The boundary of each hatch object is defined by a path (or loop) that consists of one or more segments. Path segment data varies depending on the entity type (or types) that make up the path. Each path segment is defined by its own set of group codes.
Hatch boundary path data group codes 


Group code 
Description 
92 
Boundary path type flag (bit coded): 0 = Default 1 = External 2 = Polyline 4 = Derived 8 = Textbox 16 = Outermost 
varies 
Polyline boundary type data (only if boundary = polyline). See Polyline boundary data table below 
93 
Number of edges in this boundary path (only if boundary is not a polyline) 
72 
Edge type (only if boundary is not a polyline): 1 = Line 2 = Circular arc 3 = Elliptic arc 4 = Spline 
varies 
Edge type data (only if boundary is not a polyline). See appropriate Edge data table below 
97 
Number of source boundary objects 
330 
Reference to source boundary objects (multiple entries) 
Polyline boundary data group codes 


Group code 
Description 
72 
Has bulge flag 
73 
Is closed flag 
93 
Number of polyline vertices 
10 
Vertex location (in OCS) DXF: X value; APP: 2D point (multiple entries) 
20 
DXF: Y value of vertex location (in OCS) (multiple entries) 
42 
Bulge (optional, default = 0) 
Line edge data group codes 


Group code 
Description 
10 
Start point (in OCS) DXF: X value; APP: 2D point 
20 
DXF: Y value of start point (in OCS) 
11 
Endpoint (in OCS) DXF: X value; APP: 2D point 
21 
DXF: Y value of endpoint (in OCS) 
Arc edge data group codes 


Group code 
Description 
10 
Center point (in OCS) DXF: X value; APP: 2D point 
20 
DXF: Y value of center point (in OCS) 
40 
Radius 
50 
Start angle 
51 
End angle 
73 
Is counterclockwise flag 
Ellipse edge data group codes 


Group code 
Description 
10 
Center point (in OCS) DXF: X value; APP: 2D point 
20 
DXF: Y value of center point (in OCS) 
11 
Endpoint of major axis relative to center point (in OCS) DXF: X value; APP: 2D point 
21 
DXF: Y value of endpoint of major axis (in OCS) 
40 
Length of minor axis (percentage of major axis length) 
50 
Start angle 
51 
End angle 
73 
Is counterclockwise flag 
Spline edge data group codes 


Group code 
Description 
94 
Degree 
73 
Rational 
74 
Periodic 
95 
Number of knots 
96 
Number of control points 
40 
Knot values (multiple entries) 
10 
Control point (in OCS) DXF: X value; APP: 2D point 
20 
DXF: Y value of control point (in OCS) 
42 
Weights (optional, default = 1) 
97 
Number of fit data 
11 
Fit datum (in OCS) DXF: X value; APP: 2D point 
21 
DXF: Y value of fit datum (in OCS) 
12 
Start tangent DXF: X value; APP: 2D vector 
22 
DXF: Y value of start tangent (in OCS) 
13 
End tangent DXF: X value; APP: 2D vector 
23 
DXF: Y value of end tangent (in OCS) 