Why Canvas is not an obvious choice for web games

I'm with this guy. Canvas is great, but it's an element to include in your scene to render vector graphics, not a container for you to render your scene inside. Often you'll have dozens of them layered about the place, happily doing their thing and unaware of each other.<p>Use it right and it's a great tool. Try to use it as a panacea Flash replacement and you're in for a bunch of headache.

I think he is comparing apples to oranges here. Using HTMl as the "rendering device" works on a different (higher) level of abstraction. The additional layer of abstraction in HTML has already solved the complexity of doing efficient partial redraws based on changes to a subset of a scene graph. This isn't something that the canvas API was meant to handle. If one were to use a scene graph (or display list) abstraction on top of canvas, it would shield the application developer from this complexity just as well as the HTML does now. However, the HTML abstraction, although more general, is implemented in native code while a canvas based scene-graph would need to go through java-script, so it is at a disadvantage as to how far it can be optimized. Basically, what he needs is SVG. :-)

This depends on the type of the game, but a fellow developer is beta-testing a canvas based game <a href="http://esdao.com" rel="nofollow">http://esdao.com</a> . It's works quite well, with the exception of Mobile Safari to my recollection which is supposed to perform better with the next iOS update.

For anyone wondering what happened to Dextrose (the company Bakaus founded to make the Aves HTML5 game engine), it was bought by Zynga back in May. He is now the CTO of Zynga Germany.

WebGL should fix this problem.

I have found that the performance you get with canvas as opposed to using a DOM based rendering varies greatly with the device and rendering engine that your code runs on (shouldnt be a suprise really).<p>For my game I have encapsulated redering to use webkitTransform and translate3d if hardware acceleration is present. Otherwise use canvas, or in the worst case (IE6-8), use DOM with left and top css attributes.<p>If your game, like mine, can use a form of dirty-rectangle, invalidation strategy to rendering, its possible to do 60fps rendering with low CPU usage on iOS and desktop browsers.

So is UO or a good, top down perspective rpg coming to canvas soon? Which have been announced?