1 files changed, 101 insertions, 0 deletions
diff --git a/castle_gates/class_pointset.lua b/castle_gates/class_pointset.lua
new file mode 100644
index 0000000..3cbbd89
--- /dev/null
+++ b/castle_gates/class_pointset.lua
@@ -0,0 +1,101 @@
+-- A simple special-purpose class, this is used for building up sets of three-dimensional points for fast reference
+
+Pointset = {}
+Pointset.__index = Pointset
+
+function Pointset.create()
+	local set = {}
+	setmetatable(set,Pointset)
+	set.points = {}
+	return set
+end
+
+function Pointset:set(x, y, z, value)
+	-- sets a value in the 3D array "points".
+	if self.points[x] == nil then
+		self.points[x] = {}
+	end
+	if self.points[x][y] == nil then
+		self.points[x][y] = {}
+	end
+	self.points[x][y][z] = value	
+end
+
+function Pointset:set_if_not_in(excluded, x, y, z, value)
+	-- If a value is not already set for this point in the 3D array "excluded", set it in "points"
+	if excluded:get(x, y, z) ~= nil then
+		return
+	end
+	self:set(x, y, z, value)
+end
+
+function Pointset:get(x, y, z)
+	-- return a value from the 3D array "points"
+	if self.points[x] == nil or self.points[x][y] == nil then
+		return nil
+	end
+	return self.points[x][y][z]
+end
+
+function Pointset:set_pos(pos, value)
+	self:set(pos.x, pos.y, pos.z, value)
+end
+
+function Pointset:set_pos_if_not_in(excluded, pos, value)
+	self:set_if_not_in(excluded, pos.x, pos.y, pos.z, value)
+end
+
+function Pointset:get_pos(pos)
+	return self:get(pos.x, pos.y, pos.z)
+end
+
+function Pointset:pop()
+	-- returns a point that's in the 3D array, and then removes it.
+	local pos = {}
+	local ytable
+	local ztable
+	local val
+
+	local count = 0
+	for _ in pairs(self.points) do count = count + 1 end
+	if count == 0 then
+		return nil
+	end
+	
+	pos.x, ytable = next(self.points)
+	pos.y, ztable = next(ytable)
+	pos.z, val = next(ztable)
+
+	self.points[pos.x][pos.y][pos.z] = nil
+	
+	count = 0
+	for _ in pairs(self.points[pos.x][pos.y]) do count = count + 1 end
+	if count == 0 then
+		self.points[pos.x][pos.y] = nil
+	end
+	
+	count = 0
+	for _ in pairs(self.points[pos.x]) do count = count + 1 end
+	if count == 0 then
+		self.points[pos.x] = nil
+	end
+	
+	return pos, val
+end
+
+function Pointset:get_pos_list(value)
+	-- Returns a list of all points with the given value in standard Minetest vector format. If no value is provided, returns all points
+	local outlist = {}
+	for x, ytable in ipairs(self.points) do
+		for y, ztable in ipairs(ytable) do
+			for z, val in ipairs(ztable) do
+				if (value == nil and val ~= nil ) or val == value then
+					table.insert(outlist, {x=x, y=y, z=z})
+				end
+			end
+		end
+	end
+	return outlist
+end
+			
+	
+\ No newline at end of file