From 0a3680aa7d1e64a2fc0aff4f5b61673ad7c7486b Mon Sep 17 00:00:00 2001
From: Starbeamrainbowlabs <sbrl@starbeamrainbowlabs.com>
Date: Sat, 26 Jun 2021 16:56:26 +0100
Subject: [PATCH] Vector3: add unit / normalise

---
 .tests/Vector3/unit.test.lua         | 37 ++++++++++++++++++++++++++++
 worldeditadditions/utils/vector3.lua | 12 +++++++++
 2 files changed, 49 insertions(+)
 create mode 100644 .tests/Vector3/unit.test.lua

diff --git a/.tests/Vector3/unit.test.lua b/.tests/Vector3/unit.test.lua
new file mode 100644
index 0000000..3d3b01d
--- /dev/null
+++ b/.tests/Vector3/unit.test.lua
@@ -0,0 +1,37 @@
+local Vector3 = require("worldeditadditions.utils.vector3")
+
+-- To find these numbers, in Javascript:
+-- function t(x) { return Math.sqrt((x*x)*3); }
+-- for(let i = 0; i < 1000000000; i++) { let r = t(i); if(Math.floor(r) === r) console.log(`i ${i}, r ${r}`); }
+
+
+describe("Vector3.unit", function()
+	it("should work with a positive vector", function()
+		local a = Vector3.new(10, 10, 10)
+		assert.are.same(
+			Vector3.new(57735, 57735, 57735),
+			a:unit():multiply(100000):floor()
+		)
+	end)
+	it("should work with a the normalise alias", function()
+		local a = Vector3.new(10, 10, 10)
+		assert.are.same(
+			Vector3.new(57735, 57735, 57735),
+			a:normalise():multiply(100000):floor()
+		)
+	end)
+	it("should work with a negative vector", function()
+		local a = Vector3.new(10, 10, 10)
+		assert.are.same(
+			Vector3.new(57735, 57735, 57735),
+			a:unit():multiply(100000):floor()
+		)
+	end)
+	it("should work with a mixed vector", function()
+		local a = Vector3.new(-371635731, 371635731, -371635731)
+		assert.are.same(
+			Vector3.new(-57736, 57735, -57736),
+			a:unit():multiply(100000):floor()
+		)
+	end)
+end)
diff --git a/worldeditadditions/utils/vector3.lua b/worldeditadditions/utils/vector3.lua
index 30771ff..3d4bcc5 100644
--- a/worldeditadditions/utils/vector3.lua
+++ b/worldeditadditions/utils/vector3.lua
@@ -208,6 +208,18 @@ function Vector3.set_to(a, length)
 	return (a / a:length()) * length
 end
 
+--- Returns the unit vector of this vector.
+-- The unit vector is a vector with a length of 1.
+-- Returns a new vector.
+-- Does not change the direction of the vector.
+-- @param	a		Vector3		The vector to operate on.
+-- @returns	Vector3	The unit vector of this vector.
+function Vector3.unit(a)
+	return a / a:length()
+end
+--- Alias of Vector3.unit.
+function Vector3.normalise(a) return a:unit() end
+
 
 --- Return a vector that is amount distance towards b from a.
 -- @param	a		Vector3		The vector to move from.