01-create-a-scenic-app.md

1. Create a scenic app

First off we'll create a new Scenic application using our previously installed scenic_new mix task. We are building a snake game, so let's call our project snake. The scenic_new package gives us the handy scenic.new task which can be used to bootstrap a new Scenic application.

The task makes some assumptions about the typical structure of a Scenic application. It will generate a skeleton for our snake app with all directories and files already in place. This is "boilerplate" code we would otherwise need to write by hand.

Run this in you terminal:

$ mix scenic.new snake

You will see output like this:

* creating .formatter.exs
* creating .gitignore
* creating README.md
* creating mix.exs
* creating config
* creating config/config.exs
* creating lib
* creating lib/components
* creating lib/snake.ex
* creating lib/scenes
* creating lib/scenes/home.ex
* creating priv/static
Your Scenic project was created successfully.
Next steps for getting started:
    $ cd snake
    $ mix deps.get
You can start your app with:
    $ mix scenic.run
You can also run it interactively like this:
    $ iex -S mix

We see it generated some files inside a new snake folder and gives us hints about what we can do next.

First, we need to navigate into our new project directory:

$ cd snake

Let's see what we got:

$ ls

We will have a look at the mix.exs file - open the file in your editor.

This file contains some core information about our project. There is a deps section at the bottom of the file listing the dependencies needed for running the project. The dependencies are other Elixir libraries, hosted as "hex" packages on hex.pm.

Coach: talks about hex and package managers

defp deps do
  [
    {:scenic, "~> 0.10"},
    {:scenic_driver_glfw, "~> 0.10", targets: :host}
  ]
end

To run the app, we need install the listed libraries. mix also gives us a task to do that, let's run it in the terminal:

$ mix deps.get

Now we are ready to run new Scenic project and check that everything is working 🤞. The scenic_new package also gives us a command to run our project:

$ mix scenic.run

We should see a window similar to this:

Let's draw a snake