Minetest-WorldEditAdditions/worldeditadditions/lib/rotate.lua
Starbeamrainbowlabs 717a651bd8
typos in comments
2024-10-02 01:20:08 +01:00

128 lines
6.0 KiB
Lua

local weac = worldeditadditions_core
local Vector3 = weac.Vector3
---
-- @module worldeditadditions
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--- Rotates the given region around a given origin point using a set of rotations.
-- TODO Learn quaternions and make this more effiient.
-- @param pos1 Vector3 Position 1 of the defined region to rotate.
-- @param pos2 Vector3 Position 2 of the defined region to rotate.
-- @param origin Vector3 The coordinates of the origin point around which we should rotate the region defined by pos1..pos2.
-- @param rotlist table<{axis: string, rad: number}> The list of rotations. Rotations will be processed in order. Each rotation is a table with a SINGLE axis as a string (x, y, z, -x, -y, or -z; the axis parameter), and an amount in radians to rotate by (the rad parameter).
-- @returns bool,string|table<{changed: number}> A success boolean (true == success; false == failure), followed by either an error message as a string if success == false or a table of statistics if success == true.
--
-- Currently the only parameter in the statistics table is changed, which is a number representing the number of nodes that were rotated.
--
-- This is NOT NECESSARILY the number of nodes in the target region..... since rotations and roundings mean the target area the source region was rotated into could have slightly more or less nodes than the source region.
function worldeditadditions.rotate(pos1, pos2, origin, rotlist)
pos1, pos2 = Vector3.sort(pos1, pos2)
--- 1: Compile the rotation list
local rotlist_c = weac.rotation.rotlist_compile(rotlist)
--- 2: Find the target area we will be rotating into
-- First, rotate the defined region to find the target region
-- local pos1_rot, pos2_rot = pos1:clone(), pos2:clone()
-- for i, rot in ipairs(rotlist_c) do
-- pos1_rot = Vector3.rotate3d(origin, pos1_rot, rot)
-- pos2_rot = Vector3.rotate3d(origin, pos2_rot, rot)
-- end
-- Then, align it to the world axis so we can grab a VoxelManipulator
-- We add 1 node either side for safety just in case of rounding errors when actually rotating
local pos1_dstvm, pos2_dstvm = weac.rotation.find_rotated_vm(pos1, pos2, origin, rotlist)
pos1_dstvm = pos1_dstvm:floor() - Vector3.new(1, 1, 1)
pos2_dstvm = pos2_dstvm:ceil() + Vector3.new(1, 1, 1)
-- print("DEBUG:rotate pos1", pos1, "pos1_rot", pos1_rot, "pos1_dstvm", pos1_dstvm, "pos2", pos2, "pos2_rot", pos2_rot, "pos2_dstvm", pos2_dstvm)
--- 3: Check out a VoxelManipulator for the source and target regions
-- TODO support param2 here. We zero out the source.... but don't carry over to the target. This probably requires //orient+ first.
local manip_src, area_src = worldedit.manip_helpers.init(pos1, pos2)
local data_src = manip_src:get_data()
local param2_src = manip_src:get_param2_data()
-- TODO: grab only an area at this point for dest and a blank target table. Then copy over to the real dest later to ensure consistency. This is important because we are dealing in (potentially) non-cardinal rectangles here
-- local area = VoxelArea:new({MinEdge=emerged_pos1, MaxEdge=emerged_pos2})
-- BUT WAIT.... the we hafta write to a blank table first!
-- We HAVE to grab a VoxelManip here, since there's no other way to confirm the actual area the VoxelManip actually loaded given VoxelManip instances can load more than you ask them for 'cause chunks are a thing
local manip_dest, area_dest = worldedit.manip_helpers.init(pos1_dstvm, pos2_dstvm)
local data_dest = {}
-- TODO: Also carry param2 along for the ride
--- 4: Do the rotation operation
local count_rotated = 0
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 cpos_src = Vector3.new(x, y, z)
local cpos_dest = cpos_src:clone()
-- TODO: This is very inefficient. If we could use quaternions here to stack up the rotations, it would be much more efficient.
for i, rot in ipairs(rotlist_c) do
cpos_dest = Vector3.rotate3d(origin, cpos_dest, rot)
end
cpos_dest = cpos_dest:round()
local i_src = area_src:index(cpos_src.x, cpos_src.y, cpos_src.z)
local i_dest = area_dest:index(cpos_dest.x, cpos_dest.y, cpos_dest.z)
data_dest[i_dest] = data_src[i_src]
count_rotated = count_rotated + 1
end
end
end
--- 5: Wipe the source area & save it back to disk
local id_air = minetest.get_content_id("air")
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 src_i = area_src:index(x, y, z)
data_src[src_i] = id_air
param2_src[src_i] = 0
end
end
end
manip_src:set_param2_data(param2_src)
worldedit.manip_helpers.finish(manip_src, data_src)
manip_src, area_src, data_src, param2_src = nil, nil, nil, nil
--- 6: Reinitialise the destination VoxelManip and copy data over
-- This has the net effect of changing ONLY the nodes we rotate to, while preserving changes from wiping the source
manip_dest, area_dest = worldedit.manip_helpers.init(pos1_dstvm, pos2_dstvm)
data_dest_real = manip_dest:get_data()
for index, value in pairs(data_dest) do
data_dest_real[index] = value
end
--- 7: Save the destination back to disk
-- Note that this MUST be AFTER the source is saved to disk, since the rotated region needs to overwrite the WIPED source area to avoid leaving an unrotated copy behind
worldedit.manip_helpers.finish(manip_dest, data_dest_real)
--- 8: Return
return true, {
count_rotated = count_rotated,
-- Undo the +/-1 when passing back
pos1_dstvm = pos1_dstvm + Vector3.new(1, 1, 1),
pos2_dstvm = pos2_dstvm - Vector3.new(1, 1, 1)
}
end