Avoid node tree update tag when changed nodes which are not affecting result

This was we don't have re-compo or viewport re-rendering happening when changing
nodes which are not connected to the output at all (for example when adding new
nodes or changing settings for unconnected nodes).

Only basic operations are covered for now. checks could be added to more tools
when needed.

Currently it's not fully optimal implementation, but seems to work fast enough.
Don't see reliable alternative to that -- keeping tag in the node wouldn't work
because of the node groups (which are probably already broken, but should be
easy to solve with current approach). So guess it's more matter of optimizing
path search from a node to output.

Before processing forward let's check whether it's indeed something we want
and whether the approach is indeed not fully bad.

Reviewers: campbellbarton, mont29

Subscribers: sebastian_k

Differential Revision: https://developer.blender.org/D1765

3 files changed, 20 insertions, 13 deletions

diff --git a/source/blender/makesrna/intern/rna_color.c b/source/blender/makesrna/intern/rna_color.c
index c418ef3ceb6..021bc608564 100644
--- a/source/blender/makesrna/intern/rna_color.c
+++ b/source/blender/makesrna/intern/rna_color.c
@@ -326,7 +326,7 @@ static void rna_ColorRamp_update(Main *bmain, Scene *UNUSED(scene), PointerRNA *
 
 				for (node = ntree->nodes.first; node; node = node->next) {
 					if (ELEM(node->type, SH_NODE_VALTORGB, CMP_NODE_VALTORGB, TEX_NODE_VALTORGB)) {
-						ED_node_tag_update_nodetree(bmain, ntree);
+						ED_node_tag_update_nodetree(bmain, ntree, node);
 					}
 				}
 				break;
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index 7561a7405f7..a701cf6182d 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -657,11 +657,12 @@ static bool rna_NodeTree_check(bNodeTree *ntree, ReportList *reports)
 static void rna_NodeTree_update(Main *bmain, Scene *UNUSED(scene), PointerRNA *ptr)
 {
 	bNodeTree *ntree = (bNodeTree *)ptr->id.data;
+	bNode *node = (bNode *)ptr->data;
 
 	WM_main_add_notifier(NC_NODE | NA_EDITED, NULL);
 	WM_main_add_notifier(NC_SCENE | ND_NODES, &ntree->id);
 
-	ED_node_tag_update_nodetree(bmain, ntree);
+	ED_node_tag_update_nodetree(bmain, ntree, node);
 }
 
 static bNode *rna_NodeTree_node_new(bNodeTree *ntree, bContext *C, ReportList *reports, const char *type)
@@ -1048,7 +1049,7 @@ static void rna_NodeTree_interface_update(bNodeTree *ntree, bContext *C)
 	ntree->update |= NTREE_UPDATE_GROUP;
 	ntreeUpdateTree(G.main, ntree);
 	
-	ED_node_tag_update_nodetree(CTX_data_main(C), ntree);
+	ED_node_tag_update_nodetree(CTX_data_main(C), ntree, NULL);
 }
 
 
@@ -1545,12 +1546,13 @@ static int rna_Node_parent_poll(PointerRNA *ptr, PointerRNA value)
 static void rna_Node_update(Main *bmain, Scene *UNUSED(scene), PointerRNA *ptr)
 {
 	bNodeTree *ntree = (bNodeTree *)ptr->id.data;
-	ED_node_tag_update_nodetree(bmain, ntree);
+	bNode *node = (bNode *)ptr->data;
+	ED_node_tag_update_nodetree(bmain, ntree, node);
 }
 
-static void rna_Node_socket_value_update(ID *id, bNode *UNUSED(node), bContext *C)
+static void rna_Node_socket_value_update(ID *id, bNode *node, bContext *C)
 {
-	ED_node_tag_update_nodetree(CTX_data_main(C), (bNodeTree *)id);
+	ED_node_tag_update_nodetree(CTX_data_main(C), (bNodeTree *)id, node);
 }
 
 static void rna_Node_select_set(PointerRNA *ptr, int value)
@@ -1916,7 +1918,11 @@ static PointerRNA rna_NodeSocket_node_get(PointerRNA *ptr)
 static void rna_NodeSocket_update(Main *bmain, Scene *UNUSED(scene), PointerRNA *ptr)
 {
 	bNodeTree *ntree = (bNodeTree *)ptr->id.data;
-	ED_node_tag_update_nodetree(bmain, ntree);
+	bNodeSocket *sock = (bNodeSocket *)ptr->data;
+	bNode *node;
+	if (nodeFindNode(ntree, sock, &node, NULL)) {
+		ED_node_tag_update_nodetree(bmain, ntree, node);
+	}
 }
 
 static int rna_NodeSocket_is_output_get(PointerRNA *ptr)
@@ -2182,7 +2188,7 @@ static void rna_NodeSocketInterface_update(Main *bmain, Scene *UNUSED(scene), Po
 	ntree->update |= NTREE_UPDATE_GROUP;
 	ntreeUpdateTree(G.main, ntree);
 	
-	ED_node_tag_update_nodetree(bmain, ntree);
+	ED_node_tag_update_nodetree(bmain, ntree, NULL);
 }
 
 
@@ -2438,8 +2444,9 @@ static void rna_CompositorNode_tag_need_exec(bNode *node)
 static void rna_Node_tex_image_update(Main *bmain, Scene *UNUSED(scene), PointerRNA *ptr)
 {
 	bNodeTree *ntree = (bNodeTree *)ptr->id.data;
+	bNode *node = (bNode *)ptr->data;
 
-	ED_node_tag_update_nodetree(bmain, ntree);
+	ED_node_tag_update_nodetree(bmain, ntree, node);
 	WM_main_add_notifier(NC_IMAGE, NULL);
 }
 
@@ -2451,7 +2458,7 @@ static void rna_Node_material_update(Main *bmain, Scene *UNUSED(scene), PointerR
 	if (node->id)
 		nodeSetActive(ntree, node);
 
-	ED_node_tag_update_nodetree(bmain, ntree);
+	ED_node_tag_update_nodetree(bmain, ntree, node);
 }
 
 static void rna_NodeGroup_update(Main *bmain, Scene *UNUSED(scene), PointerRNA *ptr)
@@ -2462,7 +2469,7 @@ static void rna_NodeGroup_update(Main *bmain, Scene *UNUSED(scene), PointerRNA *
 	if (node->id)
 		ntreeUpdateTree(bmain, (bNodeTree *)node->id);
 	
-	ED_node_tag_update_nodetree(bmain, ntree);
+	ED_node_tag_update_nodetree(bmain, ntree, node);
 }
 
 static void rna_NodeGroup_node_tree_set(PointerRNA *ptr, const PointerRNA value)
@@ -2972,7 +2979,7 @@ static void rna_ShaderNodeScript_update(Main *bmain, Scene *scene, PointerRNA *p
 		RE_engine_free(engine);
 	}
 
-	ED_node_tag_update_nodetree(bmain, ntree);
+	ED_node_tag_update_nodetree(bmain, ntree, node);
 }
 
 static void rna_ShaderNodeSubsurface_update(Main *bmain, Scene *scene, PointerRNA *ptr)
diff --git a/source/blender/makesrna/intern/rna_texture.c b/source/blender/makesrna/intern/rna_texture.c
index 71069dc9751..b44482dc2c1 100644
--- a/source/blender/makesrna/intern/rna_texture.c
+++ b/source/blender/makesrna/intern/rna_texture.c
@@ -174,7 +174,7 @@ static void rna_Texture_update(Main *bmain, Scene *UNUSED(scene), PointerRNA *pt
 	}
 	else if (GS(id->name) == ID_NT) {
 		bNodeTree *ntree = ptr->id.data;
-		ED_node_tag_update_nodetree(bmain, ntree);
+		ED_node_tag_update_nodetree(bmain, ntree, NULL);
 	}
 }