FixedMathSharp v2.1.1

v2.1.1 is a hardening release focused on correctness, packaging reliability, and overall library quality.

This update adds a few small API improvements, including component-wise epsilon helpers for Vector2d and Vector3d, a convenience Fixed4x4.NormalizeRotationMatrix() extension, and a new companion package, FixedMathSharp.FluentAssertions, for reusable assertions in downstream test projects.

It also fixes several edge cases uncovered during the hardening pass: negative midpoint rounding in FixedMath.Round, clamped-dot handling in Vector3d.Slerp, FixedCurve nullability and small-array construction issues that triggered MemoryPack warnings, and incomplete hashing in Fixed4x4.GetHashCode. On the packaging side, .NET Standard 2.1 dependency handling was cleaned up and the temporary JSON shim was removed in favor of explicit System.Text.Json dependency handling.

Internally, BoundingArea.Intersects, BoundingBox.Intersects, and Vector3d.ClosestPointsOnTwoLines were refactored to reduce complexity without changing behavior, and an unreachable branch in FixedTrigonometry.Pow2 was removed. Along the way, test coverage was expanded substantially across the core math surface, and the repository now publishes coverage reports as part of the project’s documentation and release quality bar.