Processing WIF Weaving Drafts

1. Parse WIF file sections (INI-style: [WIF], [CONTENTS], [THREADING], [TIEUP], [TREADLING], [LIFTPLAN]?, [WARP], [WEFT], [COLOR TABLE])
2. Run mechanical validation → structured report (pass/fail + issue list)
3. Run provenance validation → structured report (metadata completeness)
4. Compute drawdown from threading + tie-up + treadling/liftplan
5. Render 4-panel draft chart + color-accurate preview
6. Package into print-ready PDF with repeat count, sett, yardage

Output validation as a structured report, not a thrown exception:

JSON
{
  "status": "fail",
  "errors": [
    {"code": "TREADLE_OUT_OF_RANGE", "section": "TIEUP", "detail": "Treadle 9 referenced but Treadles=8", "severity": "blocking"}
  ],
  "warnings": [
    {"code": "MISSING_PROVENANCE", "detail": "No [TEXT] author field found", "severity": "advisory"}
  ]
}

Use severity: blocking to halt rendering; advisory issues can pass through with a flag in the final PDF appendix.

Progress:

• Step 1: Parse all WIF sections into structured data
• Step 2: Detect draft type (treadle-loom vs. liftplan/dobby) and branch accordingly
• Step 3: Mechanical validation
• Step 4: Provenance validation
• Step 5: Compute drawdown
• Step 6: Render chart + color preview
• Step 7: Package as print-ready PDF

Step 1: Parse

Map each section to structured data:

• [THREADING]: warp thread number → shaft number
• [TIEUP]: shaft number → set of treadles it's tied to
• [TREADLING]: pick number → treadle number(s)
• [LIFTPLAN]: pick number → set of shafts (alternative to TIEUP+TREADLING on dobby looms)
• [WARP]/[WEFT]: thread color indices, referencing [COLOR TABLE]
• [WEAVING]: Shafts=, Treadles=, RisingShed= (loom capability declarations)

Edge case — missing [TIEUP] entirely: Check for [LIFTPLAN] as the alternative mechanism. If neither exists, fail with code: NO_SHED_MECHANISM, blocking — the draft cannot be rendered.

Edge case — liftplan-only file: Skip tie-up/treadling validation; validate liftplan shaft references directly against Shafts= count instead.

Edge case — malformed [COLOR TABLE]: If color indices in [WARP]/[WEFT] reference table entries that don't exist, fall back to a default greyscale palette and emit code: COLOR_INDEX_UNRESOLVED as a warning — do not block rendering over cosmetic data.

Step 2: Detect draft type

If [LIFTPLAN] is present and non-empty, treat as liftplan-driven (common on computer-assisted/dobby looms). If [TREADLING]+[TIEUP] are present, treat as treadle-driven. If both exist, prefer [LIFTPLAN] and emit an advisory noting the file is dual-encoded.

Step 3: Mechanical validation

Checks, each emitted as a discrete report entry:

• Every threading entry's shaft number ≤ Shafts=
• Every tie-up entry's treadle number ≤ Treadles=
• Every treadling pick references a treadle that exists in tie-up (no orphan picks)
• Every warp end (by thread count) has a threading assignment — flag gaps as UNASSIGNED_THREAD
• Shaft count and treadle count are both ≥ 1 and within realistic loom bounds (warn above 40 shafts/treadles as likely data corruption)

Step 4: Provenance validation

Checks against [TEXT] and [WEAVING] metadata:

• Author/source field present
• Date or era present
• For named historical patterns (filename matches known pattern-family naming conventions, e.g., "Overshot", "Summer_Winter", "Crackle" followed by a number), cross-check against known archives (e.g., Marguerite Davison's A Handweaver's Pattern Book, Bergman's collections) and flag if unattributed.

This never blocks rendering — provenance issues are always severity: advisory.

Step 5: Compute drawdown

For each pick (row) and each warp end (column), determine warp-over or weft-under:

• Treadle-driven: pick → treadle → (via tie-up) → shafts raised → for each thread, if its assigned shaft is raised, warp shows; else weft shows
• Liftplan-driven: pick → shafts raised directly → same per-thread logic

Output as a 2D boolean grid (rows = picks, columns = ends), suitable for rendering or for structural analysis (identifying plain weave, twill, satin, overshot blocks).

Step 6: Render

4-panel layout:

• Top: threading chart (shaft assignments per warp end)
• Top-right: tie-up grid
• Center: drawdown grid (from Step 5)
• Left: treadling/liftplan sequence

Apply [COLOR TABLE] for warp/weft thread colors in the preview; separately generate a high-contrast black/white version for structural clarity.

Step 7: Package

Compute and include:

• Pattern repeat count (detect periodicity in drawdown grid)
• Sett (ends per inch / picks per inch, if present in [WEAVING])
• Yardage estimate (requires finished width/length inputs, or flag as "not computable — missing dimensions")
• Provenance appendix (even if advisory warnings exist, archive all available metadata in PDF document properties + a printed appendix page)

Example 1 — Mechanical validation failure: Input: WIF with [TIEUP] referencing treadle 9, [WEAVING] states Treadles=8 Output:

JSON
{"status": "fail", "errors": [{"code": "TREADLE_OUT_OF_RANGE", "section": "TIEUP", "detail": "Treadle 9 referenced, max is 8", "severity": "blocking"}]}

Example 2 — Missing TIEUP, liftplan present: Input: WIF with no [TIEUP] section, [LIFTPLAN] fully populated, Shafts=16 Output:

JSON
{"status": "pass", "mode": "liftplan", "warnings": []}

Proceeds to drawdown computation using liftplan path, skipping tie-up checks entirely.

Example 3 — No shed mechanism at all: Input: WIF with neither [TIEUP] nor [LIFTPLAN] Output:

JSON
{"status": "fail", "errors": [{"code": "NO_SHED_MECHANISM", "detail": "Cannot compute drawdown without TIEUP or LIFTPLAN", "severity": "blocking"}]}

Example 4 — Provenance warning (non-blocking): Input: File named Colonial_Overshot_47.wif, no [TEXT] section Output:

JSON
{"status": "pass", "warnings": [{"code": "MISSING_PROVENANCE", "detail": "No author/source found; filename suggests historical Overshot pattern — recommend cross-referencing Davison archive", "severity": "advisory"}]}

Rendering and packaging proceed; warning is included in the PDF appendix.

Example 5 — Malformed color table: Input: [WARP] references color index 12, [COLOR TABLE] only defines indices 0–9 Output:

JSON
{"status": "pass", "warnings": [{"code": "COLOR_INDEX_UNRESOLVED", "detail": "Warp thread references color 12, undefined. Using greyscale fallback.", "severity": "advisory"}]}