possibleMoves: [], //filled after each valid click/dragstart
choices: [], //promotion pieces, or checkered captures... (as moves)
selectedPiece: null, //moving piece (or clicked piece)
incheck: [],
start: {}, //pixels coordinates + id of starting square (click or drag)
possibleMoves: [], //filled after each valid click/dragstart
choices: [], //promotion pieces, or checkered captures... (as moves)
selectedPiece: null, //moving piece (or clicked piece)
incheck: [],
start: {}, //pixels coordinates + id of starting square (click or drag)