From 3db8c1a32d28838370385d7c99c3104e4ad996d7 Mon Sep 17 00:00:00 2001
From: Victor Woeltjen <victor.woeltjen@nasa.gov>
Date: Mon, 6 Apr 2015 14:15:34 -0700
Subject: [PATCH] [Plot] Try multiple chart options

Choose among multiple chart options, WTD-1070.
---
 platform/features/plot/src/Canvas2DChart.js |  2 +-
 platform/features/plot/src/MCTChart.js      | 49 ++++++++++++++++-----
 2 files changed, 38 insertions(+), 13 deletions(-)

diff --git a/platform/features/plot/src/Canvas2DChart.js b/platform/features/plot/src/Canvas2DChart.js
index 251b6c49d9..244fe75ec3 100644
--- a/platform/features/plot/src/Canvas2DChart.js
+++ b/platform/features/plot/src/Canvas2DChart.js
@@ -87,7 +87,7 @@ define(
                     }
 
                     // ...and add points to it...
-                    for (i = 2; i < buf.length - 1; i = i + 2) {
+                    for (i = 2; i < points * 2; i = i + 2) {
                         c2d.lineTo(x(buf[i]), y(buf[i + 1]));
                     }
 
diff --git a/platform/features/plot/src/MCTChart.js b/platform/features/plot/src/MCTChart.js
index 43ebaa891f..da044fe39f 100644
--- a/platform/features/plot/src/MCTChart.js
+++ b/platform/features/plot/src/MCTChart.js
@@ -4,8 +4,8 @@
  * Module defining MCTChart. Created by vwoeltje on 11/12/14.
  */
 define(
-    ["./GLChart"],
-    function (GLChart) {
+    ["./GLChart", "./Canvas2DChart"],
+    function (GLChart, Canvas2DChart) {
         "use strict";
 
         var TEMPLATE = "<canvas style='position: absolute; background: none; width: 100%; height: 100%;'></canvas>";
@@ -43,22 +43,38 @@ define(
          * @constructor
          */
         function MCTChart($interval, $log) {
+            // Get an underlying chart implementation
+            function getChart(Charts, canvas) {
+                // Try the first available option...
+                var Chart = Charts[0];
+
+                // This function recursively try-catches all options;
+                // if these all fail, issue a warning.
+                if (!Chart) {
+                    $log.warn("Cannot initialize mct-chart.");
+                    return undefined;
+                }
+
+                // Try first option; if it fails, try remaining options
+                try {
+                    return new Chart(canvas);
+                } catch (e) {
+                    $log.warn([
+                        "Could not instantiate chart",
+                        Chart.name,
+                        ";",
+                        e.message
+                    ].join(" "));
+
+                    return getChart(Charts.slice(1), canvas);
+                }
+            }
 
             function linkChart(scope, element) {
                 var canvas = element.find("canvas")[0],
                     activeInterval,
                     chart;
 
-                // Try to initialize GLChart, which allows drawing using WebGL.
-                // This may fail, particularly where browsers do not support
-                // WebGL, so catch that here.
-                try {
-                    chart = new GLChart(canvas);
-                } catch (e) {
-                    $log.warn("Cannot initialize mct-chart; " + e.message);
-                    return;
-                }
-
                 // Handle drawing, based on contents of the "draw" object
                 // in scope
                 function doDraw(draw) {
@@ -118,6 +134,15 @@ define(
                     }
                 }
 
+                // Try to initialize a chart.
+                chart = getChart([GLChart, Canvas2DChart], canvas);
+
+                // If that failed, there's nothing more we can do here.
+                // (A warning will already have been issued)
+                if (!chart) {
+                    return;
+                }
+
                 // Check for resize, on a timer
                 activeInterval = $interval(drawIfResized, 1000);