sweeping node graph changes for new rendering pipeline

The new rendering pipeline strives to simplify the nodes themselves as much
as possible and move much of the logic to an external rendering engine. This
change removes all of the responsibilities that no longer belong to the
nodes themselves and will soon be folded into the renderer.

app/node/input.h

@@ -77,35 +77,36 @@ public:
   Node* get_connected_node();
 
   /**
-   * @brief Get the value at a given time
-   *
-   * This function will automatically retrieve the correct value for this input at the given time.
-   *
-   * If an output is connected to this input, a request is made to that output for its value at this time. If multiple
-   * outputs are connected (\see can_accept_multiple_inputs()), a QList<QVariant> (casted to a QVariant) is returned
-   * instead, listing all the outputs' values currently connected.
-   *
-   * If no output is connected, this will return a user-defined value, either a static value if this input is not
-   * keyframed, or an interpolated value between the keyframes at this time.
+   * @brief Get currently stored value
    */
-  QVariant get_value(const rational &in, const rational &out = -1);
+  const QVariant& value();
+
+  /**
+   * @brief Calculate what the stored value should be at a certain time
+   */
+  QVariant get_value_at_time(const rational& time);
+
+  /**
+   * @brief Sets what value should be seen at a specific time
+   */
+  void set_value_at_time(const rational& time, const QVariant& value);
 
   /**
    * @brief Set the value at a given time
-   *
-   * This function will only work if there are no outputs connected.
    */
-  void set_value(const QVariant& value);
+  void set_stored_value(const QVariant& value);
+
+  QVariant get_realtime_value_of_connected_output();
 
   /**
    * @brief Return whether keyframing is enabled on this input or not
    */
-  bool keyframing();
+  bool is_keyframing();
 
   /**
    * @brief Set whether keyframing is enabled on this input or not
    */
-  void set_keyframing(bool k);
+  void set_is_keyframing(bool k);
 
   /**
    * @brief Return whether the Node is dependent on this input or not
@@ -181,6 +182,11 @@ private:
    */
   QVariant maximum_;
 
+  /**
+   * @brief Internal stored value
+   */
+  QVariant stored_value_;
+
 };
 
 #endif // NODEINPUT_H