add a barebones vector3 class

data/scripts/vector3.lua

@@ -0,0 +1,116 @@
+local Vector3 = {
+  x = 0,
+  y = 0,
+  z = 0,
+
+  _CLASS_ = "Vector3"
+}
+
+setmetatable(Vector3, Vector3)
+
+local function is_weak_vector3(t)
+  if type(t) ~= "table" then return false end
+
+  local haskeys = t.x ~= nil and t.y ~= nil and t.z ~= nil
+  if not haskeys then
+    return type(t[1]) == "number" and type(t[2]) == "number" and type(t[3]) == "number"
+  else
+    return type(t.x) == "number" and type(t.y) == "number" and type(t.z) == "number"
+  end
+end
+
+function Vector3:__mul(b)
+  if type(b) == "number" then
+    return Vector3{
+      x = self.x * b,
+      y = self.y * b,
+      z = self.z * b,
+    }
+  elseif type(b) == "table" and is_weak_vector3(b) then
+    local other = Vector3(b)
+    return Vector3{
+      self.x * other.x,
+      self.y * other.y,
+      self.z * other.z,
+    }
+  end
+
+  error("Vector3: other must be either a number or a Vector3-like table.")
+  return Vector3()
+end
+
+function Vector3:__div(b)
+  if type(b) == "number" then
+    return Vector3{
+      x = self.x / b,
+      y = self.y / b,
+      z = self.z / b,
+    }
+  elseif type(b) == "table" and is_weak_vector3(b) then
+    local other = Vector3(b)
+    return Vector3{
+      self.x / other.x,
+      self.y / other.y,
+      self.z / other.z,
+    }
+  end
+
+  error("Vector3: other must be either a number or a Vector3-like table.")
+  return Vector3()
+end
+
+function Vector3:__add(b)
+  if not is_weak_vector3(b) then
+    error("Vector3: other must be a Vector3-like table.")
+    return self
+  end
+  local other = Vector3(b)
+  return Vector3{
+    self.x + other.x,
+    self.y + other.y,
+    self.z + other.z,
+  }
+end
+
+function Vector3:__sub(b)
+  if not is_weak_vector3(b) then
+    error("Vector3: other must be a Vector3-like table.")
+    return self
+  end
+  local other = Vector3(b)
+  return Vector3{
+    self.x - other.x,
+    self.y - other.y,
+    self.z - other.z,
+  }
+end
+
+function Vector3:__unm()
+  return Vector3{
+    -self.x,
+    -self.y,
+    -self.z,
+  }
+end
+
+function Vector3:__call(...)
+  local args = ...
+  local nv = {x = 0, y = 0, z = 0}
+  setmetatable(nv, Vector3)
+  if type(args) == "number" then
+      nv.x, nv.y, nv.z = args, args, args
+  elseif type(args) == "table" then
+    if args.x ~= nil then
+      nv.x, nv.y, nv.z = args.x, args.y, args.z
+    else
+      nv.x, nv.y, nv.z = args[1], args[2], args[3]
+    end
+  end
+  return nv
+end
+
+function Vector3:__tostring()
+  return "Vector3(" .. tostring(self.x) .. ", " .. tostring(self.y) .. ", " .. tostring(self.z) .. ")"
+end
+
+return Vector3

data/scripts/vector3test.lua

@@ -0,0 +1,5 @@
+local Vector3 = require "vector3"
+
+local v1 = Vector3{x = 10, y = 20, z = 30}
+local v2 = Vector3(5)
+print(-v2)