The throttling is simply a side effect of v-sync. Every paint request is synced with the display's refresh rate. This means you can only draw every ~16 milliseconds (== 60 fps.) Of course, if your application cannot draw in 16 ms you will be synced every 2 frames and you will fall to 30 fps.
On Sun, Oct 14, 2012 at 2:08 PM, Adam Ratana <[email protected]> wrote: > Hi Romain, > > If you don't mind, would you please describe how the implicit throttling > mechanism works, or, point to any documentation on it? > > I think I am running into this, when my activities start, and the view is > being invalidated often, it is throttled it seems for a little while (5-10 > seconds?). > > After what seems to be an initial throttling, all is fine and I am seeing > good frame rates. > > Some of my activities do a lot of of canvas drawing (using the HW > accelerated rendering) triggered by sensor updates, and since JB I believe > I've seen this throttling when the activity starts. I'd love to avoid this, > while still getting 30fps+ when necessary. I could be wrong but it also > seems the throttling is more prevalent/present if text is being drawn using > canvas.drawText, but have not yet dug deeper into experimenting and figuring > out how I can trigger or not trigger the throttling. > > Adam > > On Thursday, October 11, 2012 5:41:08 PM UTC-4, Romain Guy (Google) wrote: >> >> There is an implicit throttling mechanism as of 4.1 but even then it's >> bad. If you don't need to draw, don't draw. You're going to waste >> battery. >> >> On Thu, Oct 11, 2012 at 2:34 PM, bob <[email protected]> wrote: >> > As you may know, you can create a View subclass and then call >> > invalidate() >> > at the end of the painting method. >> > >> > >> > This produces continuous updating. >> > >> > >> > Is this really really bad? >> > >> > >> > It sure is attractive due to its simplicity. >> > >> > >> > However, there is no explicit throttling mechanism, which can be an >> > issue if >> > there is also no implicit one. >> > >> > >> > -- >> > You received this message because you are subscribed to the Google >> > Groups "Android Developers" group. >> > To post to this group, send email to [email protected] >> > To unsubscribe from this group, send email to >> > [email protected] >> > For more options, visit this group at >> > http://groups.google.com/group/android-developers?hl=en >> >> >> >> -- >> Romain Guy >> Android framework engineer >> [email protected] > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en -- Romain Guy Android framework engineer [email protected] -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
