phaser/src/math/snap/SnapTo.js
2020-01-15 12:07:09 +00:00

37 lines
1 KiB
JavaScript

/**
* @author Richard Davey <rich@photonstorm.com>
* @copyright 2020 Photon Storm Ltd.
* @license {@link https://opensource.org/licenses/MIT|MIT License}
*/
/**
* Snap a value to nearest grid slice, using rounding.
*
* Example: if you have an interval gap of `5` and a position of `12`... you will snap to `10` whereas `14` will snap to `15`.
*
* @function Phaser.Math.Snap.To
* @since 3.0.0
*
* @param {number} value - The value to snap.
* @param {number} gap - The interval gap of the grid.
* @param {number} [start=0] - Optional starting offset for gap.
* @param {boolean} [divide=false] - If `true` it will divide the snapped value by the gap before returning.
*
* @return {number} The snapped value.
*/
var SnapTo = function (value, gap, start, divide)
{
if (start === undefined) { start = 0; }
if (gap === 0)
{
return value;
}
value -= start;
value = gap * Math.round(value / gap);
return (divide) ? (start + value) / gap : start + value;
};
module.exports = SnapTo;