Autodetect a Wayland environment and configure SDL correctly. Fixes #211

app/backend/systemproperties.cpp

@@ -1,11 +1,14 @@
 #include "systemproperties.h"
 
+#include <QGuiApplication>
+
 #include "streaming/session.h"
 #include "streaming/streamutils.h"
 
 SystemProperties::SystemProperties()
 {
     isRunningWayland = qgetenv("XDG_SESSION_TYPE") == "wayland";
+    isRunningXWayland = qgetenv("XDG_SESSION_TYPE") == "wayland" && QGuiApplication::platformName() == "xcb";
 
 #ifdef Q_OS_WIN32
     isWow64 = QSysInfo::currentCpuArchitecture() != QSysInfo::buildCpuArchitecture();

app/backend/systemproperties.h

@@ -12,6 +12,7 @@ public:
 
     Q_PROPERTY(bool hasHardwareAcceleration MEMBER hasHardwareAcceleration CONSTANT)
     Q_PROPERTY(bool isRunningWayland MEMBER isRunningWayland CONSTANT)
+    Q_PROPERTY(bool isRunningXWayland MEMBER isRunningXWayland CONSTANT)
     Q_PROPERTY(bool isWow64 MEMBER isWow64 CONSTANT)
     Q_PROPERTY(bool hasBrowser MEMBER hasBrowser CONSTANT)
     Q_PROPERTY(QString unmappedGamepads MEMBER unmappedGamepads NOTIFY unmappedGamepadsChanged)
@@ -28,6 +29,7 @@ private:
 
     bool hasHardwareAcceleration;
     bool isRunningWayland;
+    bool isRunningXWayland;
     bool isWow64;
     bool hasBrowser;
     QString unmappedGamepads;

app/gui/main.qml

@@ -138,14 +138,16 @@ ApplicationWindow {
             // onAfterRendering call and potentially reenter this code.
             initialized = true;
 
-            if (SystemProperties.isRunningWayland) {
-                waylandDialog.open()
-            }
-            else if (SystemProperties.isWow64) {
+            if (SystemProperties.isWow64) {
                 wow64Dialog.open()
             }
             else if (!SystemProperties.hasHardwareAcceleration) {
-                noHwDecoderDialog.open()
+                if (SystemProperties.isRunningXWayland) {
+                    xWaylandDialog.open()
+                }
+                else {
+                    noHwDecoderDialog.open()
+                }
             }
 
             if (SystemProperties.unmappedGamepads) {
@@ -385,9 +387,9 @@ ApplicationWindow {
     }
 
     ErrorMessageDialog {
-        id: waylandDialog
-        text: "Moonlight does not support hardware acceleration on Wayland. Continuing on Wayland may result in poor streaming performance. " +
-              "Please switch to an X session for optimal performance."
+        id: xWaylandDialog
+        text: "Hardware acceleration doesn't work on XWayland. Continuing on XWayland may result in poor streaming performance. " +
+              "Try running with QT_QPA_PLATFORM=wayland or switch to X11."
         helpText: "Click the Help button for more information."
         helpUrl: "https://github.com/moonlight-stream/moonlight-docs/wiki/Fixing-Hardware-Decoding-Problems"
     }

app/main.cpp

@@ -346,6 +346,17 @@ int main(int argc, char *argv[])
 
     QGuiApplication app(argc, argv);
 
+    // After the QGuiApplication is created, the platform stuff will be initialized
+    // and we can set the SDL video driver to match Qt.
+    if (qgetenv("XDG_SESSION_TYPE") == "wayland" && QGuiApplication::platformName() == "xcb") {
+        SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                    "Detected XWayland. This will probably break hardware decoding! Try running with QT_QPA_PLATFORM=wayland or switch to X11.");
+    }
+    else if (QGuiApplication::platformName().startsWith("wayland")) {
+        SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION, "Detected Wayland. Performance may be worse than X11.");
+        qputenv("SDL_VIDEODRIVER", "wayland");
+    }
+
 #ifdef STEAM_LINK
     // Qt 5.9 from the Steam Link SDK is not able to load any fonts
     // since the Steam Link doesn't include any of the ones it looks