[gre]

Hi, this is @gre, I'm the author of bezier-easing, which is also embedded in this project (packages/plugin-bezier/src/bezier-utils.ts). The library was recently improved with better performance and more reliability, and I wanted to backport the benefits here.

This brings its 3.2 solver (closed-form, no sample table) to evaluate:

• Fixes steep curves. For (1, 0, 0, 1), evaluate(0.4996) returned 0.348 instead of 0.431, and the value went backwards around the middle.
• Exact. Error goes from up to ~1e-3 to ~1e-14 on regular curves.
• Faster and smaller. No table is built when a curve is created, and the file goes from 566 to 468 bytes min+gz.
• x outside [0, 1] now saturates to 0 / 1. The old search returned arbitrary values there.

Includes a patch changeset for @leva-ui/plugin-bezier. Compared against bezier-easing 3.2 on ~7.6M values: bit-identical. prettier is clean, and tsc reports no new errors.

Summary by CodeRabbit

• Bug Fixes
  • Improved Bézier curve evaluation, including on steep curves, to prevent backward jumps.
  • Inputs at or beyond the curve’s endpoints now return the corresponding endpoint values.

[changeset-bot]

🦋 Changeset detected

Latest commit: abebcc2

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@leva-ui/plugin-bezier	Patch

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ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: defaults
• Review profile: CHILL
• Plan: Advanced
• Run ID: 0e49392f-228f-46cf-9e3b-0f44bb90dd47

📥 Commits

Reviewing files that changed from the base of the PR and between 402a1e9 and abebcc2.

📒 Files selected for processing (2)

• .changeset/bezier-easing-solver.md
• packages/plugin-bezier/src/bezier-utils.ts

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📝 Walkthrough

Walkthrough

The Bézier easing function replaces its sampled-table and iterative solver with a cubic solver. It clamps inputs at the endpoints and evaluates the y polynomial for interior inputs. A patch changeset records the update.

Changes

Bézier easing evaluation

Layer / File(s)	Summary
Cubic Bézier evaluation packages/plugin-bezier/src/bezier-utils.ts, .changeset/bezier-easing-solver.md	The solver computes cubic coefficients, selects a real root, and caps the parameter at 1. The easing function returns 0 for inputs at or below 0, returns 1 for inputs at or above 1, and evaluates the y polynomial for interior inputs. The changeset records the solver update.

Priority: ⬇️ Low

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Bug fix

Merge Risk: ⚪ Minimal · up to abebc

The Bézier evaluation change appears ready to merge after normal checks; no material issue remains identified.

Architecture Summary

Architecture risk: 🟡 Medium · up to abebc

The change affects 1 system.

Changed systems: packages/plugin-bezier

Architecture concerns
No architecture-level concerns identified.

Review details

Systems and components

• observed — packages/plugin-bezier (library) was modified; 1 changed file maps to changed impact.

Before / after behavior

• observed — Modified behavior in packages/plugin-bezier/src/bezier-utils.ts: The file replaces the prior constants and helpers for sampling, Newton iteration, and binary subdivision with solveTForX, which computes a cubic root using Cardano’s method for one-real-root cases or selects the largest real root for three-real-root cases, then caps the solved parameter at 1.
• observed — Modified behavior in packages/plugin-bezier/src/bezier-utils.ts: bezier now computes x- and y-polynomial coefficients directly instead of building a sample table and selecting among Newton iteration, binary subdivision, or a zero-slope estimate. Its returned easing function now maps x <= 0 to 0 and x >= 1 to 1, then solves for t and evaluates the y polynomial for interior inputs.
• observed — Modified behavior in .changeset/bezier-easing-solver.md: Adds a patch changeset for @leva-ui/plugin-bezier with a description of the Bézier evaluation change.

Reliability and maintainability

• inferred — Risk-relevant change factors for packages/plugin-bezier: blast_radius_1; direct_dependents_1

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely identifies the main change: replacing the plugin's solver with the bezier-easing 3.2 closed-form solver.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 1…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches 💡 1

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