https://github.com/yanone/speedpunk/

1. How would this look?

It would not be a single indicator but a lightweight overlay directly on the curve.

The idea is a combination of:

• A color-based curvature heatmap along the path (low - high curvature)
• Optional curvature comb lines, mainly emphasized around problem areas
• Small visual highlights where curvature changes abruptly (spikes / G2 breaks)

So instead of showing full technical data everywhere, it highlights where attention is needed.

2. Would this be a separate tool?

No, I think it should work as a toggleable overlay, not a separate tool.

For example:
View --- Curvature Overlay (on/off)

This allows users to enable it during editing without interrupting the workflow.

Auto Smooth / Harmonization would be a separate action:

• Applied to selected nodes or segments
• Redistributes curvature more evenly
• Preserves the overall shape while improving flow

The goal is to make curvature issues immediately visible and easy to correct during normal editing.

For reference, here is a quick example of how curvature visualization works in practice (around 2:50)

https://www.youtube.com/watch?v=LtyQ3r_S740

From what I found, a similar feature was requested in Affinity Designer a few years ago

https://forum.affinity.serif.com/index.php?/topic/55085-show-curvature-combs-on-bezier-paths/

G2 at nodes makes connections look smooth, but it doesn’t show how the curve behaves in between.

With a visual overlay like this, you can actually see where the curve tightens or breaks flow, and adjust it until the whole curve feels balanced.

What I had in mind is a way to visualize how the curve “flows” where curvature increases, tightens, or changes abruptly.

As a first step, even adding G2 continuity at nodes would already be very helpful.
But in the longer termm a visual curvature feedback system like this could make curve editing much more precise and intuitive.

In Glyphs, this kind of functionality exists as a plugin rather than a built-in feature.

Thank you for taking the time.

1. how would this look? is this an indicator? some visual examples would help. (G2 continuity at nodes can be easily added, but I sense that this is more).

2)would this be a separate tool?