From: Dan Vanderkam <danvdk@gmail.com>
Date: Tue, 21 Oct 2014 16:28:11 +0000 (-0400)
Subject: Only plot a point in range selector if it changes the x-value
X-Git-Tag: v1.1.0~33^2~2
X-Git-Url: https://adrianiainlam.tk/git/?a=commitdiff_plain;h=5575fa3660cca92dd0564ac3647e3440fb0a0c07;p=dygraphs.git

Only plot a point in range selector if it changes the x-value
---

diff --git a/plugins/range-selector.js b/plugins/range-selector.js
index 3a70e7d..d8a3c7a 100644
--- a/plugins/range-selector.js
+++ b/plugins/range-selector.js
@@ -594,6 +594,13 @@ rangeSelector.prototype.drawMiniPlot_ = function() {
     var dataPoint = combinedSeriesData.data[i];
     var x = ((dataPoint[0] !== null) ? ((dataPoint[0] - xExtremes[0])*xFact) : NaN);
     var y = ((dataPoint[1] !== null) ? (canvasHeight - (dataPoint[1] - combinedSeriesData.yMin)*yFact) : NaN);
+
+    // Skip points that don't change the x-value. Overly fine-grained points
+    // can cause major slowdowns with the ctx.fill() call below.
+    if (prevX !== null && Math.round(x) == Math.round(prevX)) {
+      continue;
+    }
+
     if (isFinite(x) && isFinite(y)) {
       if(prevX === null) {
         ctx.lineTo(x, canvasHeight);