Ball.lua

--[[
    Pong Remake '24

    -- Ball Class --

    Author: Izzy
    tellmlaye@gmail.com

    Represents a ball that moves back and forth between paddles and walls. 
    The ball continues to bounce until it reaches either the left or right 
    boundary of the screen. When this happens, the opponent scores a point.
]]

Ball = Class{}

function Ball:init(x, y, width, height)
    self.x = x
    self.y = y
    self.width = width
    self.height = height

    -- these variables are for keeping track of our velocity on both the
    -- X and Y axis, since the ball can move in two dimensions
    self.dy = 0
    self.dx = 0
end

--[[
    Expects a paddle as an argument and returns true or false, depending
    on whether their rectangles overlap.
]]
function Ball:collides(paddle)
    -- first, check to see if the left edge of either is farther to the right
    -- than the right edge of the other
    if self.x > paddle.x + paddle.width or paddle.x > self.x + self.width then
        return false
    end

    -- then check to see if the bottom edge of either is higher than the top
    -- edge of the other
    if self.y > paddle.y + paddle.height or paddle.y > self.y + self.height then
        return false
    end 

    -- if the above aren't true, they're overlapping
    return true
end

--[[
    The ball is centered on the screen and stationary.
]]
function Ball:reset()
    self.x = VIRTUAL_WIDTH / 2 - 2
    self.y = VIRTUAL_HEIGHT / 2 - 2
    self.dx = 0
    self.dy = 0
end

function Ball:update(dt)
    self.x = self.x + self.dx * dt
    self.y = self.y + self.dy * dt
end

function Ball:render()
    love.graphics.rectangle('fill', self.x, self.y, self.width, self.height)
end