Class AcDbPolyline

Represents a polyline entity in AutoCAD.

A polyline is a complex geometric object composed of connected line segments and/or arc segments. Polylines can have:

  • Straight line segments
  • Bulge (arc segments) between vertices
  • Constant and variable width
  • Thickness
  • Multiple vertices

Polylines are commonly used for creating complex shapes, paths, and boundaries in drawings.

Example

// Create a polyline
const polyline = new AcDbPolyline();

// Add vertices to create a rectangle
polyline.addVertexAt(0, new AcGePoint2d(0, 0));
polyline.addVertexAt(1, new AcGePoint2d(10, 0));
polyline.addVertexAt(2, new AcGePoint2d(10, 5));
polyline.addVertexAt(3, new AcGePoint2d(0, 5));
polyline.closed = true; // Close the polyline

// Access polyline properties
console.log(`Number of vertices: ${polyline.numberOfVertices}`);
console.log(`Is closed: ${polyline.closed}`);

Hierarchy (View Summary)

Constructors

constructor

Accessors

attrs closed color database elevation geometricExtents layer lineStyle lineType linetypeScale lineWeight numberOfVertices objectId ownerId rgbColor transparency type visibility

Methods

addVertexAt close draw getAttr getAttrWithoutException getLayerColor getPoint2dAt getPoint3dAt setAttr subGetGripPoints subGetOsnapPoints transformBy triggerModifiedEvent

Constructors

constructor

Accessors

attrs

closed

  • get closed(): boolean

  • Gets whether this polyline is closed.

    A closed polyline has a segment drawn from the last vertex to the first vertex, forming a complete loop.

    Returns boolean

    True if the polyline is closed, false otherwise

    Example

    const isClosed = polyline.closed;
    console.log(`Polyline is closed: ${isClosed}`);
  • set closed(value: boolean): void

  • Sets whether this polyline is closed.

    Parameters

    • value: boolean

      True to close the polyline, false to open it

    Returns void

    Example

    polyline.closed = true; // Close the polyline

color

database

  • get database(): AcDbDatabase

  • Gets the database in which this object is resident.

    When an object isn't added to a database, this property returns the current working database. After it is added to a database, it will be set automatically. You should never set this value manually.

    Returns AcDbDatabase

    The database this object belongs to

    Example

    const db = obj.database;
  • set database(db: AcDbDatabase): void

  • Sets the database for this object.

    This is typically set automatically when the object is added to a database. Manual setting should be avoided unless you know what you're doing.

    Parameters

    Returns void

    Example

    obj.database = myDatabase;

elevation

  • get elevation(): number

  • Gets the elevation of this polyline.

    The elevation is the distance of the polyline's plane from the WCS origin along the Z-axis.

    Returns number

    The elevation value

    Example

    const elevation = polyline.elevation;
    console.log(`Polyline elevation: ${elevation}`);
  • set elevation(value: number): void

  • Sets the elevation of this polyline.

    Parameters

    • value: number

      The new elevation value

    Returns void

    Example

    polyline.elevation = 10;

geometricExtents

  • get geometricExtents(): AcGeBox3d

  • Gets the geometric extents (bounding box) of this polyline.

    Returns AcGeBox3d

    The bounding box that encompasses the entire polyline

    Example

    const extents = polyline.geometricExtents;
    console.log(`Polyline bounds: ${extents.minPoint} to ${extents.maxPoint}`);

layer

  • get layer(): string

  • Gets the name of the layer referenced by this entity.

    Returns string

    The layer name

    Example

    const layerName = entity.layer;
  • set layer(value: string): void

  • Sets the name of the layer for this entity.

    Parameters

    • value: string

      The new layer name

    Returns void

    Example

    entity.layer = 'MyLayer';

ProtectedlineStyle

  • get lineStyle(): AcGiLineStyle

  • Gets the line style for this entity.

    This method returns the line style based on the entity's linetype and other properties.

    Returns AcGiLineStyle

    The line style object

    Example

    const lineStyle = entity.lineStyle;

lineType

  • get lineType(): string

  • Gets the name of the line type referenced by this entity.

    Returns string

    The linetype name

    Example

    const lineType = entity.lineType;
  • set lineType(value: string): void

  • Sets the name of the line type for this entity.

    Parameters

    • value: string

      The new linetype name

    Returns void

    Example

    entity.lineType = 'DASHED';

linetypeScale

  • get linetypeScale(): number

  • Gets the line type scale factor of this entity.

    When an entity is first instantiated, its line type scale is initialized to an invalid value. When the entity is added to the database, if a linetype scale has not been specified for the entity, it is set to the database's current line type scale value.

    Returns number

    The linetype scale factor

    Example

    const scale = entity.linetypeScale;
  • set linetypeScale(value: number): void

  • Sets the line type scale factor for this entity.

    Parameters

    • value: number

      The new linetype scale factor

    Returns void

    Example

    entity.linetypeScale = 2.0;

lineWeight

  • get lineWeight(): number

  • Gets the line weight used by this entity.

    Returns number

    The line weight value

    Example

    const weight = entity.lineWeight;
  • set lineWeight(value: number): void

  • Sets the line weight for this entity.

    Parameters

    • value: number

      The new line weight value

    Returns void

    Example

    entity.lineWeight = 2;

numberOfVertices

  • get numberOfVertices(): number

  • Gets the number of vertices in this polyline.

    Returns number

    The number of vertices

    Example

    const vertexCount = polyline.numberOfVertices;
    console.log(`Polyline has ${vertexCount} vertices`);

objectId

  • get objectId(): string

  • Gets the object ID.

    AutoCAD uses 64-bit integers to represent handles, which exceed the maximum integer value of JavaScript. Therefore, strings are used to represent object handles.

    Returns string

    The object ID as a string

    Example

    const id = obj.objectId;
    console.log(`Object ID: ${id}`);
  • set objectId(value: string): void

  • Sets the object ID.

    Parameters

    • value: string

      The new object ID

    Returns void

    Example

    obj.objectId = 'new-object-id';

ownerId

  • get ownerId(): string

  • Gets the object ID of the owner of this object.

    Returns string

    The owner object ID

    Example

    const ownerId = obj.ownerId;
  • set ownerId(value: string): void

  • Sets the object ID of the owner of this object.

    Parameters

    • value: string

      The new owner object ID

    Returns void

    Example

    obj.ownerId = 'parent-object-id';

rgbColor

  • get rgbColor(): number

  • Gets the RGB color of this entity after converting color index.

    This method handles the conversion of color indices (including ByLayer and ByBlock) to actual RGB colors. It resolves layer colors and block colors as needed.

    Returns number

    The RGB color value as a number

    Example

    const rgbColor = entity.rgbColor;
    console.log(`RGB: ${rgbColor.toString(16)}`);

transparency

  • get transparency(): number

  • Gets the transparency level of this entity.

    Returns number

    The transparency value (0-1, where 0 is opaque and 1 is fully transparent)

    Example

    const transparency = entity.transparency;
  • set transparency(value: number): void

  • Sets the transparency level of this entity.

    Parameters

    • value: number

      The transparency value (0-1, where 0 is opaque and 1 is fully transparent)

    Returns void

    Example

    entity.transparency = 0.5; // 50% transparent

type

  • get type(): string

  • Gets the type name of this entity.

    This method returns the entity type by removing the "AcDb" prefix from the constructor name.

    Returns string

    The entity type name

    Example

    const entity = new AcDbLine();
    console.log(entity.type); // "Line"

visibility

  • get visibility(): boolean

  • Gets whether this entity is visible.

    Returns boolean

    True if the entity is visible, false otherwise

    Example

    const isVisible = entity.visibility;
  • set visibility(value: boolean): void

  • Sets whether this entity is visible.

    Parameters

    • value: boolean

      True to make the entity visible, false to hide it

    Returns void

    Example

    entity.visibility = false; // Hide the entity

Methods

addVertexAt

  • addVertexAt(
        index: number,
        pt: AcGePoint2d,
        bulge?: number,
        startWidth?: number,
        endWidth?: number,
    ): void

  • Adds a vertex to this polyline at the specified index.

    This method inserts a vertex at the specified position. If the index is 0, the vertex becomes the first vertex. If the index equals the number of vertices, the vertex becomes the last vertex. Otherwise, the vertex is inserted before the specified index.

    Parameters

    • index: number

      The index (0-based) before which to insert the vertex

    • pt: AcGePoint2d

      The vertex location point

    • bulge: number = 0

      The bulge value for the vertex (0 for straight line, >0 for arc)

    • startWidth: number = -1

      The starting width for the vertex (-1 for default)

    • endWidth: number = -1

      The ending width for the vertex (-1 for default)

    Returns void

    Example

    // Add a straight line vertex
    polyline.addVertexAt(0, new AcGePoint2d(0, 0));

    // Add a vertex with arc bulge
    polyline.addVertexAt(1, new AcGePoint2d(5, 0), 0.5);

    // Add a vertex with custom width
    polyline.addVertexAt(2, new AcGePoint2d(10, 0), 0, 2, 1);

close

  • close(): void

  • Closes the object.

    All changes made to the object since it was opened are committed to the database, and a "closed" notification is sent. This method can be overridden by subclasses to provide specific cleanup behavior.

    Returns void

    Example

    obj.close();

draw

getAttr

  • getAttr(attrName: string): any

  • Gets the value of the specified attribute.

    This method will throw an exception if the specified attribute doesn't exist. Use getAttrWithoutException() if you want to handle missing attributes gracefully.

    Parameters

    • attrName: string

      The name of the attribute to retrieve

    Returns any

    The value of the specified attribute

    Throws

    When the specified attribute doesn't exist

    Example

    try {
      const value = obj.getAttr('objectId');
    } catch (error) {
      console.error('Attribute not found');
    }

getAttrWithoutException

  • getAttrWithoutException(attrName: string): any

  • Gets the value of the specified attribute without throwing an exception.

    This method returns undefined if the specified attribute doesn't exist, making it safer for optional attributes.

    Parameters

    • attrName: string

      The name of the attribute to retrieve

    Returns any

    The value of the specified attribute, or undefined if it doesn't exist

    Example

    const value = obj.getAttrWithoutException('optionalAttribute');
    if (value !== undefined) {
      // Use the value
    }

ProtectedgetLayerColor

  • getLayerColor(): null | AcCmColor

  • Gets the color of the layer this entity belongs to.

    This method retrieves the color from the layer table for the layer this entity belongs to.

    Returns null | AcCmColor

    The layer color, or undefined if the layer doesn't exist

    Example

    const layerColor = entity.getLayerColor();

getPoint2dAt

  • getPoint2dAt(index: number): AcGePoint2d

  • Gets the 2D location of a vertex at the specified index.

    The point is returned in the polyline's own object coordinate system (OCS).

    Parameters

    • index: number

      The index (0-based) of the vertex

    Returns AcGePoint2d

    The 2D point location of the vertex

    Example

    const point2d = polyline.getPoint2dAt(0);
    console.log(`Vertex 0: ${point2d.x}, ${point2d.y}`);

getPoint3dAt

  • getPoint3dAt(index: number): AcGePoint3d

  • Gets the 3D location of a vertex at the specified index.

    The point is returned in World Coordinates, with the Z-coordinate set to the polyline's elevation.

    Parameters

    • index: number

      The index (0-based) of the vertex

    Returns AcGePoint3d

    The 3D point location of the vertex

    Example

    const point3d = polyline.getPoint3dAt(0);
    console.log(`Vertex 0: ${point3d.x}, ${point3d.y}, ${point3d.z}`);

setAttr

subGetGripPoints

  • subGetGripPoints(): AcGePoint3d[]

  • Gets the grip points for this polyline.

    Grip points are control points that can be used to modify the polyline. For a polyline, the grip points are all the vertices.

    Returns AcGePoint3d[]

    Array of grip points (all vertices)

    Example

    const gripPoints = polyline.subGetGripPoints();
    // gripPoints contains all vertices of the polyline

subGetOsnapPoints

  • subGetOsnapPoints(
        osnapMode: AcDbOsnapMode,
        gsSelectionMark: number,
        pickPoint: AcGePoint3d,
        lastPoint: AcGePoint3d,
        snapPoints: AcGePoint3d[],
    ): void

  • Gets the object snap points for this entity.

    Object snap points are the points that can be used for precise positioning when drawing or editing. This method should be overridden by subclasses to provide entity-specific snap points.

    Parameters

    Returns void

    Example

    const snapPoints: AcGePoint3d[] = [];
    entity.subGetOsnapPoints(AcDbOsnapMode.Endpoint, 0, pickPoint, lastPoint, snapPoints);

transformBy

  • transformBy(matrix: AcGeMatrix3d): this

  • Transforms this entity by the specified matrix.

    This method applies a geometric transformation to the entity. Subclasses should override this method to provide entity-specific transformation behavior.

    Parameters

    Returns this

    This entity after transformation

    Example

    const matrix = AcGeMatrix3d.translation(10, 0, 0);
    entity.transformBy(matrix);

triggerModifiedEvent

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