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/Backends/CompatLayer/CompatLayerHardwareDeviceDriver.cs

@@ -0,0 +1,146 @@
+//
+// 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.Backends.Common;
+using Ryujinx.Audio.Backends.Dummy;
+using Ryujinx.Audio.Common;
+using Ryujinx.Audio.Integration;
+using Ryujinx.Common.Logging;
+using Ryujinx.Memory;
+using System;
+using System.Threading;
+
+using static Ryujinx.Audio.Integration.IHardwareDeviceDriver;
+
+namespace Ryujinx.Audio.Backends.CompatLayer
+{
+    public class CompatLayerHardwareDeviceDriver : IHardwareDeviceDriver
+    {
+        private IHardwareDeviceDriver _realDriver;
+
+        public CompatLayerHardwareDeviceDriver(IHardwareDeviceDriver realDevice)
+        {
+            _realDriver = realDevice;
+        }
+
+        public void Dispose()
+        {
+            _realDriver.Dispose();
+        }
+
+        public ManualResetEvent GetUpdateRequiredEvent()
+        {
+            return _realDriver.GetUpdateRequiredEvent();
+        }
+
+        private uint SelectHardwareChannelCount(uint targetChannelCount)
+        {
+            if (_realDriver.SupportsChannelCount(targetChannelCount))
+            {
+                return targetChannelCount;
+            }
+
+            return targetChannelCount switch
+            {
+                6 => SelectHardwareChannelCount(2),
+                2 => SelectHardwareChannelCount(1),
+                1 => throw new ArgumentException("No valid channel configuration found!"),
+                _ => throw new ArgumentException($"Invalid targetChannelCount {targetChannelCount}")
+            };
+        }
+
+        public IHardwareDeviceSession OpenDeviceSession(Direction direction, IVirtualMemoryManager memoryManager, SampleFormat sampleFormat, uint sampleRate, uint channelCount)
+        {
+            if (channelCount == 0)
+            {
+                channelCount = 2;
+            }
+
+            if (sampleRate == 0)
+            {
+                sampleRate = Constants.TargetSampleRate;
+            }
+
+            if (!_realDriver.SupportsDirection(direction))
+            {
+                if (direction == Direction.Input)
+                {
+                    Logger.Warning?.Print(LogClass.Audio, "The selected audio backend doesn't support audio input, fallback to dummy...");
+
+                    return new DummyHardwareDeviceSessionInput(this, memoryManager, sampleFormat, sampleRate, channelCount);
+                }
+
+                throw new NotImplementedException();
+            }
+
+            uint hardwareChannelCount = SelectHardwareChannelCount(channelCount);
+
+            IHardwareDeviceSession realSession = _realDriver.OpenDeviceSession(direction, memoryManager, sampleFormat, sampleRate, hardwareChannelCount);
+
+            if (hardwareChannelCount == channelCount)
+            {
+                return realSession;
+            }
+
+            if (direction == Direction.Input)
+            {
+                Logger.Warning?.Print(LogClass.Audio, $"The selected audio backend doesn't support the requested audio input configuration, fallback to dummy...");
+
+                // TODO: We currently don't support audio input upsampling/downsampling, implement this.
+                realSession.Dispose();
+
+                return new DummyHardwareDeviceSessionInput(this, memoryManager, sampleFormat, sampleRate, channelCount);
+            }
+
+            // It must be a HardwareDeviceSessionOutputBase.
+            if (realSession is not HardwareDeviceSessionOutputBase realSessionOutputBase)
+            {
+                throw new InvalidOperationException($"Real driver session class type isn't based on {typeof(HardwareDeviceSessionOutputBase).Name}.");
+            }
+
+            // If we need to do post processing before sending to the hardware device, wrap around it.
+            return new CompatLayerHardwareDeviceSession(realSessionOutputBase, channelCount);
+        }
+
+        public bool SupportsChannelCount(uint channelCount)
+        {
+            return channelCount == 1 || channelCount == 2 || channelCount == 6;
+        }
+
+        public bool SupportsSampleFormat(SampleFormat sampleFormat)
+        {
+            // TODO: More formats.
+            return sampleFormat == SampleFormat.PcmInt16;
+        }
+
+        public bool SupportsSampleRate(uint sampleRate)
+        {
+            // TODO: More sample rates.
+            return sampleRate == Constants.TargetSampleRate;
+        }
+
+        public IHardwareDeviceDriver GetRealDeviceDriver()
+        {
+            return _realDriver;
+        }
+
+        public bool SupportsDirection(Direction direction)
+        {
+            return direction == Direction.Input || direction == Direction.Output;
+        }
+    }
+}