Table des matières
Wwise SDK 2018.1.11
 /*******************************************************************************

 The content of this file includes portions of the AUDIOKINETIC Wwise Technology

 released in source code form as part of the SDK installer package.

 Commercial License Usage

 Licensees holding valid commercial licenses to the AUDIOKINETIC Wwise Technology

 may use this file in accordance with the end user license agreement provided 

 with the software or, alternatively, in accordance with the terms contained in a

 written agreement between you and Audiokinetic Inc.

 Apache License Usage

 Alternatively, this file may be used under the Apache License, Version 2.0 (the 

 "Apache License"); you may not use this file except in compliance with the 

 Apache License. You may obtain a copy of the Apache License at 

 http://www.apache.org/licenses/LICENSE-2.0.

 Unless required by applicable law or agreed to in writing, software distributed

 under the Apache License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES

 OR CONDITIONS OF ANY KIND, either express or implied. See the Apache License for

 the specific language governing permissions and limitations under the License.

   Version: <VERSION>  Build: <BUILDNUMBER>

   Copyright (c) <COPYRIGHTYEAR> Audiokinetic Inc.

 *******************************************************************************/

 #ifndef _AKFXTAILHANDLER_H_

 #define _AKFXTAILHANDLER_H_

 #include <AK/SoundEngine/Common/AkTypes.h>

 #include <AK/SoundEngine/Common/AkCommonDefs.h>

 #include <AK/Tools/Common/AkPlatformFuncs.h>

 /// Default value when effect has not enterred tail mode yet.

 #define AKFXTAILHANDLER_NOTINTAIL 0xFFFFFFFF

 /// Effect tail handling utility class.

 /// Handles varying number of tail frames from frame to frame (i.e. based on RTPC parameters).

 /// Handles effect revived (quit tail) and reenters etc.

 class AkFXTailHandler

 {

 public:

     /// Constructor

     inline AkFXTailHandler() 

         : uTailFramesRemaining( AKFXTAILHANDLER_NOTINTAIL )

         , uTotalTailFrames(0) {}

     /// Handle FX tail and zero pads AkAudioBuffer if necessary

     inline void HandleTail( 

         AkAudioBuffer * io_pBuffer, 

         AkUInt32 in_uTotalTailFrames )

     {

         bool bPreStop = io_pBuffer->eState == AK_NoMoreData;

         if ( bPreStop )

         {   

             // Tail not yet finished processing

             if ( uTailFramesRemaining > 0  

                 || io_pBuffer->uValidFrames > 0 // <-- there are valid frames, so last (maybe partially filled) buffer.

                 )

             {

                 // Not previously in tail, compute tail time

                 if (uTailFramesRemaining == AKFXTAILHANDLER_NOTINTAIL  

                     || io_pBuffer->uValidFrames > 0 // <- ANY valid frames in the buffer should reset the tail.

                     )

                 {

                     uTailFramesRemaining = in_uTotalTailFrames;

                     uTotalTailFrames     = in_uTotalTailFrames;

                 }

                 // Tail time changed, augment if necessary but preserve where we are so that effect will 

                 // still finish when constantly changing this based on RTPC parameters

                 else if ( in_uTotalTailFrames > uTotalTailFrames )

                 {

                     AkUInt32 uFramesElapsed = uTotalTailFrames - uTailFramesRemaining;

                     uTailFramesRemaining = in_uTotalTailFrames - uFramesElapsed;

                     uTotalTailFrames     = in_uTotalTailFrames;

                 }

                 // Always full buffers while in tail

                 AkUInt32 uNumTailFrames = (AkUInt32)(io_pBuffer->MaxFrames()-io_pBuffer->uValidFrames); 

                 uTailFramesRemaining -= AkMin( uTailFramesRemaining, uNumTailFrames ); 

                 io_pBuffer->ZeroPadToMaxFrames();

                 if ( uTailFramesRemaining > 0 )

                     io_pBuffer->eState = AK_DataReady;

             }

         }

         else

         {

             // Reset tail mode for next time if exits tail mode (on bus only)

             uTailFramesRemaining = AKFXTAILHANDLER_NOTINTAIL;

         }

     }

     inline bool HasTailRemaining() { return uTailFramesRemaining > 0; } // Also true when AKFXTAILHANDLER_NOTINTAIL

 protected:

     AkUInt32    uTailFramesRemaining; // AKFXTAILHANDLER_NOTINTAIL, otherwise value represents number of frames remaining in tail

     AkUInt32    uTotalTailFrames;

 } AK_ALIGN_DMA;

 #endif // _AKFXTAILHANDLER_H_