Best way to draw shapes/lines/paths on MCU?

[markrossington]

I'm doing some audio visualisation on an MCU platform.

Currently I'm managing a buffer in my back end code and just refreshing/reloading a slint image widget in a callback when I want the visualisation to change.

While this works: this isn't very performant and I'm manually doing the maths to draw, e.g. circles. So not even ergonomic either. I know my target: esp32s3 can manage better performance as I have it running in LVGL.

I was considering using an embedded-graphics wrapper around this buffer and loading that into the image. This would increase ergonomics but I don't imagine it'll increase performance.

I wondered, without Path available in Slint for MCU yet: what do people recommend for custom rendering?

Is there some overhead to loading images in this way? Are partial redraws possible?

An idea I had was a slint built in widget that supports embedded-graphics API to the area of that one widget. That way Slint could focus on optimising that pipeline and it would really open the door to custom widgets. ( If this doesn't already happen)

Thanks

[tronical]

For Path support there is #6032 . It has some requirements in terms of ram, but I think it’s a viable option for systems with enough ram. Any help finishing the PR is greatly appreciated:)