pong.lua

-- INSTALLATIONS
-- https://cs50.harvard.edu/x/2021/seminars/#a-taste-of-game-development
-- https://love2d.org/
-- https://code.visualstudio.com/download
-- https://github.com/Ulydev/push

VIRTUAL_WIDTH = 384
VIRTUAL_HEIGHT = 216
WINDOW_WIDTH = 1280
WINDOW_HEIGHT = 720

PADDLE_WIDTH = 8
PADDLE_HEIGHT = 32
PADDLE_SPEED =  140

BALL_SIZE = 4

LARGE_FONT = love.graphics.newFont(32)
SMALL_FONT = love.graphics.newFont(16)

POINTS_WINNER = 2

-- #include.....
push = require 'push'

gamestate = 'title'

player1 = {
    x = 10, y = 10 , score = 0
}

player2 = {
    x = VIRTUAL_WIDTH - PADDLE_WIDTH - 10,
    y = VIRTUAL_HEIGHT - PADDLE_HEIGHT - 10,
    score = 0
}

ball = {
    x = (VIRTUAL_WIDTH / 2) - (BALL_SIZE/2),
    y = (VIRTUAL_HEIGHT / 2) - (BALL_SIZE/2),
    dx = 0, dy = 0
}

function love.load()
    math.randomseed(os.time())
    love.graphics.setDefaultFilter('nearest','nearest')
    push:setupScreen(VIRTUAL_WIDTH, VIRTUAL_HEIGHT, WINDOW_WIDTH, WINDOW_HEIGHT)

    resetBall()
end

function love.update(dt)
    if love.keyboard.isDown('w') then
        player1.y = player1.y - PADDLE_SPEED * dt
    elseif  love.keyboard.isDown('s') then
        player1.y = player1.y + PADDLE_SPEED * dt
    end

    if love.keyboard.isDown('up') then
        player2.y = player2.y - PADDLE_SPEED * dt
    elseif  love.keyboard.isDown('down') then
        player2.y = player2.y + PADDLE_SPEED * dt
    end

    if gamestate == 'play' then
        ball.x = ball.x + ball.dx * dt
        ball.y = ball.y + ball.dy * dt

        --1P mode
        if ball.dx > 0 then
            if (ball.y < player2.y) then
                player2.y = player2.y - PADDLE_SPEED * dt
            else
                player2.y = player2.y + PADDLE_SPEED * dt
            end
        end

        if ball.y <= 0 then
            ball.dy = -ball.dy
        elseif ball.y >= VIRTUAL_HEIGHT - BALL_SIZE then
            ball.dy = -ball.dy
        end

        if collides(ball, player1) then
            ball.x = player1.x + PADDLE_WIDTH
            ball.dx = -ball.dx
        elseif collides(ball, player2) then
            ball.x = player2.x - BALL_SIZE
            ball.dx = -ball.dx
        end

        if ball.x <= 0 then
            resetBall()
            gamestate = 'serve'
            player2.score = player2.score + 1
            if player2.score >= POINTS_WINNER then
                gamestate = 'win'
            end
        elseif ball.x >= VIRTUAL_WIDTH - BALL_SIZE then
            resetBall()
            gamestate = 'serve'
            player1.score = player1.score + 1
            if player1.score >= POINTS_WINNER then
                gamestate = 'win'
            end
        end

    end
end

function love.keypressed(key)
    if key == 'escape' then
        love.event.quit()
    end

    if key == 'enter' or key == 'return' then
        if gamestate == 'title' then
            gamestate = 'serve'
        elseif gamestate == 'serve' then
            gamestate = 'play'
        elseif gamestate == 'win' then
            player1.score = 0
            player2.score = 0
            gamestate = 'title'
        end
    end

end

function love.draw()
    push:start()
    --love.graphics.print('Hello, world!')

    --set RBG of background
    love.graphics.clear(40/255, 45/255, 52/255, 255/255)
    if gamestate == 'title' then
        love.graphics.setFont(LARGE_FONT)
        love.graphics.printf('Pre50 Pong', 0, 10, VIRTUAL_WIDTH, 'center')
        love.graphics.setFont(SMALL_FONT)
        love.graphics.printf("Press Enter to start the game!", 0, VIRTUAL_HEIGHT-32, VIRTUAL_WIDTH, 'center')
    elseif gamestate == 'serve' then
        love.graphics.setFont(SMALL_FONT)
        love.graphics.printf("Press Enter to Serve!", 0, 10, VIRTUAL_WIDTH, 'center')
    elseif gamestate == 'win' then
        love.graphics.setFont(LARGE_FONT)
        --local winner = player1.score >= 10 and '1' or '2'

        local winner
        if player1.score >= POINTS_WINNER then
            winner = '1'
        else
            winner = '2'
        end
        love.graphics.printf('Player ' .. winner .. ' wins!', 0, 10, VIRTUAL_WIDTH, 'center')
        love.graphics.setFont(SMALL_FONT)
        love.graphics.printf("Press Enter to restart the game!", 0, VIRTUAL_HEIGHT-32, VIRTUAL_WIDTH, 'center')
    end

    love.graphics.setFont(LARGE_FONT)
    love.graphics.print(player1.score, VIRTUAL_WIDTH / 2 - 32, VIRTUAL_HEIGHT / 2 - 16)
    love.graphics.print(player2.score, VIRTUAL_WIDTH / 2 + 16, VIRTUAL_HEIGHT / 2 - 16)
    love.graphics.setFont(SMALL_FONT)

    love.graphics.rectangle('fill',player1.x, player1.y, PADDLE_WIDTH, PADDLE_HEIGHT)
    love.graphics.rectangle('fill',player2.x, player2.y, PADDLE_WIDTH, PADDLE_HEIGHT)
    love.graphics.rectangle('fill',ball.x, ball.y, BALL_SIZE, BALL_SIZE)
    push:finish()
 end


 function collides(b, p)
    return not (b.y > p.y + PADDLE_HEIGHT or b.x > p.x + PADDLE_WIDTH or p.y > b.y + BALL_SIZE or p.x > b.x + BALL_SIZE)

end

function resetBall()

    ball.x = (VIRTUAL_WIDTH / 2) - (BALL_SIZE/2)
    ball.y = (VIRTUAL_HEIGHT / 2) - (BALL_SIZE/2)

    ball.dx = 60 + math.random(60)
    if math.random(2) == 1 then
        ball.dx = -ball.dx
    end

    ball.dy = 30 + math.random(60)
    if math.random(2) == 1 then
        ball.dy = -ball.dy
    end

end