gistfile1.diff

diff --git a/builtin/voxelarea.lua b/builtin/voxelarea.lua
index dd9af79..f546cd3 100644
--- a/builtin/voxelarea.lua
+++ b/builtin/voxelarea.lua
@@ -60,3 +60,28 @@ function VoxelArea:containsi(i)
 	return (i >= 1) and (i <= self:getVolume())
 end
 
+function VoxelArea:iter(minx, miny, minz, maxx, maxy, maxz)
+	local i = self:index(minx, miny, minz) - 1
+	local last = self:index(maxx, maxy, maxz)
+	local ystride = self.ystride
+	local zstride = self.zstride
+	local yoff = (last+1) % ystride
+	local zoff = (last+1) % zstride
+	local ystridediff = (i - last) % ystride
+	local zstridediff = (i - last) % zstride
+	return function()
+		i = i + 1
+		if i % zstride == zoff then
+			i = i + zstridediff
+		elseif i % ystride == yoff then
+			i = i + ystridediff
+		end
+		if i <= last then
+			return i
+		end
+	end
+end
+
+function VoxelArea:iterp(minp, maxp)
+	return self:iter(minp.x, minp.y, minp.z, maxp.x, maxp.y, maxp.z)
+end