autocad-com-drawing

name	autocad-com-drawing
description	Create or modify AutoCAD DWG drawings through AutoCAD COM/ActiveX on Windows. Use when Codex needs to draw model-space geometry with AutoCAD COM, especially dimensioned 2D parts such as rectangles, plates, holes, centerlines, layers, text, and linear/diameter dimensions, or when the user asks in Chinese or English to use COM to draw in AutoCAD.

AutoCAD COM Drawing

Overview

Use AutoCAD COM through Python/pywin32 for deterministic DWG creation. Prefer model space, millimeters, and explicit layers unless the user specifies otherwise.

Workflow

1. Extract the geometry, dimensions, units, layers, text, and save path from the user request. If a critical dimension is missing, ask one concise question; otherwise use sensible drafting assumptions.
2. Before drawing annotations, create a simple layout plan: reserve the main geometry, dimensions, title block, tables, and detail views as forbidden rectangles.
3. Use scripts/cad_layout.py for labels, tables, legends, and callouts whenever a drawing has many annotations. It chooses candidate positions with rectangle collision checks and reserves the accepted location.
4. For rectangular plates with circular holes, run scripts/draw_plate_with_holes.py and pass dimensions as CLI arguments.
5. For other 2D drawings, reuse the COM patterns in that script: VARIANT(VT_ARRAY | VT_R8) points, retry COM calls when AutoCAD is busy, create layers before assigning them, and validate ModelSpace.Count.
6. Save output DWG files in the current workspace unless the user gives another path.
7. Report the DWG path and a short verification summary. Do not claim success until the COM script returns entity counts or the saved DWG exists.

Annotation Conflict Avoidance

Use this rule for engineering drawings with crowded dimensions or notes:

1. Reserve fixed zones first: structure outline, dimensions, title block, tables, legends, enlarged details, and margins.
2. For each label, generate candidate boxes around its anchor: right, left, above, below, then diagonal positions.
3. Score candidates by collision count, distance from anchor, and preferred side. Pick the lowest-score conflict-free candidate.
4. If no candidate is conflict-free, move the label to an external note lane and draw a leader line.
5. Keep repeated labels sparse: do not label every identical component when numbering every 2nd or 5th item is clearer.
6. After drawing, run a bounding-box conflict report for planned labels/tables before calling the final AutoCAD save.

Implementation helper: scripts/cad_layout.py.

Plate Script

Use this for requests like "draw a 1000 x 600 rectangle with two diameter 80 holes, 250 from left and right, and add dimensions":

python "$env:USERPROFILE\.codex\skills\autocad-com-drawing\scripts\draw_plate_with_holes.py" `
  --output "C:\path\to\plate.dwg" `
  --width 1000 --height 600 `
  --hole-diameter 80 `
  --left-offset 250 --right-offset 250 `
  --title-text "1000 x 600 plate, 2-%%c80 holes"

Useful options:

• --hole-centers "250,300;750,300": explicit hole centers; overrides left/right offsets.
• --no-dimensions: draw geometry without dimensions.
• --active-document: draw into the current active DWG instead of a new drawing.
• --units mm|unitless: set AutoCAD insertion units; defaults to mm.

COM Notes

• AutoCAD COM is Windows-only and requires AutoCAD installed and accessible as AutoCAD.Application.
• If AutoCAD returns RPC_E_CALL_REJECTED, retry briefly instead of failing immediately.
• Use radians for AddDimRotated rotation.
• Use %%c for the AutoCAD diameter symbol in dimension text.
• If MCP AutoCAD tools are unavailable, continue with Python COM.