Types - STEP#

API reference for ./io/step on @huukhanhnguyen/types — the option and result records of @huukhanhnguyen/io's STEP reader/writer.

See the Guide for the package's role.

API reference#

Signatures are generated from the live package .d.ts - not hand-written.

StepBrepDocument#

interface

interface StepBrepDocument

StepCurveRow#

type

The STEP writer's narrowed slice of the document curve union: the four curve kinds, without the segment trim wrapper (STEP has no window-onto-parent carrier — a trim is written as its own bounded curve).

Unit F: no kind "circle" — full circle is an arc with sweepAngle 2π.

type StepCurveRow
// = ({ type: "line"; } & LineCurve) | ({ type: "arc"; } & ArcCurve) | ({ type: "ellipse"; } & EllipseCurve) | ({ type: "nurbs"; } & NurbsCurve)

StepEntity#

interface

interface StepEntity

StepOptions#

interface

Options for the entity-level STEP door (entitiesToStep / sceneToStep, which orchestrate in @huukhanhnguyen/model — this tier writes DOCUMENTS, not entities). Same rule as every other writer: without definitions a BlockEntity resolves to nothing and writes NOTHING, never a copy left untransformed at the origin.

A placement is EXPANDED, not written as MAPPED_ITEM over a REPRESENTATION_MAP (STEP's own instancing, the entity IFC's IfcMappedItem derives from). Expansion here costs no geometry: the placement matrix goes through the kernel's exact B-rep transform, so a placed cylinder is still a CYLINDRICAL_SURFACE in the file — it costs repeated entity ROWS. MAPPED_ITEM would buy that file size back at the price of a second representation tier (one SHAPE_REPRESENTATION + REPRESENTATION_MAP per definition, plus a CARTESIAN_TRANSFORMATION_OPERATOR_3D per placement) that every reader on the other side has to support; the exact geometry — the reason this format exists here — is identical either way.

interface StepOptions

StepShellBody#

interface

interface StepShellBody

StepSurfaceRow#

type

type StepSurfaceRow
// = {
    type: "plane";
    normal: Vector;
    d: number;
    uvMin: [number, number];
    uvMax: [number, number];
}

StepWriteBody#

interface

interface StepWriteBody