Summary

In this chapter we took a few extra steps into the fascinating world of 2D rendering using the long-awaited canvas API. We took advantage of the canvas' ability to export images to make our game more engaging, and potentially more social. We also made the game more engaging and social by adding a persistence layer on top of the game, whereby we were able to save a player's high score.

Two other new powerful features of HTML5, web messaging and IndexedDB, were explored in this chapter, although there were no uses for these features in this version of the game. The web messaging API provides a mechanism for two or more windows to communicate directly through message passing. The exciting bit is that these windows (or HTML contexts) do not need to be in the same domain. Although this could sound like a security issue, there are several systems in place to ensure that cross-document and cross-domain messaging is secure and efficient.

The web storage interface brings with it three distinct...