Linear scale improvements

diff --git a/src/scales/scale.linear.js b/src/scales/scale.linear.js
index 90fcab9fec8158416f730f4e53e133b6e5d04449..15db914ba628d3730a7c4719152e5003d0af9205 100644 (file)
--- a/src/scales/scale.linear.js
+++ b/src/scales/scale.linear.js
@@ -228,41 +228,44 @@ module.exports = function(Chart) {
                        return +this.getRightValue(this.chart.data.datasets[datasetIndex].data[index]);
                },
                convertTicksToLabels: function() {
-                       this.ticksAsNumbers = this.ticks.slice();
-                       this.zeroLineIndex = this.ticks.indexOf(0);
+                       var _this = this;
+                       _this.ticksAsNumbers = _this.ticks.slice();
+                       _this.zeroLineIndex = _this.ticks.indexOf(0);
 
-                       Chart.Scale.prototype.convertTicksToLabels.call(this);
+                       Chart.Scale.prototype.convertTicksToLabels.call(_this);
                },
                // Utils
                getPixelForValue: function(value, index, datasetIndex, includeOffset) {
                        // This must be called after fit has been run so that
                        //      this.left, this.top, this.right, and this.bottom have been defined
-                       var rightValue = +this.getRightValue(value);
+                       var _this = this;
+                       var paddingLeft = _this.paddingLeft;
+                       var paddingBottom = _this.paddingBottom;
+                       var start = _this.start;
+
+                       var rightValue = +_this.getRightValue(value);
                        var pixel;
-                       var range = this.end - this.start;
+                       var innerDimension;
+                       var range = _this.end - start;
 
-                       if (this.isHorizontal()) {
-                               var innerWidth = this.width - (this.paddingLeft + this.paddingRight);
-                               pixel = this.left + (innerWidth / range * (rightValue - this.start));
-                               return Math.round(pixel + this.paddingLeft);
+                       if (_this.isHorizontal()) {
+                               innerDimension = _this.width - (paddingLeft + _this.paddingRight);
+                               pixel = _this.left + (innerDimension / range * (rightValue - start));
+                               return Math.round(pixel + paddingLeft);
                        } else {
-                               var innerHeight = this.height - (this.paddingTop + this.paddingBottom);
-                               pixel = (this.bottom - this.paddingBottom) - (innerHeight / range * (rightValue - this.start));
+                               innerDimension = _this.height - (_this.paddingTop + paddingBottom);
+                               pixel = (_this.bottom - paddingBottom) - (innerDimension / range * (rightValue - start));
                                return Math.round(pixel);
                        }
                },
                getValueForPixel: function(pixel) {
-                       var offset;
-
-                       if (this.isHorizontal()) {
-                               var innerWidth = this.width - (this.paddingLeft + this.paddingRight);
-                               offset = (pixel - this.left - this.paddingLeft) / innerWidth;
-                       } else {
-                               var innerHeight = this.height - (this.paddingTop + this.paddingBottom);
-                               offset = (this.bottom - this.paddingBottom - pixel) / innerHeight;
-                       }
-
-                       return this.start + ((this.end - this.start) * offset);
+                       var _this = this;
+                       var isHorizontal = _this.isHorizontal();
+                       var paddingLeft = _this.paddingLeft;
+                       var paddingBottom = _this.paddingBottom;
+                       var innerDimension = isHorizontal ? _this.width - (paddingLeft + _this.paddingRight) : _this.height - (_this.paddingTop + paddingBottom);
+                       var offset = (isHorizontal ? pixel - _this.left - paddingLeft : _this.bottom - paddingBottom - pixel) / innerDimension;
+                       return _this.start + ((_this.end - _this.start) * offset);
                },
                getPixelForTick: function(index, includeOffset) {
                        return this.getPixelForValue(this.ticksAsNumbers[index], null, null, includeOffset);