Address performance issue with ArrayBuffers

Address an unavoidable loop phase inside color clean function where
it iterates all over the graph points if data used is an ArrayBuffer.
This causes graph to have way less performance relative to Array types.

Author: Serafim Barroca

src/components/color/index.js

@@ -116,7 +116,7 @@ color.clean = function(container) {
             if(!Array.isArray(el0) && el0 && typeof el0 === 'object') {
                 for(j = 0; j < val.length; j++) color.clean(val[j]);
             }
-        } else if(val && typeof val === 'object') color.clean(val);
+        } else if(val && typeof val === 'object' && !ArrayBuffer.isView(val)) color.clean(val);
     }
 };
 

src/traces/scattergl/calc.js

@@ -27,7 +27,7 @@ module.exports = function calc(gd, trace) {
     var hasTooManyPoints = len >= TOO_MANY_POINTS;
     var len2 = len * 2;
     var stash = {};
-    var i, xx, yy;
+    var i;
 
     var origX = xa.makeCalcdata(trace, 'x');
     var origY = ya.makeCalcdata(trace, 'y');
@@ -42,11 +42,12 @@ module.exports = function calc(gd, trace) {
     // we need hi-precision for scatter2d,
     // regl-scatter2d uses NaNs for bad/missing values
     var positions = new Array(len2);
+    var _ids = new Array(len);
     for(i = 0; i < len; i++) {
-        xx = x[i];
-        yy = y[i];
-        positions[i * 2] = xx === BADNUM ? NaN : xx;
-        positions[i * 2 + 1] = yy === BADNUM ? NaN : yy;
+        positions[i * 2] = x[i] === BADNUM ? NaN : x[i];
+        positions[i * 2 + 1] = y[i] === BADNUM ? NaN : y[i];
+        // Pre-compute ids.
+        _ids[i] = i;
     }
 
     if(xa.type === 'log') {
@@ -66,10 +67,7 @@ module.exports = function calc(gd, trace) {
         // FIXME: delegate this to webworker
         stash.tree = cluster(positions);
     } else {
-        var ids = stash.ids = new Array(len);
-        for(i = 0; i < len; i++) {
-            ids[i] = i;
-        }
+        stash.ids = _ids;
     }
 
     // create scene options and scene