Nodes: Add a callback to check for valid socket type

This adds a callback to bNodeTreeType to check which socket types are
valid for the tree type. Function has been implemented for the normal
tree types, and can be implemented for custom node trees with python,
by adding a `classmethod` to the tree. However, only builtin socket
types are supported.

This is relevant for T87049, but it also has the advantage that it is
now clear which node trees support which sockets. Previously this
was assumed to be known by all developers.

Differential Revision: https://developer.blender.org/D10938

1 files changed, 7 insertions, 0 deletions

diff --git a/source/blender/nodes/texture/node_texture_tree.c b/source/blender/nodes/texture/node_texture_tree.c
index 48027dc847b..2ae722e3cd8 100644
--- a/source/blender/nodes/texture/node_texture_tree.c
+++ b/source/blender/nodes/texture/node_texture_tree.c
@@ -152,6 +152,12 @@ static void update(bNodeTree *ntree)
   }
 }
 
+static bool texture_node_tree_socket_type_valid(eNodeSocketDatatype socket_type,
+                                                bNodeTreeType *UNUSED(ntreetype))
+{
+  return ELEM(socket_type, SOCK_FLOAT, SOCK_VECTOR, SOCK_RGBA);
+}
+
 bNodeTreeType *ntreeType_Texture;
 
 void register_node_tree_type_tex(void)
@@ -171,6 +177,7 @@ void register_node_tree_type_tex(void)
   tt->local_sync = local_sync;
   tt->local_merge = local_merge;
   tt->get_from_context = texture_get_from_context;
+  tt->valid_socket_type = texture_node_tree_socket_type_valid;
 
   tt->rna_ext.srna = &RNA_TextureNodeTree;