started node graph design

nodes/nodegraph.cpp

@@ -2,7 +2,13 @@
 
 #include <QDebug>
 
-NodeGraph::NodeGraph()
+NodeGraph::NodeGraph() :
+  output_node_(nullptr)
 {
 
 }
+
+Effect *NodeGraph::OutputNode()
+{
+  return output_node_.get();
+}

nodes/nodegraph.h

@@ -8,7 +8,46 @@ class NodeGraph
 public:
   NodeGraph();
 
-private:
+  /**
+   * @brief Add a node to this graph
+   *
+   * The graph takes ownership of the node.
+   *
+   * @param node
+   */
+  void AddNode(EffectPtr node);
+
+  /**
+   * @brief Process the graph
+   *
+   * Using the output node set by SetOutputNode(), this function will work backwards and perform every action in the
+   * node hierarchy necessary to eventually process the output node. After this function returns, the output node should
+   * contain valid values ready for accessing.
+   *
+   * Each node will cache its output for optimized playback and rendering. This will happen transparently and under most
+   * circumstances, this function will be able to return immediately.
+   */
+  void Process();
+
+  /**
+   * @brief Set the output node for this node graph
+   *
+   * This node will be presented as the final node that all other nodes converge on. This node can be used to retrieve
+   * the result of the graph.
+   *
+   * @param node
+   *
+   * The node to set as the output node. The graph takes ownership of the node and the user cannot delete it.
+   */
+  void SetOutputNode(EffectPtr node);
+
+  /**
+   * @brief Returns the currently set output node
+   */
+  Effect* OutputNode();
+
+private:  
+  EffectPtr output_node_;
 };
 
 #endif // NODEGRAPH_H

timeline/clip.h

@@ -38,6 +38,7 @@
 #include "rendering/framebufferobject.h"
 #include "marker.h"
 #include "track.h"
+#include "nodes/nodegraph.h"
 
 struct ClipSpeed {
   ClipSpeed();
@@ -180,6 +181,8 @@ private:
   Cacher cacher;
   long cacher_frame;
 
+  NodeGraph pipeline_;
+
   QVector<Marker> markers;
   QColor color_;
   bool open_;