/** By Dingding */
private Set<Line.Segment> getRemovableLineSegments(
Map<Position, Piece> pieceMap, PieceColor pieceColor) {
Set<Line.Segment> removableLines = new HashSet<>();
Set<Line> linesOnTheBoard =
Line.getLinesOnTheBoard(
this); // Get all the possible lines on the board. Positions don't need to be occupied.
for (Line line : linesOnTheBoard) {
Position currentPosition = line.getStartPosition();
Position startOfSegment = null;
Position endOfSegment = null;
Direction direction = line.getDirection();
int consecutivePieces =
0; // We start at a dot position, so we can assume that we don't start in a set of
// consecutive pieces
boolean isInLineSegment = false;
// Break the for-loop if an endOfSegment has been found (because the largest lines only have 7
// positions on the board, there
// can't be more than one set of four pieces of the same color (requiring at least 9
// positions) on the board.
for (;
endOfSegment == null && isPositionOnPlayAreaOrOuterDots(currentPosition);
currentPosition = currentPosition.next(direction)) {
PieceColor currentPieceColor =
pieceMap.containsKey(currentPosition)
? pieceMap.get(currentPosition).getPieceColor()
: null;
// Update the consecutivePieces
if (currentPieceColor == pieceColor) consecutivePieces++;
if (consecutivePieces == 4) isInLineSegment = true;
if (currentPieceColor != pieceColor) consecutivePieces = 0;
if (isInLineSegment) {
if (isDotPosition(currentPosition) || currentPieceColor == null) {
endOfSegment = currentPosition.previous(direction);
}
}
// Update the startOfSegment if necessary
if (startOfSegment == null) {
if (currentPieceColor != null) {
startOfSegment = currentPosition;
}
}
if (currentPieceColor == null && endOfSegment == null) {
startOfSegment = null;
}
// Add a line segment to the list if we have found one
if (endOfSegment != null) {
removableLines.add(new Line.Segment(this, startOfSegment, endOfSegment, direction));
}
}
}
return removableLines;
}
/** recalculates the Line */
private void recalculate() {
// aggregate
Point2d point_sum = new Point2d();
Vector2d direction_sum = new Vector2d();
int n = points.size();
for (int i = 0; i < n; i++) {
Line c = new Line(points.get(i), points.get((i + 1) % n));
c.getDirection().normalize();
// make sure y dir is positive
if (c.getDirection().y < 0 || (c.getDirection().y == 0 && c.getDirection().x < 0))
c.getDirection().scale(-1);
direction_sum.add(c.getDirection());
point_sum.add(c.getPoint());
}
direction_sum.scale(1.0 / ((double) n));
point_sum.scale(1.0 / ((double) n));
// calc mean and save
meanLine = new Line(point_sum, direction_sum);
dirty = false;
}