165 lines
3.8 KiB
C
165 lines
3.8 KiB
C
/**
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* OpenAL cross platform audio library
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* Copyright (C) 2010 by Chris Robinson
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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* Or go to http://www.gnu.org/copyleft/lgpl.html
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*/
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#include "config.h"
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#include <stdlib.h>
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#include "alMain.h"
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#include "AL/al.h"
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#include "AL/alc.h"
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typedef struct {
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volatile int killNow;
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ALvoid *thread;
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} null_data;
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static const ALCchar nullDevice[] = "No Output";
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static ALuint NullProc(ALvoid *ptr)
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{
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ALCdevice *Device = (ALCdevice*)ptr;
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null_data *data = (null_data*)Device->ExtraData;
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ALuint now, start;
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ALuint64 avail, done;
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const ALuint restTime = (ALuint64)Device->UpdateSize * 1000 /
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Device->Frequency / 2;
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done = 0;
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start = timeGetTime();
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while(!data->killNow && Device->Connected)
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{
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now = timeGetTime();
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avail = (ALuint64)(now-start) * Device->Frequency / 1000;
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if(avail < done)
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{
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/* Timer wrapped. Add the remainder of the cycle to the available
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* count and reset the number of samples done */
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avail += (ALuint64)0xFFFFFFFFu*Device->Frequency/1000 - done;
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done = 0;
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}
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if(avail-done < Device->UpdateSize)
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{
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Sleep(restTime);
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continue;
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}
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while(avail-done >= Device->UpdateSize)
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{
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aluMixData(Device, NULL, Device->UpdateSize);
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done += Device->UpdateSize;
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}
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}
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return 0;
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}
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static ALCenum null_open_playback(ALCdevice *device, const ALCchar *deviceName)
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{
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null_data *data;
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if(!deviceName)
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deviceName = nullDevice;
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else if(strcmp(deviceName, nullDevice) != 0)
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return ALC_INVALID_VALUE;
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data = (null_data*)calloc(1, sizeof(*data));
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device->szDeviceName = strdup(deviceName);
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device->ExtraData = data;
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return ALC_NO_ERROR;
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}
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static void null_close_playback(ALCdevice *device)
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{
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null_data *data = (null_data*)device->ExtraData;
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free(data);
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device->ExtraData = NULL;
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}
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static ALCboolean null_reset_playback(ALCdevice *device)
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{
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null_data *data = (null_data*)device->ExtraData;
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SetDefaultWFXChannelOrder(device);
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data->thread = StartThread(NullProc, device);
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if(data->thread == NULL)
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return ALC_FALSE;
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return ALC_TRUE;
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}
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static void null_stop_playback(ALCdevice *device)
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{
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null_data *data = (null_data*)device->ExtraData;
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if(!data->thread)
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return;
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data->killNow = 1;
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StopThread(data->thread);
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data->thread = NULL;
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data->killNow = 0;
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}
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static const BackendFuncs null_funcs = {
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null_open_playback,
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null_close_playback,
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null_reset_playback,
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null_stop_playback,
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NULL,
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NULL,
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NULL,
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NULL,
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NULL,
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NULL
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};
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ALCboolean alc_null_init(BackendFuncs *func_list)
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{
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*func_list = null_funcs;
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return ALC_TRUE;
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}
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void alc_null_deinit(void)
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{
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}
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void alc_null_probe(enum DevProbe type)
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{
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switch(type)
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{
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case DEVICE_PROBE:
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AppendDeviceList(nullDevice);
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break;
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case ALL_DEVICE_PROBE:
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AppendAllDeviceList(nullDevice);
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break;
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case CAPTURE_DEVICE_PROBE:
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break;
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}
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}
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