Add circular spirals :D

worldeditadditions/init.lua

@@ -51,6 +51,7 @@ dofile(wea.modpath.."/lib/scale_up.lua")
 dofile(wea.modpath.."/lib/scale_down.lua")
 dofile(wea.modpath.."/lib/scale.lua")
 dofile(wea.modpath.."/lib/spiral_square.lua")
+dofile(wea.modpath.."/lib/spiral_circle.lua")
 dofile(wea.modpath.."/lib/conv/conv.lua")
 dofile(wea.modpath.."/lib/erode/erode.lua")
 dofile(wea.modpath.."/lib/noise/init.lua")

worldeditadditions/lib/spiral_circle.lua

@@ -0,0 +1,86 @@
+local wea = worldeditadditions
+local Vector3 = wea.Vector3
+
+-- ███████ ██████  ██ ██████   █████  ██
+-- ██      ██   ██ ██ ██   ██ ██   ██ ██
+-- ███████ ██████  ██ ██████  ███████ ██
+--      ██ ██      ██ ██   ██ ██   ██ ██
+-- ███████ ██      ██ ██   ██ ██   ██ ███████
+-- 
+--  ██████ ██ ██████   ██████ ██      ███████
+-- ██      ██ ██   ██ ██      ██      ██
+-- ██      ██ ██████  ██      ██      █████
+-- ██      ██ ██   ██ ██      ██      ██
+--  ██████ ██ ██   ██  ██████ ███████ ███████
+
+
+--- Creates a circular spiral that fills the defined region.
+-- @param	pos1				Vector3		The 1st position of the defined region.
+-- @param	pos2				Vector3		The 2nd position of the defined region.
+-- @param	target_node			Vector3		The *normalised* name of the node to use to build the square spiral with.
+-- @param	interval_initial	number		The distance between the walls of the spiral.
+-- @param	acceleration=0		number		Increate the interval by this number every time we hit a corner of the square spiral.
+-- @returns	bool,number|string	A success boolean value, followed by either the number of the nodes set or an error message string.
+function worldeditadditions.spiral_circle(pos1, pos2, target_node, interval_initial, acceleration)
+	if not acceleration then acceleration = 0 end
+	
+	pos1, pos2 = Vector3.sort(pos1, pos2)
+	local volume = pos2:subtract(pos1)
+	local volume_half = volume:divide(2)
+	
+	print("DEBUG:spiral_square | pos1", pos1, "pos2", pos2, "target_node", target_node, "interval_initial:", interval_initial, "acceleration", acceleration)
+	
+	interval_initial = interval_initial + 1
+	
+	-- Fetch the nodes in the specified area
+	local manip, area = worldedit.manip_helpers.init(pos1, pos2)
+	local data = manip:get_data()
+	
+	local node_id = minetest.get_content_id(target_node)
+	
+	local count = 0 -- The number of nodes replaced
+	
+	local centre = pos2:subtract(pos1):floor():divide(2):add(pos1)
+	
+	local pos_current = centre:clone():floor()
+	local interval = interval_initial
+	local radius = 1
+	local angle = 0
+	-- local sides_acc = 0
+	
+	while pos_current:is_contained(pos1, pos2) do
+		
+		for y = pos2.y, pos1.y, -1 do
+			data[area:index(
+				math.floor(pos_current.x),
+				y,
+				math.floor(pos_current.z)
+			)] = node_id
+			count = count + 1
+		end
+		
+		-- print("DEBUG:spiral_circle centre", centre, "bearing", Vector3.fromBearing(angle, 0, radius))
+		pos_current = centre:add(Vector3.fromBearing(angle, 0, radius))
+		
+		local circumference_now = 2 * math.pi * radius
+		local step = (math.pi*2)/(circumference_now*2)
+		if angle < math.pi then step = step / 10 end
+		angle = angle + (step)
+		
+		local acceleration_constant = 0
+		if angle > math.pi / 2 then
+			acceleration_constant = (interval/angle * acceleration) * step
+		end
+		radius = 1 + interval*(angle / (math.pi*2))
+		interval = interval_initial + acceleration_constant
+		
+		
+		print("DEBUG cpos", pos_current:multiply(1000):floor():divide(1000), "angle", math.deg(angle), "step", wea.round(math.deg(step), 3), "radius", wea.round(radius, 3), "interval", wea.round(interval, 3), "accel_const", acceleration_constant)
+		
+	end
+	
+	-- Save the modified nodes back to disk & return
+	worldedit.manip_helpers.finish(manip, data)
+	
+	return true, count
+end

worldeditadditions/utils/vector3.lua

@@ -361,6 +361,22 @@ function Vector3.max(pos1, pos2)
 	)
 end
 
+--- Given 2 angles and a length, return a Vector3 pointing in that direction.
+-- Consider a sphere, with the 2 angles defining a point on the sphere's surface.
+-- This function returns that point as a Vector3.
+-- @source	https://math.stackexchange.com/a/1881767/221181
+-- @param	angle_x		number	The X angle.
+-- @param	angle_y		number	The Y angle.
+-- @param	length		number	The radius of the sphere in question.
+-- @returns	Vector3		The point on the sphere defined by the aforementioned parameters.
+function Vector3.fromBearing(angle_x, angle_y, length)
+	return Vector3.new( -- X and Y swapped
+		length * math.cos(angle_x),
+		length * math.sin(angle_x) * math.sin(angle_y),
+		length * math.sin(angle_x) * math.cos(angle_y)
+	)
+end
+
 
 
 --  ██████  ██████  ███████ ██████   █████  ████████  ██████  ██████