Geometry Nodes: new Viewer node

This adds a viewer node similar to the one in the compositor.
The icon in the headers of nodes is removed because it served
the same purpose and is not necessary anymore.

Node outputs can be connected to the active viewer using
ctrl+shift+LMB, just like in the compositor. Right now this collides
with the shortcut used in the node wrangler addon, which will
be changed separately.

As of now, the viewed geometry is only visible in the spreadsheet.
Viewport visualization will be added separately.

There are a couple of benefits of using a viewer node compared
to the old approach with the icon in the node header:
* Better support for nodes that have more than one geometry output.
* It's more consistent with the compositor.
* If attributes become decoupled from geometry in the future,
  the viewer can have a separate input for the attribute to visualize.
* The viewer node could potentially have visualization settings.
* Allows to keep "visualization points" around by having multiple
  viewer nodes.
* Less visual clutter in node headers.

Differential Revision: https://developer.blender.org/D11470

1 files changed, 28 insertions, 5 deletions

diff --git a/source/blender/editors/space_node/node_relationships.cc b/source/blender/editors/space_node/node_relationships.cc
index a1b8e4e3395..aadf93961e9 100644
--- a/source/blender/editors/space_node/node_relationships.cc
+++ b/source/blender/editors/space_node/node_relationships.cc
@@ -40,11 +40,14 @@
 #include "ED_node.h" /* own include */
 #include "ED_render.h"
 #include "ED_screen.h"
+#include "ED_spreadsheet.h"
 #include "ED_util.h"
 
 #include "RNA_access.h"
 #include "RNA_define.h"
 
+#include "DEG_depsgraph.h"
+
 #include "WM_api.h"
 #include "WM_types.h"
 
@@ -160,6 +163,11 @@ bool node_connected_to_output(Main *bmain, bNodeTree *ntree, bNode *node)
         return true;
       }
     }
+    if (current_node->type == GEO_NODE_VIEWER) {
+      if (ntree_check_nodes_connected(ntree, node, current_node)) {
+        return true;
+      }
+    }
   }
   return false;
 }
@@ -610,14 +618,14 @@ static int node_link_viewer(const bContext *C, bNode *tonode)
   if (tonode == nullptr || BLI_listbase_is_empty(&tonode->outputs)) {
     return OPERATOR_CANCELLED;
   }
-  if (ELEM(tonode->type, CMP_NODE_VIEWER, CMP_NODE_SPLITVIEWER)) {
+  if (ELEM(tonode->type, CMP_NODE_VIEWER, CMP_NODE_SPLITVIEWER, GEO_NODE_VIEWER)) {
     return OPERATOR_CANCELLED;
   }
 
   /* get viewer */
   bNode *viewer_node = nullptr;
   LISTBASE_FOREACH (bNode *, node, &snode->edittree->nodes) {
-    if (ELEM(node->type, CMP_NODE_VIEWER, CMP_NODE_SPLITVIEWER)) {
+    if (ELEM(node->type, CMP_NODE_VIEWER, CMP_NODE_SPLITVIEWER, GEO_NODE_VIEWER)) {
       if (node->flag & NODE_DO_OUTPUT) {
         viewer_node = node;
         break;
@@ -627,7 +635,7 @@ static int node_link_viewer(const bContext *C, bNode *tonode)
   /* no viewer, we make one active */
   if (viewer_node == nullptr) {
     LISTBASE_FOREACH (bNode *, node, &snode->edittree->nodes) {
-      if (ELEM(node->type, CMP_NODE_VIEWER, CMP_NODE_SPLITVIEWER)) {
+      if (ELEM(node->type, CMP_NODE_VIEWER, CMP_NODE_SPLITVIEWER, GEO_NODE_VIEWER)) {
         node->flag |= NODE_DO_OUTPUT;
         viewer_node = node;
         break;
@@ -686,7 +694,8 @@ static int node_link_viewer(const bContext *C, bNode *tonode)
     /* add a new viewer if none exists yet */
     if (!viewer_node) {
       /* XXX location is a quick hack, just place it next to the linked socket */
-      viewer_node = node_add_node(C, nullptr, CMP_NODE_VIEWER, sock->locx + 100, sock->locy);
+      const int viewer_type = ED_node_is_compositor(snode) ? CMP_NODE_VIEWER : GEO_NODE_VIEWER;
+      viewer_node = node_add_node(C, nullptr, viewer_type, sock->locx + 100, sock->locy);
       if (!viewer_node) {
         return OPERATOR_CANCELLED;
       }
@@ -712,8 +721,13 @@ static int node_link_viewer(const bContext *C, bNode *tonode)
       /* make sure the dependency sorting is updated */
       snode->edittree->update |= NTREE_UPDATE_LINKS;
     }
+    if (ED_node_is_geometry(snode)) {
+      ED_spreadsheet_context_paths_set_geometry_node(CTX_data_main(C), snode, viewer_node);
+    }
+
     ntreeUpdateTree(CTX_data_main(C), snode->edittree);
     snode_update(snode, viewer_node);
+    DEG_id_tag_update(&snode->edittree->id, 0);
   }
 
   return OPERATOR_FINISHED;
@@ -739,6 +753,15 @@ static int node_active_link_viewer_exec(bContext *C, wmOperator *UNUSED(op))
   return OPERATOR_FINISHED;
 }
 
+static bool node_active_link_viewer_poll(bContext *C)
+{
+  if (!ED_operator_node_editable(C)) {
+    return false;
+  }
+  SpaceNode *snode = CTX_wm_space_node(C);
+  return ED_node_is_compositor(snode) || ED_node_is_geometry(snode);
+}
+
 void NODE_OT_link_viewer(wmOperatorType *ot)
 {
   /* identifiers */
@@ -748,7 +771,7 @@ void NODE_OT_link_viewer(wmOperatorType *ot)
 
   /* api callbacks */
   ot->exec = node_active_link_viewer_exec;
-  ot->poll = composite_node_editable;
+  ot->poll = node_active_link_viewer_poll;
 
   /* flags */
   ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;