25 lines
725 B
JavaScript

/**
* @typedef {function} interpolator
* @param {number} current the current value.
* @param {number} dest the destination value.
* @param {number} frameDelta the time elapsed since the last update.
* @returns {number} the new current value.
*/
// TODO: Add some interpolation functions.
/**
*
* @param {number} rate the number of frequency values to shift by per second.
* @returns {interpolator} the interpolation function with the given rate.
*/
export function createEaseLinear(rate) {
return (current, dest, frameDelta) => {
let direction = 1;
if (dest < current) {
direction = -1;
}
return current + (Math.min(rate * frameDelta, dest) * direction);
};
}