Good afternoon.

Good evening, depending on where you are in the world.

My name is Colton Ogden, and this is CS50 on Twitch,

where we code stuff from scratch, or where I typically

code things from scratch.

If you're a first time viewer, that's what we'll be doing today.

We're going to be looking at the typing game.

So this is kind of an archetype for games.

It's not a very common archetype, certainly.

But it's a game that you may have seen implemented in such games

as Typing of the Dead, where you have a word in front of you,

and your goal is to type this word without mistakes.

And when you do, you do something like shoot a zombie,

or there are certain top down versions where you're a mage

and you cast spells.

Or you can just do it for sport and see how many points

you can accrue over a span of time.

And that's what we'll be doing today.

So shout outs to everybody that's in the chat already.

So we have a bunch of folks.

I'm going to go scroll up to the very top.

So Whipstreak was here actually from the very beginning.

So he says, I'm here.

Bhavik Knight says, hey all--

Bhavik Knight, a regular.

Whipstreak also very much a regular, but I

think Bhavik Knight hasn't missed a single stream, if I'm not mistaken.

The Korean Bot says, hello there.

The Quran Bot, sorry.

I mispronounced that.

TazNoor, hi everybody.

Hello, TazNoor.

Sashikant32, another regular, says hello.

Buddha Nag says, this is old student, with a smiley face.

And then later on, I believe mentioned here she was doing a final project

and looking for suggestions.

Bella Kirs, hello to you.

Let me just make sure I'm not missing anybody.

Asley, Nuwanda3333.

So shout outs to Asley.

She's responsible for this particular stream and the stream preceding it.

So she recommended that we do a typing game based stream.

And so that's what we're doing today.

So shout outs to her.

Everybody can thank Asley for her recommendation.

She's also recommended many other streams that we have done so far.

And asking Buddha Nag, who asked, you guys can suggest me a final year

project, please.

And then Asley was saying, no one can actually give you

an answer on your final project.

It needs to be something you're passionate about.

And I agree with that.

It's definitely something when you're doing

a final project or some sort of large project,

it helps to do something that is pertinent to your interests,

but also intersects with your area of expertise.

To Bhavik Knight's point, asking for, what is your expertise area, Buddha?

And then Bella says, you can watch the CS50 Fair

for inspiration, which is true.

Yes, we did showcase many awesome projects

for the CS50 Fair, which is on YouTube.

Kirayue says hi, CS50.

Hello, Kirayue.

Hello Shamxr.

I suggest having a brainstorm session, be it here or with your friends.

Yes, very true.

Brainstorm sessions are amazing.

I was wondering how to make an application about finding

teachers near us, says Buddha.

OK, that's an interesting use case, certainly.

Whipstreak says, where's my Colton at?

JP Guy is waving, says hello.

Hello, JP Guy.

Good to see you as well.

Nice rhythm, Colton.

Thank you.

I was thinking to make an app that a student will hire a teacher

and make an appointment near him or her.

Yeah, that'd be pretty cool.

An app like that would therefore require you

to have some sort of database of teachers,

and then maybe a separate log in system for teachers and students

so that they could both register and be sort of paired up with one another.

But that'd be very interesting.

I saw a project very similar to that at the Yale Fair, actually.

There was a student that had something similar to that.

So good idea.

[INAUDIBLE] says, hi, Colton.

Glad to see you.

Yay.

Hey, Colton.

Hey, Colton.

Everybody is very awesome.

Not for engineering.

It's for computer applications final year.

Oh, I see.

OK.

Kirayue, Colton, good to see you.

Sashikant, Asley.

I missed one CDCI.

Oh, right.

OK.

So just one out of 24 or 25 streams, Bhavik has missed only one,

the continuous integration with Travis.

That's OK.

At least you can watch the VOD thereafter.

But still, that's like higher than a 90% attendance rate.

So awesome.

Well, thanks everybody for joining today.

So let's sort of get into what we're talking about.

I'm going to flip over to my screen.

In case you're unfamiliar with what I'm going to be using to make today's game,

it's a framework called LOVE and a language called Lua.

So the framework is here, love2d.org.

It's an awesome 2D graphics programming framework.

Definitely grab it if you're not familiar with it.

There are other streams where I've talked about how to set it up

and the basics of it.

And today we're going to be kind of taking a lot of the principles we

talked about on Monday.

So on Monday of this week--

and you can watch the video on YouTube if you're watching it after the fact--

but we did Hangman, which is mostly textual, looking for text input

from the user, drawing simple shapes, and then trying to fill out a word,

and therefore looking at the letters of the word

to make sure that they match up with letters that we've already typed,

and so on and so forth.

Today we're taking some of those ideas and kind

of making a different game that has more of a time-based mechanic,

insofar as you have 60 seconds to type a word

or a series of words that are presented to the user.

And for every word you complete, you get a point.

And then at the end of the 60 seconds, you're

basically graded on how many words you successfully complete.

So if you did 20, 25, however many words--

it's not quite the same as maybe a typing test on, for example,

typing test or whatnot, where you can see a body of text

and then write it out, and then be graded

on how fast your words per minute would be sort of traditionally typing.

This is more like reactively typing, and only

being able to see one word at a time.

So it's a little bit different, a little more gamey.

This principle, this idea, has been used in commercial games, some pretty cool

commercial games, like Typing of the Dead,

which was a game that they recently added a new version for Windows, I

believe, Typing of the Dead Overkill.

That's what the more recent incarnation is of the game.

But if we look here-- and I'll try to make it nice and large--

this is what Typing of the Dead looked like, the original version that

came out circa 2000.

And this game basically has--

it's kind of like House of the Dead, which

is a shooter game, a arcade game where you had a light gun,

and you would shoot zombies as they come into the view of the screen.

And it was kind of tangible in that sense, in that you actually

had the physical gun and you're shooting at the zombies.

But this game doesn't require you to shoot at any zombies.

This game is kind of like, there are zombies coming at you,

and you are figuratively shooting at them by just typing words reactively

as they come onto the screen.

And so for every word that comes on that you successfully type-- in this case,

ping-pong and bang-bang--

the game will shoot the zombie for you, and treat it

as if you had successfully shot it.

And if you miss a letter, essentially the zombie will get closer to you

and attack you, and eventually you will lose.

Now, of course, to make a game like this, there's a lot of layers.

A full 3D game or even a 2D game that has these sort of mechanics,

we don't have time to do that in a single stream.

Instead, what we're going to do is just illustrate

the simple mechanic of a bit of text comes up in a screen,

a word comes up on the screen, and you have to type it out.

And it will show the full word and your progress.

And if you type it successfully in the right order,

the letters will fully appear.

Eventually you'll get the word.

You'll get a point.

If you miss a letter, then you'll go back to the beginning of the word,

and you'll act as if you failed that.

And that's effectively how you not lose, but do more poorly,

is that you just don't get as many words typed onto the screen, right?

So that's today's game.

That's the gist of--

at least the mechanic that we're going to illustrate today

in a couple of hours, a few hours.

The first thing I'm going to do, as always,

is I'm going to go to my Streams folder, where I have all of the repos

that I've done so far.

And I'm just going to create a folder called Typing Game.

I'm going to click and drag this to my text editor of choice,

which is Visual Studio Code.

If anybody isn't familiar, it's an awesome text editor.

It's free.

Definitely grab it.

And it's an empty folder.

So I'm just going to create a new file called main.lua.

The language that we're going to be using today is Lua.

If you're unfamiliar with Lua and LOVE, definitely

check out, for example, the Hangman stream, which we did on Monday.

I feel like we did a pretty good job of covering

a lot of the basics of LOVE 2D.

But certainly, if you go back farther onto some of the Twitch VODs

on YouTube or on Twitch--

more so on YouTube, because the Twitch VODs have an expiration day--

if you go back to some of those older videos,

you'll see that we cover LOVE 2D the framework in a little

more granular detail, and cover things like a game loop

and like the love.load, love.update, love.draw, in a bit more

detail and a little bit slower.

But today we're going to kind of go a little faster.

But we'll still cover more or less the basics.

And I'll give you the rundown of what's going on.

Another important thing that I do want to do--

and this is sort of what I try to do most of the time when we do streams--

is I'm going to go to GitHub.

And it's a little bit slow.

For some reason, GitHub always takes a minute to load up.

GitHub is an awesome website, if you're unfamiliar,

which allows you to store source code and allows

you to store the history of source code and collaborate with other people

and do a bunch of other awesome things, automate deployments

of your applications.

I'm going to create a repo called Typing Game Stream.

Typing game implemented on Twitch.

I'm going to make this public.

This is so that I can push all my code at the end of today.

And if you want, you can take the source code, mess with it,

do your own stuff to it, and get some more value out

of it if you decide not to code along with me, which might be--

maybe if you're busy at this exact moment in time,

you don't want to do that.

That's fine.

Or if you want to get the code right away