mirror of
https://github.com/photonstorm/phaser
synced 2024-12-17 16:43:30 +00:00
19 lines
631 B
JavaScript
19 lines
631 B
JavaScript
var GetPoint = require('./GetPoint');
|
|
|
|
/**
|
|
* Calculate and return the angle, in radians, of the curves tangent based on time.
|
|
*
|
|
* @param {number} [t=0] - The `t` (time) value at which to find the angle. Must be between 0 and 1.
|
|
* @return {number} The angle of the line at the specified `t` time value along the curve. The value is in radians.
|
|
*/
|
|
var GetAngle = function (curve, t)
|
|
{
|
|
if (t === undefined) { t = 0; }
|
|
|
|
GetPoint(curve, t - 0.01, curve._temp1);
|
|
GetPoint(curve, t + 0.01, curve._temp2);
|
|
|
|
return Math.atan2(curve._temp2.y - curve._temp1.y, curve._temp2.x - curve._temp1.x);
|
|
};
|
|
|
|
module.exports = GetAngle;
|