Professional HTML5 Mobile Game Development

Creating Your Own Script

Although there have been hundreds of useful node modules written, you’ll have specific needs when you build your game in which some simple server-side scripting is useful. There are plenty of options for scripting languages you could use, including Bash, Windows Script, Python, Ruby, or PHP, but because your game is going to be JavaScript and your game libraries are going to be in JavaScript, it make some sense to write command-line scripts in JavaScript as well.

To gain some experience building a node module, this section walks you through building a script for generating spritesheets and some corresponding JSON from a directory of image files. Figure 8-1 shows a sample output image with sprites lined up in a row.

Figure 8-1: A generated spritesheet.

The only hiccup in this process is that the module used in this section, node-canvas, doesn’t compile easily on Windows because of its native-C dependencies. (To get around this, see the earlier section on getting a virtual Linux machine up and running on Windows.)

Creating a package.json File

To start, create a new directory called spriter for the script you want to write; then open a package.json file in that directory. The package.json is a file npm uses to get information about your module and its dependencies. Fill in the contents of your package.json file to match Listing 8-1, replacing your name and ...