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