Other selection shapes

[PeterC-DLS]

We required shapes other than lines or rectangles to overlay plots. Circular sectors are often used in powder diffraction images to select areas to be integrated.

Would using d3-shape be okay in introducing an additional dependency?

[axelboc]

With v7, we introduce SvgElement, which allows rendering any SVG elements you want on top of the canvas. The release notes include an example for this feature: https://github.com/silx-kit/h5web/releases/tag/v7.0.0. SvgRect and SvgLine are just for convenience; you are free to render SVG elements directly, like path, circle, g, etc. with any event listeners you like for interaction purposes.

In one of our applications, Braggy, we've actually implemented a line+circle profile selection feature. We've added a little SvgCircle component for convenience, but its implementation is very trivial: https://gitlab.esrf.fr/ui/h5web-braggy/-/blob/main/src/imageview/profile/ProfileSelectionTool.tsx#L47

So basically what I'm saying is: use SVG directly and build your own abstractions when you need them. Later on, if you think some of your abstractions can benefit other consumers of @h5web/lib, let us know and we'll consider bringing them in. We'll probably bring in that SvgCircle component from Braggy, for instance.

That being said, you may want to look at visx. We use this library for rendering SVG axes and such. It provides a number of packages such as @visx/shape or @visx/drag that you may find useful to build more complex SVG-based features (like for #1363).