apply sunburst rotation as the base angle during transitions

Author: archmoj

src/traces/sunburst/plot.js

@@ -311,7 +311,7 @@ function plotOne(gd, cd, element, transitionOpts) {
         var next;
 
         if(entryPrev) {
-            var a = pt.x1 > entryPrev.x1 ? 2 * Math.PI : 0;
+            var a = (pt.x1 > entryPrev.x1 ? 2 * Math.PI : 0) + baseX;
             // if pt to remove:
             // - if 'below' where the root-node used to be: shrink it radially inward
             // - otherwise, collapse it clockwise or counterclockwise which ever is shortest to theta=0
@@ -361,7 +361,7 @@ function plotOne(gd, cd, element, transitionOpts) {
                         // if new branch, twist it in clockwise or
                         // counterclockwise which ever is shorter to
                         // its final angle
-                        var a = pt.x1 > nextX1ofPrevEntry ? 2 * Math.PI : 0;
+                        var a = (pt.x1 > nextX1ofPrevEntry ? 2 * Math.PI : 0) + baseX;
                         prev = {x0: a, x1: a};
                     } else {
                         // if new leaf (when maxdepth is set),
@@ -376,7 +376,7 @@ function plotOne(gd, cd, element, transitionOpts) {
                 }
             } else {
                 // start sector of new traces from theta=0
-                prev = {x0: 0, x1: 0};
+                prev = {x0: baseX, x1: baseX};
             }
         }
 
@@ -419,11 +419,11 @@ function plotOne(gd, cd, element, transitionOpts) {
                     }
                 } else {
                     // if new root-node
-                    prev.x0 = prev.x1 = 0;
+                    prev.x0 = prev.x1 = baseX;
                 }
             } else {
                 // on new traces
-                prev.x0 = prev.x1 = 0;
+                prev.x0 = prev.x1 = baseX;
             }
         }