In the preceding chapter, you achieved a smooth animation of thousands of points by doing away with the DOM. The DOM is a representation of each element in browser memory. Bypassing it, you were dealing with much less overhead during animation. However, the DOM can be very useful for other goals in web development. High up on that list – especially for data visualization – is the interaction with elements on screen.
You can just add an onmousemove or onclick listener to an element. You can’t do that to elements on a Canvas. They are a pixel manifestation of past code, not represented as a model within the browser.
However, don’t despair, there are indirect yet simple techniques to interact with your Canvas. We’ll be looking at the most important techniques in this chapter, building an interactive globe:
