Depsgraph: Begin concept of active dependency graph

When active dependency graph is evaluated, it will apply animation,
drivers and scalar evaluation data (such as object matrix) to an
original datablock. This way operators and tools can easily read
data from original datablock.

This will simplify porting them to copy-on-write, and solve issues
when some operator will allocate new datablock based on original one,
and will want to read data from it.

1 files changed, 10 insertions, 0 deletions

diff --git a/source/blender/depsgraph/intern/depsgraph.h b/source/blender/depsgraph/intern/depsgraph.h
index a368158a6c4..3c1233cd5bb 100644
--- a/source/blender/depsgraph/intern/depsgraph.h
+++ b/source/blender/depsgraph/intern/depsgraph.h
@@ -210,6 +210,16 @@ struct Depsgraph {
 	 */
 	Scene *scene_cow;
 
+	/* Active dependency graph is a dependency graph which is used by the
+	 * currently active window. When dependency graph is active, it is allowed
+	 * for evaluation functions to write animation f-curve result, drivers
+	 * result and other selective things (object matrix?) to original object.
+	 *
+	 * This way we simplify operators, which don't need to worry about where
+	 * to read stuff from.
+	 */
+	bool is_active;
+
 	/* NITE: Corresponds to G_DEBUG_DEPSGRAPH_* flags. */
 	int debug_flags;
 	string debug_name;