@fourjs/math

Math primitives. Part of fourJS.

Implements §7 and the §7b math conventions of docs/SPECIFICATION.md; shipped in Phase 1 (§104). Mutable types with out-parameter hot paths (out? optional-allocation policy), radians everywhere, right-handed Y-up.

What's here

• Vectors — Vector2, Vector3, Vector4.
• Quaternion — with shortest-arc slerp (decision D8).
• Matrices — Matrix3 and Matrix4, including depth-range-parameterized projections (DepthRange).
• Frustum (§87) — the six clip planes of a view-projection matrix, with setFromViewProjection (both DepthRange conventions) and a conservative intersectsSphere. The one culling primitive; the world bounds it tests come from @fourjs/render.
• ColorRGBA — the shared color tuple type used by materials, animation, and particles.
• Allocation counter — constructionCount / resetConstructionCount / noteConstruction, the test hook that keeps hot paths allocation-free.

Notes

• Transform (position/rotation/scale with the dirty channel) lives in @fourjs/scene, not here.

Unit tests are colocated in tests/ per §92.

Workspace name @fourjs/math; publishes as @danielsimonjr/fourjs-math.