Skip to content

Changelog

Unreleased

Native DWG writer

  • HATCH writing (add_hatch): polyline or edge boundary paths, solid and pattern fills with built-in or acad.pat definitions.
  • DIMENSION writing for all seven kinds with a Standard DIMSTYLE and a rendered anonymous block; helpers add_linear_dim, add_aligned_dim, add_radius_dim, add_diameter_dim, add_angular_dim, add_ordinate_dim.
  • IMAGE writing with Drawing.image_defs/add_image, the raster classes and dictionary entries; the reader decodes IMAGE entities and their IMAGEDEF.
  • true_color on entities and layers is rounded to the nearest ACI and reported as approximated (informational in strict mode).
  • The header DIMDSEP is now ..

Added

  • Layouts. Document.layouts() returns the layout table: the model tab and the paper-space sheets with their name, tab order, block record, paper size, margins, units and rotation. It marks the sheet that was current when the file was saved: the entities of that sheet are the ones stored without an owner handle (entity_placement() gives (1, None)), the entities of every other sheet name their block record. The raw function is decode_layout_objects. Every version is covered, R14 files that carry layout objects included; the layouts of the ACadSharp sample drawing read the same from all seven saves and match its DXF export. In 483 real-world drawings, 1,479 of 1,481 layout objects decode, and the current sheet is identified in 472 of the 476 drawings that have layouts.
  • Paper-space viewports. A VIEWPORT entity carries its window on the sheet (center, width, height) and, from R2000 on, what it shows (view_center, view_height, view_target, view_direction, view_twist_angle), its status_flags, the layers that are frozen in it (frozen_layers, frozen_layer_handles) and its clip boundary. The raw function is decode_viewport_details. Until now a viewport had a handle, a layer and a color only. R13/R14 keep the view in the extended data of the entity, which is not read: their viewports have a window but no view. The viewports of the ACadSharp sample drawing match its DXF export in every version, and all 1,716 viewports of the real-world drawings decode.
  • R13/R14 (AC1012, AC1014) decode POLYLINE_3D, POLYLINE_MESH, POLYLINE_PFACE and their vertices and faces. The 3D polyline and the polyface mesh of the R14 save of the ACadSharp sample drawing decode to the same values as in its R2004 save, and the 82 3D polylines of the real-world R13/R14 drawings have their vertices.
  • Layer state and lineweights. Document.layers() reports off, frozen, locked, plot and lineweight for every layer, and every entity carries lineweight and invisible in Entity.dxf. The raw functions are decode_layer_states and decode_entity_lineweights. Lineweights use the values of DXF group 370 (hundredths of a millimetre, -1 BYLAYER, -2 BYBLOCK, -3 default). Checked against DXF exports of the same drawings: the state and lineweight of 1,659 layers and the lineweight and visibility of 34,444 entities agree. R13/R14 files have neither lineweights nor a plot flag.
  • R13/R14 (AC1012, AC1014) decode INSERT, MINSERT, MTEXT, HATCH, SOLID, TRACE, 3DFACE, SPLINE, ATTRIB, ATTDEF, LEADER, TOLERANCE, MLINE, SHAPE and every DIMENSION type, with the layouts these versions have (plain doubles where R2000 introduced flagged and compressed forms, no fields that later versions added). They also report where each entity lives (Document.entity_placement()), the names of their blocks, and the dimension style and anonymous block of a dimension. Until now such a file yielded lines, arcs, circles, ellipses, points, lightweight polylines and single-line text only, all of them in model space, and dimensions without any of their points. The R14 save of the ACadSharp sample drawing decodes to the same values as its R2004 save for all of these types.
  • Dimension style sizes: Document.dimstyles() (dimscale, dimtxt, dimasz by style name) and the raw function decode_dimstyles.
  • Linetypes. Document.linetypes() returns the linetype table (name, description and dash pattern), Document.layers() the layer table with each layer's linetype, and every entity carries linetype, linetype_handle and linetype_scale in Entity.dxf. The raw functions are decode_linetypes, decode_layer_linetypes and decode_entity_linetypes. All versions from R13 to R2018 are covered; checked against DXF exports of the same drawings (linetype patterns, layer linetypes and entity linetypes of every standard entity type agree).
  • HATCH pattern definitions: pattern_angle, pattern_scale, pattern_double and pattern_lines (angle, base point, offset and dashes of each family of pattern lines) in Entity.dxf of pattern-filled hatches, and the decode_hatch_patterns raw function.
  • Added ezdwg plot to display model-space drawings or save PNG, SVG, and PDF files, with entity filtering, image resolution, and title options. Requires the optional plot extra; file output works without a display. Falls back to an SVG preview in the browser when no interactive matplotlib backend is available.
  • Added ezdwg.clear_decode_caches() so long-running batch converters can release per-file decoded tables and entity metadata after finishing a DWG.
  • Header-variables decoding across AC1015-AC1032: Document.header_variables() ($INSUNITS, $LUNITS/$LUPREC, $AUNITS/$AUPREC, $LTSCALE, $TEXTSIZE, model-space $EXTMIN/$EXTMAX/$LIMMIN/$LIMMAX) plus the Document.units / Document.insunits conveniences and the decode_header_variables raw function. R14 has no $INSUNITS and yields None values. Validated against paired DXF headers for every supported version family.
  • Bundled the MIT LICENSE file in wheels (License-Expression metadata via PEP 639 license / license-files in pyproject.toml).
  • Completed high-level coordinate extraction and API documentation for INSERT/MINSERT, HATCH, and SPLINE.
  • Added fixture-backed high-level INSERT regression coverage for block name and transform metadata.
  • Native AC1021 (R2007) read path in the high-level API (ezdwg.read) without compatibility conversion.
  • Native AC1024 (R2010) read path in the high-level API (ezdwg.read) for LINE, ARC, and LWPOLYLINE.
  • Native AC1027 (R2013) read path in the high-level API (ezdwg.read) for LINE, ARC, and LWPOLYLINE.
  • AC1021 regression suite covering:
  • Rust object/entity decode checks for LINE, ARC, LWPOLYLINE.
  • Python high-level and raw API checks with paired sample files.
  • CLI inspect verification for native decode_version: AC1021.
  • AC1024 regression suite covering high-level and raw geometry checks against paired DXF samples for:
  • LINE
  • ARC
  • LWPOLYLINE
  • AC1027 regression suite covering high-level and raw geometry checks against paired DXF samples for:
  • LINE
  • ARC
  • LWPOLYLINE
  • R2007+/R2010+/R2013+ regression coverage for:
  • POINT
  • CIRCLE
  • ELLIPSE
  • TEXT/MTEXT regression coverage for R2000/R2004 sample pairs.

Changed

  • Centralized the Rust and Python release version in the root Cargo.toml, with uv run scripts/bump_version.py <version> to refresh locks and CI checks for version/tag mismatches.
  • Removed the external DWG compatibility-conversion path from ezdwg.read; AC10xx versions in scope now use native decode paths.
  • R2007/R2010/R2013 entity decoding now uses version-aware common header paths for:
  • LINE
  • ARC
  • LWPOLYLINE
  • POINT
  • CIRCLE
  • ELLIPSE
  • TEXT
  • MTEXT
  • DIMENSION (linear/radius/diameter) to account for material flags, shadow flags, R2010 visual-style bits, and the R2013+ ds-binary-data flag.

Fixed

  • A spline-fit 3D polyline is returned along its fitted vertices (decode_polyline_3d_with_vertices, POLYLINE_3D points). The control points of its frame, which the file stores in front of them, used to be part of the path.
  • The members of a polyline in an R13-R2000 file (vertex_handles, face_handles, seqend_handle, and the owner_handle of its vertices) are resolved from the vertices that follow it. These versions list no owned objects, and the members stayed empty.
  • TEXT and MTEXT of R2007 and later are read from where the format keeps them. These versions store every string of an object in its string stream, but the decoders looked for the text in the data stream and settled on the most plausible candidate. In drawings compared against an exact read, 373 of 6,665 TEXT entities came out with another text or justification (two-digit numbers read as other characters, a middle-aligned text reported as baseline) and 286 of 2,572 MTEXT entities with another text. The search only remains as a fallback for records that do not have the specified layout.
  • ATTRIB and ATTDEF of R2007 and later were almost never decoded: 0 of 57 attributes in R2007 drawings, 0 of 159 in R2010, 7 of 2,986 in R2013 and 0 of 1,510 in R2018. They are read with their specified layout now (text, tag and prompt from the string stream, the attribute fields from the end of the data stream), including the multi-line attributes of R2018, whose text comes without formatting codes. All but 3 of those attributes decode.
  • ATTDEF of R2000 and R2004: the prompt was empty and a definition with an empty default value lost its tag and flags (so a constant definition was not recognizable). These versions have no lock position flag; reading one shifted the prompt by a bit.
  • R2010+ entities with a saved graphic of 256 bytes or more: the size of the graphic (a BLL) was assembled with its bytes in the wrong order, so the common entity data was looked for at a shifted position. Such entities (multileaders, tables, entities of add-on applications) reported a wrong lineweight, visibility, linetype or layer.
  • Layer names of R2010+ files: a layer whose color comes from a color book was named after the book. The name is the first string of the string stream.
  • TOLERANCE was not decoded in any version: two fields that only R13/R14 store were read from every file, and R2007+ keep the text in the string stream. Later versions take the text height from the dimension style, and so does Entity.dxf["height"] when the entity stores none (the raw rows keep the stored value, 0).
  • Dimension text overrides of R2007 and later (text) were always empty; they are read from the string stream.
  • INSERT and MINSERT of R2000: the count of owned attributes only exists from R2004 on. Reading it shifted the array counts of a MINSERT with attributes.
  • R13/R14 POINT entities could come out at a wrong location (the layout was searched for instead of read), and R13/R14 POLYLINE_2D read its thickness and extrusion in the R2000 form, which shifted the elevation.
  • Lineweight index 28 is BYLAYER, like 29. Some writers store it for every entity.
  • R2000 (AC1015) entities lost their layer: the common entity data was read with the R2004 meaning of one flag bit ("XDic Missing Flag", which R2000 does not have; the bit is "Nolinks" there), so the xdictionary handle was taken for the layer handle and about 95% of the entities reported layer handle 0. The layer, linetype and plotstyle handles of R2000 entities are now read from their real position, including entities that store previous/next links.
  • Layer names were empty for R13, R14, R2000 and R2007 files, and layer colors and block names were unreadable for R2000: the table records of these versions are now read with their own layout (no "XDic Missing Flag" before R2004, the object size after the EED in R13/R14, names in the string stream in R2007).
  • The layer handle of every entity now comes from the common entity data. The type-specific decoders reported a wrong layer for some INSERT, POLYLINE, DIMENSION and POINT entities (about 4% of the entities in drawings compared against their DXF export).
  • DIMENSION entities lost their saved graphics in R2000, R2004 and R2007 files: the dimension style and the anonymous block were read before the common entity handles instead of after them, so anonymous_block_handle, anonymous_block_name and the block-derived char_height never resolved. R2010+ files relied on a scan of the handle stream that missed some dimensions and could pick an arrowhead block for a dimension that has no block. Both handles are now read from their place in the handle stream (the block lines of all 485 dimensions compared against DXF exports of the same drawings agree); the scan only remains as a fallback.
  • Block names of R2010+ files: the name is now read from the string stream before the record data in front of it. That data was read with a layout these versions do not have, and when the read failed the name was left to a scan that only accepts ASCII names. Block headers named with Japanese characters only could come out unnamed (3 to 18 per drawing in the R2018 drawings compared against their DXF export), and two anonymous blocks could get the same number (*D3 twice). Every block header of those drawings is named now, and anonymous blocks are numbered once, in handle order.
  • Entities with a color book color (ENC flag 0x4000) were misread: no RGB value follows the flags for them, and the color handle precedes the layer handle in the handle stream.
  • R13/R14 entities with previous/next links: the links follow the layer and linetype handles in these versions.
  • The R2000 writer stores the xdictionary handle that the format requires, so other readers find the layer handle where they expect it.
  • Improve plot readability with smaller point markers, faint crosses for block references, thinner geometry and dimension strokes, light-background color contrast, and rectangular view bounds. The CLI hides coordinate axes and uses a larger canvas. Dimension ticks/overshoot use text height rather than measured length, and labels honor their attachment point.
  • Plot text in drawing units instead of treating DWG text heights as matplotlib point sizes. Text now scales with geometry across zoom levels, figure sizes, and output DPI; automatic view bounds include the text outlines.
  • Use saved anonymous-block text heights for dimensions where available, instead of sizing dimension labels as a percentage of their measured length. The high-level DIMENSION entity exposes resolved char_height and its source.

  • R2007 (AC1021) data pages: the Reed-Solomon block count is now derived from the compressed size padded to the 8-byte CRC block (ODA 5.4). A bare ceil(compressed / 251) was one block short whenever that padding crossed a 251-byte boundary, so the de-interleave stride was wrong and decompression failed with "back-reference offset exceeds decompressed prefix" (seen on the AcDb:Handles section of real files). A page-size based stride is tried as a fallback before giving up.

  • HATCH on R2007+ (AC1021+): the pattern/gradient names live in the object's string stream and consume no bits in the data stream. The decoder used to read them inline, which shifted every following field; most R2007+ hatches only survived through the polyline-scan fallback and some produced empty boundaries. Candidate scoring now penalizes empty/degenerate paths and a zero extrusion, so a misaligned candidate can no longer outrank the real one.

  • HATCH spline boundary edges (edge type 4, including the R2010+ fit-point block) are decoded and sampled instead of failing the entity.

  • DIMENSION on R2007 (AC1021) now tries the string-stream layout first (no version byte, user text not in the data stream) — the same class of bug as the HATCH one; the R2000-style inline-text variants remain a fallback. Real R2007 drawings no longer yield dimensions with absurd/non-planar values.

  • DIMENSION plausibility scoring now penalizes garbage magnitudes (0 < |v| < 1e-30, the signature of doubles read at the wrong bit offset) and the R2000/R2004 spec layout is tried first, so a mis-aligned candidate can no longer win a tie against the correct one (real AC1018 files had 31/108 dimensions with unit-vector-like definition points and spurious Z values).
  • DIAMETER/RADIUS dimensions on R2000-R2007 decode their own specific data (15-pt / 10-pt / leader length) instead of being delegated to the LINEAR layout.
  • ANG2LN / ANG3PT / ALIGNED / ORDINATE dimensions decode their own type-specific tail (ODA 20.4.23-20.4.27: ANG2LN 2RD 16-pt, 3BD 13/14/15/10, ANG3PT 3BD 10/13/14/15, ALIGNED without the dimension rotation, ORDINATE 3BD 10/13/14, RC flags) instead of the LINEAR tail. With the LINEAR tail every point after the 12-pt was read at the wrong bit offset (for ANG2LN the leading 16 raw bytes of the 16-pt shifted everything), the candidate was rejected as implausible and the entity surfaced as an all-zero placeholder row. Verified against the paired ACadSharp DXF samples for AC1015-AC1032.
  • Dimension rows gained a 12th element (point15, point16) — DXF codes 15/16 (angular vertex / second line start, and the 2-line angular arc point; RADIUS/DIAMETER expose their 15-pt there too). The high-level document maps them to defpoint4 / defpoint5; the first 11 elements are unchanged.
  • R13 (AC1012) files are accepted and decoded through the R13/R14 path.
  • The R13/R14 common entity header is parsed with the ODA layout first (RL bitsize, BB entmode, BL numreactors, B isbylayerlt, B nolinks, BS color, BD ltscale, BS invisibility — no xdictionary flag, no ltype/plotstyle flag pair, no lineweight byte); the previous guessed layouts remain as fallbacks. Real R13 drawings that decoded to garbage coordinates now decode cleanly.

Notes

  • This release keeps API signatures stable (ezdwg.read, ezdwg.raw, entity decode functions).
  • ARC angles remain radians in ezdwg.raw and degrees in the high-level API.
  • AC1021/AC1024/AC1027 style-handle and layer-color resolution for LINE/ARC/LWPOLYLINE is currently best-effort on some files.