Cycles API: encapsulate Node socket members

This encapsulates Node socket members behind a set of specific methods;
as such it is no longer possible to directly access Node class members
from exporters and parts of Cycles.

The methods are defined via the NODE_SOCKET_API macros in `graph/
node.h`, and are for getting or setting a specific socket's value, as
well as querying or modifying the state of its update flag.

The setters will check whether the value has changed and tag the socket
as modified appropriately. This will let us know how a Node has changed
and what to update, which is the first concrete step toward a more
granular scene update system.

Since the setters will tag the Node sockets as modified when passed
different data, this patch also removes the various `modified` methods
on Nodes in favor of `Node::is_modified` which checks the sockets'
update flags status.

Reviewed By: brecht

Maniphest Tasks: T79174

Differential Revision: https://developer.blender.org/D8544

1 files changed, 23 insertions, 18 deletions

diff --git a/intern/cycles/render/object.h b/intern/cycles/render/object.h
index ac9b4c331f5..e0d221114de 100644
--- a/intern/cycles/render/object.h
+++ b/intern/cycles/render/object.h
@@ -18,6 +18,11 @@
 #define __OBJECT_H__
 
 #include "graph/node.h"
+
+/* included as Object::set_particle_system defined through NODE_SOCKET_API does
+ * not select the right Node::set overload as it does not know that ParticleSystem
+ * is a Node */
+#include "render/particles.h"
 #include "render/scene.h"
 
 #include "util/util_array.h"
@@ -46,26 +51,26 @@ class Object : public Node {
  public:
   NODE_DECLARE
 
-  Geometry *geometry;
-  Transform tfm;
+  NODE_SOCKET_API(Geometry *, geometry)
+  NODE_SOCKET_API(Transform, tfm)
   BoundBox bounds;
-  uint random_id;
-  int pass_id;
-  float3 color;
-  ustring asset_name;
+  NODE_SOCKET_API(uint, random_id)
+  NODE_SOCKET_API(int, pass_id)
+  NODE_SOCKET_API(float3, color)
+  NODE_SOCKET_API(ustring, asset_name)
   vector<ParamValue> attributes;
-  uint visibility;
-  array<Transform> motion;
-  bool hide_on_missing_motion;
-  bool use_holdout;
-  bool is_shadow_catcher;
-  float shadow_terminator_offset;
-
-  float3 dupli_generated;
-  float2 dupli_uv;
-
-  ParticleSystem *particle_system;
-  int particle_index;
+  NODE_SOCKET_API(uint, visibility)
+  NODE_SOCKET_API_ARRAY(array<Transform>, motion)
+  NODE_SOCKET_API(bool, hide_on_missing_motion)
+  NODE_SOCKET_API(bool, use_holdout)
+  NODE_SOCKET_API(bool, is_shadow_catcher)
+  NODE_SOCKET_API(float, shadow_terminator_offset)
+
+  NODE_SOCKET_API(float3, dupli_generated)
+  NODE_SOCKET_API(float2, dupli_uv)
+
+  NODE_SOCKET_API(ParticleSystem *, particle_system);
+  NODE_SOCKET_API(int, particle_index);
 
   Object();
   ~Object();