Solid fill of an ellipse in python dxf - python-2.7

Question

I'd like to draw filled ellipse with python. This would be easy if I could use PIL oder some other libraries. The problem is I need the ellipse in a .dxf file format. Therefore I used the dxfwrite package. This allows me to draw an ellipse but I couldn't find a way to fill it with a solid color. The following code does draw an ellipse line, but does not fill it.
import dxfwrite
from dxfwrite import DXFEngine as dxf
name = 'ellipse.dxf'
dwg = dxf.drawing(name)
dwg.add(dxf.ellipse((0,0), 5., 10., segments=200))
dwg.save()
Does anybody of you guys know a solution?

Answer 1

The HATCH entity is not supported by dxfwrite, if you use ezdxf this is the solution:
import ezdxf
dwg = ezdxf.new('AC1015') # hatch requires the DXF R2000 (AC1015) format or later
msp = dwg.modelspace() # adding entities to the model space
# important: major axis >= minor axis (ratio <= 1.) else AutoCAD crashes
msp.add_ellipse((0, 0), major_axis=(0, 10), ratio=0.5)
hatch = msp.add_hatch(color=2)
with hatch.edit_boundary() as boundary: # edit boundary path (context manager)
edge_path = boundary.add_edge_path()
# an edge path can contain line, arc, ellipse or spline elements
edge_path.add_ellipse((0, 0), major_axis_vector=(0, 10), minor_axis_length=0.5)
# upcoming ezdxf 0.7.7:
# renamed major_axis_vector to major_axis
# renamed minor_axis_length to ratio
dwg.saveas("solid_hatch_ellipse.dxf")

Answer 2

You could fill an ellipse by using a solid hatch object:
For the above example, here is a snippet from the DXF file that contains the ellipse and the hatch:
AcDbEntity
8
0
100
AcDbEllipse
10
2472.192919
20
1311.37942
30
0.0
11
171.0698134145308
21
-27.61597470964863
31
0.0
210
0.0
220
0.0
230
1.0
40
0.2928953354556341
41
0.0
42
6.283185307179586
0
HATCH
5
5A
330
2
100
AcDbEntity
8
0
100
AcDbHatch
10
0.0
20
0.0
30
0.0
210
0.0
220
0.0
230
1.0
2
SOLID
70
1
71
1
91
1
92
5
93
1
72
3
10
2472.192919357234
20
1311.379420138197
11
171.0698134145308
21
-27.61597470964863
40
0.2928953354556341
50
0.0
51
360.0
73
1
97
1
330
59
75
1
76
1
47
0.794178
98
1
10
2428.34191358924
20
1317.777876434349
450
0
451
0
460
0.0
461
0.0
452
0
462
1.0
453
2
463
0.0
63
5
421
255
463
1.0
63
2
421
16776960
470
LINEAR
1001
GradientColor1ACI
1070
5
1001
GradientColor2ACI
1070
2
1001
ACAD
1010
0.0
1020
0.0
1030
0.0
There are a lot of DXF codes involved. This is the information Autodesk provide:
Hatch group codes
Group code
Description
100
Subclass marker (AcDbHatch)
10
Elevation point (in OCS)
DXF: X value = 0; APP: 3D point (X and Y always equal 0, Z represents the elevation)
20, 30
DXF: Y and Z values of elevation point (in OCS)
Y value = 0, Z represents the elevation
210
Extrusion direction (optional; default = 0, 0, 1)
DXF: X value; APP: 3D vector
220, 230
DXF: Y and Z values of extrusion direction
2
Hatch pattern name
70
Solid fill flag (solid fill = 1; pattern fill = 0); for MPolygon, the version of MPolygon
63
For MPolygon, pattern fill color as the ACI
71
Associativity flag (associative = 1; non-associative = 0); for MPolygon, solid-fill flag (has solid fill = 1; lacks solid fill = 0)
91
Number of boundary paths (loops)
varies
Boundary path data. Repeats number of times specified by code 91. See Boundary Path Data
75
Hatch style:
0 = Hatch “odd parity” area (Normal style)
1 = Hatch outermost area only (Outer style)
2 = Hatch through entire area (Ignore style)
76
Hatch pattern type:
0 = User-defined; 1 = Predefined; 2 = Custom
52
Hatch pattern angle (pattern fill only)
41
Hatch pattern scale or spacing (pattern fill only)
73
For MPolygon, boundary annotation flag (boundary is an annotated boundary = 1; boundary is not an annotated boundary = 0)
77
Hatch pattern double flag (pattern fill only):
0 = not double; 1 = double
78
Number of pattern definition lines
varies
Pattern line data. Repeats number of times specified by code 78. See Pattern Data
47
Pixel size used to determine the density to perform various intersection and ray casting operations in hatch pattern computation for associative hatches and hatches created with the Flood method of hatching
98
Number of seed points
11
For MPolygon, offset vector
99
For MPolygon, number of degenerate boundary paths (loops), where a degenerate boundary path is a border that is ignored by the hatch
10
Seed point (in OCS)
DXF: X value; APP: 2D point (multiple entries)
20
DXF: Y value of seed point (in OCS); (multiple entries)
450
Indicates solid hatch or gradient; if solid hatch, the values for the remaining codes are ignored but must be present. Optional; if code 450 is in the file, then the following codes must be in the file: 451, 452, 453, 460, 461, 462, and 470. If code 450 is not in the file, then the following codes must not be in the file: 451, 452, 453, 460, 461, 462, and 470
0 = Solid hatch
1 = Gradient
451
Zero is reserved for future use
452
Records how colors were defined and is used only by dialog code:
0 = Two-color gradient
1 = Single-color gradient
453
Number of colors:
0 = Solid hatch
2 = Gradient
460
Rotation angle in radians for gradients (default = 0, 0)
461
Gradient definition; corresponds to the Centered option on the Gradient Tab of the Boundary Hatch and Fill dialog box. Each gradient has two definitions, shifted and unshifted. A Shift value describes the blend of the two definitions that should be used. A value of 0.0 means only the unshifted version should be used, and a value of 1.0 means that only the shifted version should be used.
462
Color tint value used by dialog code (default = 0, 0; range is 0.0 to 1.0). The color tint value is a gradient color and controls the degree of tint in the dialog when the Hatch group code 452 is set to 1.
463
Reserved for future use:
0 = First value
1 = Second value
470
String (default = LINEAR)
I hope this may be of some use to you. I apologize if I missunderstood your issue.