Add support for converting and rendering volumetric data in the cdf format. Replace DataConverter by a more general purpose TaskRunner.

Conflicts:
	modules/volume/CMakeLists.txt
	modules/volume/linearlrucache.h
	src/engine/openspaceengine.cpp

src/util/taskloader.cpp

@@ -0,0 +1,89 @@
+/*****************************************************************************************
+*                                                                                       *
+* OpenSpace                                                                             *
+*                                                                                       *
+* Copyright (c) 2014-2016                                                               *
+*                                                                                       *
+* Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
+* software and associated documentation files (the "Software"), to deal in the Software *
+* without restriction, including without limitation the rights to use, copy, modify,    *
+* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
+* permit persons to whom the Software is furnished to do so, subject to the following   *
+* conditions:                                                                           *
+*                                                                                       *
+* The above copyright notice and this permission notice shall be included in all copies *
+* or substantial portions of the Software.                                              *
+*                                                                                       *
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
+* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
+* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
+* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
+* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
+* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
+****************************************************************************************/
+
+#include <openspace/util/taskloader.h>
+
+#include <ghoul/filesystem/filesystem.h>
+#include <ghoul/logging/logmanager.h>
+#include <ghoul/lua/lua_helper.h>
+#include <ghoul/misc/onscopeexit.h>
+
+#include <openspace/engine/openspaceengine.h>
+#include <openspace/scripting/scriptengine.h>
+#include <algorithm>
+
+namespace {
+    const std::string _loggerCat = "TaskRunner";
+}
+
+namespace openspace {
+
+
+std::vector<std::unique_ptr<Task>> TaskLoader::tasksFromDictionary(const ghoul::Dictionary& tasksDictionary) {
+    std::vector<std::unique_ptr<Task>> tasks;
+    std::vector<std::string> keys = tasksDictionary.keys();
+    for (const std::string key : keys) {
+        std::string taskName;
+        ghoul::Dictionary subTask;
+        if (tasksDictionary.getValue(key, taskName)) {
+            std::string path = "${TASKS}/" + taskName + ".task";
+            std::vector<std::unique_ptr<Task>> subTasks = tasksFromFile(path);
+            std::move(subTasks.begin(), subTasks.end(), std::back_inserter(tasks));
+        } else if (tasksDictionary.getValue(key, subTask)) {
+            std::string taskType = subTask.value<std::string>("Type");
+            std::unique_ptr<Task> task = Task::createFromDictionary(subTask);
+            if (task == nullptr) {
+                LERROR("Failed to create a Task object of type '" << taskType << "'");
+            }
+            tasks.push_back(std::move(task));
+        }
+    }
+    return tasks;
+}
+
+std::vector<std::unique_ptr<Task>> TaskLoader::tasksFromFile(const std::string& path) {
+    std::string absTasksFile = absPath(path);
+    using RawPath = ghoul::filesystem::FileSystem::RawPath;
+    if (!FileSys.fileExists(absTasksFile, RawPath::Yes)) {
+        LERROR("Could not load tasks file '" << absTasksFile << "'. " <<
+            "File not found");
+        return std::vector<std::unique_ptr<Task>>();
+    }
+
+    ghoul::Dictionary tasksDictionary;
+    try {
+        ghoul::lua::loadDictionaryFromFile(
+            absTasksFile,
+            tasksDictionary
+            );
+    } catch (...) {
+        LERROR("Could not load tasks file '" << absTasksFile << "'. " <<
+            "Lua parse error");
+        return std::vector<std::unique_ptr<Task>>();
+    }
+    return tasksFromDictionary(tasksDictionary);
+}
+
+
+}