1 files changed, 99 insertions, 0 deletions
diff --git a/Game/Code/Classes/UAudioCore_Portaudio.pas b/Game/Code/Classes/UAudioCore_Portaudio.pas
new file mode 100644
index 00000000..952b211b
--- /dev/null
+++ b/Game/Code/Classes/UAudioCore_Portaudio.pas
@@ -0,0 +1,99 @@
+unit UAudioCore_Portaudio;
+
+interface
+
+{$IFDEF FPC}
+  {$MODE Delphi}
+{$ENDIF}
+
+{$I ../switches.inc}
+
+
+uses
+  Classes,
+  SysUtils,
+  portaudio;
+
+type
+  TAudioCore_Portaudio = class
+    public
+      class function GetPreferredApiIndex(): TPaHostApiIndex;
+  end;
+
+implementation
+
+uses
+  ULog;
+
+{*
+ * The default API used by Portaudio is the least common denominator
+ * and might lack efficiency. In addition it might not even work.
+ * We use an array named ApiPreferenceOrder with which we define the order of
+ * preferred APIs to use. The first API-type in the list is tried first.
+ * If it is not available the next one is tried and so on ...
+ * If none of the preferred APIs was found the default API (detected by
+ * portaudio) is used.
+ *
+ * Pascal does not permit zero-length static arrays, so you must use paDefaultApi
+ * as an array's only member if you do not have any preferences.
+ * You can also append paDefaultApi to a non-zero length preferences array but
+ * this is optional because the default API is always used as a fallback.
+ *}
+const
+  paDefaultApi = -1;
+const
+  ApiPreferenceOrder:
+{$IF Defined(MSWINDOWS)}
+    // Note1: Portmixer has no mixer support for paASIO and paWASAPI at the moment
+    // Note2: Windows Default-API is MME, but DirectSound is faster
+    array[0..0] of TPaHostApiTypeId = ( paDirectSound );
+{$ELSEIF Defined(LINUX)}
+    // Note: Portmixer has no mixer support for JACK at the moment
+    array[0..2] of TPaHostApiTypeId = ( paALSA, paJACK, paOSS );
+{$ELSEIF Defined(DARWIN)}
+    array[0..0] of TPaHostApiTypeId = ( paDefaultApi ); // paCoreAudio
+{$ELSE}
+    array[0..0] of TPaHostApiTypeId = ( paDefaultApi );
+{$IFEND}
+
+
+{ TAudioInput_Portaudio }
+
+class function TAudioCore_Portaudio.GetPreferredApiIndex(): TPaHostApiIndex;
+var
+  i: integer;
+  apiIndex: TPaHostApiIndex;
+  apiInfo:  PPaHostApiInfo;
+begin
+  result := -1;
+
+  // select preferred sound-API
+  for i:= 0 to High(ApiPreferenceOrder) do
+  begin
+    if(ApiPreferenceOrder[i] <> paDefaultApi) then
+    begin
+      // check if API is available
+      apiIndex := Pa_HostApiTypeIdToHostApiIndex(ApiPreferenceOrder[i]);
+      if(apiIndex >= 0) then
+      begin
+        // we found an API but we must check if it works
+        // (on linux portaudio might detect OSS but does not provide
+        // any devices if ALSA is enabled)
+        apiInfo := Pa_GetHostApiInfo(apiIndex);
+        if (apiInfo^.deviceCount > 0) then
+        begin
+          Result := apiIndex;
+          break;
+        end;
+      end;
+    end;
+  end;
+
+  // None of the preferred APIs is available -> use default
+  if(result < 0) then
+  begin
+    result := Pa_GetDefaultHostApi();
+  end;
+end;
+
+end.