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------- Comment #1 From Max Horn 2006-04-17 03:08 [reply] ------- Created an attachment (id=106) [edit] Patch for src/joystick/win32/SDL_mmjoystick.c I am not even a Windows user, so take the following with a grain of salt: SDL_mmjoystick.c has a function GetJoystickName which obtains the joystick name by looking at the registry. The way it does that seems very fishy to me. Namely, it uses the parameter "index" to construct a registry value name (BTW, those variables used in the code are really badly named). The value of "index" in turn equals the current value of "numdevs", as called from SDL_SYS_JoystickInit. I read through the MSDN docs at <http://msdn.microsoft.com/archive/default.asp?url=/archive/en-us/dnarinput/html/msdn_extdirect.asp>, and I believe the simple fix is to replace line 183 of said file SYS_JoystickName[numdevs] = GetJoystickName(numdevs, joycaps.szRegKey); by the following: SYS_JoystickName[numdevs] = GetJoystickName(SYS_JoystickID[i], joycaps.szRegKey); However, that is only *hiding* the real issue. Problem is, the list of joysticks as returned by windows may contains "gaps", and the code deals incorrectly with that. Namely those gaps occur if joysticks are removed/(re)added, as the reporter observed. The attached patch fixes this and another (off-by-one) issue in the code. But since I have no Windows machine, I can't even test-compile it, so use with caution.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 29 Apr 2006 20:22:31 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.TH "SDL_AudioCVT" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_AudioCVT\- Audio Conversion Structure
.SH "STRUCTURE DEFINITION"
.PP
.nf
\f(CWtypedef struct{
  int needed;
  Uint16 src_format;
  Uint16 dest_format;
  double rate_incr;
  Uint8 *buf;
  int len;
  int len_cvt;
  int len_mult;
  double len_ratio;
  void (*filters[10])(struct SDL_AudioCVT *cvt, Uint16 format);
  int filter_index;
} SDL_AudioCVT;\fR
.fi
.PP
.SH "STRUCTURE DATA"
.TP 20
\fBneeded\fR
Set to one if the conversion is possible
.TP 20
\fBsrc_format\fR
Audio format of the source
.TP 20
\fBdest_format\fR
Audio format of the destination
.TP 20
\fBrate_incr\fR
Rate conversion increment
.TP 20
\fBbuf\fR
Audio buffer
.TP 20
\fBlen\fR
Length of the original audio buffer in bytes
.TP 20
\fBlen_cvt\fR
Length of converted audio buffer in bytes (calculated)
.TP 20
\fBlen_mult\fR
\fBbuf\fR must be \fBlen\fR*\fBlen_mult\fR bytes in size(calculated)
.TP 20
\fBlen_ratio\fR
Final audio size is \fBlen\fR*\fBlen_ratio\fR
.TP 20
\fBfilters[10](\&.\&.)\fR
Pointers to functions needed for this conversion
.TP 20
\fBfilter_index\fR
Current conversion function
.SH "DESCRIPTION"
.PP
The \fBSDL_AudioCVT\fR is used to convert audio data between different formats\&. A \fBSDL_AudioCVT\fR structure is created with the \fI\fBSDL_BuildAudioCVT\fP\fR function, while the actual conversion is done by the \fI\fBSDL_ConvertAudio\fP\fR function\&.
.PP
Many of the fields in the \fBSDL_AudioCVT\fR structure should be considered private and their function will not be discussed here\&.
.IP "\fBUint8 *\fP\fBbuf\fR" 10This points to the audio data that will be used in the conversion\&. It is both the source and the destination, which means the converted audio data overwrites the original data\&. It also means that the converted data may be larger than the original data (if you were converting from 8-bit to 16-bit, for instance), so you must ensure \fBbuf\fR is large enough\&. See below\&.
.IP "\fBint\fP \fBlen\fR" 10This is the length of the original audio data in bytes\&.
.IP "\fBint\fP \fBlen_mult\fR" 10As explained above, the audio buffer needs to be big enough to store the converted data, which may be bigger than the original audio data\&. The length of \fBbuf\fR should be \fBlen\fR*\fBlen_mult\fR\&.
.IP "\fBdouble\fP \fBlen_ratio\fR" 10When you have finished converting your audio data, you need to know how much of your audio buffer is valid\&. \fBlen\fR*\fBlen_ratio\fR is the size of the converted audio data in bytes\&. This is very similar to \fBlen_mult\fR, however when the convert audio data is shorter than the original \fBlen_mult\fR would be 1\&. \fBlen_ratio\fR, on the other hand, would be a fractional number between 0 and 1\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_BuildAudioCVT\fP\fR, \fI\fBSDL_ConvertAudio\fP\fR, \fI\fBSDL_AudioSpec\fR\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58