First stages of easier "expressions" creation...

It is now possible to create "scripted expression" drivers by simply
clicking on some property, and typing some short Python expression
prefixed with a '#'. This will result in a scripted expression driver,
with the typed-in text being created.

For example, you can click on X-Location of the default cube, and
type:
#sin(frame)
and a new driver will be created for the x-location of the cube. This
will use the current frame value, and modulate this with a sine wave.

Do note though, that the current frame is a special case here. In the
current implementation, a special "frame" driver variable, which
references the current scene frame is created automatically, so that
this simple and (assumed) common case will work straight out of the
box.

Future improvements:
- Explore possibilities of semi-automated extraction of variables from
such expressions, resulting in automated variable extraction. (Doing
away with variables completely is definitely 100% off the agenda
though)
- Look into some ways of defining some shorthands for referencing
local data (possibly related to variable extraction?)

1 files changed, 7 insertions, 0 deletions

diff --git a/source/blender/editors/include/ED_keyframing.h b/source/blender/editors/include/ED_keyframing.h
index 294b9b8475a..0ca3a932266 100644
--- a/source/blender/editors/include/ED_keyframing.h
+++ b/source/blender/editors/include/ED_keyframing.h
@@ -225,6 +225,13 @@ typedef enum eCreateDriverFlags {
 
 /* -------- */
 
+/* Low-level call to add a new driver F-Curve. This shouldn't be used directly for most tools,
+ * although there are special cases where this approach is preferable.
+ */
+struct FCurve *verify_driver_fcurve(struct ID *id, const char rna_path[], const int array_index, short add);
+
+/* -------- */
+
 /* Returns whether there is a driver in the copy/paste buffer to paste */
 short ANIM_driver_can_paste(void);