Spike: how to keep the node icon legible at high background opacity

[kmcginnes]

Goal

Decide how a node icon should stay legible as its background opacity approaches 100%, where a solid background color currently obscures the icon (#1994). This is a prototyping spike: produce a recommendation and a rough prototype to react to, not a shipped fix.

Questions to resolve:

• Threshold approach — does switching the icon to white or black once background opacity passes a threshold read well across the range of background colors and icons? Where does the threshold sit, and how is the white-vs-black choice made (e.g. background luminance)?
• Compositing approach — can the icon be drawn above the background layer so opacity applies to the fill only, leaving the icon untouched? What does this cost in the Cytoscape node style mapping (toCyNodeStyle)?
• Separate control — is a distinct icon-opacity (or icon-color) control warranted instead of deriving behavior from background opacity?
• Interaction with the styling model — how does the chosen approach fit the direction in [Roadmap] Improved Style Options #1943 (Improved Style Options), so we do not build something the style revamp will immediately rework?

Related Issues

• Parent Node icon disappears when background opacity is set to 100% #1994 — the bug this spike scopes a fix for
• Related to [Roadmap] Improved Style Options #1943 — Improved Style Options roadmap

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Important

Internal only — this issue is maintained by the core team and is not accepting external contributions.