audio: Implement a SDL2 backend (#2258)

* audio: Implement a SDL2 backend

This adds support to SDL2 as an audio backend.
It has the same compatibility level as OpenAL without its issues.

I also took the liberty of restructuring the SDL2 code to have one
shared project between audio and input.

The configuration version was also incremented.

* Address gdkchan's comments

* Fix update logic

* Add an heuristic to pick the correct target sample count wanted by the game

* Address gdkchan's comments

* Address Ac_k's comments

* Fix audren output

* Address gdkchan's comments

3 files changed, 10 insertions, 2 deletions

diff --git a/Ryujinx.Common/Configuration/AudioBackend.cs b/Ryujinx.Common/Configuration/AudioBackend.cs
index 28233354..e42df039 100644
--- a/Ryujinx.Common/Configuration/AudioBackend.cs
+++ b/Ryujinx.Common/Configuration/AudioBackend.cs
@@ -4,6 +4,7 @@
     {
         Dummy,
         OpenAl,
-        SoundIo
+        SoundIo,
+        SDL2
     }
 }
\ No newline at end of file
diff --git a/Ryujinx.Common/Configuration/ConfigurationFileFormat.cs b/Ryujinx.Common/Configuration/ConfigurationFileFormat.cs
index 092bb9dd..be9c6864 100644
--- a/Ryujinx.Common/Configuration/ConfigurationFileFormat.cs
+++ b/Ryujinx.Common/Configuration/ConfigurationFileFormat.cs
@@ -14,7 +14,7 @@ namespace Ryujinx.Configuration
         /// <summary>
         /// The current version of the file format
         /// </summary>
-        public const int CurrentVersion = 24;
+        public const int CurrentVersion = 25;
 
         public int Version { get; set; }
 
diff --git a/Ryujinx.Common/Configuration/ConfigurationState.cs b/Ryujinx.Common/Configuration/ConfigurationState.cs
index e65bcfcb..9ea5c282 100644
--- a/Ryujinx.Common/Configuration/ConfigurationState.cs
+++ b/Ryujinx.Common/Configuration/ConfigurationState.cs
@@ -803,6 +803,13 @@ namespace Ryujinx.Configuration
                 configurationFileUpdated = true;
             }
 
+            if (configurationFileFormat.Version < 25)
+            {
+                Common.Logging.Logger.Warning?.Print(LogClass.Application, $"Outdated configuration version {configurationFileFormat.Version}, migrating to version 25.");
+
+                configurationFileUpdated = true;
+            }
+
             Logger.EnableFileLog.Value             = configurationFileFormat.EnableFileLog;
             Graphics.ResScale.Value                = configurationFileFormat.ResScale;
             Graphics.ResScaleCustom.Value          = configurationFileFormat.ResScaleCustom;