Function to return a list of keyframe segments

Add a function that returns a list of keyframe segments
A segment being a continuous selection of keyframes
Will be used by future operators in the graph editor

Reviewed by: Sybren A. Stüvel
Differential Revision: https://developer.blender.org/D13531
Ref: D13531

1 files changed, 27 insertions, 8 deletions

diff --git a/source/blender/editors/animation/keyframes_general.c b/source/blender/editors/animation/keyframes_general.c
index dc5d71b5a1e..4fa5dee99a6 100644
--- a/source/blender/editors/animation/keyframes_general.c
+++ b/source/blender/editors/animation/keyframes_general.c
@@ -345,6 +345,28 @@ static bool find_fcurve_segment(FCurve *fcu,
   return in_segment;
 }
 
+/* Return a list of FCurveSegment with a start index and a length.
+ * A segment is a continuous selection of keyframes.
+ * Keys that have BEZT_FLAG_IGNORE_TAG set are treated as unselected.
+ * The caller is responsible for freeing the memory. */
+ListBase find_fcurve_segments(FCurve *fcu)
+{
+  ListBase segments = {NULL, NULL};
+  int segment_start_idx = 0;
+  int segment_len = 0;
+  int current_index = 0;
+
+  while (find_fcurve_segment(fcu, current_index, &segment_start_idx, &segment_len)) {
+    FCurveSegment *segment;
+    segment = MEM_callocN(sizeof(*segment), "FCurveSegment");
+    segment->start_index = segment_start_idx;
+    segment->length = segment_len;
+    BLI_addtail(&segments, segment);
+    current_index = segment_start_idx + segment_len;
+  }
+  return segments;
+}
+
 /* ---------------- */
 
 /* Check if the keyframe interpolation type is supported */
@@ -440,15 +462,12 @@ bool decimate_fcurve(bAnimListElem *ale, float remove_ratio, float error_sq_max)
     fcu->bezt[i].f2 &= ~BEZT_FLAG_TEMP_TAG;
   }
 
-  /* Only decimate the individual selected curve segments. */
-  int segment_start_idx = 0;
-  int segment_len = 0;
-  int current_index = 0;
-
-  while (find_fcurve_segment(fcu, current_index, &segment_start_idx, &segment_len)) {
-    decimate_fcurve_segment(fcu, segment_start_idx, segment_len, remove_ratio, error_sq_max);
-    current_index = segment_start_idx + segment_len;
+  ListBase segments = find_fcurve_segments(fcu);
+  LISTBASE_FOREACH (FCurveSegment *, segment, &segments) {
+    decimate_fcurve_segment(
+        fcu, segment->start_index, segment->length, remove_ratio, error_sq_max);
   }
+  BLI_freelistN(&segments);
 
   uint old_totvert = fcu->totvert;
   fcu->bezt = NULL;