An engine-neutral port of the CesiumJS 1.138 core maths gev uses: angle
maths, the WGS84 ellipsoid and geodetic coordinates, 2D/3D vectors, 3x3/4x4
matrices, quaternions and local east-north-up / heading-pitch-roll frames.
Formulas and operation order match Cesium, so outputs are bit-identical
(golden tests pin the centre, pole, -0 and quaternion branches).
- Values are plain-data instances of module-private constructors (own
enumerable fields only), so geo's hot functions keep their own V8 hidden
classes; matrices are plain column-major arrays Cesium accepts.
- Cesium's debug argument checks are ported with the same conditions, order
and DeveloperError messages, gated on DEBUG (src/geo/debug.js): on in Node
and the dev server, folded away by vite build, as Cesium's Build strips
them. A release-parity test compares DEBUG=false geo with Build/Cesium.
- The import-direction check forbids cesium and @cesium/* in src/geo;
CODE-BOUNDARIES.md and THIRD_PARTY_NOTICES.md document the port.
