Converting Weaving Drafts to WIF

Python
converter = DraftConverter(
    shafts=4,
    treadles=4,
    threading=[1, 2, 3, 4],              # 1-indexed shaft per warp end, left to right
    tieup={1: [1, 2], 2: [2, 3], 3: [3, 4], 4: [4, 1]},  # treadle -> shafts raised
    treadling=[1, 2, 3, 4]               # 1-indexed treadle per weft pick, top to bottom
)

print(converter.to_ascii())             # drawdown preview
wif_text = converter.export_wif(title="2/2 Straight Twill")
open("draft.wif", "w").write(wif_text)

Progress:

• Step 1: Gather the four draft components — shaft/treadle counts, threading, tie-up, treadling
• Step 2: Validate indices (all shaft/treadle numbers must be within declared ranges, 1-indexed)
• Step 3: Instantiate DraftConverter with the four components
• Step 4: Compute and review the drawdown via to_ascii() to sanity-check the pattern visually
• Step 5: Export to WIF 1.1 via export_wif() and save with .wif extension
• Step 6: Spot-check the WIF sections ([TIEUP], [THREADING], [TREADLING]) against the source draft

Drawdown logic: For each pick, look up the shafts raised by that pick's treadle in the tie-up. A warp end shows as raised (1/warp float) if its threaded shaft is in that raised set, otherwise it's a weft float (0).

Rising vs. sinking shed: The converter assumes rising shed (Rising Shed=on). If source draft uses a sinking-shed (jack-less) loom convention, invert the raised-shaft logic before computing the drawdown, or set Rising Shed=off and invert bit values in the WIF output.

Example 1: 2/2 Straight Twill Input:

• threading=[1,2,3,4], tieup={1:[1,2],2:[2,3],3:[3,4],4:[4,1]}, treadling=[1,2,3,4]

Output (drawdown ASCII):

x x . .
. x x .
. . x x
x . . x

Example 2: Plain Weave (2-shaft) Input:

• shafts=2, treadles=2, threading=[1,2,1,2], tieup={1:[1],2:[2]}, treadling=[1,2,1,2]

Output (drawdown ASCII):

x . x .
. x . x
x . x .
. x . x

Example 3: Malformed tie-up reference Input: tieup={1:[1,2]} but treadling contains treadle 3 (undefined)

Output: compute_drawdown() treats pick as raising no shafts (empty set via .get(tr, [])), producing an all-weft-float row — flag this before export, don't silently export it.