Modern examples of integrating Dear ImGui with Qt Quick.

These serve both as

• a PoC for integrating external engines (that do not render on its own but provide vertex and image data) in Qt 6,
• and as a test bed to make experimenting with ImGui and related 3rd party widgets simple and easy.

Here we use QRhi, the Qt Rendering Hardware Interface, to render. No direct OpenGL usage anymore. QRhi is a private (but exported) API in the foreseeable future, so the examples all pull in gui-private to get access to qrhi_p.h. They are expected to work identically with Vulkan, Metal, D3D11, and OpenGL, on all platforms supported by Qt

There are two demos at the moment, one targeting a QWindow (so no widgets, no QML), and one as an overlay in a Qt Quick scene. The latter saves ~600 lines of setup code because QQuickWindow takes care of all that.

When it comes to Qt Quick, this approach is different than what was taken in imgui-qtquick, an older OpenGL and Qt 5 based implementation. That one used QSGRenderNode to get a true QQuickItem, while this one is an overlay that always renders after Quick's done with recording the draw calls for the scene.

The Quick-based example needs the 'dev' branch (so Qt 6.0) of qtbase and qtdeclarative, and, at the time of writing, an additional patch on top

It also uses imnodes and ImGuiColorTextEdit with some dummy content, just for fun.

The obligatory rotating red rectangle and some text in QML, with the ImGui overlay opened on top.