summaryrefslogtreecommitdiff
path: root/indra/newview/llvieweraudio.cpp
blob: b93fc5d2fb4db607bbf82bb92beb8259288f1022 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
/**
 * @file llvieweraudio.cpp
 * @brief Audio functions that used to be in viewer.cpp
 *
 * $LicenseInfo:firstyear=2002&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "llviewerprecompiledheaders.h"

#include "llaudioengine.h"
#include "llagent.h"
#include "llagentcamera.h"
#include "llappviewer.h"
#include "lldeferredsounds.h"
#include "llvieweraudio.h"
#include "llviewercamera.h"
#include "llviewercontrol.h"
#include "llviewerwindow.h"
#include "llvoiceclient.h"
#include "llviewermedia.h"
#include "llviewerregion.h"
#include "llprogressview.h"
#include "llcallbacklist.h"
#include "llstartup.h"
#include "llviewerparcelmgr.h"
#include "llparcel.h"
#include "llviewermessage.h"

#include "llstreamingaudio.h"

/////////////////////////////////////////////////////////

LLViewerAudio::LLViewerAudio() :
    mDone(true),
    mFadeState(FADE_IDLE),
    mFadeTime(),
    mIdleListnerActive(false),
    mForcedTeleportFade(false),
    mWasPlaying(false)
{
    mTeleportFailedConnection = LLViewerParcelMgr::getInstance()->
        setTeleportFailedCallback(boost::bind(&LLViewerAudio::onTeleportFailed, this));
    mTeleportFinishedConnection = LLViewerParcelMgr::getInstance()->
        setTeleportFinishedCallback(boost::bind(&LLViewerAudio::onTeleportFinished, this, _1, _2));
    mTeleportStartedConnection = LLViewerMessage::getInstance()->
        setTeleportStartedCallback(boost::bind(&LLViewerAudio::onTeleportStarted, this));
}

LLViewerAudio::~LLViewerAudio()
{
    mTeleportFailedConnection.disconnect();
    mTeleportFinishedConnection.disconnect();
    mTeleportStartedConnection.disconnect();
}

void LLViewerAudio::registerIdleListener()
{
    if(mIdleListnerActive==false)
    {
        mIdleListnerActive = true;
        doOnIdleRepeating(boost::bind(boost::bind(&LLViewerAudio::onIdleUpdate, this)));
    }
}

void LLViewerAudio::startInternetStreamWithAutoFade(const std::string &streamURI)
{
    LL_DEBUGS("AudioEngine") << "Start with outo fade: " << streamURI << LL_ENDL;

    // Old and new stream are identical
    if (mNextStreamURI == streamURI)
    {
        return;
    }

    if (!gAudiop)
    {
        LL_WARNS("AudioEngine") << "LLAudioEngine instance doesn't exist!" << LL_ENDL;
        return;
    }

    // Record the URI we are going to be switching to
    mNextStreamURI = streamURI;

    switch (mFadeState)
    {
    case FADE_IDLE:
        // If a stream is playing fade it out first
        if (!gAudiop->getInternetStreamURL().empty())
        {
            // The order of these tests is important, state FADE_OUT will be processed below
            mFadeState = FADE_OUT;
        }
        // Otherwise the new stream can be faded in
        else
        {
            mFadeState = FADE_IN;

            LLStreamingAudioInterface *stream = gAudiop->getStreamingAudioImpl();
            if (stream && stream->supportsAdjustableBufferSizes())
                stream->setBufferSizes(gSavedSettings.getU32("FMODExStreamBufferSize"), gSavedSettings.getU32("FMODExDecodeBufferSize"));

            gAudiop->startInternetStream(mNextStreamURI);
        }

        startFading();
        break;

    case FADE_OUT:
        startFading();
        break;

    case FADE_IN:
        break;

    default:
        LL_WARNS() << "Unknown fading state: " << mFadeState << LL_ENDL;
        return;
    }

    registerIdleListener();
}

// A return of false from onIdleUpdate means it will be called again next idle update.
// A return of true means we have finished with it and the callback will be deleted.
bool LLViewerAudio::onIdleUpdate()
{
    bool fadeIsFinished = false;

    // There is a delay in the login sequence between when the parcel information has
    // arrived and the music stream is started and when the audio system is called to set
    // initial volume levels.  This code extends the fade time so you hear a full fade in.
    if ((LLStartUp::getStartupState() < STATE_STARTED))
    {
        stream_fade_timer.reset();
        stream_fade_timer.setTimerExpirySec(mFadeTime);
    }

    if (mDone)
    {
        //  This should be a rare or never occurring state.
        if (mFadeState == FADE_IDLE)
        {
            deregisterIdleListener();
            fadeIsFinished = true; // Stop calling onIdleUpdate
        }

        // we have finished the current fade operation
        if (mFadeState == FADE_OUT)
        {
            if (gAudiop)
            {
                // Clear URI
                LL_DEBUGS("AudioEngine") << "Done with audio fade" << LL_ENDL;
                gAudiop->startInternetStream(LLStringUtil::null);
                gAudiop->stopInternetStream();
            }

            if (!mNextStreamURI.empty())
            {
                mFadeState = FADE_IN;

                if (gAudiop)
                {
                    LL_DEBUGS("AudioEngine") << "Audio fade in: " << mNextStreamURI << LL_ENDL;
                    LLStreamingAudioInterface *stream = gAudiop->getStreamingAudioImpl();
                    if(stream && stream->supportsAdjustableBufferSizes())
                        stream->setBufferSizes(gSavedSettings.getU32("FMODExStreamBufferSize"),gSavedSettings.getU32("FMODExDecodeBufferSize"));

                    gAudiop->startInternetStream(mNextStreamURI);
                }

                startFading();
            }
            else
            {
                mFadeState = FADE_IDLE;
                deregisterIdleListener();
                fadeIsFinished = true; // Stop calling onIdleUpdate
            }
        }
        else if (mFadeState == FADE_IN)
        {
            if (gAudiop && mNextStreamURI != gAudiop->getInternetStreamURL())
            {
                mFadeState = FADE_OUT;
                startFading();
            }
            else
            {
                mFadeState = FADE_IDLE;
                deregisterIdleListener();
                fadeIsFinished = true; // Stop calling onIdleUpdate
            }
        }
    }

    return fadeIsFinished;
}

void LLViewerAudio::stopInternetStreamWithAutoFade()
{
    mFadeState = FADE_IDLE;
    mNextStreamURI = LLStringUtil::null;
    mDone = true;

    if (gAudiop)
    {
        LL_DEBUGS("AudioEngine") << "Stop audio fade" << LL_ENDL;
        gAudiop->startInternetStream(LLStringUtil::null);
        gAudiop->stopInternetStream();
    }
}

void LLViewerAudio::startFading()
{
    const F32 AUDIO_MUSIC_FADE_IN_TIME = 3.0f;
    const F32 AUDIO_MUSIC_FADE_OUT_TIME = 2.0f;
    // This minimum fade time prevents divide by zero and negative times
    const F32 AUDIO_MUSIC_MINIMUM_FADE_TIME = 0.01f;

    if (mDone)
    {
        // The fade state here should only be one of FADE_IN or FADE_OUT, but, in case it is not,
        // rather than check for both states assume a fade in and check for the fade out case.
        mFadeTime = LLViewerAudio::getInstance()->getFadeState() == LLViewerAudio::FADE_OUT ?
            AUDIO_MUSIC_FADE_OUT_TIME : AUDIO_MUSIC_FADE_IN_TIME;

        // Prevent invalid fade time
        mFadeTime = llmax(mFadeTime, AUDIO_MUSIC_MINIMUM_FADE_TIME);

        stream_fade_timer.reset();
        stream_fade_timer.setTimerExpirySec(mFadeTime);
        mDone = false;
    }
}

F32 LLViewerAudio::getFadeVolume()
{
    F32 fade_volume = 1.0f;

    if (stream_fade_timer.hasExpired())
    {
        mDone = true;
        // If we have been fading out set volume to 0 until the next fade state occurs to prevent
        // an audio transient.
        if (LLViewerAudio::getInstance()->getFadeState() == LLViewerAudio::FADE_OUT)
        {
            fade_volume = 0.0f;
        }
    }

    if (!mDone)
    {
        // Calculate how far we are into the fade time
        fade_volume = stream_fade_timer.getElapsedTimeF32() / mFadeTime;

        if (LLViewerAudio::getInstance()->getFadeState() == LLViewerAudio::FADE_OUT)
        {
            // If we are not fading in then we are fading out, so invert the fade
            // direction; start loud and move towards zero volume.
            fade_volume = 1.0f - fade_volume;
        }
    }

    return fade_volume;
}

void LLViewerAudio::onTeleportStarted()
{
    if (gAudiop && !LLViewerAudio::getInstance()->getForcedTeleportFade())
    {
        // Even though the music was turned off it was starting up (with autoplay disabled) occasionally
        // after a failed teleport or after an intra-parcel teleport.  Also, the music sometimes was not
        // restarting after a successful intra-parcel teleport. Setting mWasPlaying fixes these issues.
        LLViewerAudio::getInstance()->setWasPlaying(!gAudiop->getInternetStreamURL().empty());
        LLViewerAudio::getInstance()->setForcedTeleportFade(true);
        LLViewerAudio::getInstance()->startInternetStreamWithAutoFade(LLStringUtil::null);
        LLViewerAudio::getInstance()->setNextStreamURI(LLStringUtil::null);
    }
}

void LLViewerAudio::onTeleportFailed()
{
    // Calling audio_update_volume makes sure that the music stream is properly set to be restored to
    // its previous value
    audio_update_volume(false);

    if (gAudiop && mWasPlaying)
    {
        LLParcel* parcel = LLViewerParcelMgr::getInstance()->getAgentParcel();
        if (parcel)
        {
            mNextStreamURI = parcel->getMusicURL();
            LL_INFOS() << "Teleport failed -- setting music stream to " << mNextStreamURI << LL_ENDL;
        }
    }
    mWasPlaying = false;
}

void LLViewerAudio::onTeleportFinished(const LLVector3d& pos, const bool& local)
{
    // Calling audio_update_volume makes sure that the music stream is properly set to be restored to
    // its previous value
    audio_update_volume(false);

    if (gAudiop && local && mWasPlaying)
    {
        LLParcel* parcel = LLViewerParcelMgr::getInstance()->getAgentParcel();
        if (parcel)
        {
            mNextStreamURI = parcel->getMusicURL();
            LL_INFOS() << "Intraparcel teleport -- setting music stream to " << mNextStreamURI << LL_ENDL;
        }
    }
    mWasPlaying = false;
}

void init_audio()
{
    if (!gAudiop)
    {
        LL_WARNS() << "Failed to create an appropriate Audio Engine" << LL_ENDL;
        return;
    }
    LLVector3d lpos_global = gAgentCamera.getCameraPositionGlobal();
    LLVector3 lpos_global_f;

    lpos_global_f.setVec(lpos_global);

    gAudiop->setListener(lpos_global_f,
                          LLVector3::zero,  // LLViewerCamera::getInstance()->getVelocity(),    // !!! BUG need to replace this with smoothed velocity!
                          LLViewerCamera::getInstance()->getUpAxis(),
                          LLViewerCamera::getInstance()->getAtAxis());

// load up our initial set of sounds we'll want so they're in memory and ready to be played

    BOOL mute_audio = gSavedSettings.getBOOL("MuteAudio");

    if (!mute_audio && FALSE == gSavedSettings.getBOOL("NoPreload"))
    {
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndAlert")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndBadKeystroke")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndChatFromObject")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndClick")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndClickRelease")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndHealthReductionF")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndHealthReductionM")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndIncomingChat")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndIncomingIM")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndInvApplyToObject")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndInvalidOp")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndInventoryCopyToInv")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndMoneyChangeDown")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndMoneyChangeUp")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndObjectCopyToInv")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndObjectCreate")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndObjectDelete")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndObjectRezIn")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndObjectRezOut")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndSnapshot")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndStartAutopilot")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndStartFollowpilot")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndStartIM")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndStopAutopilot")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndTeleportOut")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndTextureApplyToObject")));
        //gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndTextureCopyToInv")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndTyping")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndWindowClose")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndWindowOpen")));
        gAudiop->preloadSound(LLUUID(gSavedSettings.getString("UISndRestart")));
    }

    audio_update_volume(true);
}

void audio_update_volume(bool force_update)
{
    F32 master_volume = gSavedSettings.getF32("AudioLevelMaster");
    BOOL mute_audio = gSavedSettings.getBOOL("MuteAudio");

    LLProgressView* progress = gViewerWindow->getProgressView();
    BOOL progress_view_visible = FALSE;

    if (progress)
    {
        progress_view_visible = progress->getVisible();
    }

    if (!gViewerWindow->getActive() && gSavedSettings.getBOOL("MuteWhenMinimized"))
    {
        mute_audio = TRUE;
    }
    F32 mute_volume = mute_audio ? 0.0f : 1.0f;

    if (gAudiop)
    {
        // Sound Effects

        gAudiop->setMasterGain ( master_volume );

        gAudiop->setDopplerFactor(gSavedSettings.getF32("AudioLevelDoppler"));

        if(!LLViewerCamera::getInstance()->cameraUnderWater())
        gAudiop->setRolloffFactor(gSavedSettings.getF32("AudioLevelRolloff"));
        else
            gAudiop->setRolloffFactor(gSavedSettings.getF32("AudioLevelUnderwaterRolloff"));

        gAudiop->setMuted(mute_audio || progress_view_visible);

        //Play any deferred sounds when unmuted
        if(!gAudiop->getMuted())
        {
            LLDeferredSounds::instance().playdeferredSounds();
        }

        if (force_update)
        {
            audio_update_wind(true);
        }

        // handle secondary gains
        gAudiop->setSecondaryGain(LLAudioEngine::AUDIO_TYPE_SFX,
                                  gSavedSettings.getBOOL("MuteSounds") ? 0.f : gSavedSettings.getF32("AudioLevelSFX"));
        gAudiop->setSecondaryGain(LLAudioEngine::AUDIO_TYPE_UI,
                                  gSavedSettings.getBOOL("MuteUI") ? 0.f : gSavedSettings.getF32("AudioLevelUI"));
        gAudiop->setSecondaryGain(LLAudioEngine::AUDIO_TYPE_AMBIENT,
                                  gSavedSettings.getBOOL("MuteAmbient") ? 0.f : gSavedSettings.getF32("AudioLevelAmbient"));

        // Streaming Music

        if (!progress_view_visible && LLViewerAudio::getInstance()->getForcedTeleportFade())
        {
            LLViewerAudio::getInstance()->setWasPlaying(!gAudiop->getInternetStreamURL().empty());
            LLViewerAudio::getInstance()->setForcedTeleportFade(false);
        }

        F32 music_volume = gSavedSettings.getF32("AudioLevelMusic");
        BOOL music_muted = gSavedSettings.getBOOL("MuteMusic");
        F32 fade_volume = LLViewerAudio::getInstance()->getFadeVolume();

        music_volume = mute_volume * master_volume * music_volume * fade_volume;
        gAudiop->setInternetStreamGain (music_muted ? 0.f : music_volume);
    }

    // Streaming Media
    F32 media_volume = gSavedSettings.getF32("AudioLevelMedia");
    BOOL media_muted = gSavedSettings.getBOOL("MuteMedia");
    media_volume = mute_volume * master_volume * media_volume;
    LLViewerMedia::getInstance()->setVolume( media_muted ? 0.0f : media_volume );

    // Voice, this is parametric singleton, it gets initialized when ready
    if (LLVoiceClient::instanceExists())
    {
        F32 voice_volume = gSavedSettings.getF32("AudioLevelVoice");
        voice_volume = mute_volume * master_volume * voice_volume;
        BOOL voice_mute = gSavedSettings.getBOOL("MuteVoice");
        LLVoiceClient *voice_inst = LLVoiceClient::getInstance();
        voice_inst->setVoiceVolume(voice_mute ? 0.f : voice_volume);
        voice_inst->setMicGain(voice_mute ? 0.f : gSavedSettings.getF32("AudioLevelMic"));

        if (!gViewerWindow->getActive() && (gSavedSettings.getBOOL("MuteWhenMinimized")))
        {
            voice_inst->setMuteMic(true);
        }
        else
        {
            voice_inst->setMuteMic(false);
        }
    }
}

void audio_update_listener()
{
    if (gAudiop)
    {
        // update listener position because agent has moved
        static LLUICachedControl<S32> mEarLocation("MediaSoundsEarLocation", 0);
        LLVector3d ear_position;
        switch(mEarLocation)
        {
        case 0:
        default:
            ear_position = gAgentCamera.getCameraPositionGlobal();
            break;

        case 1:
            ear_position = gAgent.getPositionGlobal();
            break;
        }
        LLVector3d lpos_global = ear_position;
        LLVector3 lpos_global_f;
        lpos_global_f.setVec(lpos_global);

        gAudiop->setListener(lpos_global_f,
                             // LLViewerCamera::getInstance()VelocitySmoothed,
                             // LLVector3::zero,
                             gAgent.getVelocity(),    // !!! *TODO: need to replace this with smoothed velocity!
                             LLViewerCamera::getInstance()->getUpAxis(),
                             LLViewerCamera::getInstance()->getAtAxis());
    }
}

void audio_update_wind(bool force_update)
{
#ifdef kAUDIO_ENABLE_WIND

    LLViewerRegion* region = gAgent.getRegion();
    if (region)
    {
        // Scale down the contribution of weather-simulation wind to the
        // ambient wind noise.  Wind velocity averages 3.5 m/s, with gusts to 7 m/s
        // whereas steady-state avatar walk velocity is only 3.2 m/s.
        // Without this the world feels desolate on first login when you are
        // standing still.
        static LLUICachedControl<F32> wind_level("AudioLevelWind", 0.5f);
        LLVector3 scaled_wind_vec = gWindVec * wind_level;

        // Mix in the avatar's motion, subtract because when you walk north,
        // the apparent wind moves south.
        LLVector3 final_wind_vec = scaled_wind_vec - gAgent.getVelocity();

        // rotate the wind vector to be listener (agent) relative
        gRelativeWindVec = gAgent.getFrameAgent().rotateToLocal( final_wind_vec );

        // don't use the setter setMaxWindGain() because we don't
        // want to screw up the fade-in on startup by setting actual source gain
        // outside the fade-in.
        F32 master_volume  = gSavedSettings.getBOOL("MuteAudio") ? 0.f : gSavedSettings.getF32("AudioLevelMaster");
        F32 ambient_volume = gSavedSettings.getBOOL("MuteAmbient") ? 0.f : gSavedSettings.getF32("AudioLevelAmbient");
        F32 max_wind_volume = master_volume * ambient_volume;

        const F32 WIND_SOUND_TRANSITION_TIME = 2.f;
        // amount to change volume this frame
        F32 volume_delta = (LLFrameTimer::getFrameDeltaTimeF32() / WIND_SOUND_TRANSITION_TIME) * max_wind_volume;
        if (force_update)
        {
            // initialize wind volume (force_update) by using large volume_delta
            // which is sufficient to completely turn off or turn on wind noise
            volume_delta = 1.f;
        }

        if (!gAudiop)
        {
            LL_WARNS("AudioEngine") << "LLAudioEngine instance doesn't exist!" << LL_ENDL;
            return;
        }

        // mute wind when not flying
        if (gAgent.getFlying())
        {
            // volume increases by volume_delta, up to no more than max_wind_volume
            gAudiop->mMaxWindGain = llmin(gAudiop->mMaxWindGain + volume_delta, max_wind_volume);
        }
        else
        {
            // volume decreases by volume_delta, down to no less than 0
            gAudiop->mMaxWindGain = llmax(gAudiop->mMaxWindGain - volume_delta, 0.f);
        }

        gAudiop->updateWind(gRelativeWindVec, gAgentCamera.getCameraPositionAgent()[VZ] - gAgent.getRegion()->getWaterHeight());
    }
#endif
}