Method read

Engine/source/sfx/sfxMemoryStream.cpp:57–117

}

U32 SFXMemoryStream::read( U8* buffer, U32 length )
{
   U32 bufferOffset = 0;
   
   // Determine how much we're supposed to read.
   
   U32 numBytesToCopy = length;
   if( mNumSamplesLeft != U32_MAX )
      numBytesToCopy = getMin( length, mNumSamplesLeft * mFormat.getBytesPerSample() );
   numBytesToCopy -= numBytesToCopy % mFormat.getBytesPerSample();
      
   // Copy the data.
   
   U32 numBytesLeftToCopy = numBytesToCopy;
   while( numBytesLeftToCopy )
   {
      // If we have a current packet, use its data.
      
      if( mCurrentPacket )
      {
         U32 numBytesLeftInCurrentPacket = mCurrentPacket->size - mCurrentPacketOffset;
         
         // Copy data.
         
         if( numBytesLeftInCurrentPacket )
         {
            const U32 remainingNumBytesToCopy = getMin( numBytesLeftInCurrentPacket, numBytesLeftToCopy );
            dMemcpy( &buffer[ bufferOffset ], &mCurrentPacket->data[ mCurrentPacketOffset ], remainingNumBytesToCopy);
            
            bufferOffset                  += remainingNumBytesToCopy;
            mCurrentPacketOffset          += remainingNumBytesToCopy;
            numBytesLeftInCurrentPacket   -= remainingNumBytesToCopy;
            numBytesLeftToCopy            -= remainingNumBytesToCopy;
         }
         
         // Discard the packet if there's no data left.
         
         if( !numBytesLeftInCurrentPacket )
         {
            destructSingle( mCurrentPacket );
            mCurrentPacket = NULL;
            mCurrentPacketOffset = 0;
         }
      }
      else
      {
         // Read a new packet.
         
         if( !getSourceStream()->read( &mCurrentPacket, 1 ) )
            break;
      }
   }
   
   // Update count of remaining samples.
   
   U32 numBytesCopied = numBytesToCopy - numBytesLeftToCopy;
   if( mNumSamplesLeft != U32_MAX )
      mNumSamplesLeft -= ( numBytesCopied / mFormat.getBytesPerSample() );