Metal-accelerated QPainter on macOS with MoltenGL?
The QPainter calls used for 2D drawing can be run on QOpenGLPaintDevice ( http://doc.qt.io/qt-5/qopenglpaintdevice.html ) as shown in http://doc.qt.io/qt-5/qtgui-openglwindow-example.html
I can construct a QOpenGLWidget ( http://doc.qt.io/qt-5/qopenglwidget.html ) and then possibly set the format to OpenGL ES 2.0.
The commercial MoltenGL library ( https://moltengl.com/moltengl/ ) provides a live translation of OpenGL ES 2.0 into the Apple Metal API on macOS and iOS.
So — would it be possible to use the QPainter engine with QOpenGLWidget in such a way that Qt actually “draws to MoltenGL” on macOS and then MoltenGL uses Metal to accelerate the drawing?
Since Apple is deprecating OpenGL and there is currently no Vulkan-based QPainter engine (where then MoltenVK could be used) — I think Qt widgets with QOpenGLWidget that uses OpenGL ES 2.0 and with MoltenGL could provide a sensible way forward for hardware-accelerared Qt widget rendering on the Apple platforms.
But is this easily possible?
That's something you should rather bring to the interest mailing list. You'll find the Qt's developers/maintainers. This forum is more user oriented.
Note that there's experimental support for MoltenVK on macOS planned for 5.12. You should be able to play with it using the dev branch.