Move interpolation methods to helpers.math

Author: kurkle

src/elements/element.line.js

@@ -59,41 +59,14 @@ function getLineMethod(line) {
 		: helpers.canvas._bezierCurveTo;
 }
 
-function pointInLine(p1, p2, t) {
-	return {
-		x: p1.x + t * (p2.x - p1.x),
-		y: p1.y + t * (p2.y - p1.y)
-	};
-}
-
-function steppeInterpolation(p1, p2, t, mode) {
-	return {
-		x: p1.x + t * (p2.x - p1.x),
-		y: mode === 'middle' ? t < 0.5 ? p1.y : p2.y
-		: mode === 'after' ? t < 1 ? p1.y : p2.y
-		: t > 0 ? p2.y : p1.y
-	};
-}
-
-function bezierInterpolation(p1, p2, t) {
-	const cp1 = {x: p1.controlPointNextX, y: p1.controlPointNextY};
-	const cp2 = {x: p2.controlPointPreviousX, y: p2.controlPointPreviousY};
-	const a = pointInLine(p1, cp1, t);
-	const b = pointInLine(cp1, cp2, t);
-	const c = pointInLine(cp2, p2, t);
-	const d = pointInLine(a, b, t);
-	const e = pointInLine(b, c, t);
-	return pointInLine(d, e, t);
-}
-
 function getInterpolationMethod(line) {
 	if (line.steppedLine) {
-		return steppeInterpolation;
+		return helpers.math.steppeInterpolation;
 	}
 	if (!line.tension) {
-		return pointInLine;
+		return helpers.math.pointInLine;
 	}
-	return bezierInterpolation;
+	return helpers.math.bezierInterpolation;
 }
 
 function lineEnd(points, bounds) {

src/helpers/helpers.math.js

@@ -1,5 +1,12 @@
 'use strict';
 
+function pointInLine(p1, p2, t) {
+	return {
+		x: p1.x + t * (p2.x - p1.x),
+		y: p1.y + t * (p2.y - p1.y)
+	};
+}
+
 /**
  * @alias Chart.helpers.math
  * @namespace
@@ -38,6 +45,28 @@ var exports = {
 		var isPowerOf10 = x === Math.pow(10, powerOf10);
 
 		return isPowerOf10 ? powerOf10 : exponent;
+	},
+
+	pointInLine: pointInLine,
+
+	steppeInterpolation: function(p1, p2, t, mode) {
+		return {
+			x: p1.x + t * (p2.x - p1.x),
+			y: mode === 'middle' ? t < 0.5 ? p1.y : p2.y
+			: mode === 'after' ? t < 1 ? p1.y : p2.y
+			: t > 0 ? p2.y : p1.y
+		};
+	},
+
+	bezierInterpolation: function(p1, p2, t) {
+		const cp1 = {x: p1.controlPointNextX, y: p1.controlPointNextY};
+		const cp2 = {x: p2.controlPointPreviousX, y: p2.controlPointPreviousY};
+		const a = pointInLine(p1, cp1, t);
+		const b = pointInLine(cp1, cp2, t);
+		const c = pointInLine(cp2, p2, t);
+		const d = pointInLine(a, b, t);
+		const e = pointInLine(b, c, t);
+		return pointInLine(d, e, t);
 	}
 };