Add VoxelArea:position, VoxelArea:iter and VoxelArea:iterp

diff --git a/builtin/voxelarea.lua b/builtin/voxelarea.lua
index dd9af7910b718d33bb5240a916e78a45f16a3630..93bbf73a8bedf6ecec9e563444af0bf65ce3b005 100644 (file)
--- a/builtin/voxelarea.lua
+++ b/builtin/voxelarea.lua
@@ -44,6 +44,22 @@ function VoxelArea:indexp(p)
        return math.floor(i)
 end
 
+function VoxelArea:position(i)
+       local p = {}
+ 
+       i = i - 1
+
+       p.z = math.floor(i / self.zstride) + self.MinEdge.z
+       i = i % self.zstride
+
+       p.y = math.floor(i / self.ystride) + self.MinEdge.y
+       i = i % self.ystride
+
+       p.x = math.floor(i) + self.MinEdge.x
+
+       return p
+end
+
 function VoxelArea:contains(x, y, z)
        return (x >= self.MinEdge.x) and (x <= self.MaxEdge.x) and
                   (y >= self.MinEdge.y) and (y <= self.MaxEdge.y) and
@@ -60,3 +76,28 @@ 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

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 12892e5b55c5b3dd376e61199bb8d10bdbbfa765..74b3d3ba5a72ebc141fb7a77ebe5e17820667604 100644 (file)
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -1676,6 +1676,13 @@ methods:
 - index(x, y, z):  returns the index of an absolute position in a flat array starting at 1
   ^ useful for things like VoxelManip, raw Schematic specifiers, PerlinNoiseMap:get2d/3dMap, and so on
 - indexp(p):  same as above, except takes a vector
+- position(i):  returns the absolute position vector corresponding to index i
+- contains(x, y, z):  check if (x,y,z) is inside area formed by MinEdge and MaxEdge
+- containsp(p):  same as above, except takes a vector
+- containsi(i):  same as above, except takes an index
+- iter(minx, miny, minz, maxx, maxy, maxz):  returns an iterator that returns indices
+  ^ from (minx,miny,minz) to (maxx,maxy,maxz) in the order of [z [y [x]]]
+- iterp(minp, maxp):  same as above, except takes a vector
 
 Mapgen objects
 ---------------