A point in the XY plane — the input currency of every 2D builder and of the
tessellator (§7a: the 2D plane of this engine is the XY plane of the same
right-handed, Y-up space 3D lives in).
Declared here rather than beside the 3D primitives because §52's module is
the one that owns 2D geometry; primitives-3d.ts imports it for the outline
of an extrusion and the profile of a lathe.
A point in the XY plane — the input currency of every 2D builder and of the tessellator (§7a: the 2D plane of this engine is the XY plane of the same right-handed, Y-up space 3D lives in).
Declared here rather than beside the 3D primitives because §52's module is the one that owns 2D geometry;
primitives-3d.tsimports it for the outline of an extrusion and the profile of a lathe.