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

53 lines
1,017 B
JavaScript

/**
* @author Richard Davey <rich@photonstorm.com>
* @copyright 2020 Photon Storm Ltd.
* @license {@link https://opensource.org/licenses/MIT|MIT License}
*/
/**
* @ignore
*/
function P0 (t, p)
{
var k = 1 - t;
return k * k * p;
}
/**
* @ignore
*/
function P1 (t, p)
{
return 2 * (1 - t) * t * p;
}
/**
* @ignore
*/
function P2 (t, p)
{
return t * t * p;
}
// https://github.com/mrdoob/three.js/blob/master/src/extras/core/Interpolations.js
/**
* A quadratic bezier interpolation method.
*
* @function Phaser.Math.Interpolation.QuadraticBezier
* @since 3.2.0
*
* @param {number} t - The percentage of interpolation, between 0 and 1.
* @param {number} p0 - The start point.
* @param {number} p1 - The control point.
* @param {number} p2 - The end point.
*
* @return {number} The interpolated value.
*/
var QuadraticBezierInterpolation = function (t, p0, p1, p2)
{
return P0(t, p0) + P1(t, p1) + P2(t, p2);
};
module.exports = QuadraticBezierInterpolation;