Minetest-WorldEditAdditions/test_count_chunks.lua
Starbeamrainbowlabs 25e659321a
//subdivide: reimplement count_chunks
this does the maths properly, so we'e going from O(n³) to O(1) :D

//subdivide should get started *so much faster* now :D
2021-02-03 02:25:33 +00:00

77 lines
2.1 KiB
Lua

--[[
test_count_chunks
Test script for the new count_chunks implementation for //subdivide.
The new implementation does the maths properly and is functionally identical to
the previous algorithm - we've tested it with 1000 totally random pos1, pos2,
and chunk_size values.
]]--
local function count_chunks(pos1, pos2, chunk_size)
local count = 0
for z = pos2.z, pos1.z, -chunk_size.z do
for y = pos2.y, pos1.y, -chunk_size.y do
for x = pos2.x, pos1.x, -chunk_size.x do
count = count + 1
end
end
end
return count
end
local function count_chunks_new(pos1, pos2, chunk_size)
-- Assume pos1 & pos2 are sorted
local dimensions = {
x = pos2.x - pos1.x + 1,
y = pos2.y - pos1.y + 1,
z = pos2.z - pos1.z + 1,
}
-- print("[new] dimensions", dimensions.x, dimensions.y, dimensions.z)
return math.ceil(dimensions.x / chunk_size.x)
* math.ceil(dimensions.y / chunk_size.y)
* math.ceil(dimensions.z / chunk_size.z)
end
local pos1 = { x = 16000, y = 0, z = 16000 }
local pos2 = { x = 16100, y = 100, z = 16100 }
local count = { x = 7, y = 9, z = 10 }
print("Reference: ", count_chunks(pos1, pos2, count))
print("New: ", count_chunks_new(pos1, pos2, count))
local ok = 0
local failed = false
for i=1,1000 do
pos1.x = 16000 + math.floor(math.random() * 99)
pos1.y = 16000 + math.floor(math.random() * 99)
pos1.z = 16000 + math.floor(math.random() * 99)
pos2.x = 16100 + math.floor(math.random() * 2000)
pos2.y = 16100 + math.floor(math.random() * 2000)
pos2.z = 16100 + math.floor(math.random() * 2000)
count.x = math.floor(math.random() * 25) + 1
count.y = math.floor(math.random() * 25) + 1
count.z = math.floor(math.random() * 25) + 1
io.write(ok..": ( "..pos1.x..", "..pos1.y..", "..pos1.z.." ) - ( "..pos2.x..", "..pos2.y..", "..pos2.z.." ), size ( ", count.x, ", ", count.y, ", ", count.z, " ) | ")
local val_ref = count_chunks(pos1, pos2, count)
local val_new = count_chunks_new(pos1, pos2, count)
if val_ref == val_new then
print("OK")
ok = ok + 1
else
print("FAIL! ( "..val_ref.." / "..val_new.." )")
failed = true
break
end
end
io.write(ok.." ok")
if failed then io.write(", 1 failed") end
print()