vector2d

A simple and flexible 2D vector class written in Lua.

Features

• Create 2D vectors with x, y components and precomputed magnitude
• Operator overloading:
  • Addition (+)
  • Division (/)
  • Subtraction (-)
  • Multiplication (*)
  • Equality check (==)
• In-place operations:
  • :iadd(vector) — modifies the current vector by adding another
  • :isub(vector) — modifies the current vector by subtracting another
  • :imul(vector) — modifies the current vector by multiplying by another
• Convert a vector to a formatted string with :tostring()

Functions

vector2d:new(x, y)

Creates a new vector with the specified x and y values. Parameters:

• x (number): The x-component of the vector.
• y (number): The y-component of the vector.

Returns:

• A new vector2d instance.

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vector2d:update_magnitude()

Calculates the magnitude of the vector using the formula: √(x² + y²). This is called automatically when creating a new vector or modifying it with operations.

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vector2d:normalize()

Normalizes the vector (scales it to have a magnitude of 1), unless the vector is (0, 0).

Returns:

• The normalized vector2d instance (modifies the current vector).

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In-place Operations

• vector2d:iadd(v) Adds another vector v to the current vector, modifying the original vector.

• vector2d:isub(v) Subtracts another vector v from the current vector, modifying the original vector.

• vector2d:imul(v) Multiplies the current vector by another vector v, modifying the original vector.

• vector2d:idiv(v) Divides the current vector by another vector v, modifying the original vector.

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vector2d:tostring()

Returns the vector as a formatted string in the format: (x, y) Returns:

• A string representation of the vector.

Usage

local vector2d = require("vector2d")

-- Creating vectors
local a = vector2d:new(3, 4)
local b = vector2d:new(1, 2)

-- Operator-based (returns new vectors)
local sum = a + b
local diff = a - b
local prod = a * 10

print(sum:tostring())    -- Output: (4.000000, 6.000000)
print(diff:tostring())   -- Output: (2.000000, 2.000000)
print(prod:tostring())   -- Output: (30.000000, 40.000000)

print(a == vector2d:new(3, 4))  -- Output: true
print("Magnitude of a:", a.magnitude) -- Output: 5

-- In-place modification (modifies the object and returns self)
a:iadd(b):isub(b):imul(10)
print("Modified a:", a:tostring())

Examples

Using love2d I created an example of use, just run love2 in the examples folder

love examples

output: