Reduced lag when hardware acceleration is turned on

This essentially disabled vsync, though with composited window managers
there should not be visible tearing anyway. It does seem to affect
animation timing as well though, which affects scrolling with arrow keys.

Related to issue mapeditor#3584

src/tiledapp/main.cpp

@@ -22,16 +22,15 @@
 
 #include "commandlineparser.h"
 #include "exporthelper.h"
-#include "languagemanager.h"
 #include "logginginterface.h"
 #include "mainwindow.h"
-#include "mapdocument.h"
 #include "mapformat.h"
-#include "mapreader.h"
 #include "pluginmanager.h"
 #include "preferences.h"
 #include "scriptmanager.h"
+#ifdef TILED_SENTRY
 #include "sentryhelper.h"
+#endif
 #include "tiledapplication.h"
 #include "tileset.h"
 #include "tmxmapformat.h"
@@ -40,6 +39,7 @@
 #include <QFileInfo>
 #include <QJsonArray>
 #include <QJsonDocument>
+#include <QSurfaceFormat>
 #include <QtPlugin>
 
 #include "qtcompat_p.h"
@@ -571,6 +571,11 @@ int main(int argc, char *argv[])
 
     Session::initialize();
 
+    // Disable vsync to make hardware accelerated mode more responsive
+    QSurfaceFormat format;
+    format.setSwapInterval(0);
+    QSurfaceFormat::setDefaultFormat(format);
+
     MainWindow w;
     w.show();