Research usage of custom shapes for markers

[thinkh]

Plotly allows to add arbitrary D3 shapes. We could use this to create and inject our markers.

Requirements

• Markers must be rendered above brush selections
• Markers must be clickable

Ask Thomas

Library support

• [x] Plotly (works with d3)
• [x] Vega-Lite (works with d3)
• [x] ECharts (works very well with "graphic" from the ECharts library)

[thinkh]

Maybe we can also use/enhance https://plotly.com/javascript/text-and-annotations/