2 * OpenAL cross platform audio library
3 * Copyright (C) 2010 by Chris Robinson
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
18 * Or go to http://www.gnu.org/copyleft/lgpl.html
35 static const ALCchar nullDevice
[] = "No Output";
37 static ALuint
NullProc(ALvoid
*ptr
)
39 ALCdevice
*Device
= (ALCdevice
*)ptr
;
40 null_data
*data
= (null_data
*)Device
->ExtraData
;
43 const ALuint restTime
= (ALuint64
)Device
->UpdateSize
* 1000 /
44 Device
->Frequency
/ 2;
47 start
= timeGetTime();
48 while(!data
->killNow
&& Device
->Connected
)
52 avail
= (ALuint64
)(now
-start
) * Device
->Frequency
/ 1000;
55 /* Timer wrapped (50 days???). Add the remainder of the cycle to
56 * the available count and reset the number of samples done */
57 avail
+= ((ALuint64
)1<<32)*Device
->Frequency
/1000 - done
;
60 if(avail
-done
< Device
->UpdateSize
)
66 while(avail
-done
>= Device
->UpdateSize
)
68 aluMixData(Device
, NULL
, Device
->UpdateSize
);
69 done
+= Device
->UpdateSize
;
76 static ALCenum
null_open_playback(ALCdevice
*device
, const ALCchar
*deviceName
)
81 deviceName
= nullDevice
;
82 else if(strcmp(deviceName
, nullDevice
) != 0)
83 return ALC_INVALID_VALUE
;
85 data
= (null_data
*)calloc(1, sizeof(*data
));
87 device
->DeviceName
= strdup(deviceName
);
88 device
->ExtraData
= data
;
92 static void null_close_playback(ALCdevice
*device
)
94 null_data
*data
= (null_data
*)device
->ExtraData
;
97 device
->ExtraData
= NULL
;
100 static ALCboolean
null_reset_playback(ALCdevice
*device
)
102 SetDefaultWFXChannelOrder(device
);
106 static ALCboolean
null_start_playback(ALCdevice
*device
)
108 null_data
*data
= (null_data
*)device
->ExtraData
;
110 data
->thread
= StartThread(NullProc
, device
);
111 if(data
->thread
== NULL
)
117 static void null_stop_playback(ALCdevice
*device
)
119 null_data
*data
= (null_data
*)device
->ExtraData
;
125 StopThread(data
->thread
);
132 static ALint64
null_get_latency(ALCdevice
*device
)
134 /* FIXME: Time until next update + "safe" offset */
140 static const BackendFuncs null_funcs
= {
155 ALCboolean
alc_null_init(BackendFuncs
*func_list
)
157 *func_list
= null_funcs
;
161 void alc_null_deinit(void)
165 void alc_null_probe(enum DevProbe type
)
169 case ALL_DEVICE_PROBE
:
170 AppendAllDevicesList(nullDevice
);
172 case CAPTURE_DEVICE_PROBE
: