Getting started with game mechanisms

Let's start with the UI rendering first and then add the font management in order to display the game information in real time.

Rendering UI

With the current code base, very few changes are required in order to be able to have a fully working Tetris.

Rendering initialization

For now, the main function is very small. First, let's add the following lines at the top of the function:

    let sdl_context = sdl2::init().expect("SDL initialization 
      failed");
    let video_subsystem = sdl_context.video().expect("Couldn't get
       SDL video subsystem");
    let width = 600;
    let height = 800;

No need for explanations, we've already explained everything in the previous chapters, so let's continue.

Just after the following lines:

    let sdl_context = sdl2::init().expect("SDL initialization
      failed");
    let mut tetris = Tetris::new();
    let mut timer = SystemTime::now();

    let mut event_pump = sdl_context.event_pump().expect("Failed to
      get SDL...