mirror of
https://github.com/photonstorm/phaser
synced 2024-11-24 05:33:35 +00:00
32 lines
754 B
JavaScript
32 lines
754 B
JavaScript
/**
|
|
* Get the X component of a point on the curve based on the `t` (time) value, which must be between 0 and 1.
|
|
*
|
|
* @param {number} [t=0] - The time value along the curve from which to extract a point. This is a value between 0 and 1, where 0 represents the start of the curve and 1 the end.
|
|
* @return {number} The X component of a point on the curve based on the `t` (time) value.
|
|
*/
|
|
var GetX = function (curve, t)
|
|
{
|
|
if (t === undefined)
|
|
{
|
|
t = 0;
|
|
}
|
|
else
|
|
{
|
|
if (t < 0)
|
|
{
|
|
t = 0;
|
|
}
|
|
|
|
if (t > 1)
|
|
{
|
|
t = 1;
|
|
}
|
|
}
|
|
|
|
var t2 = t * t;
|
|
var t3 = t * t2;
|
|
|
|
return (t3 * curve._ax + t2 * curve._bx + t * curve._v1x + curve._p1x);
|
|
};
|
|
|
|
module.exports = GetX;
|