public Set<Position> getAllMatches(
Playfield<E> haystack, Playfield<E> needle, Matcher<E, E> matcher) {
Set<Position> results = new HashSet<Position>();
IntegerElement haystackWidth = haystack.getMaxX().subtract(haystack.getMinX()).succ();
IntegerElement haystackHeight = haystack.getMaxY().subtract(haystack.getMinY()).succ();
IntegerElement needleWidth = needle.getMaxX().subtract(needle.getMinX()).succ();
IntegerElement needleHeight = needle.getMaxY().subtract(needle.getMinY()).succ();
if (needleWidth.compareTo(haystackWidth) > 0 || needleHeight.compareTo(haystackHeight) > 0) {
// thing being sought is larger than the thing seeking in, so, no
return results;
}
IntegerElement xSpan = haystackWidth.subtract(needleWidth).succ();
IntegerElement ySpan = haystackHeight.subtract(needleHeight).succ();
IntegerElement x, y;
for (x = IntegerElement.ZERO; x.compareTo(xSpan) < 0; x = x.succ()) {
for (y = IntegerElement.ZERO; y.compareTo(ySpan) < 0; y = y.succ()) {
if (isMatchAt(haystack, needle, matcher, x, y)) {
results.add(new Position(x, y));
} else {
}
}
}
return results;
}
public boolean isMatchAt(
Playfield<E> haystack,
Playfield<E> needle,
Matcher<E, E> m,
IntegerElement x,
IntegerElement y) {
IntegerElement width = needle.getMaxX().subtract(needle.getMinX()).succ();
IntegerElement height = needle.getMaxY().subtract(needle.getMinY()).succ();
if (x.pred().add(width).compareTo(haystack.getMaxX()) > 0
|| y.pred().add(height).compareTo(haystack.getMaxY()) > 0) {
// exceeds the right or bottom edge, so, no
return false;
}
IntegerElement cx, cy, dx, dy;
for (cx = x, dx = needle.getMinX();
dx.compareTo(needle.getMaxX()) <= 0;
cx = cx.succ(), dx = dx.succ()) {
for (cy = y, dy = needle.getMinY();
dy.compareTo(needle.getMinY()) <= 0;
cy = cy.succ(), dy = dy.succ()) {
E soughtElem = needle.get(dx, dy);
E foundElem = haystack.get(cx, cy);
// System.out.printf("sought (%s,%s): '%s', found (%s,%s): '%s'\n",
// dx, dy, soughtElem.getName(),
// cx, cy, foundElem.getName());
if (m.match(soughtElem, foundElem)) {
// add something to the result-list
} else {
return false;
}
}
}
return true;
}