VoxelArea: faster iter function (#4490)

This commit is contained in:
HybridDog 2016-10-08 14:42:17 +02:00 committed by Zeno-
parent 09cefc3dfd
commit 9978d0796f

@ -50,7 +50,7 @@ end
function VoxelArea:position(i)
local p = {}
local MinEdge = self.MinEdge
i = i - 1
p.z = math.floor(i / self.zstride) + MinEdge.z
@ -84,23 +84,46 @@ 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
local xrange = maxx - minx + 1
local nextaction = i + 1 + xrange
local y = 0
local yrange = maxy - miny + 1
local yreqstride = self.ystride - xrange
local z = 0
local zrange = maxz - minz + 1
local multistride = self.zstride - ((yrange - 1) * self.ystride + xrange)
return function()
-- continue i until it needs to jump
i = i + 1
if i % zstride == zoff then
i = i + zstridediff
elseif i % ystride == yoff then
i = i + ystridediff
end
if i <= last then
if i ~= nextaction then
return i
end
-- continue y until maxy is exceeded
y = y + 1
if y ~= yrange then
-- set i to index(minx, miny + y, minz + z) - 1
i = i + yreqstride
nextaction = i + xrange
return i
end
-- continue z until maxz is exceeded
z = z + 1
if z == zrange then
-- cuboid finished, return nil
return
end
-- set i to index(minx, miny, minz + z) - 1
i = i + multistride
y = 0
nextaction = i + xrange
return i
end
end