Minetest-WorldEditAdditions/worldeditadditions/lib/convolution/convolution.lua

90 lines
3.0 KiB
Lua

worldeditadditions.conv = {}
dofile(worldeditadditions.modpath.."/lib/conv/kernels.lua")
dofile(worldeditadditions.modpath.."/lib/conv/kernel_gaussian.lua")
dofile(worldeditadditions.modpath.."/lib/conv/convolve.lua")
--- Creates a new kernel.
-- Note that the gaussian kernel only allows for creating a square kernel.
-- arg is only used by the gaussian kernel as the sigma value (default: 2)
-- @param name string The name of the kernel to create (possible values: box, pascal, gaussian).
-- @param width number The width of the kernel to create (must be an odd integer).
-- @param height number The height of the kernel to create (must be an odd integer).
-- @param arg number The argument to pass when creating the kernel. Currently only used by gaussian kernel as the sigma value.
function worldeditadditions.get_kernel(name, width, height, arg)
if width % 2 ~= 1 then
return false, "Error: The width must be an odd integer.";
end
if height % 2 ~= 1 then
return false, "Error: The height must be an odd integer";
end
if name == "box" then
return true, worldeditadditions.conv.kernel_box(width, height)
elseif name == "pascal" then
return true, worldeditadditions.conv.kernel_pascal(width, height, true)
elseif name == "gaussian" then
if width ~= height then
return false, "Error: When using a gaussian kernel the width and height must be identical."
end
-- Default to sigma = 2
if arg == nil then arg = 2 end
local success, result = worldeditadditions.conv.kernel_gaussian(width, arg)
return success, result
end
end
function worldeditadditions.convolve(pos1, pos2, kernel, kernel_size)
pos1, pos2 = worldedit.sort_pos(pos1, pos2)
local manip, area = worldedit.manip_helpers.init(pos1, pos2)
local data = manip:get_data()
local stats = { added = 0, removed = 0 }
local node_id_air = minetest.get_content_id("air")
local heightmap = worldeditadditions.make_heightmap(pos1, pos2, manip, area, data)
local heightmap_conv = worldeditadditions.shallowcopy(heightmap)
local heightmap_size = {}
heightmap_size[0] = pos2.z - pos1.z
heightmap_size[1] = pos2.x - pos1.x
worldeditadditions.conv.convolve(
heightmap_conv,
heightmap_size,
kernel,
kernel_size
)
for z = heightmap_size[0], 0, -1 do
for x = heightmap_size[1], 0, -1 do
local hi = z*heightmap_size[1] + x
local diff = heightmap_conv[hi] - heightmap[hi]
-- Lua doesn't have a continue statement :-/
if diff ~= 0 then
local node_id = data[area:index(pos1.x + x, pos1.y + heightmap[hi], pos1.z + z)]
if diff > 0 then
stats.added = stats.added + diff
for y = pos1.y + heightmap[hi], pos1.y + heightmap_conv[hi], 1 do
data[area:index(pos1.x + x, y, pos1.z + z)] = node_id
end
else
stats.removed = stats.removed + math.abs(diff)
for y = pos1.y + heightmap_conv[hi], pos1.y + heightmap[hi], 1 do
data[area:index(pos1.x + x, y, pos1.z + z)] = node_id_air
end
end
end
end
end
worldedit.manip_helpers.finish(manip, data)
return true, stats
end