Reduce number of simultaneous creature walk sounds. Battlefield

src/fheroes2/audio/audio_manager.cpp

@@ -906,6 +906,16 @@ namespace AudioManager
         g_asyncSoundManager.pushSound( m82, Settings::Get().SoundVolume() );
     }
 
+    double getSoundDurationMs( const int m82 )
+    {
+        const std::scoped_lock<std::recursive_mutex> lock( g_asyncSoundManager.resourceMutex() );
+
+        const std::vector<uint8_t> & v = GetWAV( m82 );
+
+        // Sound duration is: (wavSize - headerSize) / sampleRateKHz / channelCount / byesPerSample.
+        return ( static_cast<double>( v.size() ) - 44. ) / 22.050;
+    }
+
     bool isExternalMusicFileAvailable( const int trackId )
     {
         return !getExternalMusicFile( trackId ).empty();

src/fheroes2/audio/audio_manager.h

@@ -93,6 +93,9 @@ namespace AudioManager
     int PlaySound( const int m82 );
     void PlaySoundAsync( const int m82 );
 
+    // Returns specified sound duration in milliseconds.
+    double getSoundDurationMs( const int m82 );
+
     // Returns true if an external music file is available for the music track with the specified ID, otherwise returns false.
     bool isExternalMusicFileAvailable( const int trackId );
 

src/fheroes2/battle/battle_interface.cpp

@@ -3834,12 +3834,15 @@ void Battle::Interface::RedrawActionMove( Unit & unit, const Indexes & path )
 
     Cursor::Get().SetThemes( Cursor::WAR_POINTER );
 
-    Indexes::const_iterator dst = path.begin();
     Bridge * bridge = Arena::GetBridge();
 
+    const int walkSoundId = unit.M82Move();
+
     // Get the time to animate movement for one cell.
     uint32_t frameDelay = Game::ApplyBattleSpeed( unit.animation.getMoveSpeed() );
-    if ( unit.Modes( SP_HASTE ) ) {
+    const int cellCountForOneSound = static_cast<int>( std::round( AudioManager::getSoundDurationMs( walkSoundId ) / frameDelay ) ) - 1;
+
+    if ( unit.Modes( SP_HASTE ) && frameDelay > 1 ) {
         frameDelay = frameDelay * 65 / 100; // by 35% faster
     }
     else if ( unit.Modes( SP_SLOW ) ) {
@@ -3848,6 +3851,7 @@ void Battle::Interface::RedrawActionMove( Unit & unit, const Indexes & path )
 
     // Set the delay between movement animation frames. This delay will be used for all types of movement animations.
     unit.SwitchAnimation( Monster_Info::MOVING );
+
     Game::setCustomUnitMovementDelay( frameDelay / unit.animation.animationLength() );
 
     std::string msg = _( "Moved %{monster}: from [%{src}] to [%{dst}]." );
@@ -3863,7 +3867,10 @@ void Battle::Interface::RedrawActionMove( Unit & unit, const Indexes & path )
     const bool canFly = unit.isAbilityPresent( fheroes2::MonsterAbilityType::FLYING );
     // If it is a wide creature (cache this boolean to use in the loop).
     const bool isWide = unit.isWide();
+
+    Indexes::const_iterator dst = path.begin();
     const Indexes::const_iterator pathEnd = path.end();
+    const Indexes::const_iterator finalStep = pathEnd - 1;
 
     const bool isOneStepPath = [&unit, &path]() {
         if ( path.size() == 1 ) {
@@ -3952,15 +3959,22 @@ void Battle::Interface::RedrawActionMove( Unit & unit, const Indexes & path )
         }
     }
 
+    // For Battle speed 9 and 10 we play sound by sound without any simultaneous playbacks
+    // and do not use calculated 'cellCountForOneSound' as the real count may differ as
+    // some monitors may use 50 Hz refresh rate with V-sync on (or a low CPU may not allow so high FPS).
+    const bool playSoundBySound = Settings::Get().BattleSpeed() > 8;
+    int soundStatus = -1;
+
     while ( dst != pathEnd ) {
         // Check if a wide unit changes its horizontal direction.
         if ( isWide && unit.GetTailIndex() == *dst ) {
             // We must not reflect the flyers at the and of the path (just before the landing).
-            if ( !canFly || ( dst != ( pathEnd - 1 ) ) ) {
+            if ( !canFly || ( dst != finalStep ) ) {
                 unit.SetReflection( !unit.isReflect() );
             }
             // After changing the direction go to the next step in the path.
             ++dst;
+
             continue;
         }
 
@@ -3977,7 +3991,7 @@ void Battle::Interface::RedrawActionMove( Unit & unit, const Indexes & path )
             unit.SwitchAnimation( Monster_Info::STAND_STILL );
             bridge->ActionDown();
             _movingUnit = &unit;
-            if ( dst == ( pathEnd - 1 ) ) {
+            if ( dst == finalStep ) {
                 // There is only one cell left to move after standing.
                 unit.SwitchAnimation( Monster_Info::MOVE_QUICK );
             }
@@ -3992,9 +4006,20 @@ void Battle::Interface::RedrawActionMove( Unit & unit, const Indexes & path )
             _movingPos.x -= CELLW;
         }
 
-        // Render the unit movement with the movement sound.
-        // TODO: adjust sounds calls and synchronize them with frames. Take into account that some sounds (like for Cavalry) consists of a sequence of steps.
-        AudioManager::PlaySound( unit.M82Move() );
+        // Limit the simultaneous walk sounds.
+        if ( playSoundBySound ) {
+            if ( soundStatus < 0 || !Mixer::isPlaying( soundStatus ) ) {
+                soundStatus = AudioManager::PlaySound( walkSoundId );
+            }
+        }
+        else {
+            if ( soundStatus < 1 ) {
+                AudioManager::PlaySound( walkSoundId );
+                soundStatus = cellCountForOneSound;
+            }
+            --soundStatus;
+        }
+
         AnimateUnitWithDelay( unit );
         unit.SetPosition( *dst );
 
@@ -4014,7 +4039,7 @@ void Battle::Interface::RedrawActionMove( Unit & unit, const Indexes & path )
                 unit.SwitchAnimation( Monster_Info::STAND_STILL );
                 bridge->ActionUp();
                 _movingUnit = &unit;
-                if ( dst == ( pathEnd - 1 ) ) {
+                if ( dst == finalStep ) {
                     // There is only one cell left to move after standing.
                     unit.SwitchAnimation( Monster_Info::MOVE_QUICK );
                 }
@@ -4023,7 +4048,7 @@ void Battle::Interface::RedrawActionMove( Unit & unit, const Indexes & path )
                     unit.SwitchAnimation( Monster_Info::MOVE_START );
                 }
             }
-            else if ( dst == ( pathEnd - 1 ) ) {
+            else if ( dst == finalStep ) {
                 // There is only one cell left to move.
                 unit.SwitchAnimation( Monster_Info::MOVE_END );
             }
@@ -4087,7 +4112,10 @@ void Battle::Interface::RedrawActionFly( Unit & unit, const Position & pos )
 
     const uint32_t step = unit.animation.getFlightSpeed();
     uint32_t frameDelay = Game::ApplyBattleSpeed( unit.animation.getMoveSpeed() );
-    if ( unit.Modes( SP_HASTE ) ) {
+    const int flySoundId = unit.M82Move();
+    const int cellCountForOneSound = static_cast<int>( std::round( AudioManager::getSoundDurationMs( flySoundId ) / frameDelay ) ) - 1;
+
+    if ( unit.Modes( SP_HASTE ) && frameDelay > 1 ) {
         frameDelay = frameDelay * 8 / 10; // 20% faster
     }
     else if ( unit.Modes( SP_SLOW ) ) {
@@ -4129,11 +4157,30 @@ void Battle::Interface::RedrawActionFly( Unit & unit, const Position & pos )
         ++currentPoint;
     }
 
+    // For Battle speed 9 and 10 we play sound by sound without any simultaneous playbacks
+    // and do not use calculated 'cellCountForOneSound' as the real count may differ as
+    // some monitors may use 50 Hz refresh rate with V-sync on (or a low CPU may not allow so high FPS).
+    const bool playSoundBySound = Settings::Get().BattleSpeed() > 8;
+    int soundStatus = -1;
+
     unit.SwitchAnimation( Monster_Info::MOVING );
     while ( currentPoint != points.end() ) {
         _movingPos = *currentPoint;
 
-        AudioManager::PlaySound( unit.M82Move() );
+        // Limit the simultaneous fly sounds.
+        if ( playSoundBySound ) {
+            if ( soundStatus < 0 || !Mixer::isPlaying( soundStatus ) ) {
+                soundStatus = AudioManager::PlaySound( flySoundId );
+            }
+        }
+        else {
+            if ( soundStatus < 1 ) {
+                AudioManager::PlaySound( flySoundId );
+                soundStatus = cellCountForOneSound;
+            }
+            --soundStatus;
+        }
+
         unit.animation.restartAnimation();
         AnimateUnitWithDelay( unit );