For radar chart background colors, don't recalculate center offset multiple times...

diff --git a/src/Chart.Core.js b/src/Chart.Core.js
index e51d4d4b2e6b1234d12db3fe41e140607cb9fd8d..d7314aca97d496049f89f3ed1d35cdbf6d7e81c8 100755 (executable)
--- a/src/Chart.Core.js
+++ b/src/Chart.Core.js
@@ -2005,16 +2005,17 @@
                                        ctx.strokeStyle = this.angleLineColor;
                                        for (var i = this.valuesCount - 1; i >= 0; i--) {
                                                if (this.angleLineWidth > 0){
-                                                       var outerPosition = this.getPointPosition(i, this.calculateCenterOffset(this.max));
+                                                       var centerOffset = this.calculateCenterOffset(this.max);
+                                                       var outerPosition = this.getPointPosition(i, centerOffset);
                                                        ctx.beginPath();
                                                        ctx.moveTo(this.xCenter, this.yCenter);
                                                        ctx.lineTo(outerPosition.x, outerPosition.y);
                                                        ctx.stroke();
                                                        ctx.closePath();
 
-                                                       if (this.backgroundColors) {
-                                                               var previousOuterPosition = this.getPointPosition(i === 0 ? this.valuesCount - 1 : i - 1, this.calculateCenterOffset(this.max));
-                                                               var nextOuterPosition = this.getPointPosition(i === this.valuesCount - 1 ? 0 : i + 1, this.calculateCenterOffset(this.max));
+                                                       if (this.backgroundColors && this.backgroundColors.length == this.valuesCount) {
+                                                               var previousOuterPosition = this.getPointPosition(i === 0 ? this.valuesCount - 1 : i - 1, centerOffset);
+                                                               var nextOuterPosition = this.getPointPosition(i === this.valuesCount - 1 ? 0 : i + 1, centerOffset);
 
                                                                var previousOuterHalfway = { x: (previousOuterPosition.x + outerPosition.x) / 2, y: (previousOuterPosition.y + outerPosition.y) / 2 };
                                                                var nextOuterHalfway = { x: (outerPosition.x + nextOuterPosition.x) / 2, y: (outerPosition.y + nextOuterPosition.y) / 2 };