Add an option to do keyframe insertion in a cycle-aware fashion.

When enabled, inserting keyframes into F-Curves with simple cyclic
extrapolation (the same conditions as required for cycle-aware auto
handle smoothing to activate) will take the cycle into account:

- Keyframes that are being inserted outside of the cycle bounds
  are remapped to be inside the cycle. Thus it is not necessary
  to be within the main iteration of the cycle when tweaking.

  This becomes especially useful in the final animation tweaking
  phase when the channel keys may be staggered for overlap, so
  the actual master period is different for different channels.

- Modifying one of the end points of a cycle also changes the
  other end point when appropriate, to preserve smooth transition.

This feature applies to both manual keyframe insertion using
'I', and auto-keyframing.

Differential Revision: https://developer.blender.org/D3140

1 files changed, 3 insertions, 4 deletions

diff --git a/source/blender/editors/animation/keyingsets.c b/source/blender/editors/animation/keyingsets.c
index 1d6ced02332..e97f88afffd 100644
--- a/source/blender/editors/animation/keyingsets.c
+++ b/source/blender/editors/animation/keyingsets.c
@@ -924,7 +924,8 @@ short ANIM_validate_keyingset(bContext *C, ListBase *dsources, KeyingSet *ks)
 /* Determine which keying flags apply based on the override flags */
 static short keyingset_apply_keying_flags(const short base_flags, const short overrides, const short own_flags)
 {
-	short result = 0;
+	/* Pass through all flags by default (i.e. even not explicitly listed ones). */
+	short result = base_flags;
 
 	/* The logic for whether a keying flag applies is as follows:
 	 *  - If the flag in question is set in "overrides", that means that the
@@ -934,10 +935,8 @@ static short keyingset_apply_keying_flags(const short base_flags, const short ov
 	 */
 #define APPLY_KEYINGFLAG_OVERRIDE(kflag) \
 	if (overrides & kflag) {             \
+		result &= ~kflag;                \
 		result |= (own_flags & kflag);   \
-	}                                    \
-	else {                               \
-		result |= (base_flags & kflag);  \
 	}
 
 	/* Apply the flags one by one...