Author: David Flanagan
Publisher: O'Reilly, 2010
Pages: 112 pages
ISBN: 978-1449396800
Aimed at: Intermediate Javascript programmers
Rating: 4
Pros: Concise introduction and handy reference
Cons: Occasionally short on explanation
Reviewed by: Ian Elliot

Canvas - it's new but if you have used almost any 2D graphics framework the way that it works will already be familiar to you. As a result you probably don't need a full book on the topic - perhaps a pocket reference would do.

Surprisingly this book manages to get through most of the material you might need in an introduction to canvas in fewer than 100 pages. It is an extract from the forthcoming edition of David Flanagan's JavaScript the Definitive Guide, but if you are in a hurry to get to grips with Canvas and want something more portable it's well worth considering.

The book only has two chapters - a Canvas tutorial and a reference section. The tutorial starts off explaining how to get a canvas object on a web page. Most of the explanations are straightforward - how to draw a line, a shape, controlling the fill, the line style and so on. Every now and again there is a more expansive idea introduced, such as how to save the drawing state in another object and restore it.

Occasionally you might wish that the explanation given was a little longer - for example the discussion of security and bitmaps from other sites doesn't explain the ideas sufficiently and doesn't deal with the tricky problem of working with local files.

The second chapter is a reference section that take each canvas method and object and describes it in detail. This goes beyond the simple statement of what they are to include a discussion to make sure you understand - this chapter is useful when you have forgotten what a method or property does.

Overall this is a useful book if you already know JavaScript and have encountered a 2D graphics facility before. It isn't of much use to the complete novice, but then you wouldn't expect it to be.

Recommended if you find you can't remember exactly how methods and properties work.

Related I-Programmer articles:

A Programmer's Guide to Canvas

Canvas bitmap operations - bitblt in JavaScript