concept easing in category jQuery
This is an excerpt from Manning's book jQuery UI in Action.
What are easings? An easing is a function that dictates the rate at which an animation progresses. jQuery Core includes two of them: linear and swing. The linear easing runs the entire animation at a constant pace, and the swing easing starts the animation slowly and speeds up toward the end. The swing easing is the default easing used in both jQuery Core and jQuery UI. A full list of easings in jQuery UI can be found at http://api.jqueryui.com/easings/ and is shown in figure 6.2.
Figure 6.2. A list of the easings provided by jQuery UI from http://api.jqueryui.com/easings/. Each graph plots the progress of the animation (the y-axis) against time (the x-axis). Clicking on each graph runs an animation with the corresponding easing. If you’re having trouble understanding easings, it’s worth taking a minute to run these; easings are far easier to understand visually.
This is an excerpt from Manning's book Extending jQuery.
Easings define how an attribute value changes over time, and they may be applied to animations to control the acceleration and deceleration of the movements. Although easings are part of basic jQuery, only two instances are offered—linear and swing. jQuery UI provides an additional 30 easings. To add your own easing, you extend $.easing to define a function that returns the amount of change in an attribute value (normalized to be between 0 and 1) given the current elapsed time within the animation duration (also normalized to be between 0 and 1).
For more information on jQuery UI effects, and easings in general, see chapter 10.
Easing is the acceleration or deceleration of an object in motion. In the real world, this could be due to external forces such as gravity or friction. In animation terms, it’s a definition of the way that the speed of an attribute change varies over time.