X-Git-Url: https://adrianiainlam.tk/git/?a=blobdiff_plain;f=dygraph-canvas.js;h=cba4f44939db504aac3903017f42807a54765ad3;hb=30a5cfc6c8dfe0ff412e63498eac09d31e9004a7;hp=ef6cf1f85afb0b5133425003426c82cfcb1be739;hpb=34655aba0589dc5f9bdc1f03319d4e7bd9dcfff6;p=dygraphs.git

diff --git a/dygraph-canvas.js b/dygraph-canvas.js
index ef6cf1f..cba4f44 100644
--- a/dygraph-canvas.js
+++ b/dygraph-canvas.js
@@ -702,7 +702,14 @@ DygraphCanvasRenderer._fillPlotter = function(e) {
   var stackedGraph = g.getOption("stackedGraph");
   var colors = g.getColors();
 
-  var baseline = {};  // for stacked graphs: baseline for filling
+  // For stacked graphs, track the baseline for filling.
+  //
+  // The filled areas below graph lines are trapezoids with two
+  // vertical edges. The top edge is the line segment being drawn, and
+  // the baseline is the bottom edge. Each baseline corresponds to the
+  // top line segment from the previous stacked line. In the case of
+  // step plots, the trapezoids are rectangles.
+  var baseline = {};
   var currBaseline;
   var prevStepPlot;  // for different line drawing modes (line/step) per series
 
@@ -739,6 +746,9 @@ DygraphCanvasRenderer._fillPlotter = function(e) {
       var point = iter.next();
       if (!Dygraph.isOK(point.y)) {
         prevX = NaN;
+        if (point.y_stacked !== null && !isNaN(point.y_stacked)) {
+          baseline[point.canvasx] = area.h * point.y_stacked + area.y;
+        }
         continue;
       }
       if (stackedGraph) {