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view docs/man3/SDL_AudioCVT.3 @ 2268:4baee598306d
Date: Thu, 05 Jul 2007 14:02:33 -0700
From: Sam Lantinga
Subject: SDL 1.3 keyboard plan
After lots of discussion with Christian, this is what we came up with:
> So, to sum up...
> SDLK_* become the physical keys, starting at > (1<<21)
> We create a macro SDLK_INDEX(X)
> We have two functions SDL_GetLayoutKey(SDLKey) and SDL_GetKeyName()
> SDL_GetLayoutKey maps to UCS4 for printable characters, and SDLK* for
non-printable characters
> and does so based on the OS's current keyboard layout
> SDL_GetKeyName() handles both SDLK_* and UCS4, converting UCS4 to UTF-8 and
converting SDLK_* into our names, which are UTF-8 for printable characters.
> WASD folks use SDLK_*, and 'I' folks use SDL_GetLayoutKey(SDLK_*)
Here is the patch he came up with, and his e-mail about it:
Date: Fri, 17 Aug 2007 19:50:28 +0200
From: Christian Walther
Subject: Re: SDL 1.3 keyboard plan
> Sounds great, go ahead and send me a patch.
Here goes! Thanks for having a look. Don't hesitate to comment if
anything does not conform to your ideas.
One caveat: Committing this now may break compilability of some video
drivers - specifically, if they use any of the SDLK_* codes that were
obsoleted and moved into SDL_compat.h. I only tried Cocoa (which did
break, but is already fixed) and X11 (which didn't, but then its key
handling is #iffed out). If that's a problem, it may need to go into
a branch.
-Christian
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 19 Aug 2007 14:52:52 +0000 |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
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.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