[mstange]

  this.img.src = this.img.src.replace(/Fish[a-zA-Z0-9]\./, "Fish"+this.direction+".")

It looks like this line is executed on every frame for all fish in the level. For Firefox users who have the Ghostery addon installed, this makes things rather slow because every setting of the src property invokes Ghostery to check whether or not it wants to block the image load.

Granted, that should be another reason for me to uninstall Ghostery, but I wanted to let you know.

[fiblye]

That was the first NPC I ever made and it's evidence of my dumb code from back then. Guess I forgot to change it.

[kami8845]

how did you figure out that this LOC slowed things down?

[mstange]

Using the new Firefox profiler [0], which isn't quite ready for public consumption yet but already very helpful:

1. Download Firefox Nightly [1]

2. Install the profiler addon [2]

3. Play the game

4. Press Cmd+Shift+O to open a profile of the most recent few seconds

5. Wade through the tree until you find nsIDOMHTMLImageElement_SetSrc, which is called by <Anonymous>() @ CompletedEnemies.js:2460. This function contains only one line which assigns to the src property of an image, and that's the line I pasted.

[0] https://developer.mozilla.org/en-US/docs/Performance/Profili... [1] http://nightly.mozilla.org/ [2] https://addons.mozilla.org/en-us/firefox/addon/gecko-profile...