Another major enhancement we've just learned about with the announcement of Jelly Bean is called Project Butter. Butter (so named likely due to the colloquialism "smooth as butter") represents a new, more efficient processing framework for Android's latest and greatest iteration, making the OS much faster (allowing animation up to 60fps). Android 4.1 also makes apps more responsive, reducing touch latency and "anticipating where your finger will be at the time of screen refresh."
"How is such an enhancement possible?" I can almost hear you wondering. Take it from the Android developer site:
To ensure a consistent framerate, Android 4.1 extends vsync timing across all drawing and animation done by the Android framework. Everything runs in lockstep against a 16 millisecond vsync heartbeat — application rendering, touch events, screen composition, and display refresh — so frames don’t get ahead or behind.
Android 4.1 also adds triple buffering in the graphics pipeline, for more consistent rendering that makes everything feel smoother, from scrolling to paging and animations.
Android 4.1 reduces touch latency not only by synchronizing touch to vsync timing, but also by actually anticipatingwhere your finger will be at the time of the screen refresh. This results in a more reactive and uniform touch response. In addition, after periods of inactivity, Android applies a CPU input boost at the next touch event, to make sure there’s no latency.
Besides these enhancements, Project Butter also brings something called "Tooling" to the table. Tooling involves the use of a new tool called systrace. Systrace uses Android's Linux kernel to essentially paint an overall picture of what's happening on the system at any given moment, stacking time-series graphs representing happenings and allowing developers to "isolate rendering interruptions and other issues." For those interested, the tool is already available in the Android SDK (Tools R20 and higher).
Project Butter, on top of all the other new features we're learning about today, brings a major enhancement to Android, finally delivering on the age-old cliché of "smooth as butter" transitions and animation, while delivering myriad behind-the-scenes enhancements as well.