Minetest-WorldEditAdditions/worldeditadditions/lib/scale_down.lua
2021-02-07 23:39:09 +00:00

79 lines
4.1 KiB
Lua

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--- Scales the defined region down by the given scale factor in the given directions.
-- @param pos1 Vector Position 1 of the defined region,
-- @param pos2 Vector Position 2 of the defined region.
-- @param scale Vector The scale factor - as a vector - by which to scale down.
-- @param direction Vector The direction to scale in - as a vector. e.g. { x = -1, y = 1, z = -1 } would mean scale in the negative x, positive y, and nevative z directions.
-- @return boolean, string|table Whether the operation was successful or not. If not, then an error messagea as a string is also passed. If it was, then a statistics object is returned instead.
function worldeditadditions.scale_down(pos1, pos2, scale, direction)
pos1, pos2 = worldedit.sort_pos(pos1, pos2)
if scale.x > 1 or scale.y > 1 or scale.z > 1 or scale.x < -1 or scale.y < -1 or scale.z < -1 then
return false, "Error: Scale factor vectors may not mix values -1 < factor < 1 and (1 < factor or factor < -1) - in other words, you can't scale both up and down at the same time (try worldeditadditions.scale, which automatically applies such scale factor vectors as 2 successive operations)"
end
if direction.x == 0 or direction.y == 0 or direction.z == 0 then
return false, "Error: One of the components of the direction vector was 0 (direction components should either be greater than or less than 0 to indicate the direction to scale in.)"
end
local scale_down = {
x = math.floor(1 / scale.x),
y = math.floor(1 / scale.y),
z = math.floor(1 / scale.z)
}
print("[DEBUG] scale_down", worldeditadditions.vector.tostring(scale_down))
local size = vector.subtract(pos2, pos1)
local data = manip:get_data()
local data_copy = worldeditadditions.shallowcopy(data)
local node_id_air = minetest.get_content_id("air")
local count = 0 -- The number of nodes replaced
local stats = { updated = 0, scale = scale_down }
-- Zero out the area we're scaling down into
for i in area:iterp(pos1, pos2) do
data_copy[i] = node_id_air
-- We update the entire area, even though we're scaling down
-- ....because we fill in the area we left behind with air
stats.updated = stats.updated + 1
end
for z = pos2.z, pos1.z, -1 do
for y = pos2.y, pos1.y, -1 do
for x = pos2.x, pos1.x, -1 do
local posi_rel = vector.subtract({ x = x, y = y, z = z }, pos1)
local posi_copy = worldeditadditions.shallowcopy(posi_rel)
posi_copy = vector.floor(vector.divide(scale_down))
if direction.x < 0 then posi_copy.x = size.x - posi_copy.x end
if direction.y < 0 then posi_copy.y = size.y - posi_copy.y end
if direction.z < 0 then posi_copy.z = size.z - posi_copy.z end
local posi_copy = vector.add(pos1, posi_copy)
local i_source = area:index(x, y, z)
local i_target = area:index(posi_copy.x, posi_copy.y, posi_copy.z)
-- Technically we could save some operations here by not setting
-- the target multiple times per copy, but the calculations
-- above are probably a lot more taxing
-- TODO Be more intelligent about deciding what node to replace with here
data_copy[i_target] = data[i_source]
end
end
end
-- Save the modified nodes back to disk & return
worldedit.manip_helpers.finish(manip, data_copy)
return true, changes
end