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.venv/lib/python3.12/site-packages/ezdxf/addons/gerber_D6673.py

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+# Copyright (c) 2022, Manfred Moitzi
+# License: MIT License
+# This add-on was created to solve this problem: https://github.com/mozman/ezdxf/discussions/789
+from __future__ import annotations
+from typing import TextIO
+import os
+import io
+
+import ezdxf
+from ezdxf.document import Drawing
+from ezdxf.layouts import Modelspace
+from ezdxf.lldxf.tagwriter import TagWriter, AbstractTagWriter
+
+__all__ = ["export_file", "export_stream"]
+
+
+def export_file(doc: Drawing, filename: str | os.PathLike) -> None:
+    """Exports the specified DXF R12 document, which should contain content conforming
+    to the ASTM-D6673-10 standard, in a special way so that Gerber Technology applications
+    can parse it by their low-quality DXF parser.
+    """
+    fp = io.open(filename, mode="wt", encoding="ascii", errors="dxfreplace")
+    export_stream(doc, fp)
+
+
+def export_stream(doc: Drawing, stream: TextIO) -> None:
+    """Exports the specified DXF R12 document into a `stream` object."""
+
+    if doc.dxfversion != ezdxf.const.DXF12:
+        raise ezdxf.DXFVersionError("only DXF R12 format is supported")
+    tagwriter = TagWriter(stream, write_handles=False, dxfversion=ezdxf.const.DXF12)
+    _export_sections(doc, tagwriter)
+
+
+def _export_sections(doc: Drawing, tagwriter: AbstractTagWriter) -> None:
+    _export_header(tagwriter)
+    _export_blocks(doc, tagwriter)
+    _export_entities(doc.modelspace(), tagwriter)
+
+
+def _export_header(tagwriter: AbstractTagWriter) -> None:
+    # export empty header section
+    tagwriter.write_str("  0\nSECTION\n  2\nHEADER\n")
+    tagwriter.write_tag2(0, "ENDSEC")
+
+
+def _export_blocks(doc: Drawing, tagwriter: AbstractTagWriter) -> None:
+    # This is the important part:
+    #
+    # Gerber Technology applications have a bad DXF parser which do not accept DXF
+    # files that contain blocks without ASTM-D6673-10 content, such as the standard
+    # $MODEL_SPACE and $PAPER_SPACE block definitions.
+    #
+    # This is annoying but the presence of these blocks is NOT mandatory for
+    # the DXF R12 standard.
+    #
+    tagwriter.write_str("  0\nSECTION\n  2\nBLOCKS\n")
+    for block_record in doc.block_records:
+        # export only BLOCK definitions, ignore LAYOUT definition blocks
+        if block_record.is_block_layout:
+            block_record.export_block_definition(tagwriter)
+    tagwriter.write_tag2(0, "ENDSEC")
+
+
+def _export_entities(msp: Modelspace, tagwriter: AbstractTagWriter) -> None:
+    tagwriter.write_str("  0\nSECTION\n  2\nENTITIES\n")
+    msp.entity_space.export_dxf(tagwriter)
+    tagwriter.write_tag2(0, "ENDSEC")
+    tagwriter.write_tag2(0, "EOF")