Libgdx "Drop" game tutorial, HTML really slow fps

I was able to get the Libgdx tutorial game “Drop” working as a desktop application.
Here’s the url for the tutorial:
http://code.google.com/p/libgdx/wiki/SimpleApp

I have a couple questions about the HTML5 project.

First of all, it seems to be running at a really slow fps. It takes a good second to respond to keystrokes or mouse button clicks, and the sound effect comes considerably after the event on the screen.

Is this normal?

Also, I am getting this warning repeatedly:

[WARN] [com.badlogic.drop.GwtDefinition] - Something other than an int was returned from JSNI method
'@com.google.gwt.dom.client.DOMImplStandardBase$ClientRect::getLeft()': Rounding double (178.33334350585938) to int for int

Any thoughts or advice?

[EDIT] Just noticed, there’s lots of messages being posted to the Console, and during the ‘game’ lots of ‘keydown’ lines. I could see where this might be slowing down performance. Is there a way to optionally turn off the console messaging? It seems like that might help some but maybe HTML5 is just going to be slower, regardless? Or I have to get out of Eclipse and try running it?

When you run a GWT application from Eclipse (via Debug as Web Application or Run as Web Application) it runs in so-called hosted mode, where much of the code is still running as Java. The slowness is caused by this as everything has to marshaled between the browser and the code server. There are a couple ways to get around this.

The first is easier, but makes debugging nearly impossible. By instead compiling the GWT project and putting it on a server (local, or on the web), you’ll get normal frame rates as all code will be compiled to javascript. Unfortunately, compiling can take a long time and as previously noted makes debugging very difficult.

The second way is setting up “super dev” mode. Here, the code is compiled as before but it takes less time. Debugging is possible but takes some steps to do. Mario wrote up a nice post on how to set it up so I’ll just point you to that.

http://www.badlogicgames.com/wordpress/?p=3073

Hope it helps.