Haydn: Part 1 (#2007)

* Haydn: Part 1

Based on my reverse of audio 11.0.0.

As always, core implementation under LGPLv3 for the same reasons as for Amadeus.

This place the bases of a more flexible audio system while making audout & audin accurate.

This have the following improvements:
- Complete reimplementation of audout and audin.
- Audin currently only have a dummy backend.
- Dramatically reduce CPU usage by up to 50% in common cases (SoundIO and OpenAL).
- Audio Renderer now can output to 5.1 devices when supported.
- Audio Renderer init its backend on demand instead of keeping two up all the time.
- All backends implementation are now in their own project.
- Ryujinx.Audio.Renderer was renamed Ryujinx.Audio and was refactored because of this.

As a note, games having issues with OpenAL haven't improved and will not
because of OpenAL design (stopping when buffers finish playing causing
possible audio "pops" when buffers are very small).

* Update for latest hexkyz's edits on Switchbrew

* audren: Rollback channel configuration changes

* Address gdkchan's comments

* Fix typo in OpenAL backend driver

* Address last comments

* Fix a nit

* Address gdkchan's comments

Ryujinx.Audio/Integration/HardwareDeviceImpl.cs

@@ -0,0 +1,82 @@
+//
+// Copyright (c) 2019-2021 Ryujinx
+//
+// This program 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, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program 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 program.  If not, see <https://www.gnu.org/licenses/>.
+//
+
+using Ryujinx.Audio.Common;
+using System;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Audio.Integration
+{
+    public class HardwareDeviceImpl : IHardwareDevice
+    {
+        private IHardwareDeviceSession _session;
+        private uint _channelCount;
+        private uint _sampleRate;
+        private uint _currentBufferTag;
+
+        private byte[] _buffer;
+
+        public HardwareDeviceImpl(IHardwareDeviceDriver deviceDriver, uint channelCount, uint sampleRate)
+        {
+            _session = deviceDriver.OpenDeviceSession(IHardwareDeviceDriver.Direction.Output, null, SampleFormat.PcmInt16, sampleRate, channelCount);
+            _channelCount = channelCount;
+            _sampleRate = sampleRate;
+            _currentBufferTag = 0;
+
+            _buffer = new byte[Constants.TargetSampleCount * channelCount * sizeof(ushort)];
+
+            _session.Start();
+        }
+
+        public void AppendBuffer(ReadOnlySpan<short> data, uint channelCount)
+        {
+            data.CopyTo(MemoryMarshal.Cast<byte, short>(_buffer));
+
+            _session.QueueBuffer(new AudioBuffer
+            {
+                DataPointer = _currentBufferTag++,
+                Data        = _buffer,
+                DataSize    = (ulong)_buffer.Length,
+            });
+
+            _currentBufferTag = _currentBufferTag % 4;
+        }
+
+        public uint GetChannelCount()
+        {
+            return _channelCount;
+        }
+
+        public uint GetSampleRate()
+        {
+            return _sampleRate;
+        }
+
+        public void Dispose()
+        {
+            Dispose(true);
+        }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                _session.Dispose();
+            }
+        }
+    }
+}