Instead of getting the loudness data for the whole file in advance, we now get it piece by piece as the sound is streamed.
The benefit is that we need to decode the audio just once instead of twice.
We no longer need to rewind() the stream when the first decoding is done, this should hopefully fix bug #3453 .
In between the startUpdate/finishUpdate calls, changes are deferred so that
they can happen all at once. This includes starting sounds, so when the
underwater sound is started it will be immediately checked to see if it's
playing. Since it's not yet playing, it'll be seen as stopped and get cleaned
up before ever playing.
Can't instantiate a container (at least with MSVC) without knowing the exact size of the object being stored, forward-declares only work with pointers.
I couldn't see a simple way to remove the forward declare, so pointers and memory management it is.
The cache size is specified with a min/max range, intended to avoid constant
unloading once the limit is reached. This way, buffers can be unloaded down to
a reasonable mimimum, allowing some more buffers to be subsequently loaded
without causing more unloading.
A deque allows existing Sound_Buffer references to remain valid as long as new
ones are back-inserted. These references can be used instead of indices.
Certain OpenAL implementations, including Rapture3D, Creative's hardware
drivers, and more recent versions of OpenAL Soft, can batch together changes so
that they all occur at once, avoiding potential discontinuities with one sound
being changed before another, or the listeenr being changed before sounds are.
On other implementaitons, this is a no-op and maintains existing behavior.
This simply sets up the Sound record data to be used by the sound output. The
actual audio buffers, stored in the Sound_Handle, are still loaded on-demand.
