: Max Horn
Subject: Re: Again Audio CD patch
Am 04.01.2004 um 22:38 schrieb Sam Lantinga:
>
> Okay, I fixed the buffering problems by simply using a 4 second buffer
> instead of a 1 second buffer. However, using your code I can't play an
> entire CD - the playback stops after the first song.
>
Found the problem: FSReadFork returns eofErr when the file is finished.
However, we check its return value for errors, and if anything but
noErr occurs, the reader thread aborts its current iteration. That is
bad, because it aborts before it can ever set the flag which tells that
the file is over (also, any remaining data which FSRead did return is
lost - so you'd not hear about to 4 seconds from the end of the file.
Furthermore, the computed data size was 8 bytes to high (I forgot to
account for the fact that the size of an (A)IFF chunk always contains
the chunk header & size fields, too). This is enough to make it work.
However, the end condition is rather fragile, so I tuned some other
things to be pessimistic (check for <= 0 instead of == 0, when eofErr
is encountered enforce mReadFilePosition == mFileLength). You never
know...
The attached patch fixes the issue for me.
author | Sam Lantinga <slouken@libsdl.org> |
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date | Mon, 05 Jan 2004 00:57:51 +0000 (2004-01-05) |
parents | e5bc29de3f0a |
children | 355632dca928 |
rev | line source |
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0 | 1 <HTML |
2 ><HEAD | |
3 ><TITLE | |
4 >SDL_MapRGBA</TITLE | |
5 ><META | |
6 NAME="GENERATOR" | |
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7 CONTENT="Modular DocBook HTML Stylesheet Version 1.64 |
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_MapRGB" | |
17 HREF="sdlmaprgb.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="SDL_GetRGB" | |
20 HREF="sdlgetrgb.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 | |
31 WIDTH="100%" | |
32 BORDER="0" | |
33 CELLPADDING="0" | |
34 CELLSPACING="0" | |
35 ><TR | |
36 ><TH | |
37 COLSPAN="3" | |
38 ALIGN="center" | |
39 >SDL Library Documentation</TH | |
40 ></TR | |
41 ><TR | |
42 ><TD | |
43 WIDTH="10%" | |
44 ALIGN="left" | |
45 VALIGN="bottom" | |
46 ><A | |
47 HREF="sdlmaprgb.html" | |
48 >Prev</A | |
49 ></TD | |
50 ><TD | |
51 WIDTH="80%" | |
52 ALIGN="center" | |
53 VALIGN="bottom" | |
54 ></TD | |
55 ><TD | |
56 WIDTH="10%" | |
57 ALIGN="right" | |
58 VALIGN="bottom" | |
59 ><A | |
60 HREF="sdlgetrgb.html" | |
61 >Next</A | |
62 ></TD | |
63 ></TR | |
64 ></TABLE | |
65 ><HR | |
66 ALIGN="LEFT" | |
67 WIDTH="100%"></DIV | |
68 ><H1 | |
69 ><A | |
70 NAME="SDLMAPRGBA" | |
71 >SDL_MapRGBA</A | |
72 ></H1 | |
73 ><DIV | |
74 CLASS="REFNAMEDIV" | |
75 ><A | |
181
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76 NAME="AEN1303" |
0 | 77 ></A |
78 ><H2 | |
79 >Name</H2 | |
80 >SDL_MapRGBA -- Map a RGBA color value to a pixel format.</DIV | |
81 ><DIV | |
82 CLASS="REFSYNOPSISDIV" | |
83 ><A | |
181
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84 NAME="AEN1306" |
0 | 85 ></A |
86 ><H2 | |
87 >Synopsis</H2 | |
88 ><DIV | |
89 CLASS="FUNCSYNOPSIS" | |
90 ><A | |
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91 NAME="AEN1307" |
0 | 92 ></A |
93 ><P | |
94 ></P | |
95 ><PRE | |
96 CLASS="FUNCSYNOPSISINFO" | |
97 >#include "SDL.h"</PRE | |
98 ><P | |
99 ><CODE | |
100 ><CODE | |
101 CLASS="FUNCDEF" | |
102 >Uint32 <B | |
103 CLASS="FSFUNC" | |
104 >SDL_MapRGBA</B | |
105 ></CODE | |
106 >(SDL_PixelFormat *fmt, Uint8 r, Uint8 g, Uint8 b, Uint8 a);</CODE | |
107 ></P | |
108 ><P | |
109 ></P | |
110 ></DIV | |
111 ></DIV | |
112 ><DIV | |
113 CLASS="REFSECT1" | |
114 ><A | |
181
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115 NAME="AEN1313" |
0 | 116 ></A |
117 ><H2 | |
118 >Description</H2 | |
119 ><P | |
120 >Maps the RGBA color value to the specified pixel format and returns the | |
121 pixel value as a 32-bit int.</P | |
122 ><P | |
123 >If the format has a palette (8-bit) the index of the closest matching | |
124 color in the palette will be returned.</P | |
125 ><P | |
126 >If the specified pixel format has no alpha component the alpha value | |
127 will be ignored (as it will be in formats with a palette).</P | |
128 ></DIV | |
129 ><DIV | |
130 CLASS="REFSECT1" | |
131 ><A | |
181
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132 NAME="AEN1318" |
0 | 133 ></A |
134 ><H2 | |
135 >Return Value</H2 | |
136 ><P | |
137 >A pixel value best approximating the given RGBA color value for a given | |
138 pixel format. If the pixel format bpp (color depth) is less than 32-bpp | |
139 then the unused upper bits of the return value can safely be ignored | |
140 (e.g., with a 16-bpp format the return value can be assigned to a | |
141 <SPAN | |
142 CLASS="TYPE" | |
143 >Uint16</SPAN | |
144 >, and similarly a <SPAN | |
145 CLASS="TYPE" | |
146 >Uint8</SPAN | |
147 > for an 8-bpp | |
148 format).</P | |
149 ></DIV | |
150 ><DIV | |
151 CLASS="REFSECT1" | |
152 ><A | |
181
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153 NAME="AEN1323" |
0 | 154 ></A |
155 ><H2 | |
156 >See Also</H2 | |
157 ><P | |
158 ><A | |
159 HREF="sdlgetrgb.html" | |
160 >SDL_GetRGB</A | |
161 >, | |
162 <A | |
163 HREF="sdlgetrgba.html" | |
164 >SDL_GetRGBA</A | |
165 >, | |
166 <A | |
167 HREF="sdlmaprgb.html" | |
168 >SDL_MapRGB</A | |
169 >, | |
170 <A | |
171 HREF="sdlpixelformat.html" | |
172 >SDL_PixelFormat</A | |
173 ></P | |
174 ></DIV | |
175 ><DIV | |
176 CLASS="NAVFOOTER" | |
177 ><HR | |
178 ALIGN="LEFT" | |
179 WIDTH="100%"><TABLE | |
180 WIDTH="100%" | |
181 BORDER="0" | |
182 CELLPADDING="0" | |
183 CELLSPACING="0" | |
184 ><TR | |
185 ><TD | |
186 WIDTH="33%" | |
187 ALIGN="left" | |
188 VALIGN="top" | |
189 ><A | |
190 HREF="sdlmaprgb.html" | |
191 >Prev</A | |
192 ></TD | |
193 ><TD | |
194 WIDTH="34%" | |
195 ALIGN="center" | |
196 VALIGN="top" | |
197 ><A | |
198 HREF="index.html" | |
199 >Home</A | |
200 ></TD | |
201 ><TD | |
202 WIDTH="33%" | |
203 ALIGN="right" | |
204 VALIGN="top" | |
205 ><A | |
206 HREF="sdlgetrgb.html" | |
207 >Next</A | |
208 ></TD | |
209 ></TR | |
210 ><TR | |
211 ><TD | |
212 WIDTH="33%" | |
213 ALIGN="left" | |
214 VALIGN="top" | |
215 >SDL_MapRGB</TD | |
216 ><TD | |
217 WIDTH="34%" | |
218 ALIGN="center" | |
219 VALIGN="top" | |
220 ><A | |
221 HREF="video.html" | |
222 >Up</A | |
223 ></TD | |
224 ><TD | |
225 WIDTH="33%" | |
226 ALIGN="right" | |
227 VALIGN="top" | |
228 >SDL_GetRGB</TD | |
229 ></TR | |
230 ></TABLE | |
231 ></DIV | |
232 ></BODY | |
233 ></HTML | |
234 > |