ImageGear for C and C++ on Windows v21.0 - Updated
User Guide / File Formats and Compressions / File Formats / File Formats Reference / DWG
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    DWG
    In This Topic
    Full Name DWG (AutoDesk AutoCAD)
    Format ID IG_FORMAT_DWG = 69
    File Extension(s) *.dwg
    Data Type Vector/CAD image
    Data Encoding Binary
    Color Profile Support No
    Multi-Page Support No
    Alpha Channel Support No
    ImageGear 3D Image Support Yes
    ImageGear Raster to Vector Format Conversion Support No
    ImageGear Unicode Text Display Support Yes
    To support the DWG format, attach the ImageGear CAD/Vector DWG, DXF Component to Core ImageGear. See Attaching Components.

    ImageGear Supported Versions:

    ImageGear Supported Features:

    ImageGear Read Support:

    ImageGear Write Support:

    ImageGear Filter Control Parameters:

    Filter Control Parameter Type Default Value Available Values Description
    BACKCOLOR UINT 0 Any positive value This parameter sets view background color for image reading. If 0, black background color is set, otherwise white background color is set.
    FONTPATH LP | CHAR "" Any string up to 262 characters Defines a path to the vector font files. Format - <Path1>;< Path2>;... .
    LINEWIDTHDEF DOUBLE 0 Any positive value This parameter has been deprecated and will be removed from the public API in a future release.
    PASSWORD LP | CHAR "" Any string up to 262 characters Sets password for reading encrypted files.
    SHOWHIDDEN AT_BOOL FALSE TRUE, FALSE If TRUE, hidden layers are shown by default.
    TRUETYPE AT_BOOL FALSE TRUE, FALSE This parameter has been deprecated and will be removed from the public API in a future release.
    TTFWIDTH DOUBLE 0 Any positive value This parameter has been deprecated and will be removed from the public API in a future release.
    VERSION LP | CHAR ACAD2004 ACAD12, ACAD13, ACAD14, ACAD2000, ACAD2004, ACAD2007 Used to specify version to save the file as.
    WIDTH INT 512 Any positive value Defines the width of the empty DIB associated with the image after loading. DIB height is calculated using the file's scale factors. See Working with Vector Images.

    Comments:

    DWG, short for "DraWinG", is a CAD file format which serves as the native file format for drawings created in AutoCAD.

    DWG/DXF Elements Supported for Reading

    CAD Element

    Supported Attributes

    Imported into ImageGear as:

    VIEWPORT

    Center point

    Width

    Height

    View target

    View direction

    Frozen layers

    Non-rectangle clipping

    IG_VECT_ENT_VIEWPORT entity.

    LINE

    Start point

    End point

    Draw color

    Line type

    Line weight

    IG_VECT_ENT_EASYLINE entity.

    2D Simple polyline

    Vertices

    Draw color

    Line type

    Start width

    IG_VECT_ENT_POLYLINE entity.

    2D Quadratic spline

    Vertices

    Draw color

    Line type

    Start width

    IG_VECT_ENT_BEZIER_CURVE entity, interpolated as Bezier with degree=2.

    2D Cubic spline

    Vertices

    Draw color

    Line type

    Start width

    IG_VECT_ENT_BEZIER_CURVE entity, interpolated as Bezier with degree=3.

    2D Fit polyline

    Vertices

    Draw color

    Line type

    Start width

    IG_VECT_ENT_BEZIER_CURVE entity, interpolated as cubic B-spline.

    3D Simple polyline

    Vertices

    Draw color

    Line type

    Line weight

    IG_VECT_ENT_POLYLINE entity.

    3D Quadratic spline

    Vertices

    Draw color

    Line type

    Line weight

    IG_VECT_ENT_BEZIER_CURVE entity, interpolated as Bezier with degree=2.

    3D Cubic spline

    Vertices

    Draw color

    Line type

    Line weight

    IG_VECT_ENT_BEZIER_CURVE entity, interpolated as Bezier with degree=3.

    Polyface mesh (if contains faces)

    Draw color

    Line type

    Fill color

    Fill type

    IG_VECT_ENT_SHELL entity.

    The entity contains the result of breaking the polyface into simple objects such as vertices, edges, faces, etc.

    Polyface mesh (if does not contain faces)

    Draw color

    Line type

    Line weight

    Hidden vertices

    IG_VECT_ENT_POLYLINE entity.

    Block reference

    Scale

    Position

    Orientation

    Draw color

    Fill color

    Line type

    Fill type

    IG_VECT_ENT_INSERTION entity.

    Spline

    Knots

    Vertices (weights are supported)

    Draw color

    Line type

    IG_VECT_ENT_NURBS_CURVE entity.

    Ellipse

    Orientation

    Major axe

    Ratio

    Start angle

    End angle

    Center

    Draw color

    Line type

    Line weight

    IG_VECT_ENT_ARC entity.

    Solid

    Points [0…3]

    Draw color

    Line type

    Fill color

    Fill type

    Thickness

    IG_VECT_ENT_SOLID entity.

    Trace

    Points [0…3]

    Draw color

    Line type

    Fill color

    Fill type

    Thickness

    IG_VECT_ENT_SOLID entity.

    3D solid

    Draw color

    Line type

    Fill color

    Fill type

    IG_VECT_ENT_SHELL entity.

    The entity contains the result of breaking the polyface into simple objects such as vertices, edges, faces, etc.

    Polyline (don’t confuse with 2D polyline and 3D polyline)

    Vertices (Bulge attribute is supported)

    Draw color

    Line type

    Constant width

    IG_VECT_ENT_POLYLINE entity.

    Hatch

    Draw color

    Line type

    Fill color

    Fill type

    Gradient filling

    Hatch lines

    IG_VECT_ENT_FIGURE entity.

    Circle

    Orientation

    Center

    Radius

    Draw color

    Line type

    Line weight

    IG_VECT_ENT_ELLIPSE entity.

    Region

    Draw color

    Line type

    Fill color

    Fill type

    IG_VECT_ENT_SHELL entity.

    The entity contains the result of breaking the polyface into simple objects such as vertices, edges, faces, etc.

     

     

    MText

    Orientation

    Text color

    Location

    Font

    Font height

    Font width factor

    Underlined flag

    IG_VECT_ENT_BLOCK entitywith several IG_VECT_ENT_TEXT entities and IG_VECT_ENT_INSERT that references this block.

    Text

    Orientation

    Font

    Italic

    Weight

    Font height

    Font width factor

    Text color

    Underlined flag

    Alignment

    Position

    Alignment point

    IG_VECT_ENT_TEXT entity.

    Attribute

    Orientation

    Font

    Italic

    Weight

    Font height

    Font width factor

    Text color

    Underlined flag

    Alignment

    Position

    Alignment point

    IG_VECT_ENT_TEXT entity.

    Attribute definition

    Orientation

    Font

    Italic

    Weight

    Font height

    Font width factor

    Text color

    Underlined flag

    Alignment

    Position

    Alignment point

    IG_VECT_ENT_TEXT entity.

    Raster image

    Units

    File name

    Image size

    Image scale

    Clip boundary

    IG_VECT_ENT_RASTER entity.

    Face

    Vertices

    Draw color

    Line type

    IG_VECT_ENT_POLYLINE entity.

    Arc

    Orientation

    Center

    Start angle

    End angle

    Radius

    Draw color

    Line type

    Thickness

    IG_VECT_ENT_ARC entity.

    Dimension

    Block position

    Draw color

    Line type

    Fill color

    Fill type

    IG_VECT_ENT_INSERTION entity that references the existing block.

    Leader

    Arrow head

    Vertices

    Scale

    Arrow head size

    Reference box

    Fill color

    Fill type

    Draw color

    Line type

    IG_VECT_ENT_INSERTION and IG_VECT_ENT_BLOCK with IG_VECT_ENT_POLYLINE and IG_VECT_ENT_SOLID entities inside it.

    Tolerance

    Location

    Text

    Size of the text

    Draw color

    Line type

    Fill color

    Different shape attributes of included entities

    IG_VECT_ENT_INSERTION and IG_VECT_ENT_BLOCK with several entities inside it, such as IG_VECT_ENT_TEXT, IG_VECT_ENT_ELLIPSE, and so on.

    Block table record

    Draw color

    Line type

    Fill color

    Fill type

    IG_VECT_ENT_BLOCK entity.

    Viewport table record (don’t confuse with VIEWPORT entity)

    View name

    View content as a block

    Direction

    Target point

    Twist (angle)

    Clip distance

    Background color

    HIG_VECT_VIEW object.

    ImageGear Vector Entities Supported for Writing to DWG and DXF Formats

    ImageGear Entity or Object

    Saved as DWG/DXF Element

    IG_VECT_ENT_BLOCK

    Block table record.

    IG_VECT_ENT_INSERTION

    Block reference.

    IG_VECT_ENT_EASYLINE

    Line.

    IG_VECT_ENT_POLYLINE

    Depending on fill type and vertex count:

    • Polyline
    • Face
    • 3D Polyline
    • Hatch

      Hatch is created if non-zero fill type object is attached to the polyline and its type is one of the following:

      • IG_VECT_FP_SOLID
      • IG_VECT_FP_HATCH_BDIAGONAL
      • IG_VECT_FP_HATCH_CROSS
      • IG_VECT_FP_HATCH_DIAGCROSS
      • IG_VECT_FP_HATCH_FDIAGONAL
      • IG_VECT_FP_HATCH_HORIZONTAL
      • IG_VECT_FP_HATCH_VERTICAL
      • IG_VECT_FP_GRADIENT

    IG_VECT_ENT_POLYLINEEX

    3D polyline for every contour. If non-zero fill type object is attached to the polyline, then a Hatch is created as well.

    IG_VECT_ENT_ELLIPSE

    • If the entity contains a draw color attribute, then Ellipse object is created.
    • If the entity references a fill type, then Hatch object is created.

    IG_VECT_ENT_ARC

    • If draw color is attached to the entity, then Ellipse object is created.
    • If non-zero fill type object is attached to the entity, then Hatch object is created.

    IG_VECT_ENT_TEXT

    Several Text objects.

    IG_VECT_ENT_BEZIER_CURVE

    • If curve flag is set to IG_VECT_NURBS_MFIT, then 2D Fit polyline;
    • If Bezier degree is 2,  then 3D Quadratic spline;
    • If Bezier degree is 3, then 3D Cubic spline.

    IG_VECT_ENT_NURBS_CURVE

    Spline.

    IG_VECT_ENT_EASY_SURFACE

    Polygon mesh.

    IG_VECT_ENT_FIGURE

    • If the entity references a fill type, then hatch object is created.
    • If the entity references a line type, then internal entities are saved as Polyline objects using entity data cache.

    IG_VECT_ENT_RASTER

    Raster image (saved to a separate raster file and referenced from the DWG/DXF file). Filename must be specified for the raster entity. See IG_vect_raster_set_filename.

    IG_VECT_ENT_VIEWPORT

    Viewport (don’t confuse with Viewport table record).

    IG_VECT_ENT_SHELL

    If the entity contains only triangles and quadrilaterals then it is saved as polyface mesh. Otherwise, the entity is saved as line segments or region. 

    IG_VECT_ENT_SOLID

    Solid.

    IG_VECT_ENT_GEOMETRY

    If Fill type exists, then region; otherwise line segments.

    HIG_VECT_VIEW

    Viewport table record.