gizmo_math

Pure vector helpers for the transform gizmo's hit-testing and drag: the closest parameter between a ray and an axis line, ray-vs-plane intersection, grid/step snapping, the world size of one screen pixel at a given camera distance (for screen-constant handle sizing), and the rotation/scale of a point about a pivot. Every function is deterministic and takes plain { x, y, z } tables and numbers, so the gizmo's geometry is unit-tested without a running engine.