Converting dxf to svg

[ashisht]

I want to convert dxf into svg such that it preserves all geometry and group by layers

[mbway]

Have you read the ezdxf documentation? What have you tried so far and what problems did you encounter?

[ashisht]

elif entity.dxftype() == 'LWPOLYLINE':
        if entity.dxf.handle == '2D0':
            if entity.is_closed:
                print("Closed Polyline: ", entity.is_closed)
            if entity.has_arc:
                print("Has Arc: ", entity.has_arc)    

            print(f"LWPOLYline path_data:")  # Debugging line
            for i, point in enumerate(entity):
                print(f"Points: ", point[0], point[1], point[2], point[3], point[4])
                if point[4] != 0:
                    print(f"Bulge exists: ", point[4])



        path_data = ""
        prev_x, prev_y = None, None
        for i, point in enumerate(entity):
            x, y = point[0], point[1]
            x -= xmin
            y = invert_y(y - ymin, height)
            if i == 0:
                path_data += f"M {x},{y} "
            else:
                bulge = point[4] if len(point) > 4 else 0
                if bulge != 0:
                    # Use ezdxf.math functions to get arc parameters
                    start_point = (prev_x, prev_y)
                    end_point = (x, y)
                    center, start_angle, end_angle, radius = bulge_to_arc(start_point, end_point, bulge)
                    rotation = degrees(atan2(start_point[1] - center[1], start_point[0] - center[0]))
                    large_arc_flag = 1 if abs(degrees(end_angle - start_angle)) > 180 else 0
                    sweep_flag = 1 if (end_angle > start_angle) else 0

                    path_data += f"A {radius},{radius} {rotation} {large_arc_flag},{sweep_flag} {x},{y}"
                    #path_data += calculate_arc(prev_x, prev_y, x, y, radius, large_arc_flag, sweep_flag)
                else:
                    path_data += f"L {x},{y} "
            prev_x, prev_y = x, y

        if entity.is_closed:    
            path_data += "Z"  # Close the path

        #print(f"LWPOLYLINE path_data: {path_data}")  # Debugging line
        group.add(svgwrite.path.Path(d=path_data, stroke=stroke_color, fill='none'))

This code is not giving proper result for bulge.

[mozman]

Nobody can run this code, nobody will help you.

[mbway]

are you aware that ezdxf can export to svg using the drawing addon? https://ezdxf.readthedocs.io/en/stable/addons/drawing.html

If this addon does not suit your needs you could still take a look at how the frontend of the addon handles polylines and bulges

ezdxf/src/ezdxf/addons/drawing/frontend.py

Line 824 in 029d338

def draw_polyline_entity(self, entity: DXFGraphic, properties: Properties) -> None:

[ashisht]

I know ezdxf draw -o output.svg input.dxf but my requirement is such that I want the svg with group by layer and should maintain its geometry.
apart from this I am using ezdxf view "dxf file name" and ezdxf browse "dxf file name"
Just generating a svg is not an issue. I want to generate it using group by layers.

[mozman]

Or ... write your custom backend based on the included SVGBackend. The BackendProperties provides the required layer property:

class BackendProperties(NamedTuple):
    """The backend receives a condensed version of the entity properties."""

    color: Color = "#000000"
    lineweight: float = 0.25  # in mm
    layer: str = "0"  # maybe useful to group entities (SVG, PDF)
    pen: int = 1  # equals the ACI (1-255), for pen based backends like plotters
    handle: str = ""  # top level entity handle

    @property
    def rgb(self) -> RGB:
        """Returns color as RGB tuple."""
        return RGB.from_hex(self.color)

    @property
    def luminance(self) -> float:
        """Returns perceived color luminance in range [0, 1] from dark to light."""
        return self.rgb.luminance