Default to threaded when using opengl32

This appplies only when using opengl32.dll. When using ANGLE or
when using another non-opengl32 DLL, the "windows" single-threaded
loop is chosen, just like before.

One badly written autotest is fixed. We must never assume that
performing some QQuickWindow related work will leave a context
current on the main thread. The assumption worked by accident with
the single-threaded render loop.

[ChangeLog][QtQuick] Changed to use the threaded render loop by
default on Windows when running with desktop OpenGL (opengl32.dll).

Change-Id: I21798622c19ca510a97a96c19c1e70e29f086e3a
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Jørgen Lind <jorgen.lind@theqtcompany.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/quick/scenegraph/qsgrenderloop.cpp b/src/quick/scenegraph/qsgrenderloop.cpp
index ecfbe0323c..985be8591f 100644
--- a/src/quick/scenegraph/qsgrenderloop.cpp
+++ b/src/quick/scenegraph/qsgrenderloop.cpp
@@ -169,7 +169,12 @@ QSGRenderLoop *QSGRenderLoop::instance()
             RenderLoopType loopType = BasicRenderLoop;
 
 #ifdef Q_OS_WIN
-            loopType = WindowsRenderLoop;
+            // With desktop OpenGL (opengl32.dll), use threaded. Otherwise (ANGLE) use windows.
+            if (QOpenGLContext::openGLModuleType() == QOpenGLContext::LibGL
+                && QGuiApplicationPrivate::platformIntegration()->hasCapability(QPlatformIntegration::ThreadedOpenGL))
+                loopType = ThreadedRenderLoop;
+            else
+                loopType = WindowsRenderLoop;
 #else
             if (QGuiApplicationPrivate::platformIntegration()->hasCapability(QPlatformIntegration::ThreadedOpenGL))
                 loopType = ThreadedRenderLoop;