func findXHoles(blocks []*indexRLE, minX, maxX int32) (bestBeg, bestEnd int32, found bool) {
nx := maxX - minX + 1
used := make([]bool, nx, nx)
for _, rle := range blocks {
spanBeg := rle.start[0]
if spanBeg > maxX {
continue
}
spanEnd := spanBeg + int32(rle.span) - 1
if spanEnd < minX {
continue
}
x0 := dvid.MaxInt32(minX, spanBeg)
x1 := dvid.MinInt32(maxX, spanEnd)
for x := x0; x <= x1; x++ {
i := x - minX
used[i] = true
}
}
// See if there are holes.
var holeSize, bestSize int32
var holeBeg, holeEnd int32
var inHole bool
for x := minX; x <= maxX; x++ {
i := x - minX
if !used[i] {
if inHole {
holeEnd = x
holeSize++
} else {
inHole = true
holeBeg = x
holeEnd = x
holeSize = 1
}
} else {
inHole = false
}
if holeSize > bestSize {
bestSize = holeSize
bestBeg = holeBeg
bestEnd = holeEnd
}
}
if bestSize > 0 {
found = true
}
return
}
func findActives(blocks []*indexRLE, minX, maxX int32) int32 {
var numActive int32
for _, rle := range blocks {
spanBeg := rle.start[0]
if spanBeg > maxX {
continue
}
spanEnd := spanBeg + int32(rle.span) - 1
if spanEnd < minX {
continue
}
x0 := dvid.MaxInt32(minX, spanBeg)
x1 := dvid.MinInt32(maxX, spanEnd)
numActive += x1 - x0 + 1
}
return numActive
}