VectorPaint invented board diagrams: audit pieces through coordinates and states

English translation of the Chinese original, translated on 2026-11-04. Original publication dates, attribution, code and version notes are retained.

A position diagram needs clear piece identities and locations, not just squares. Invent a four-by-four board with four pieces and two simple moves to practise state maintenance. This is not instruction for an established game, does not claim official move legality and provides no automatic play or result calculation.

Define coordinates and the exercise rules

Create a 1200 by 800 pixel canvas with columns A–D left to right and rows 1–4 top to bottom, explicitly defining this diagram’s convention. Name four pieces 甲, 乙, 丙 and 丁. The only rules are a single orthogonal move into an adjacent empty cell, without leaving the board or overlapping. List 甲=A1, 乙=C2, 丙=B4 and 丁=D3 and verify each. Avoid real-game piece names that imply unstated rules. Reserve initial and later state space, defining coordinate direction before board and markers so superficially consistent drawings do not conceal reversed row numbering.

Build sixteen cells with external coordinates

Copy one square into four columns and four rows with clear, consistent edges rather than heavy/light shared lines from duplicates. Align outside column letters and row numbers with cell centres and avoid corner labels resembling a fifth row. Leave piece padding. Alternating light/dark squares are optional but do not encode permitted/blocked cells without a rule. Hide pieces to count sixteen cells and identify all four corners by coordinate. Group board and coordinates appropriately and keep pieces separate so later state edits do not stretch the board or displace labels.

Give every piece an explicit identity

Use equally sized circles or simple geometric pieces, each with its short 甲/乙/丙/丁 identifier rather than colour alone. Centre them at listed cells, read every coordinate and count four. Colour could indicate teams, but this exercise defines no team or winning rules, so do not introduce unexplained implications. Group text with each symbol so a move cannot leave its name behind. Save the initial source and make independent later-state copies rather than repeatedly overwriting the only original. This supports comparison of what moved and what should remain unchanged.

Move only the first piece into its adjacent cell

Define move one as 甲 from A1 to B1. Verify B1 is empty and horizontally adjacent, then move the complete group in the first-state copy. The old cell becomes empty, three other pieces stay unchanged and total count remains four. Any explanatory arrow starts and ends at the relevant cell centres on a separate explanation layer and is not a fifth piece. Do not move only the name while leaving its circle. Preserve written coordinates and compare the drawing: static paths do not automatically validate occupancy or bounds. Cross-check every condition before proceeding to move two.

Build the second move from the first state

Define move two as 乙 from C2 to C3 and copy the result of move one rather than returning to the initial position. C3 is empty and vertically adjacent to C2; 丁 at D3 is not in that cell. After moving 乙, verify 甲 remains at B1 and 丙/丁 are unchanged. Clearly title initial, after move one and after move two in reading order. If space is insufficient, separate files are preferable to unequal compression. Keep the same coordinate convention in every state so position differences are explained without guessing rotations or mirrors.

Audit every state against a position list

Write a four-row position list for each of the three states. Inspect changed positions, then unchanged ones, then total pieces; checking only the intended mover misses neighbours accidentally selected with it. Hide colour temporarily and read identities to confirm independent recognition. Hide arrows as well: each state should show its current arrangement without them. Arrows explain change but cannot replace a state. Select individual objects to detect overlapped duplicate pieces rather than merely counting labels. Remove extra test copies and retain the three states and explanations without claiming a playable game or rules checker.

Preserve grid scale and orientation in exports

Save board sources, pieces and all three state originals. Compare exports side by side at the same displayed cell spacing. Coordinates and IDs must remain readable at small size; enlarge or reduce decoration rather than deleting essential labels. For transparent output, inspect light-cell fills against the background; white objects are not automatic holes. Include state number and revision in filenames and open each before sharing to exclude a second-move explanation paired with an initial image. New rules or pieces require a new list and legality conditions before graphics; the old two-move check does not validate a new game.

Locate the exact object behind a mismatch

If 乙 lands at C4, check whether a row boundary was mistaken for a centre or row numbers were reversed rather than flipping the entire board to hide it. A count of five suggests overlapping copies; three suggests hidden layers or deleted markers. For an arrow crossing an occupied cell, return to the rule and clarify single versus multiple moves instead of drawing vaguely. If graphics are correct but the written coordinates are wrong, repair the record and recheck all states. A useful position diagram explains each identity, each move’s endpoints and every state’s count rather than merely showing colourful circles on squares.