Added Hermite class and functions.

Author: photonstorm

v3/src/checksum.js

@@ -1,4 +1,4 @@
 var CHECKSUM = {
-build: '528a0210-d341-11e6-a2a2-8fbbe27dda30'
+build: '20b3f530-d35e-11e6-b3f2-61f4b6b8c9a3'
 };
 module.exports = CHECKSUM;

v3/src/geom/hermite/FindT.js

@@ -0,0 +1,37 @@
+/**
+* Convert a distance along this curve into a `time` value which will be between 0 and 1.
+* 
+* For example if this curve has a length of 100 pixels then `findT(50)` would return `0.5`.
+*
+* @method Phaser.Hermite#findT
+* @param {integer} distance - The distance into the curve in pixels. Should be a positive integer.
+* @return {number} The time (`t`) value, a float between 0 and 1.
+*/
+var FindT = function (curve, distance)
+{
+    if (distance <= 0)
+    {
+        return 0;
+    }
+
+    //  Find the _points which bracket the distance value
+    var ti = Math.floor(distance / curve.length * curve._accuracy);
+
+    while (ti > 0 && curve._points[ti] > distance)
+    {
+        ti--;
+    }
+
+    while (ti < curve._accuracy && curve._points[ti] < distance)
+    {
+        ti++;
+    }
+
+    //  Linear interpolation to get a more accurate fix
+    var dt = curve._points[ti] - curve._points[ti - 1];
+    var d = distance - curve._points[ti - 1];
+
+    return ((ti - 1) / curve._accuracy) + d / (dt * curve._accuracy);
+};
+
+module.exports = FindT;

v3/src/geom/hermite/GetAngle.js

@@ -0,0 +1,20 @@
+var GetPoint = require('./GetPoint');
+
+/**
+* Calculate and return the angle, in radians, of the curves tangent based on time.
+*
+* @method Phaser.Hermite#getAngle
+* @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;

v3/src/geom/hermite/GetAngleWithDistance.js

@@ -0,0 +1,25 @@
+var GetAngle = require('./GetAngle');
+var FindT = require('./FindT');
+
+/**
+* Calculate and return the angle, in radians, of the curves tangent at the given pixel distance along the curves length.
+*
+* @method Phaser.Hermite#getAngleWithDistance
+* @param {number} [distance=0] - The distance along the curve to get the angle from, in pixels.
+* @return {number} The angle of the line at the specified distance along the curve. The value is in radians.
+*/
+var GetAngleWithDistance = function (curve, distance)
+{
+    if (distance === undefined) { distance = 0; }
+
+    if (distance <= 0)
+    {
+        return Math.atan2(this._v1y, this._v1x);
+    }
+    else
+    {
+        return GetAngle(curve, FindT(curve, distance));
+    }
+};
+
+module.exports = GetAngleWithDistance;

v3/src/geom/hermite/GetEntryTangent.js

@@ -0,0 +1,16 @@
+/**
+* Get the angle of the curves entry point.
+*
+* @method Phaser.Hermite#getEntryTangent
+* @param {Phaser.Point|Object} point - The Phaser.Point object, or an Object with public `x` and `y` properties, in which the tangent vector values will be stored.
+* @return {Phaser.Point} A Point object containing the tangent vector of this Hermite curve.
+*/
+var GetEntryTangent = function (curve, point)
+{
+    point.x = curve._v1x;
+    point.y = curve._v1y;
+
+    return point;
+};
+
+module.exports = GetEntryTangent;

v3/src/geom/hermite/GetPoint.js

@@ -0,0 +1,35 @@
+var Point = require('../point/Point');
+
+/**
+* Get a point on the curve using the `t` (time) value, which must be between 0 and 1.
+*
+* @method Phaser.Hermite#getPoint
+* @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.
+* @param {Phaser.Point|Object} [point] - An optional Phaser.Point, or Object containing public `x` and `y` properties. If given the resulting values will be stored in the Objects `x` and `y` properties. If omitted a new Phaser.Point object is created.
+* @return {Phaser.Point} An Object with the x, y coordinate of the curve at the specified `t` value set in its `x` and `y` properties.
+*/
+var GetPoint = function (curve, t, out)
+{
+    if (t === undefined) { t = 0; }
+    if (out === undefined) { out = new Point(); }
+
+    if (t < 0)
+    {
+        t = 0;
+    }
+
+    if (t > 1)
+    {
+        t = 1;
+    }
+
+    var t2 = t * t;
+    var t3 = t * t2;
+
+    out.x = t3 * curve._ax + t2 * curve._bx + t * curve._v1x + curve._p1x;
+    out.y = t3 * curve._ay + t2 * curve._by + t * curve._v1y + curve._p1y;
+
+    return out;
+};
+
+module.exports = GetPoint;

v3/src/geom/hermite/GetPointWithDistance.js

@@ -0,0 +1,31 @@
+var Point = require('../point/Point');
+var GetPoint = require('./GetPoint');
+var FindT = require('./FindT');
+
+/**
+* Get a point on the curve using the distance, in pixels, along the curve.
+*
+* @method Phaser.Hermite#getPointWithDistance
+* @param {integer} [distance=0] - The distance along the curve to get the point from, given in pixels.
+* @param {Phaser.Point|Object} [point] - An optional Phaser.Point, or Object containing public `x` and `y` properties. If given the resulting values will be stored in the Objects `x` and `y` properties. If omitted a new Phaser.Point object is created.
+* @return {Phaser.Point} The point on the line at the specified 'distance' along the curve.
+*/
+var GetPointWithDistance = function (curve, distance, out)
+{
+    if (distance === undefined) { distance = 0; }
+    if (out === undefined) { out = new Point(); }
+
+    if (distance <= 0)
+    {
+        out.x = this._p1x;
+        out.y = this._p1y;
+    }
+    else
+    {
+        GetPoint(curve, FindT(curve, distance), out);
+    }
+    
+    return out;
+};
+
+module.exports = GetPointWithDistance;

v3/src/geom/hermite/GetX.js

@@ -0,0 +1,33 @@
+/**
+* Get the X component of a point on the curve based on the `t` (time) value, which must be between 0 and 1.
+*
+* @method Phaser.Hermite#getX
+* @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;

v3/src/geom/hermite/GetY.js

@@ -0,0 +1,33 @@
+/**
+* Get the Y component of a point on the curve based on the `t` (time) value, which must be between 0 and 1.
+*
+* @method Phaser.Hermite#getY
+* @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 Y component of a point on the curve based on the `t` (time) value.
+*/
+var GetY = 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._ay + t2 * curve._by + t * curve._v1y + curve._p1y);
+};
+
+module.exports = GetY;