Pong

--
--  Pong
--  Made by GravityScore
--


--  -------- Variables

local w, h = term.getSize()
local refresh = 0.15

local paddle1 = {
    x = 1,
    y = 2,
    height = 5
}

local paddle2 = {
    x = w,
    y = 2,
    height = 5
}

local ball = {
    x = math.floor(w/2),
    y = math.floor(h/2),
    velx = -1,
    vely = 1,
    update = function(self)
        self.x = self.x + self.velx
        self.y = self.y + self.vely
    end
}


--  -------- Utilities

local function pointOnPaddle(x, y, paddle)
    return x == paddle.x and y >= paddle.y and y <= paddle.y + paddle.height - 1
end

local function redraw()
    term.setBackgroundColor(colors.black)
    term.setTextColor(colors.white)
    term.clear()
    term.setBackgroundColor(colors.white)
    term.setCursorPos(ball.x, ball.y)
    write(" ")
    for i = 1, paddle1.height do
        term.setCursorPos(paddle1.x, paddle1.y + i - 1)
        write(" ")
    end for i = 1, paddle2.height do
        term.setCursorPos(paddle2.x, paddle2.y + i - 1)
        write(" ")
    end
end


--  -------- Main

local function main()
    local timerId = os.startTimer(refresh)
    while true do
        local e, but, x, y = os.pullEvent()
        if e == "key" then
            if but == keys.up and paddle2.y > 1 then
                paddle2.y = paddle2.y - 1
                redraw()
            elseif but == keys.down and paddle2.y + paddle1.height <= h then
                paddle2.y = paddle2.y + 1
                redraw()
            elseif but == keys.w and paddle1.y > 1 then
                paddle1.y = paddle1.y - 1
                redraw()
            elseif but == keys.s and paddle1.y + paddle1.height <= h then
                paddle1.y = paddle1.y + 1
                redraw()
            elseif but == keys.q then
                term.setBackgroundColor(colors.black)
                term.setTextColor(colors.white)
                term.clear()
                term.setCursorPos(1, 1)
                return "quit"
            end
        elseif e == "timer" and but == timerId then
            ball.update(ball)
            redraw()
            if ball.x == 2 then
                if pointOnPaddle(ball.x - 1, ball.y, paddle1) then
                    ball.velx = 1
                else
                    ball.update(ball)
                    redraw()
                    sleep(2)
                    return "game over"
                end
            end if ball.x == w - 1 then
                if pointOnPaddle(ball.x + 1, ball.y, paddle2) then
                    ball.velx = -1
                else
                    ball.update(ball)
                    redraw()
                    sleep(1)
                    return "game over"
                end
            end
            if ball.y == 1 then ball.vely = 1 end
            if ball.y == h then ball.vely = -1 end
            timerId = os.startTimer(refresh)
        end
    end
end

-- Redraw
redraw()

-- Play
local exit = main()

-- Exit
term.setBackgroundColor(colors.black)
term.setTextColor(colors.white)
term.clear()
if exit == "game over" then
    term.setCursorPos(3, 3)
    write("Game Over!")
    sleep(2)
    term.clear()
    term.setCursorPos(1, 1)
elseif exit == "quit" then
    term.setCursorPos(1, 1)
end