What is best way to implement controls that render very fast?
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Hi,
I'm considering to create our own QML controls like dials and sliders etc.
Because I want to create UIs with hundreds of dials and sliders they need to render fast. All controls may be automated and thus move in real time. So again, rendering must be fast.What is the best way to create these controls? There seem to be many ways and I'm fairly new to QML.
To name a few methods (as far as I know):
- QQuickPaintedItem (CPU based, thus probably to slow)
- QQuickItem + QSGGeometryNode
- QQuickItem + custom shaders
- QSGRenderNode / QRhi (probably overkill)
Are there any other (more suitable?) methods?
I guess best is to inherit from Control? If so, can I still use the QQuickItem + QSGGeometryNode or QQuickItem + custom shaders implementation methods for the drawing?
What is the best way to support styles? Should/can I use the QML Style system?
Is there a tutorial or demo (video) explaining how to deal with mouse control for QQuickItem + QSGGeometryNode or QQuickItem + custom shaders implementation methods?Our final app should run on Windows, Mac and preferable mobile.
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======From Gemini:
Rendering hundreds of real-time animated controls requires minimizing GPU draw calls, avoiding offscreen framebuffers, and keeping memory bandwidth low.The Best Rendering Approaches
For a large UI with real-time updates, QQuickItem + QSGGeometryNode or SDF (Signed Distance Field) Custom Shaders are the best approaches.QQuickItem + QSGGeometryNode (Recommended)
Why: You build custom vertex geometry directly on CPU/GPU buffers. Because Qt’s scene graph automatically batches nodes that share materials and textures, rendering 100+ dials/sliders can be compressed into very few draw calls.
When to use: Great for sharp, vector-like geometry (e.g., dial ticks, slider tracks, simple needles).
