Mercurial > sdl-ios-xcode
view src/main/macosx/SDLMain.m @ 942:41a59de7f2ed
Here are patches for SDL12 and SDL_mixer for 4 or 6 channel
surround sound on Linux using the Alsa driver. To use them, naturally
you need a sound card that will do 4 or 6 channels and probably also a
recent version of the Alsa drivers and library. Since the only SDL
output driver that knows about surround sound is the Alsa driver,
you���ll want to choose it, using:
export SDL_AUDIODRIVER=alsa
There are no syntactic changes to the programming API. No new
library calls, no differences in arguments.
There are two semantic changes:
(1) For library calls with number of channels as an argument, formerly
you could use only 1 or 2 for the number of channels. Now you
can also use 4 or 6.
(2) The two "left" and "right" arguments to Mix_SetPanning, for the
case of 4 or 6 channels, no longer simply control the volumes of
the left and right channels. Now the "left" argument is converted
to an angle and Mix_SetPosition is called, and the "right" argu-
ment is ignored.
With two exceptions, so far as I know, the modified SDL12 and
SDL_mixer work the same way as the original versions, when opened for
1 or 2 channel output. The two exceptions are bugs which I fixed.
Well, the first, anyway, is a bug for sure. When rate conversions up
or down by a factor of two are applied (in src/audio/SDL_audiocvt.c),
streams with different numbers of channels (that is, mono and stereo)
are treated the same way: either each sample is copied or every other
sample is omitted. This is ok for mono, but for stereo, it is frames
that should be copied or omitted, where by "frame" I mean a portion of
the stream containing one sample for each channel. (In the SDL source,
confusingly, sometimes frames are called "samples".) So for these
rate conversions, stereo streams have to be treated differently, and
they are, in my modified version.
The other problem that might be characterized as a bug arises
when SDL_mixer is passed a multichannel chunk which does not have an
integral number of frames. Due to the way the effect_position code
loops over frames, when the chunk ends with a partial frame, memory
outside the chunk buffer will be accessed. In the case of stereo,
it���s possible that because malloc may give more memory than requested,
this potential problem never actually causes a segment fault. I don���t
know. For 6 channel chunks, I do know, and it does cause segment
faults.
If SDL_mixer is passed defective chunks and this causes a segment
fault, arguably, that���s not a bug in SDL_mixer. Still, whether or not
it counts as a bug, it���s easy to protect against, so why not? I added
code in mixer.c to discard any partial frame at the end of a chunk.
Then what about when SDL or SDL_mixer is opened for 4 or 6 chan-
nel output? What happens with the parts of the current library
designed for stereo? I don���t know whether I���ve covered all the bases,
but I���ve tried:
(1) For playing 2 channel waves, or other cases where SDL knows it has
to match up a 2 channel source with a 4 or 6 channel output, I���ve
added code in SDL_audiocvt.c to make the necessary conversions.
(2) For playing midis using timidity, I���ve converted timidity to do 4
or 6 channel output, upon request.
(3) For playing mods using mikmod, I put ad hoc code in music.c to
convert the stereo output that mikmod produces to 4 or 6 chan-
nels. Obviously it would be better to change the mikmod code to
mix down into 4 or 6 channels, but I have a hard time following
the code in mikmod, so I didn���t do that.
(4) For playing mp3s, I put ad hoc code in smpeg to copy channels in
the case when 4 or 6 channel output is needed.
(5) There seems to be no problem with .ogg files - stereo .oggs can be
up converted as .wavs are.
(6) The effect_position code in SDL_mixer is now generalized to in-
clude the cases of 4 and 6 channel streams.
I���ve done a very limited amount of compatibility testing for some
of the games using SDL I happen to have. For details, see the file
TESTS.
I���ve put into a separate archive, Surround-SDL-testfiles.tgz, a
couple of 6 channel wave files for testing and a 6 channel ogg file.
If you have the right hardware and version of Alsa, you should be able
to play the wave files with the Alsa utility aplay (and hear all
channels, except maybe lfe, for chan-id.wav, since it���s rather faint).
Don���t expect aplay to give good sound, though. There���s something
wrong with the current version of aplay.
The canyon.ogg file is to test loading of 6 channel oggs. After
patching and compiling, you can play it with playmus. (My version of
ogg123 will not play it, and I had to patch mplayer to get it to play
6 channel oggs.)
Greg Lee <greg@ling.lll.hawaii.edu>
Thus, July 1, 2004
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 21 Aug 2004 12:27:02 +0000 |
parents | a7129c0083f4 |
children | 217f119a19a0 |
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/* SDLMain.m - main entry point for our Cocoa-ized SDL app Initial Version: Darrell Walisser <dwaliss1@purdue.edu> Non-NIB-Code & other changes: Max Horn <max@quendi.de> Feel free to customize this file to suit your needs */ #import "SDL.h" #import "SDLMain.h" #import <sys/param.h> /* for MAXPATHLEN */ #import <unistd.h> /* Use this flag to determine whether we use SDLMain.nib or not */ #define SDL_USE_NIB_FILE 0 /* Use this flag to determine whether we use CPS (docking) or not */ #define SDL_USE_CPS 1 #ifdef SDL_USE_CPS /* Portions of CPS.h */ typedef struct CPSProcessSerNum { UInt32 lo; UInt32 hi; } CPSProcessSerNum; extern OSErr CPSGetCurrentProcess( CPSProcessSerNum *psn); extern OSErr CPSEnableForegroundOperation( CPSProcessSerNum *psn, UInt32 _arg2, UInt32 _arg3, UInt32 _arg4, UInt32 _arg5); extern OSErr CPSSetFrontProcess( CPSProcessSerNum *psn); #endif /* SDL_USE_CPS */ static int gArgc; static char **gArgv; static BOOL gFinderLaunch; #if SDL_USE_NIB_FILE /* A helper category for NSString */ @interface NSString (ReplaceSubString) - (NSString *)stringByReplacingRange:(NSRange)aRange with:(NSString *)aString; @end #else /* An internal Apple class used to setup Apple menus */ @interface NSAppleMenuController:NSObject {} - (void)controlMenu:(NSMenu *)aMenu; @end #endif @interface SDLApplication : NSApplication @end @implementation SDLApplication /* Invoked from the Quit menu item */ - (void)terminate:(id)sender { /* Post a SDL_QUIT event */ SDL_Event event; event.type = SDL_QUIT; SDL_PushEvent(&event); } @end /* The main class of the application, the application's delegate */ @implementation SDLMain /* Set the working directory to the .app's parent directory */ - (void) setupWorkingDirectory:(BOOL)shouldChdir { if (shouldChdir) { char parentdir[MAXPATHLEN]; char *c; strncpy ( parentdir, gArgv[0], sizeof(parentdir) ); c = (char*) parentdir; while (*c != '\0') /* go to end */ c++; while (*c != '/') /* back up to parent */ c--; *c++ = '\0'; /* cut off last part (binary name) */ assert ( chdir (parentdir) == 0 ); /* chdir to the binary app's parent */ assert ( chdir ("../../../") == 0 ); /* chdir to the .app's parent */ } } #if SDL_USE_NIB_FILE /* Fix menu to contain the real app name instead of "SDL App" */ - (void)fixMenu:(NSMenu *)aMenu withAppName:(NSString *)appName { NSRange aRange; NSEnumerator *enumerator; NSMenuItem *menuItem; aRange = [[aMenu title] rangeOfString:@"SDL App"]; if (aRange.length != 0) [aMenu setTitle: [[aMenu title] stringByReplacingRange:aRange with:appName]]; enumerator = [[aMenu itemArray] objectEnumerator]; while ((menuItem = [enumerator nextObject])) { aRange = [[menuItem title] rangeOfString:@"SDL App"]; if (aRange.length != 0) [menuItem setTitle: [[menuItem title] stringByReplacingRange:aRange with:appName]]; if ([menuItem hasSubmenu]) [self fixMenu:[menuItem submenu] withAppName:appName]; } [ aMenu sizeToFit ]; } #else void setupAppleMenu(void) { /* warning: this code is very odd */ NSAppleMenuController *appleMenuController; NSMenu *appleMenu; NSMenuItem *appleMenuItem; appleMenuController = [[NSAppleMenuController alloc] init]; appleMenu = [[NSMenu alloc] initWithTitle:@""]; appleMenuItem = [[NSMenuItem alloc] initWithTitle:@"" action:nil keyEquivalent:@""]; [appleMenuItem setSubmenu:appleMenu]; /* yes, we do need to add it and then remove it -- if you don't add it, it doesn't get displayed if you don't remove it, you have an extra, titleless item in the menubar when you remove it, it appears to stick around very, very odd */ [[NSApp mainMenu] addItem:appleMenuItem]; [appleMenuController controlMenu:appleMenu]; [[NSApp mainMenu] removeItem:appleMenuItem]; [appleMenu release]; [appleMenuItem release]; } /* Create a window menu */ void setupWindowMenu(void) { NSMenu *windowMenu; NSMenuItem *windowMenuItem; NSMenuItem *menuItem; windowMenu = [[NSMenu alloc] initWithTitle:@"Window"]; /* "Minimize" item */ menuItem = [[NSMenuItem alloc] initWithTitle:@"Minimize" action:@selector(performMiniaturize:) keyEquivalent:@"m"]; [windowMenu addItem:menuItem]; [menuItem release]; /* Put menu into the menubar */ windowMenuItem = [[NSMenuItem alloc] initWithTitle:@"Window" action:nil keyEquivalent:@""]; [windowMenuItem setSubmenu:windowMenu]; [[NSApp mainMenu] addItem:windowMenuItem]; /* Tell the application object that this is now the window menu */ [NSApp setWindowsMenu:windowMenu]; /* Finally give up our references to the objects */ [windowMenu release]; [windowMenuItem release]; } /* Replacement for NSApplicationMain */ void CustomApplicationMain (argc, argv) { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; SDLMain *sdlMain; /* Ensure the application object is initialised */ [SDLApplication sharedApplication]; #ifdef SDL_USE_CPS { CPSProcessSerNum PSN; /* Tell the dock about us */ if (!CPSGetCurrentProcess(&PSN)) if (!CPSEnableForegroundOperation(&PSN,0x03,0x3C,0x2C,0x1103)) if (!CPSSetFrontProcess(&PSN)) [SDLApplication sharedApplication]; } #endif /* SDL_USE_CPS */ /* Set up the menubar */ [NSApp setMainMenu:[[NSMenu alloc] init]]; setupAppleMenu(); setupWindowMenu(); /* Create SDLMain and make it the app delegate */ sdlMain = [[SDLMain alloc] init]; [NSApp setDelegate:sdlMain]; /* Start the main event loop */ [NSApp run]; [sdlMain release]; [pool release]; } #endif /* Called when the internal event loop has just started running */ - (void) applicationDidFinishLaunching: (NSNotification *) note { int status; /* Set the working directory to the .app's parent directory */ [self setupWorkingDirectory:gFinderLaunch]; #if SDL_USE_NIB_FILE /* Set the main menu to contain the real app name instead of "SDL App" */ [self fixMenu:[NSApp mainMenu] withAppName:[[NSProcessInfo processInfo] processName]]; #endif /* Hand off to main application code */ status = SDL_main (gArgc, gArgv); /* We're done, thank you for playing */ exit(status); } @end @implementation NSString (ReplaceSubString) - (NSString *)stringByReplacingRange:(NSRange)aRange with:(NSString *)aString { unsigned int bufferSize; unsigned int selfLen = [self length]; unsigned int aStringLen = [aString length]; unichar *buffer; NSRange localRange; NSString *result; bufferSize = selfLen + aStringLen - aRange.length; buffer = NSAllocateMemoryPages(bufferSize*sizeof(unichar)); /* Get first part into buffer */ localRange.location = 0; localRange.length = aRange.location; [self getCharacters:buffer range:localRange]; /* Get middle part into buffer */ localRange.location = 0; localRange.length = aStringLen; [aString getCharacters:(buffer+aRange.location) range:localRange]; /* Get last part into buffer */ localRange.location = aRange.location + aRange.length; localRange.length = selfLen - localRange.location; [self getCharacters:(buffer+aRange.location+aStringLen) range:localRange]; /* Build output string */ result = [NSString stringWithCharacters:buffer length:bufferSize]; NSDeallocateMemoryPages(buffer, bufferSize); return result; } @end #ifdef main # undef main #endif /* Main entry point to executable - should *not* be SDL_main! */ int main (int argc, char **argv) { /* Copy the arguments into a global variable */ int i; /* This is passed if we are launched by double-clicking */ if ( argc >= 2 && strncmp (argv[1], "-psn", 4) == 0 ) { gArgc = 1; gFinderLaunch = YES; } else { gArgc = argc; gFinderLaunch = NO; } gArgv = (char**) malloc (sizeof(*gArgv) * (gArgc+1)); assert (gArgv != NULL); for (i = 0; i < gArgc; i++) gArgv[i] = argv[i]; gArgv[i] = NULL; #if SDL_USE_NIB_FILE [SDLApplication poseAsClass:[NSApplication class]]; NSApplicationMain (argc, argv); #else CustomApplicationMain (argc, argv); #endif return 0; }