Todo/feature request

When using masks or other simple 3D elements in composites, doing
a layer re-rendering on a node is a bit clumsy all the time.

This commit does two things to help:
- new hotkey "Z" in node editor automatically finds render layer
  that changed and re-renders it + composites
- option "Auto Render" does same, but then after every transform
  edit in 3D window

The latter is experimental; real & proper system for this requires
full threaded render support (like previews). But it works!

Demo file:
http://download.blender.org/demo/test/auto_composite.blend

Important fix:
After any render, all the render layers were tagged "changed", which
caused any edit to first totally recomposte everthing. Now it only
composites changes.

Implementation notes

- DAG scene flush now sets 'changed' flags in render layer nodes
- Added notifier for 'transform finished' to trigger the update,
  this is temporarily.

4 files changed, 69 insertions, 5 deletions

diff --git a/source/blender/editors/space_node/node_edit.c b/source/blender/editors/space_node/node_edit.c
index 834f3483871..1279863802a 100644
--- a/source/blender/editors/space_node/node_edit.c
+++ b/source/blender/editors/space_node/node_edit.c
@@ -2158,6 +2158,51 @@ void NODE_OT_read_fullsamplelayers(wmOperatorType *ot)
 	ot->flag= 0;
 }
 
+int node_render_changed_exec(bContext *C, wmOperator *UNUSED(op))
+{
+	Scene *sce= CTX_data_scene(C);
+	bNode *node;
+	
+	for(node= sce->nodetree->nodes.first; node; node= node->next) {
+		if(node->id==(ID *)sce && node->need_exec) {
+			break;
+		}
+	}
+	if(node) {
+		SceneRenderLayer *srl= BLI_findlink(&sce->r.layers, node->custom1);
+		
+		if(srl) {
+			PointerRNA op_ptr;
+			
+			WM_operator_properties_create(&op_ptr, "RENDER_OT_render");
+			RNA_string_set(&op_ptr, "layer", srl->name);
+			RNA_string_set(&op_ptr, "scene", sce->id.name+2);
+			
+			WM_operator_name_call(C, "RENDER_OT_render", WM_OP_INVOKE_DEFAULT, &op_ptr);
+
+			WM_operator_properties_free(&op_ptr);
+			
+			return OPERATOR_FINISHED;
+		}
+		   
+	}
+	return OPERATOR_CANCELLED;
+}
+
+void NODE_OT_render_changed(wmOperatorType *ot)
+{
+	
+	ot->name= "Render Changed Layer";
+	ot->idname= "NODE_OT_render_changed";
+	
+	ot->exec= node_render_changed_exec;
+	
+	ot->poll= composite_node_active;
+	
+	/* flags */
+	ot->flag= 0;
+}
+
 
 /* ****************** Make Group operator ******************* */
 
diff --git a/source/blender/editors/space_node/node_intern.h b/source/blender/editors/space_node/node_intern.h
index 66bf9310db8..5d67eb77e28 100644
--- a/source/blender/editors/space_node/node_intern.h
+++ b/source/blender/editors/space_node/node_intern.h
@@ -92,7 +92,7 @@ void node_tree_verify_groups(bNodeTree *nodetree);
 void snode_autoconnect(SpaceNode *snode, int allow_multiple, int replace);
 int node_has_hidden_sockets(bNode *node);
 void node_set_hidden_sockets(SpaceNode *snode, bNode *node, int set);
-
+int node_render_changed_exec(bContext *, wmOperator *);
 
 void NODE_OT_duplicate(struct wmOperatorType *ot);
 void NODE_OT_delete(struct wmOperatorType *ot);
@@ -115,6 +115,7 @@ void NODE_OT_show_cyclic_dependencies(struct wmOperatorType *ot);
 void NODE_OT_link_viewer(struct wmOperatorType *ot);
 void NODE_OT_read_fullsamplelayers(struct wmOperatorType *ot);
 void NODE_OT_read_renderlayers(struct wmOperatorType *ot);
+void NODE_OT_render_changed(struct wmOperatorType *ot);
 
 void NODE_OT_backimage_move(struct wmOperatorType *ot);
 void NODE_OT_backimage_zoom(struct wmOperatorType *ot);
diff --git a/source/blender/editors/space_node/node_ops.c b/source/blender/editors/space_node/node_ops.c
index 781682c9185..db5c493dcd9 100644
--- a/source/blender/editors/space_node/node_ops.c
+++ b/source/blender/editors/space_node/node_ops.c
@@ -78,6 +78,7 @@ void node_operatortypes(void)
 	
 	WM_operatortype_append(NODE_OT_read_renderlayers);
 	WM_operatortype_append(NODE_OT_read_fullsamplelayers);
+	WM_operatortype_append(NODE_OT_render_changed);
 	
 	WM_operatortype_append(NODE_OT_backimage_move);
 	WM_operatortype_append(NODE_OT_backimage_zoom);
@@ -170,6 +171,8 @@ void node_keymap(struct wmKeyConfig *keyconf)
 	
 	WM_keymap_add_item(keymap, "NODE_OT_read_renderlayers", RKEY, KM_PRESS, KM_CTRL, 0);
 	WM_keymap_add_item(keymap, "NODE_OT_read_fullsamplelayers", RKEY, KM_PRESS, KM_SHIFT, 0);
+	WM_keymap_add_item(keymap, "NODE_OT_render_changed", ZKEY, KM_PRESS, 0, 0);
+	
 	
 	transform_keymap_for_space(keyconf, keymap, SPACE_NODE);
 }
diff --git a/source/blender/editors/space_node/space_node.c b/source/blender/editors/space_node/space_node.c
index eb8c34fe8bd..dab6568bea6 100644
--- a/source/blender/editors/space_node/space_node.c
+++ b/source/blender/editors/space_node/space_node.c
@@ -172,13 +172,21 @@ static void node_area_listener(ScrArea *sa, wmNotifier *wmn)
 				case ND_FRAME:
 					ED_area_tag_refresh(sa);
 					break;
+				case ND_TRANSFORM_DONE:
+					if(type==NTREE_COMPOSIT) {
+						if(snode->flag & SNODE_AUTO_RENDER) {
+							snode->recalc= 1;
+							ED_area_tag_refresh(sa);
+						}
+					}
+					break;
 			}
 			break;
 		case NC_WM:
 			if(wmn->data==ND_FILEREAD)
 				ED_area_tag_refresh(sa);
 			break;
-			
+		
 		/* future: add ID checks? */
 		case NC_MATERIAL:
 			if(type==NTREE_SHADER) {
@@ -212,7 +220,7 @@ static void node_area_listener(ScrArea *sa, wmNotifier *wmn)
 
 		case NC_IMAGE:
 			if (wmn->action == NA_EDITED) {
-				if(snode->treetype==NTREE_COMPOSIT) {
+				if(type==NTREE_COMPOSIT) {
 					Scene *scene= wmn->window->screen->scene;
 					
 					/* note that NodeTagIDChanged is alredy called by BKE_image_signal() on all
@@ -241,8 +249,15 @@ static void node_area_refresh(const struct bContext *C, struct ScrArea *sa)
 		}
 		else if(snode->treetype==NTREE_COMPOSIT) {
 			Scene *scene= (Scene *)snode->id;
-			if(scene->use_nodes)
-				snode_composite_job(C, sa);
+			if(scene->use_nodes) {
+				/* recalc is set on 3d view changes for auto compo */
+				if(snode->recalc) {
+					snode->recalc= 0;
+					node_render_changed_exec((struct bContext*)C, NULL);
+				}
+				else 
+					snode_composite_job(C, sa);
+			}
 		}
 		else if(snode->treetype==NTREE_TEXTURE) {
 			Tex *tex= (Tex *)snode->id;