Cleanup: NLA transforms, simplify `recalcData_nla()`

Refactor the `recalcData_nla()` function, which takes data from the
transform system and updates NLA strips, such that the actual logic to
change the strip is moved into its own function.

This also moves some generic code (find prev/next strip) from that
function to BKE.

This is to make the code easier to adjust when different transform
operations need to perform different modifications of the strip (i.e. to
fix T101130).

Manifest Task: T101130

Reviewed By: sybren

Differential Revision: https://developer.blender.org/D16181

1 files changed, 28 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/nla.c b/source/blender/blenkernel/intern/nla.c
index fd3580a7e88..ba63cdff917 100644
--- a/source/blender/blenkernel/intern/nla.c
+++ b/source/blender/blenkernel/intern/nla.c
@@ -1272,6 +1272,34 @@ float BKE_nlastrip_compute_frame_to_next_strip(NlaStrip *strip)
   return limit_next;
 }
 
+NlaStrip *BKE_nlastrip_next_in_track(struct NlaStrip *strip, bool skip_transitions)
+{
+  NlaStrip *next = strip->next;
+  while (next != NULL) {
+    if (skip_transitions && (next->type & NLASTRIP_TYPE_TRANSITION)) {
+      next = next->next;
+    }
+    else {
+      return next;
+    }
+  }
+  return NULL;
+}
+
+NlaStrip *BKE_nlastrip_prev_in_track(struct NlaStrip *strip, bool skip_transitions)
+{
+  NlaStrip *prev = strip->prev;
+  while (prev != NULL) {
+    if (skip_transitions && (prev->type & NLASTRIP_TYPE_TRANSITION)) {
+      prev = prev->prev;
+    }
+    else {
+      return prev;
+    }
+  }
+  return NULL;
+}
+
 NlaStrip *BKE_nlastrip_find_active(NlaTrack *nlt)
 {
   if (nlt == NULL) {