circle class example in love

README.md

Requires love 11.5.

Put files in a directory then run love path/to/directory

dir
  main.lua
  classic.lua

classic.lua

--
-- classic
--
-- Copyright (c) 2014, rxi
--
-- This module is free software; you can redistribute it and/or modify it under
-- the terms of the MIT license. See LICENSE for details.
--


local Object = {}
Object.__index = Object


function Object:new()
end


function Object:extend()
  local cls = {}
  for k, v in pairs(self) do
    if k:find("__") == 1 then
      cls[k] = v
    end
  end
  cls.__index = cls
  cls.super = self
  setmetatable(cls, self)
  return cls
end


function Object:implement(...)
  for _, cls in pairs({...}) do
    for k, v in pairs(cls) do
      if self[k] == nil and type(v) == "function" then
        self[k] = v
      end
    end
  end
end


function Object:is(T)
  local mt = getmetatable(self)
  while mt do
    if mt == T then
      return true
    end
    mt = getmetatable(mt)
  end
  return false
end


function Object:__tostring()
  return "Object"
end


function Object:__call(...)
  local obj = setmetatable({}, self)
  obj:new(...)
  return obj
end


return Object

main.lua

Object = require 'classic'

function love.load()
  circle1 = circle(400,300,50)
end

function love.draw()
  Circle2:drawShaking(0.2)
end

function love.update()
end

function love.mousepressed(x,y,btn,istouch)
  Circle2:mousePressed(x,y,btn,istouch, function() 
    print('Circle2 was pressed')
    end)
end

local circle = Object:extend()

--Creates a circle with position x,y and radius
--
--
---@param x number
---@param y number
---@param radius number
---@param r number
---@param g number
---@param b number
--**creation_time** Will have a creation_time
function circle:new(x,y,radius, r,g,b)
    self.x = x or 0
    self.y = y or 0
    self.radius = radius or 1
    self.r = r or 1
    self.g = r or 1
    self.b = r or 1
    self.creation_time = love.timer.getTime()   
end

function circle:getCreationTime()
    return self.creation_time
end

function circle:draw()
    love.graphics.circle("fill", self.x, self.y, self.radius)
    -- love.graphics.reset()
end

-- see: https://stackoverflow.com/questions/5837572/generate-a-random-point-within-a-circle-uniformly
-- how to create a shaking circle
--
-- r = R * sqrt(random())
--
-- theta = random() *2 * pi
--
-- x = centerX + r * cos(theta)
--
-- y = centerY + r * sin(theta)
---@param _shake_radius number magnitude of shaking [0..1] / default 10% of circle radius
---@return nil
function circle:drawShaking(_shake_radius)
    local shake_radius = (_shake_radius*self.radius) or (.1*self.radius)
    local pi = 3.14159
    local r = shake_radius  * math.sqrt(love.math.random())
    local theta = love.math.random() *2*pi
    local new_x = self.x + r * math.cos(theta)
    local new_y = self.y + r * math.sin(theta)
    love.graphics.circle("fill", new_x, new_y, self.radius)
end

function circle:update(dt)

end

-- Put this function inside love.mousepressed(x,y,btn,istouch)
function circle:mousePressed(x,y, btn, istouch, callback)
    if btn == 1 then
        -- For a circle button at 20, 50 coordinates with 40 radius: 
        if math.sqrt((self.x-x)^2+(self.y-y)^2) <= self.radius then
            --do your stuff because the button was pressed
            callback()
        end
    end
end