Python API: add Python-defined node groups for shaders and compositing.

This was already supported for Cycles shader nodes, but now also works for
Eevee and compositing nodes. Instead of a generic NodeCustomGroup, now
there is ShaderNodeCustomGroup and CompositorNodeCustomGroup that can be
subclassed and registered.

Differential Revision: https://developer.blender.org/D4370

5 files changed, 22 insertions, 3 deletions

diff --git a/source/blender/nodes/NOD_composite.h b/source/blender/nodes/NOD_composite.h
index 1e43b5011e6..85f4c81610b 100644
--- a/source/blender/nodes/NOD_composite.h
+++ b/source/blender/nodes/NOD_composite.h
@@ -136,4 +136,6 @@ void node_cmp_rlayers_outputs(struct bNodeTree *ntree, struct bNode *node);
 void node_cmp_rlayers_register_pass(struct bNodeTree *ntree, struct bNode *node, struct Scene *scene, struct ViewLayer *view_layer, const char *name, int type);
 const char *node_cmp_rlayers_sock_to_pass(int sock_index);
 
+void register_node_type_cmp_custom_group(bNodeType *ntype);
+
 #endif
diff --git a/source/blender/nodes/NOD_shader.h b/source/blender/nodes/NOD_shader.h
index e88f7a49d30..9e6fa0706d1 100644
--- a/source/blender/nodes/NOD_shader.h
+++ b/source/blender/nodes/NOD_shader.h
@@ -131,4 +131,6 @@ void register_node_type_sh_tex_checker(void);
 void register_node_type_sh_bump(void);
 void register_node_type_sh_tex_ies(void);
 
+void register_node_type_sh_custom_group(bNodeType *ntype);
+
 #endif
diff --git a/source/blender/nodes/composite/nodes/node_composite_common.c b/source/blender/nodes/composite/nodes/node_composite_common.c
index 9d72335d720..f9a6961c47b 100644
--- a/source/blender/nodes/composite/nodes/node_composite_common.c
+++ b/source/blender/nodes/composite/nodes/node_composite_common.c
@@ -56,3 +56,9 @@ void register_node_type_cmp_group(void)
 
 	nodeRegisterType(&ntype);
 }
+
+void register_node_type_cmp_custom_group(bNodeType *ntype)
+{
+	ntype->insert_link = node_insert_link_default;
+	ntype->update_internal_links = node_update_internal_links_default;
+}
diff --git a/source/blender/nodes/shader/node_shader_tree.c b/source/blender/nodes/shader/node_shader_tree.c
index 50bec047222..a4356dabfc0 100644
--- a/source/blender/nodes/shader/node_shader_tree.c
+++ b/source/blender/nodes/shader/node_shader_tree.c
@@ -290,7 +290,7 @@ static bNode *ntree_shader_output_node_from_group(bNodeTree *ntree, int target)
 
 	/* Search if node groups do not contain valid output nodes (recursively). */
 	for (bNode *node = ntree->nodes.first; node; node = node->next) {
-		if (!ELEM(node->type, NODE_GROUP)) {
+		if (!ELEM(node->type, NODE_GROUP, NODE_CUSTOM_GROUP)) {
 			continue;
 		}
 		if (node->id != NULL) {
@@ -453,7 +453,7 @@ static void ntree_shader_groups_expand_inputs(bNodeTree *localtree)
 
 	for (group_node = localtree->nodes.first; group_node; group_node = group_node->next) {
 
-		if (group_node->type != NODE_GROUP || group_node->id == NULL)
+		if (!(ELEM(group_node->type, NODE_GROUP, NODE_CUSTOM_GROUP)) || group_node->id == NULL)
 			continue;
 
 		/* Do it recursively. */
@@ -674,7 +674,7 @@ static void ntree_shader_link_builtin_normal(bNodeTree *ntree,
 			/* Don't connect node itself! */
 			continue;
 		}
-		if (node->type == NODE_GROUP && node->id) {
+		if ((ELEM(node->type, NODE_GROUP, NODE_CUSTOM_GROUP)) && node->id) {
 			/* Special re-linking for group nodes. */
 			ntree_shader_link_builtin_group_normal(ntree,
 			                                       node,
@@ -765,6 +765,7 @@ static bool ntree_tag_bsdf_cb(bNode *fromnode, bNode *UNUSED(tonode), void *user
 
 	switch (fromnode->type) {
 		case NODE_GROUP:
+		case NODE_CUSTOM_GROUP:
 			/* Recursive */
 			if (fromnode->id != NULL) {
 				bNodeTree *ntree = (bNodeTree *)fromnode->id;
diff --git a/source/blender/nodes/shader/nodes/node_shader_common.c b/source/blender/nodes/shader/nodes/node_shader_common.c
index c238a3d946d..0c2b8d939f5 100644
--- a/source/blender/nodes/shader/nodes/node_shader_common.c
+++ b/source/blender/nodes/shader/nodes/node_shader_common.c
@@ -239,3 +239,11 @@ void register_node_type_sh_group(void)
 
 	nodeRegisterType(&ntype);
 }
+
+void register_node_type_sh_custom_group(bNodeType *ntype)
+{
+	ntype->insert_link = node_insert_link_default;
+	ntype->update_internal_links = node_update_internal_links_default;
+	node_type_exec(ntype, group_initexec, group_freeexec, group_execute);
+	node_type_gpu(ntype, gpu_group_execute);
+}