I thought this issue was related to the Canvas plugin, but when I remove everything but the canvas it wasn't happening anymore, so trial and error to find out it might also be related to the platform behavior. But, I'm posting it here because the Canvas plugin is the part that isn't native (and seems like it may be the issue).
When a canvas and a sprite(with the platform behavior) are in the layout there is a notable decrease in FPS. Even if neither is doing anything. But ONLY when webgl is "on". Even though nothing is using webgl as far as I can tell (maybe I missed something).
Here is a capx example:http://dl.dropbox.com/u/659906/canvas_test.capx
Sorry for the complicated button presses to show FPS. But I wanted to make sure the text was not part of the issue.
In this capx, you press "enter" to save the fps to a variable, then hold "space" to show it on screen. When you release space the text will be destroyed.
Enter- save fps to variable
Space (Hold)- display saved variable on screen.
Space (Release)- destroy text on screen
1- destroy sprite with "platform" behavior
2- create sprite with "platform" behavior
0- destroy canvas
9- create canvas
If you destroy the sprite or the canvas, the FPS picks up to 60. If you add more than one sprite, there is no change in FPS. If you add more than one canvas there is additional drop of FPS.
also, if you turn off webgl there is no issue with fps.
I would appreciate a second set of eyes here, as well as any suggestions on what I may be doing wrong.
Additionally, I'd like to say this is an issue that came about with the newest C2 release, but I've yet to uninstall/reinstall/test.