https://www.mipui.net/app/magic_wand_select_gesture.js

1class MagicWandSelectGesture extends SelectGesture {
2  constructor() {
3    super();
4    this.includePredicate_ = null;
5    this.advancePredicate_ = null;
6    this.partialCellsConsideredFloor = false;
7  }
8
9  startGesture() {
10    super.startGesture();
11    if (!this.anchorCell_) return;
12    const anchorIsWall = this.anchorCell_.isKind(ct.walls, ct.walls.smooth);
13    this.includePredicate_ = cell => {
14      const isWall = cell.isKind(ct.walls, ct.walls.smooth);
15      if (isWall && anchorIsWall) return true;
16      if (!isWall && !anchorIsWall) return true;
17      if (anchorIsWall || !this.partialCellsConsideredFloor) return false;
18      const isPartialWall =
19          cell.isVariation(ct.walls, ct.walls.smooth, ct.walls.smooth.angled) ||
20          cell.isVariation(ct.walls, ct.walls.smooth, ct.walls.smooth.oval);
21      return anchorIsWall != isPartialWall;
22    };
23    this.advancePredicate_ =
24        cell => anchorIsWall == cell.isKind(ct.walls, ct.walls.smooth);
25    this.addCellsLinkedTo_(this.anchorCell_);
26  }
27
28  continueGesture(cell) {
29    this.addCellsLinkedTo_(cell);
30  }
31
32  addCellsLinkedTo_(cell) {
33    let front = new Set();
34    front.add(cell);
35    this.addSelectedCell_(cell);
36    while (front.size > 0) {
37      const newFront = new Set();
38      const newCells = new Set();
39      for (const cell of front.values()) {
40        this.getImmediateNeighborCells(cell).forEach(neighborCell => {
41          if (neighborCell &&
42              this.includePredicate_(neighborCell) &&
43              !this.selectedCells_.has(neighborCell) &&
44              !front.has(neighborCell)) {
45            newCells.add(neighborCell);
46            if (this.advancePredicate_(neighborCell)) {
47              newFront.add(neighborCell);
48            }
49          }
50        });
51      }
52      newCells.forEach(cell => this.addSelectedCell_(cell));
53      if (this.selectedCells_.size > constants.maxNumSelectedCells) return;
54      front = newFront;
55    }
56  }
57
58  getImmediateNeighborCells(cell) {
59    const result = [];
60    if (!cell) return result;
61    switch (cell.role) {
62      case 'corner':
63      case 'primary':
64        result.push(cell.getNeighbor('top', true));
65        result.push(cell.getNeighbor('right', true));
66        result.push(cell.getNeighbor('bottom', true));
67        result.push(cell.getNeighbor('left', true));
68        result.push(cell.getNeighbor('top-right', cell.role == 'primary'));
69        result.push(cell.getNeighbor('bottom-right', cell.role == 'primary'));
70        result.push(cell.getNeighbor('bottom-left', cell.role == 'primary'));
71        result.push(cell.getNeighbor('top-left', cell.role == 'primary'));
72        break;
73      case 'horizontal':
74        result.push(cell.getNeighbor('top', false));
75        result.push(cell.getNeighbor('right', true));
76        result.push(cell.getNeighbor('bottom', false));
77        result.push(cell.getNeighbor('left', true));
78        break;
79      case 'vertical':
80        result.push(cell.getNeighbor('top', true));
81        result.push(cell.getNeighbor('right', false));
82        result.push(cell.getNeighbor('bottom', true));
83        result.push(cell.getNeighbor('left', false));
84        break;
85    }
86    return result;
87  }
88}