declare namespace starling.animation
{
/** Provides Cubic Bezier Curve easing, which generalizes easing functions
* via a four-point bezier curve. That way, you can easily create custom easing functions
* that will be picked up by Starling's Tween class later. To set up your bezier curves,
* best use a visual tool like cubic-bezier.com or
* Ceaser.
*
* For example, you can add the transitions recommended by Google's Material Design
* standards (see here)
* like this:
*
*
* Transitions.register("standard", BezierEasing.create(0.4, 0.0, 0.2, 1.0));
* Transitions.register("decelerate", BezierEasing.create(0.0, 0.0, 0.2, 1.0));
* Transitions.register("accelerate", BezierEasing.create(0.4, 0.0, 1.0, 1.0));
*
* The create method returns a function that can be registered directly
* at the "Transitions" class.
*
* Code based on gre/bezier-easing
* and its Starling
* adaptation by Rodrigo Lopez.
*
* @see starling.animation.Transitions
* @see starling.animation.Juggler
* @see starling.animation.Tween
*/
export class BezierEasing
{
/** Create an easing function that's defined by two control points of a bezier curve.
* The curve will always go directly through points 0 and 3, which are fixed at
* (0, 0) and (1, 1), respectively. Points 1 and 2 define the curvature of the bezier
* curve.
*
* The result of this method is best passed directly to
* Transitions.create().
*
* @param x1 The x coordinate of control point 1.
* @param y1 The y coordinate of control point 1.
* @param x2 The x coordinate of control point 2.
* @param y2 The y coordinate of control point 2.
* @return The transition function, which takes exactly one 'ratio:Number' parameter.
*/
static create(x1:number, y1:number, x2:number, y2:number):(ratio:number)=>number;
}
}
export default starling.animation.BezierEasing;