int toRatio)
{
this();
+ fromRange = coalesceRanges(fromRange);
+ toRange = coalesceRanges(toRange);
this.fromShifts = fromRange;
this.toShifts = toRange;
this.fromRatio = fromRatio;
}
/**
+ * Consolidates a list of ranges so that any contiguous ranges are merged.
+ * This assumes the ranges are already in start order (does not sort them).
+ *
+ * @param ranges
+ * @return the same list (if unchanged), else a new merged list, leaving the
+ * input list unchanged
+ */
+ public static List<int[]> coalesceRanges(final List<int[]> ranges)
+ {
+ if (ranges == null || ranges.size() < 2) {
+ return ranges;
+ }
+
+ boolean changed = false;
+ List<int[]> merged = new ArrayList<int[]>();
+ int[] lastRange = ranges.get(0);
+ int lastDirection = lastRange[1] >= lastRange[0] ? 1 : -1;
+ lastRange = new int[] { lastRange[0], lastRange[1] };
+ merged.add(lastRange);
+ boolean first = true;
+
+ for (final int[] range : ranges)
+ {
+ if (first)
+ {
+ first = false;
+ continue;
+ }
+ if (range[0] == lastRange[0] && range[1] == lastRange[1])
+ {
+ // drop duplicate range
+ changed = true;
+ continue;
+ }
+
+ /*
+ * drop this range if it lies within the last range
+ */
+ if ((lastDirection == 1 && range[0] >= lastRange[0]
+ && range[0] <= lastRange[1] && range[1] >= lastRange[0] && range[1] <= lastRange[1])
+ || (lastDirection == -1 && range[0] <= lastRange[0]
+ && range[0] >= lastRange[1]
+ && range[1] <= lastRange[0] && range[1] >= lastRange[1]))
+ {
+ changed = true;
+ continue;
+ }
+
+ int direction = range[1] >= range[0] ? 1 : -1;
+
+ /*
+ * if next range is in the same direction as last and contiguous,
+ * just update the end position of the last range
+ */
+ boolean sameDirection = range[1] == range[0] || direction == lastDirection;
+ boolean extending = range[0] == lastRange[1] + lastDirection;
+ boolean overlapping = (lastDirection == 1 && range[0] >= lastRange[0] && range[0] <= lastRange[1])
+ || (lastDirection == -1 && range[0] <= lastRange[0] && range[0] >= lastRange[1]);
+ if (sameDirection && (overlapping || extending))
+ {
+ lastRange[1] = range[1];
+ changed = true;
+ }
+ else
+ {
+ lastRange = new int[] { range[0], range[1] };
+ merged.add(lastRange);
+ // careful: merging [5, 5] after [7, 6] should keep negative direction
+ lastDirection = (range[1] == range[0]) ? lastDirection : direction;
+ }
+ }
+
+ return changed ? merged : ranges;
+ }
+
+ /**
* get all mapped positions from 'from' to 'to'
*
* @return int[][] { int[] { fromStart, fromFinish, toStart, toFinish }, int
}
}
- public static void addRange(int[] range, List<int[]> addTo)
+ /**
+ * Adds the given range to a list of ranges. If the new range just extends
+ * existing ranges, the current endpoint is updated instead.
+ *
+ * @param range
+ * @param addTo
+ */
+ static void addRange(int[] range, List<int[]> addTo)
{
/*
* list is empty - add to it!