Abstract: Many computer applications incorporate and support animation (e.g., interactive user interfaces). Unfortunately, it may be challenging for computer applications and rendering systems to render animation frames at a smooth and consistent rate while conserving system resources. Accordingly, a technique for controlling animation rendering frame rate of an application is disclosed herein. An animation rendering update interval of an animation timer may be adjusted based upon a rendering system state (e.g., a rate of compositing visual layouts from animation frames) of a rendering system and/or an application state (e.g., a rate at which an application renders frames) of an application. Adjusting the animation rendering update interval allows the animation timer to adjust the frequency of performing rendering callback notifications (work requests to an application to render animation frames) to an application based upon rendering system performance and application performance.

Abstract: Many computer applications incorporate and support animation. Application performance may be enhanced by delegating animation management to an application program interface (animation API) for animation. Accordingly, an animation API for managing animation is disclosed herein. The animation API may be configured to sequentially interpolate values of animation variables defining animation movement of animation objects. The animation API may interpolate the values of the animation variables using animation transitions within animation storyboards. The animation API may be configured to determine durations of animation transitions based upon animation characteristics parameters (e.g., starting position, desiring ending position, starting velocity of an animation variable). Durations and start times of animation transitions may be determined based upon key frames. The animation API may be configured to resolve scheduling conflicts among one or more animation transitions.