Class AcDbLine

Represents a line entity in AutoCAD.

A line is a 3D geometric object defined by its start point and end point. Lines are fundamental drawing entities that can be used to create straight line segments in 2D or 3D space.

Example

// Create a line from point (0,0,0) to point (10,10,0)
const line = new AcDbLine(
  new AcGePoint3d(0, 0, 0),
  new AcGePoint3d(10, 10, 0)
);

// Access line properties
console.log(`Start point: ${line.startPoint}`);
console.log(`End point: ${line.endPoint}`);
console.log(`Mid point: ${line.midPoint}`);

Hierarchy (View Summary)

Constructors

constructor

Properties

typeName

Accessors

attrs closed color database endPoint extensionDictionary geometricExtents layer lineStyle lineType linetypeScale lineWeight midPoint objectId ownerId properties rgbColor startPoint transparency type visibility

Methods

close createExtensionDictionary erase getAttr getAttrWithoutException getGeneralProperties getLayerColor getXData removeXData resolveEffectiveProperties setAttr setXData subGetGripPoints subGetOsnapPoints subWorldDraw transformBy triggerModifiedEvent worldDraw

Constructors

constructor

Properties

StatictypeName

typeName: string = 'Line'

The entity type name

Accessors

attrs

closed

  • get closed(): boolean

  • Gets whether this line is closed.

    Lines are always open entities, so this always returns false.

    Returns boolean

    Always false for lines

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;

endPoint

extensionDictionary

  • get extensionDictionary(): undefined | string

  • Gets the objectId of the extension dictionary owned by this object.

    If the object does not have an extension dictionary, this returns undefined.

    In ObjectARX terms, this is equivalent to AcDbObject::extensionDictionary().

    Returns undefined | string

    The extension dictionary objectId, or undefined

    Example

    const dictId = obj.extensionDictionary
    if (dictId) {
      console.log('Has extension dictionary:', dictId)
    }
  • set extensionDictionary(value: undefined | string): void

  • Sets the objectId of the extension dictionary owned by this object.

    This does not create or delete the dictionary object itself — it only establishes or clears the ownership relationship.

    Passing undefined removes the association.

    Parameters

    • value: undefined | string

      The extension dictionary objectId, or undefined

    Returns void

    Example

    obj.extensionDictionary = dict.objectId

geometricExtents

  • get geometricExtents(): AcGeBox3d

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

    Returns AcGeBox3d

    The bounding box that encompasses the entire line

    Example

    const extents = line.geometricExtents;
    console.log(`Line 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';

lineStyle

  • 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

midPoint

  • get midPoint(): AcGePoint3d

  • Gets the middle point of this line.

    The middle point is calculated as the midpoint between the start and end points.

    Returns AcGePoint3d

    The middle point as a 3D point

    Example

    const midPoint = line.midPoint;
    console.log(`Line midpoint: ${midPoint.x}, ${midPoint.y}, ${midPoint.z}`);

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';

properties

rgbColor

  • get rgbColor(): number

  • Gets the RGB color of this entity.

    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)}`);

startPoint

transparency

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

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();

createExtensionDictionary

  • createExtensionDictionary(): undefined | string

  • Creates the extension dictionary for this object if it does not already exist.

    This method closely mirrors the behavior of AcDbObject::createExtensionDictionary() in ObjectARX.

    • If the object already owns an extension dictionary, no new dictionary is created and the existing dictionary's objectId is returned.
    • Otherwise, a new AcDbDictionary is created, added to the same database, owned by this object, and its objectId is stored on this object.

    Returns undefined | string

    The objectId of the extension dictionary

    Example

    const dictId = obj.createExtensionDictionary()

erase

  • erase(): boolean

  • Erase the current entity from the associated database.

    Returns boolean

    — true if an entity in the database existed and has been removed, or false if the entity does not exist.

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
    }

ProtectedgetGeneralProperties

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();

getXData

  • getXData(appId: string): undefined | AcDbResultBuffer

  • Retrieves the XData associated with this object for a given application ID.

    Extended Entity Data (XData) allows applications to attach arbitrary, application-specific data to an AcDbObject. Each XData entry is identified by a registered application name (AppId) and stored as an AcDbResultBuffer.

    This method is conceptually equivalent to AcDbObject::xData() in ObjectARX, but simplified to return the entire result buffer for the specified AppId.

    Parameters

    • appId: string

      The application ID (registered AppId name) that owns the XData

    Returns undefined | AcDbResultBuffer

    The AcDbResultBuffer associated with the AppId, or undefined if no XData exists for that AppId

    Example

    const xdata = obj.getXData('MY_APP')
    if (xdata) {
      // Read values from the result buffer
    }

removeXData

  • removeXData(appId: string): void

  • Removes the XData associated with the specified application ID.

    After removal, calls to getXData() for the same AppId will return undefined. If no XData exists for the given AppId, this method has no effect.

    This mirrors the behavior of clearing XData for a specific application in ObjectARX rather than removing all XData from the object.

    Parameters

    • appId: string

      The application ID whose XData should be removed

    Returns void

    Example

    obj.removeXData('MY_APP')

resolveEffectiveProperties

  • resolveEffectiveProperties(): void

  • Resolves the effective properties of this entity.

    This method determines the final, usable values for entity properties such as layer, linetype, lineweight, color, and other display-related attributes. If a property is not explicitly set on the entity (for example, it is undefined or specified as ByLayer / ByBlock), the value is resolved according to the current AutoCAD system variables and drawing context.

    Typical system variables involved in the resolution process include, but are not limited to:

    • CLAYER – Current layer
    • CELTYPE – Current linetype
    • CELWEIGHT – Current lineweight
    • CECOLOR – Current color

    The resolution follows AutoCAD semantics:

    • Explicitly assigned entity properties take precedence
    • ByLayer properties are inherited from the entity’s layer
    • ByBlock properties are inherited from the owning block reference
    • If no explicit value can be determined, the corresponding system variable or default drawing value is used

    This method does not change user-defined property settings; it only computes and applies the final effective values used for display, selection, and downstream processing.

    Returns void

setAttr

setXData

  • setXData(resbuf: AcDbResultBuffer): void

  • Attaches or replaces XData for this object.

    If XData already exists for the given AppId, it is replaced by the provided AcDbResultBuffer. The caller is responsible for ensuring that:

    • The AppId is registered in the database's AppId table
    • The result buffer follows valid DXF/XData conventions (e.g. starts with a 1001 group code for the AppId)

    This method is conceptually similar to AcDbObject::setXData() in ObjectARX.

    Parameters

    Returns void

    Example

    const rb = new AcDbResultBuffer([
      { code: AcDbDxfCode.ExtendedDataRegAppName, value: 'MY_APP' },
      { code: AcDbDxfCode.ExtendedDataAsciiString, value: 'custom value' }
    ])

    obj.setXData('MY_APP', rb)

subGetGripPoints

  • subGetGripPoints(): AcGePoint3d[]

  • Gets the grip points for this line.

    Grip points are control points that can be used to modify the line. For a line, the grip points are the midpoint, start point, and end point.

    Returns AcGePoint3d[]

    Array of grip points (midpoint, start point, end point)

    Example

    const gripPoints = line.subGetGripPoints();
    // gripPoints contains: [midPoint, startPoint, endPoint]

subGetOsnapPoints

subWorldDraw

transformBy

  • transformBy(matrix: AcGeMatrix3d): AcDbLine

  • Transforms this line by the specified matrix.

    This method applies a geometric transformation to the line, updating both the start and end points according to the transformation matrix.

    Parameters

    Returns AcDbLine

    This line after transformation

    Example

    const translationMatrix = AcGeMatrix3d.translation(10, 0, 0);
    line.transformBy(translationMatrix);
    // Line is now translated 10 units in the X direction

triggerModifiedEvent

worldDraw

  • worldDraw(
        renderer: AcGiRenderer<AcGiEntity>,
        delay?: boolean,
    ): undefined | AcGiEntity

  • Called by cad application when it wants the entity to draw itself in WCS (World Coordinate System) and acts as a wrapper / dispatcher around subWorldDraw(). The children class should never overidde this method.

    It executes the following logic:

    • Handles traits (color, linetype, lineweight, transparency, etc.)
    • Calls subWorldDraw() to do the actual geometry output

    Parameters

    • renderer: AcGiRenderer<AcGiEntity>

      The renderer to use for drawing

    • Optionaldelay: boolean

      The flag to delay creating one rendered entity and just create one dummy entity. Renderer can delay heavy calculation operation to avoid blocking UI when this flag is true. For now, text and mtext entity supports this flag only. Other types of entities just ignore this flag.

    Returns undefined | AcGiEntity

    The rendered entity, or undefined if drawing failed

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