QQuickRenderControl with multiple QQuickWindow objects

[sharder]

Hello,

is it possible to have one QQuickRenderControl instance and multiple QQuickWindow objects to draw in multiple rendertargets (one for each QQuickWindow)?

I have a project, where I want QQuickWindow objects beeing drawn as a texture and use them in a OpenGL scene (they are slapped on some meshes). This works flawlessly when I have exactly one window. Having multiple QQuickRenderControl objects with the same opengl context fails. Some other developers reported the same behavior:

• http://lists.qt-project.org/pipermail/interest/2015-July/017697.html
• https://bugreports.qt.io/browse/QTBUG-52335

I could create multiple opengl contexts but it would probably create some overhead.