Example of subclassing physics objects from Löve2d's Hardoncollider, using Class-Commons. Requires HardonCollider to work.

init.lua

-- Add this line to the main hardoncollider/init.lua file around line 136
-- to allow you to add preconstructed shapes.
function HC:addExistingShape(shape)
  return new_shape(self, shape)
end

main.lua

Sprite = require("sprite")

function love.load()
  -- Effectively Sprite:new(x, y, width, height)
  mySprite = common.instance(Sprite, 200, 200, 50, 200)
end

function love.draw()
  -- center() is from ConvexPolygonShape
  local x, y = mySprite:center()
  
  -- Run our custom method
  love.graphics.print(mySprite:hello(), x, y)

  -- Implemented by ConvexPolygonShape
  mySprite:draw('line')
end

sprite.lua

-- Have to require HC because it sets up the class stuff
HC = require("hardoncollider")

Shapes = require("hardoncollider.shapes")
Polygon = require("hardoncollider.polygon")

local Sprite = {}
function Sprite:init(x, y, width, height)
  -- ConvexPolygonShape requires an instance of Polygon
  -- set up a square with our size. Could be set based on the image
  -- in our sprite
  local polygon = common.instance(Polygon,
    x - width/2, y - height/2,
    x + width/2, y - height/2,
    x + width/2, y + height/2,
    x - width/2, y + height/2)

  -- Run our parent's constructor
	Shapes.ConvexPolygonShape.init(self, polygon)

  self.bacon = 42
end

function Sprite:hello()
  return "Hey, bacon is currently " .. self.bacon
end

Sprite = common.class("Sprite", Sprite, Shapes.ConvexPolygonShape)
return Sprite