C++ Mix_SetError函数代码示例

int Mix_EachSoundFont(int (*function)(const char*, void*), void *data)
{
	char *context, *path, *paths;
	const char* cpaths = Mix_GetSoundFonts();

	if (!cpaths) {
		Mix_SetError("No SoundFonts have been requested");
		return 0;
	}

	if (!(paths = SDL_strdup(cpaths))) {
		Mix_SetError("Insufficient memory to iterate over SoundFonts");
		return 0;
	}

#if defined(__MINGW32__) || defined(__MINGW64__)
	for (path = strtok(paths, ";"); path; path = strtok(NULL, ";")) {
#elif defined(_WIN32)
	for (path = strtok_s(paths, ";", &context); path; path = strtok_s(NULL, ";", &context)) {
#else
	for (path = strtok_r(paths, ":;", &context); path; path = strtok_r(NULL, ":;", &context)) {
#endif
		if (!function(path, data)) {
			SDL_free(paths);
			return 0;
		}
	}

	SDL_free(paths);
	return 1;
}

int Mix_SetLoopStart(int which, int loop_start)
{
    int old_loop_start;
    int position;

    if ((which >= 0) && (which < num_channels)) {
        Mix_SetError("Invalid channel specified");
        return(-1);
    }

    if ((mix_channel[which].playing == 0) && (mix_channel[which].looping == 0)) {
        Mix_SetError("Channel not playing");
        return(-1);
    }

    SDL_LockAudio();
    old_loop_start = mix_channel[which].loop_start;
    if (loop_start >= 0) {
        position = milliseconds_to_bytes(loop_start);
        if (((Uint32) position) < mix_channel[which].sound->chunk->alen) {
            mix_channel[which].loop_start = position;
        } else {
            Mix_SetError("Position out of range!");
        }
    }
    SDL_UnlockAudio();

    return bytes_to_milliseconds(old_loop_start);
}

/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
static int _Mix_remove_effect(int channel, effect_info **e, Mix_EffectFunc_t f)
{
	effect_info *cur;
	effect_info *prev = NULL;
	effect_info *next = NULL;

	if (!e) {
		Mix_SetError("Internal error");
		return(0);
	}

	for (cur = *e; cur != NULL; cur = cur->next) {
		if (cur->callback == f) {
			next = cur->next;
			if (cur->done_callback != NULL) {
				cur->done_callback(channel, cur->udata);
			}
			SDL_free(cur);

			if (prev == NULL) {   /* removing first item of list? */
				*e = next;
			} else {
				prev->next = next;
			}
			return(1);
		}
		prev = cur;
	}

	Mix_SetError("No such effect registered");
	return(0);
}

static int fluidsynth_loadsong_RW_internal(FluidSynthMidiSong *song, void *data)
{
	off_t offset;
	size_t size;
	char *buffer;
	SDL_RWops *rw = (SDL_RWops*) data;

	offset = SDL_RWtell(rw);
	SDL_RWseek(rw, 0, RW_SEEK_END);
	size = SDL_RWtell(rw) - offset;
	SDL_RWseek(rw, offset, RW_SEEK_SET);

	if ((buffer = (char*) SDL_malloc(size))) {
		if(SDL_RWread(rw, buffer, size, 1) == 1) {
			if (fluidsynth.fluid_player_add_mem(song->player, buffer, size) == FLUID_OK) {
				return 1;
			} else {
				Mix_SetError("FluidSynth failed to load in-memory song");
			}
		} else {
			Mix_SetError("Failed to read in-memory song");
		}
		SDL_free(buffer);
	} else {
		Mix_SetError("Insufficient memory for song");
	}
	return 0;
}

int Mix_SetPlayPosition(int which, int position)
{
    int old_position;
    int new_position;

    if ((which >= 0) && (which < num_channels)) {
        Mix_SetError("Invalid channel specified");
        return(-1);
    }

    if ((mix_channel[which].playing == 0) && (mix_channel[which].looping == 0)) {
        Mix_SetError("Channel not playing");
        return(-1);
    }

    SDL_LockAudio();
    old_position = mix_channel[which].sound->chunk->alen - mix_channel[which].playing;
    if (position >= 0) {
        new_position = milliseconds_to_bytes(position);
        if (((Uint32) new_position) < mix_channel[which].sound->chunk->alen) {
            mix_channel[which].playing = (mix_channel[which].sound->chunk->alen - new_position);
        } else {
            Mix_SetError("Position out of range!");
        }
    }
    SDL_UnlockAudio();

    return bytes_to_milliseconds(old_position);
}

int Mix_Init(int flags)
{
	int result = 0;

	if (flags & MIX_INIT_FLUIDSYNTH) {
#ifdef USE_FLUIDSYNTH_MIDI
		if ((initialized & MIX_INIT_FLUIDSYNTH) || Mix_InitFluidSynth() == 0) {
			result |= MIX_INIT_FLUIDSYNTH;
		}
#else
		Mix_SetError("Mixer not built with FluidSynth support");
#endif
	}
	if (flags & MIX_INIT_FLAC) {
#ifdef FLAC_MUSIC
		if ((initialized & MIX_INIT_FLAC) || Mix_InitFLAC() == 0) {
			result |= MIX_INIT_FLAC;
		}
#else
		Mix_SetError("Mixer not built with FLAC support");
#endif
	}
	if (flags & MIX_INIT_MOD) {
#ifdef MOD_MUSIC
		if ((initialized & MIX_INIT_MOD) || Mix_InitMOD() == 0) {
			result |= MIX_INIT_MOD;
		}
#else
		Mix_SetError("Mixer not built with MOD support");
#endif
	}
	if (flags & MIX_INIT_MP3) {
#ifdef MP3_MUSIC
		if ((initialized & MIX_INIT_MP3) || Mix_InitMP3() == 0) {
			result |= MIX_INIT_MP3;
		}
#else
		Mix_SetError("Mixer not built with MP3 support");
#endif
	}
	if (flags & MIX_INIT_OGG) {
#ifdef OGG_MUSIC
		if ((initialized & MIX_INIT_OGG) || Mix_InitOgg() == 0) {
			result |= MIX_INIT_OGG;
		}
#else
		Mix_SetError("Mixer not built with Ogg Vorbis support");
#endif
	}
	initialized |= result;

	return (result);
}

SDL_bool _Mix_ValidateChunk(Mix_Chunk *chunk)
{
	/* Don't play null pointers :-) */
	if ( chunk == NULL ) {
		Mix_SetError("Tried to play a NULL chunk");
		return(SDL_FALSE);
	}
	if ( !checkchunkintegral(chunk)) {
		Mix_SetError("Tried to play a chunk with a bad frame");
		return(SDL_FALSE);
	}
	return(SDL_TRUE);
}

/* Play an audio chunk on a specific channel.
   If the specified channel is -1, play on the first free channel.
   'ticks' is the number of milliseconds at most to play the sample, or -1
   if there is no limit.
   Returns which channel was used to play the sound.
*/
int Mix_PlayChannelTimed(int which, Mix_Chunk *chunk, int loops, int ticks)
{
	int i;

	/* Don't play null pointers :-) */
	if ( chunk == NULL ) {
		Mix_SetError("Tried to play a NULL chunk");
		return(-1);
	}
	if ( !checkchunkintegral(chunk)) {
		Mix_SetError("Tried to play a chunk with a bad frame");
		return(-1);
	}

	/* Lock the mixer while modifying the playing channels */
	SDL_LockAudio();
	{
		/* If which is -1, play on the first free channel */
		if ( which == -1 ) {
			for ( i=reserved_channels; i<num_channels; ++i ) {
				if ( mix_channel[i].playing <= 0 )
					break;
			}
			if ( i == num_channels ) {
				Mix_SetError("No free channels available");
				which = -1;
			} else {
				which = i;
			}
		}

		/* Queue up the audio data for this channel */
		if ( which >= 0 && which < num_channels ) {
			Uint32 sdl_ticks = SDL_GetTicks();
			if (Mix_Playing(which))
				_Mix_channel_done_playing(which);
			mix_channel[which].samples = chunk->abuf;
			mix_channel[which].playing = chunk->alen;
			mix_channel[which].looping = loops;
			mix_channel[which].chunk = chunk;
			mix_channel[which].paused = 0;
			mix_channel[which].fading = MIX_NO_FADING;
			mix_channel[which].start_time = sdl_ticks;
			mix_channel[which].expire = (ticks>0) ? (sdl_ticks + ticks) : 0;
		}
	}
	SDL_UnlockAudio();

	/* Return the channel on which the sound is being played */
	return(which);
}

int Mix_InitModPlug()
{
    if ( modplug.loaded == 0 ) {
#ifdef __MACOSX__
        extern ModPlugFile* ModPlug_Load(const void* data, int size) __attribute__((weak_import));
        if ( ModPlug_Load == NULL )
        {
            /* Missing weakly linked framework */
            Mix_SetError("Missing modplug.framework");
            return -1;
        }
#endif // __MACOSX__

        modplug.ModPlug_Load = ModPlug_Load;
        modplug.ModPlug_Unload = ModPlug_Unload;
        modplug.ModPlug_Read = ModPlug_Read;
        modplug.ModPlug_Seek = ModPlug_Seek;
        modplug.ModPlug_GetSettings = ModPlug_GetSettings;
        modplug.ModPlug_SetSettings = ModPlug_SetSettings;
        modplug.ModPlug_SetMasterVolume = ModPlug_SetMasterVolume;
    }
    ++modplug.loaded;

    return 0;
}

int Mix_InitFLAC()
{
    if ( flac.loaded == 0 ) {
#ifdef __MACOSX__
        extern FLAC__StreamDecoder *FLAC__stream_decoder_new(void) __attribute__((weak_import));
        if ( FLAC__stream_decoder_new == NULL )
        {
            /* Missing weakly linked framework */
            Mix_SetError("Missing FLAC.framework");
            return -1;
        }
#endif /*  __MACOSX__ */

        flac.FLAC__stream_decoder_new = FLAC__stream_decoder_new;
        flac.FLAC__stream_decoder_delete = FLAC__stream_decoder_delete;
        flac.FLAC__stream_decoder_init_stream =
                            FLAC__stream_decoder_init_stream;
        flac.FLAC__stream_decoder_finish = FLAC__stream_decoder_finish;
        flac.FLAC__stream_decoder_flush = FLAC__stream_decoder_flush;
        flac.FLAC__stream_decoder_process_single =
                            FLAC__stream_decoder_process_single;
        flac.FLAC__stream_decoder_process_until_end_of_metadata =
                            FLAC__stream_decoder_process_until_end_of_metadata;
        flac.FLAC__stream_decoder_process_until_end_of_stream =
                            FLAC__stream_decoder_process_until_end_of_stream;
        flac.FLAC__stream_decoder_seek_absolute =
                            FLAC__stream_decoder_seek_absolute;
        flac.FLAC__stream_decoder_get_state =
                            FLAC__stream_decoder_get_state;
    }
    ++flac.loaded;

    return 0;
}

int Mix_InitMP3()
{
    if ( smpeg.loaded == 0 ) {
#ifdef __MACOSX__
        extern SMPEG* SMPEG_new_rwops(SDL_RWops*, SMPEG_Info*, int, int) __attribute__((weak_import));
        if ( SMPEG_new_rwops == NULL )
        {
            /* Missing weakly linked framework */
            Mix_SetError("Missing smpeg2.framework");
            return -1;
        }
#endif /*  __MACOSX__ */

        smpeg.SMPEG_actualSpec = SMPEG_actualSpec;
        smpeg.SMPEG_delete = SMPEG_delete;
        smpeg.SMPEG_enableaudio = SMPEG_enableaudio;
        smpeg.SMPEG_enablevideo = SMPEG_enablevideo;
        smpeg.SMPEG_new_rwops = SMPEG_new_rwops;
        smpeg.SMPEG_play = SMPEG_play;
        smpeg.SMPEG_playAudio = SMPEG_playAudio;
        smpeg.SMPEG_rewind = SMPEG_rewind;
        smpeg.SMPEG_setvolume = SMPEG_setvolume;
        smpeg.SMPEG_skip = SMPEG_skip;
        smpeg.SMPEG_status = SMPEG_status;
        smpeg.SMPEG_stop = SMPEG_stop;
    }
    ++smpeg.loaded;

    return 0;
}

/* Play some of a stream previously started with GME_play() */
int GME_playAudio(struct MUSIC_GME *music, Uint8 *stream, int len)
{
    if(music==NULL) return 1;
    if(music->game_emu==NULL) return 1;
    if(music->playing==-1) return 1;
    if( len<0 ) return 0;
    int srgArraySize = len/music->cvt.len_ratio;
    short buf[srgArraySize];
    int srcLen = (int)((double)(len/2)/music->cvt.len_ratio);

    char *err = (char*)gme_play( music->game_emu, srcLen, buf );
    if( err != NULL)
    {
        Mix_SetError("GAME-EMU: %s", err);
        return 0;
    }
    int dest_len = srcLen*2;

    if( music->cvt.needed ) {
        music->cvt.len = dest_len;
        music->cvt.buf = (Uint8*)buf;
        SDL_ConvertAudio(&music->cvt);
        dest_len = music->cvt.len_cvt;
    }

    if ( music->volume == MIX_MAX_VOLUME )
    {
        SDL_memcpy(stream, (Uint8*)buf, dest_len);
    } else {
        SDL_MixAudioFormat(stream, (Uint8*)buf, mixer.format, dest_len, music->volume);
    }
    return len-dest_len;
}

/* Start playback of a given music stream */
void MusicCMD_Start(MusicCMD *music)
{
	music->pid = fork();
	switch(music->pid) {
	    /* Failed fork() system call */
	    case -1:
		Mix_SetError("fork() failed");
		return;

	    /* Child process - executes here */
	    case 0: {
		    char command[PATH_MAX];
		    char **argv;

		    /* Execute the command */
		    strcpy(command, music->cmd);
		    argv = parse_args(command, music->file);
		    if ( argv != NULL ) {
			execvp(argv[0], argv);
		    }

		    /* exec() failed */
		    perror(argv[0]);
		    _exit(-1);
		}
		break;

	    /* Parent process - executes here */
	    default:
		break;
	}
	return;
}

int Mix_SetMusicPosition(double position)
{
	int retval;

	SDL_LockAudio();
	if ( music_playing ) {
		retval = music_internal_position(position);
		if ( retval < 0 ) {
			Mix_SetError("Position not implemented for music type");
		}
	} else {
		Mix_SetError("Music isn't playing");
		retval = -1;
	}
	SDL_UnlockAudio();

	return(retval);
}

/* MAKE SURE you hold the audio lock (SDL_LockAudio()) before calling this! */
static int _Mix_register_effect(effect_info **e, Mix_EffectFunc_t f,
				Mix_EffectDone_t d, void *arg)
{
	effect_info *new_e;

	if (!e) {
		Mix_SetError("Internal error");
		return(0);
	}

	if (f == NULL) {
		Mix_SetError("NULL effect callback");
		return(0);
	}

	new_e = SDL_malloc(sizeof (effect_info));
	if (new_e == NULL) {
		Mix_SetError("Out of memory");
		return(0);
	}

	new_e->callback = f;
	new_e->done_callback = d;
	new_e->udata = arg;
	new_e->next = NULL;

	/* add new effect to end of linked list... */
	if (*e == NULL) {
		*e = new_e;
	} else {
		effect_info *cur = *e;
		while (1) {
			if (cur->next == NULL) {
				cur->next = new_e;
				break;
			}
			cur = cur->next;
		}
	}

	return(1);
}