optimize_polyfaces.py

# Copyright (c) 2014-2022, Manfred Moitzi
# License: MIT License
import typing
import time
import pathlib

import ezdxf
from ezdxf.entities import Polyface
from ezdxf.render import MeshVertexMerger

SRCDIR = pathlib.Path(ezdxf.EZDXF_TEST_FILES) / "CADKitSamples"
CWD = pathlib.Path("~/Desktop/Outbox").expanduser()
if not CWD.exists():
    CWD = pathlib.Path(".")

# ------------------------------------------------------------------------------
# optimize vertices of POLYFACE entities (merge coincident vertices)
#
# DXF entity docs:
# POLYFACE: https://ezdxf.mozman.at/docs/dxfentities/polyline.html#polyface
# MESH: https://ezdxf.mozman.at/docs/dxfentities/mesh.html
# ------------------------------------------------------------------------------


def optimize_polyfaces(polyfaces: typing.Iterable[Polyface]):
    count: int = 0
    runtime: float = 0
    vertex_diff: int = 0
    print("start optimizing...")
    for polyface in polyfaces:
        count += 1
        start_vertex_count = len(polyface)
        start_time = time.time()
        polyface.optimize()
        end_time = time.time()
        end_vertex_count = len(polyface)
        runtime += end_time - start_time
        vertex_diff += start_vertex_count - end_vertex_count
    print(f"removed {vertex_diff} vertices in {runtime:.2f} seconds.")


def optimize(name: str):
    filename = SRCDIR / name
    new_filename = CWD / f"optimized_{name}"
    print(f"opening DXF file: {filename}")
    start_time = time.time()
    doc = ezdxf.readfile(filename)
    msp = doc.modelspace()
    end_time = time.time()
    print(f"time for reading: {end_time - start_time:.1f} seconds")
    print(f"DXF version: {doc.dxfversion}")
    print(f"Database contains {len(doc.entitydb)} entities.")
    polyfaces = (
        typing.cast(Polyface, polyline)
        for polyline in msp.query("POLYLINE")
        if polyline.is_poly_face_mesh  # type: ignore
    )
    optimize_polyfaces(polyfaces)

    print(f"saving DXF file: {new_filename}")
    start_time = time.time()
    doc.saveas(new_filename)
    end_time = time.time()
    print(f"time for saving: {end_time - start_time:.1f} seconds")


def save_as(name: str):
    filepath = SRCDIR / name

    print(f"opening DXF file: {filepath}")
    start_time = time.time()
    doc = ezdxf.readfile(filepath)
    msp = doc.modelspace()
    end_time = time.time()
    print(f"time for reading: {end_time - start_time:.1f} seconds")
    print(f"DXF version: {doc.dxfversion}")
    print(f"Database contains {len(doc.entitydb)} entities.")
    polyfaces = (
        typing.cast(Polyface, polyline)
        for polyline in msp.query("POLYLINE")
        if polyline.is_poly_face_mesh  # type: ignore
    )

    # create a new documents
    doc1 = ezdxf.new()
    msp1 = doc1.modelspace()
    doc2 = ezdxf.new()
    msp2 = doc2.modelspace()
    for polyface in polyfaces:
        b = MeshVertexMerger.from_polyface(polyface)
        b.render_mesh(
            msp1,
            dxfattribs={
                "layer": polyface.dxf.layer,
                "color": polyface.dxf.color,
            },
        )
        b.render_polyface(
            msp2,
            dxfattribs={
                "layer": polyface.dxf.layer,
                "color": polyface.dxf.color,
            },
        )

    new_filename = CWD / f"mesh_{name}"
    print(f"saving as mesh DXF file: {new_filename}")
    start_time = time.time()
    doc1.saveas(new_filename)
    end_time = time.time()
    print(f"time for saving: {end_time - start_time:.1f} seconds")

    new_filename = CWD / f"recreated_polyface_{name}"
    print(f"saving as polyface DXF file: {new_filename}")
    start_time = time.time()
    doc2.saveas(new_filename)
    end_time = time.time()
    print(f"time for saving: {end_time - start_time:.1f} seconds")


if __name__ == "__main__":
    optimize("fanuc-430-arm.dxf")
    optimize("cnc machine.dxf")
    save_as("fanuc-430-arm.dxf")