1 files changed, 73 insertions, 0 deletions
diff --git a/class_pointset.lua b/class_pointset.lua
new file mode 100644
index 0000000..5bfd22a
--- /dev/null
+++ b/class_pointset.lua
@@ -0,0 +1,73 @@
+-- A simple special-purpose class, this is used for building up sets of three-dimensional points
+-- I only added features to it as I needed them so may not be highly useful outside of this mod's context.
+
+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: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
+\ No newline at end of file