[Kunal241207]

Resolves #9236

Changes:

• Add accessibility output support for bezier() and spline().
• Calculate approximate position and area for curves in textOutput() and gridOutput().
• Respect spline ends and tightness properties when generating accessibility output.
• Use the fill color and calculated area for filled curves, and stroke color with zero area for stroked curves.
• Calculate the centroid of the filled curve region for a more accurate position.
• Add unit tests covering bezier/spline output, spline ends and tightness, and noFill() behavior.

Screenshots of the change:
Not applicable — this change affects generated accessibility output rather than the visual canvas.

PR Checklist

• npm run lint passes
• Inline reference is included / updated
• Unit tests are included / updated

[p5-bot]

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Commit hash: 91fdd32

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[perminder-17]

Thanks for working on this, @Kunal241207! I had a look at the diff and it seems quite large (550+ lines) for the scope of #9236. I'd have expected mostly a call to _accsOutput() from bezier()/spline()?

Could you help me understand what's driving the size?

If there's a way to make it smaller?

[bhabishnu]

Hey @Kunal241207, I found a few things while testing the current branch that seem worth looking at.

• splineProperty('ends') isn't reflected correctly. INCLUDE and EXCLUDE give the same accessibility output for the same spline even though the rendered shapes are very different. There are two parts to it: ends is compared to the string 'INCLUDE' even though it's a Symbol, and the sampled control points don't match the renderer. Fixing only the first still leaves EXCLUDE wrong.

• Filled bezier area changes when the same curve is moved. One case reports 7%, then 14% after shifting the same curve 50px right, even though the painted area is unchanged. It looks like the sampled polygon isn't being closed before the shoelace calculation.

• I also found a fully visible filled spline whose calculated centroid ends up off canvas. With gridOutput() that reaches an older negative-index bug and stops the sketch. The grid bug itself predates this PR.

On the size question, quite a bit of the new sampling logic seems to overlap with existing bezierPoint() / splinePoint() and spline machinery, so I think there may be room to simplify this quite a bit.

Would be interested in your take on that too, @perminder-17.

[Kunal241207]

Thanks for the reviews and great catches @perminder-17 @bhabishnu!

Most of the original diff was test boilerplate and custom math. I've simplified it quite a bit:

• Deduplication & size: Dropped the custom Bernstein and Catmull-Rom conversion logic in favor of existing this.bezierPoint() and this.splinePoint(), and trimmed duplicate test cases.
• splineProperty('ends'): Now compared against constants.EXCLUDE, and samples just the P1 → P2 span to match the renderer.
• Shoelace closure: Closed the polygon loop in _polygonArea() so translated curves keep their expected area.
• Centroid & grid crash: Switched curve centers to the average of sampled points to prevent self-crossing curves from flying off-canvas, and added >= 0 guards in gridOutput.js so negative coordinates don't break grid indexing.

All tests and lint checks are passing now!