VSE: Make time operations self-contained

This patch makes it possible to manipulate strips without need to use
update functions to recalculate effect and meta strips.

Prior to this change function `SEQ_time_update_sequence` had to be used
to update mainly effects and meta strips. This was implemented in a way
that relied on sorted list of strips, which can't always be done and in
rare cases this approach failed.

In case of meta strips, `seqbase` had to be passed and compared with
"active" one to determine whether meta strip should be updated or not.
This is especially weak system that is prone to bugs when functions are
used by python API functions.

Finally, other strip types had startdisp` and `enddisp` fields updated
by this function and a lot of code relied on these fields even if strip
start, length and offsets are available. This is completely
unnecessary.

Implemented changes:
All effects and meta strips are updated when strip handles are moved or
strip is translated, without need to call any update function.

Function `SEQ_time_update_sequence` has been split to
`SEQ_time_update_meta_strip_range` and
`seq_time_update_effects_strip_range`. These functions should be only
used within sequencer module code. Meta update is used for versioning,
which is only reason for it not being declared internally.

Sequence fields `startdisp` and `enddisp` are now only used for
effects to store strip start and end points. These fields should be
used only internally within sequencer module code.
Use function `SEQ_time_*_handle_frame_get` to get strip start and end
points.

To update effects and meta strips with reasonable performance, cache
for "parent" meta strip and attached effects is added to
`SequenceLookup` cache, so it shares invalidation mechanisms.
All caches are populated during single iteration.

There should be no functional changes.

Differential Revision: https://developer.blender.org/D14990

1 files changed, 73 insertions, 77 deletions

diff --git a/source/blender/sequencer/intern/strip_transform.c b/source/blender/sequencer/intern/strip_transform.c
index 8ff577240d6..051dc3961ba 100644
--- a/source/blender/sequencer/intern/strip_transform.c
+++ b/source/blender/sequencer/intern/strip_transform.c
@@ -25,6 +25,9 @@
 #include "SEQ_time.h"
 #include "SEQ_transform.h"
 
+#include "strip_time.h"
+#include "sequencer.h"
+
 #include "CLG_log.h"
 
 static CLG_LogRef LOG = {"seq.strip_transform"};
@@ -86,16 +89,16 @@ bool SEQ_transform_seqbase_isolated_sel_check(ListBase *seqbase)
   return true;
 }
 
-void SEQ_transform_handle_xlimits(Sequence *seq, int leftflag, int rightflag)
+void SEQ_transform_handle_xlimits(const Scene *scene, Sequence *seq, int leftflag, int rightflag)
 {
   if (leftflag) {
     if (SEQ_time_left_handle_frame_get(seq) >= SEQ_time_right_handle_frame_get(seq)) {
-      SEQ_time_left_handle_frame_set(seq, SEQ_time_right_handle_frame_get(seq) - 1);
+      SEQ_time_left_handle_frame_set(scene, seq, SEQ_time_right_handle_frame_get(seq) - 1);
     }
 
     if (SEQ_transform_single_image_check(seq) == 0) {
       if (SEQ_time_left_handle_frame_get(seq) >= seq_tx_get_end(seq)) {
-        SEQ_time_left_handle_frame_set(seq, seq_tx_get_end(seq) - 1);
+        SEQ_time_left_handle_frame_set(scene, seq, seq_tx_get_end(seq) - 1);
       }
 
       /* TODO: This doesn't work at the moment. */
@@ -112,12 +115,12 @@ void SEQ_transform_handle_xlimits(Sequence *seq, int leftflag, int rightflag)
 
   if (rightflag) {
     if (SEQ_time_right_handle_frame_get(seq) <= SEQ_time_left_handle_frame_get(seq)) {
-      SEQ_time_right_handle_frame_set(seq, SEQ_time_left_handle_frame_get(seq) + 1);
+      SEQ_time_right_handle_frame_set(scene, seq, SEQ_time_left_handle_frame_get(seq) + 1);
     }
 
     if (SEQ_transform_single_image_check(seq) == 0) {
       if (SEQ_time_right_handle_frame_get(seq) <= seq_tx_get_start(seq)) {
-        SEQ_time_right_handle_frame_set(seq, seq_tx_get_start(seq) + 1);
+        SEQ_time_right_handle_frame_set(scene, seq, seq_tx_get_start(seq) + 1);
       }
     }
   }
@@ -129,7 +132,7 @@ void SEQ_transform_handle_xlimits(Sequence *seq, int leftflag, int rightflag)
   }
 }
 
-void SEQ_transform_fix_single_image_seq_offsets(Sequence *seq)
+void SEQ_transform_fix_single_image_seq_offsets(const Scene *scene, Sequence *seq)
 {
   int left, start, offset;
   if (!SEQ_transform_single_image_check(seq)) {
@@ -142,8 +145,8 @@ void SEQ_transform_fix_single_image_seq_offsets(Sequence *seq)
   start = seq->start;
   if (start != left) {
     offset = left - start;
-    SEQ_time_left_handle_frame_set(seq, SEQ_time_left_handle_frame_get(seq) - offset);
-    SEQ_time_right_handle_frame_set(seq, SEQ_time_right_handle_frame_get(seq) - offset);
+    SEQ_time_left_handle_frame_set(scene, seq, SEQ_time_left_handle_frame_get(seq) - offset);
+    SEQ_time_right_handle_frame_set(scene, seq, SEQ_time_right_handle_frame_get(seq) - offset);
     seq->start += offset;
   }
 }
@@ -156,7 +159,8 @@ bool SEQ_transform_sequence_can_be_translated(Sequence *seq)
 bool SEQ_transform_test_overlap_seq_seq(Sequence *seq1, Sequence *seq2)
 {
   return (seq1 != seq2 && seq1->machine == seq2->machine &&
-          ((seq1->enddisp <= seq2->startdisp) || (seq1->startdisp >= seq2->enddisp)) == 0);
+          ((SEQ_time_right_handle_frame_get(seq1) <= SEQ_time_left_handle_frame_get(seq2)) ||
+           (SEQ_time_left_handle_frame_get(seq1) >= SEQ_time_right_handle_frame_get(seq2))) == 0);
 }
 
 bool SEQ_transform_test_overlap(ListBase *seqbasep, Sequence *test)
@@ -180,9 +184,6 @@ void SEQ_transform_translate_sequence(Scene *evil_scene, Sequence *seq, int delt
     return;
   }
 
-  SEQ_offset_animdata(evil_scene, seq, delta);
-  seq->start += delta;
-
   /* Meta strips requires special handling: their content is to be translated, and then frame range
    * of the meta is to be updated for the updated content. */
   if (seq->type == SEQ_TYPE_META) {
@@ -190,16 +191,21 @@ void SEQ_transform_translate_sequence(Scene *evil_scene, Sequence *seq, int delt
     for (seq_child = seq->seqbase.first; seq_child; seq_child = seq_child->next) {
       SEQ_transform_translate_sequence(evil_scene, seq_child, delta);
     }
-    /* Ensure that meta bounds are updated, but this function prevents resets seq->start and
-     * start/end point in timeline. */
-    SEQ_time_update_meta_strip_range(evil_scene, seq);
     /* Move meta start/end points. */
-    SEQ_time_left_handle_frame_set(seq, seq->startdisp + delta);
-    SEQ_time_right_handle_frame_set(seq, seq->enddisp + delta);
+    SEQ_time_left_handle_frame_set(evil_scene, seq, SEQ_time_left_handle_frame_get(seq) + delta);
+    SEQ_time_right_handle_frame_set(evil_scene, seq, SEQ_time_right_handle_frame_get(seq) + delta);
+  }
+  else { /* All other strip types. */
+    seq->start += delta;
+    /* Only to make files usable in older versions. */
+    seq->startdisp = SEQ_time_left_handle_frame_get(seq); 
+    seq->enddisp = SEQ_time_right_handle_frame_get(seq);
   }
 
-  ListBase *seqbase = SEQ_active_seqbase_get(SEQ_editing_get(evil_scene));
-  SEQ_time_update_sequence(evil_scene, seqbase, seq);
+  SEQ_offset_animdata(evil_scene, seq, delta);
+  SEQ_time_update_meta_strip_range(evil_scene, seq_sequence_lookup_meta_by_seq(evil_scene, seq));
+  seq_time_update_effects_strip_range(evil_scene,
+                                      seq_sequence_lookup_effects_by_seq(evil_scene, seq));
 }
 
 bool SEQ_transform_seqbase_shuffle_ex(ListBase *seqbasep,
@@ -211,16 +217,12 @@ bool SEQ_transform_seqbase_shuffle_ex(ListBase *seqbasep,
   BLI_assert(ELEM(channel_delta, -1, 1));
 
   test->machine += channel_delta;
-  SEQ_time_update_sequence(evil_scene, seqbasep, test);
   while (SEQ_transform_test_overlap(seqbasep, test)) {
     if ((channel_delta > 0) ? (test->machine >= MAXSEQ) : (test->machine < 1)) {
       break;
     }
 
     test->machine += channel_delta;
-
-    /* XXX: I don't think this is needed since were only moving vertically, Campbell. */
-    SEQ_time_update_sequence(evil_scene, seqbasep, test);
   }
 
   if (!SEQ_valid_strip_channel(test)) {
@@ -228,19 +230,18 @@ bool SEQ_transform_seqbase_shuffle_ex(ListBase *seqbasep,
      * nicer to move it to the end */
 
     Sequence *seq;
-    int new_frame = test->enddisp;
+    int new_frame = SEQ_time_right_handle_frame_get(test);
 
     for (seq = seqbasep->first; seq; seq = seq->next) {
       if (seq->machine == orig_machine) {
-        new_frame = max_ii(new_frame, seq->enddisp);
+        new_frame = max_ii(new_frame, SEQ_time_right_handle_frame_get(seq));
       }
     }
 
     test->machine = orig_machine;
-    new_frame = new_frame + (test->start - test->startdisp); /* adjust by the startdisp */
+    new_frame = new_frame +
+                (test->start - SEQ_time_left_handle_frame_get(test)); /* adjust by the startdisp */
     SEQ_transform_translate_sequence(evil_scene, test, new_frame - test->start);
-
-    SEQ_time_update_sequence(evil_scene, seqbasep, test);
     return false;
   }
 
@@ -252,61 +253,57 @@ bool SEQ_transform_seqbase_shuffle(ListBase *seqbasep, Sequence *test, Scene *ev
   return SEQ_transform_seqbase_shuffle_ex(seqbasep, test, evil_scene, 1);
 }
 
-static int shuffle_seq_time_offset_test(SeqCollection *strips_to_shuffle,
-                                        ListBase *seqbasep,
-                                        char dir)
+static bool shuffle_seq_test_overlap(const Sequence *seq1, const Sequence *seq2, const int offset)
 {
-  int offset = 0;
-  Sequence *seq;
-
-  SEQ_ITERATOR_FOREACH (seq, strips_to_shuffle) {
-    LISTBASE_FOREACH (Sequence *, seq_other, seqbasep) {
-      if (!SEQ_transform_test_overlap_seq_seq(seq, seq_other)) {
-        continue;
-      }
-      if (SEQ_relation_is_effect_of_strip(seq_other, seq)) {
-        continue;
-      }
-      if (UNLIKELY(SEQ_collection_has_strip(seq_other, strips_to_shuffle))) {
-        CLOG_WARN(&LOG,
-                  "Strip overlaps with itself or another strip, that is to be shuffled. "
-                  "This should never happen.");
-        continue;
-      }
-      if (dir == 'L') {
-        offset = min_ii(offset, seq_other->startdisp - seq->enddisp);
-      }
-      else {
-        offset = max_ii(offset, seq_other->enddisp - seq->startdisp);
-      }
-    }
-  }
-  return offset;
+  return (
+      seq1 != seq2 && seq1->machine == seq2->machine &&
+      ((SEQ_time_right_handle_frame_get(seq1) + offset <= SEQ_time_left_handle_frame_get(seq2)) ||
+       (SEQ_time_left_handle_frame_get(seq1) + offset >= SEQ_time_right_handle_frame_get(seq2))) ==
+          0);
 }
 
-static int shuffle_seq_time_offset(SeqCollection *strips_to_shuffle,
-                                   ListBase *seqbasep,
-                                   Scene *scene,
-                                   char dir)
+static int shuffle_seq_time_offset_get(SeqCollection *strips_to_shuffle,
+                                       ListBase *seqbasep,
+                                       char dir)
 {
-  int ofs = 0;
-  int tot_ofs = 0;
+  int offset = 0;
   Sequence *seq;
-  while ((ofs = shuffle_seq_time_offset_test(strips_to_shuffle, seqbasep, dir))) {
+  bool all_conflicts_resolved = false;
+
+  while (!all_conflicts_resolved) {
+    all_conflicts_resolved = true;
     SEQ_ITERATOR_FOREACH (seq, strips_to_shuffle) {
-      /* seq_test_overlap only tests display values */
-      seq->startdisp += ofs;
-      seq->enddisp += ofs;
-    }
+      LISTBASE_FOREACH (Sequence *, seq_other, seqbasep) {
+        if (!shuffle_seq_test_overlap(seq, seq_other, offset)) {
+          continue;
+        }
+        if (SEQ_relation_is_effect_of_strip(seq_other, seq)) {
+          continue;
+        }
+        if (UNLIKELY(SEQ_collection_has_strip(seq_other, strips_to_shuffle))) {
+          CLOG_WARN(&LOG,
+                    "Strip overlaps with itself or another strip, that is to be shuffled. "
+                    "This should never happen.");
+          continue;
+        }
 
-    tot_ofs += ofs;
-  }
+        all_conflicts_resolved = false;
 
-  SEQ_ITERATOR_FOREACH (seq, strips_to_shuffle) {
-    SEQ_time_update_sequence(scene, seqbasep, seq); /* corrects dummy startdisp/enddisp values */
+        if (dir == 'L') {
+          offset = min_ii(offset,
+                          SEQ_time_left_handle_frame_get(seq_other) -
+                              SEQ_time_right_handle_frame_get(seq));
+        }
+        else {
+          offset = max_ii(offset,
+                          SEQ_time_right_handle_frame_get(seq_other) -
+                              SEQ_time_left_handle_frame_get(seq));
+        }
+      }
+    }
   }
 
-  return tot_ofs;
+  return offset;
 }
 
 bool SEQ_transform_seqbase_shuffle_time(SeqCollection *strips_to_shuffle,
@@ -315,8 +312,8 @@ bool SEQ_transform_seqbase_shuffle_time(SeqCollection *strips_to_shuffle,
                                         ListBase *markers,
                                         const bool use_sync_markers)
 {
-  int offset_l = shuffle_seq_time_offset(strips_to_shuffle, seqbasep, evil_scene, 'L');
-  int offset_r = shuffle_seq_time_offset(strips_to_shuffle, seqbasep, evil_scene, 'R');
+  int offset_l = shuffle_seq_time_offset_get(strips_to_shuffle, seqbasep, 'L');
+  int offset_r = shuffle_seq_time_offset_get(strips_to_shuffle, seqbasep, 'R');
   int offset = (-offset_l < offset_r) ? offset_l : offset_r;
 
   if (offset) {
@@ -346,9 +343,8 @@ void SEQ_transform_offset_after_frame(Scene *scene,
                                       const int timeline_frame)
 {
   LISTBASE_FOREACH (Sequence *, seq, seqbase) {
-    if (seq->startdisp >= timeline_frame) {
+    if (SEQ_time_left_handle_frame_get(seq) >= timeline_frame) {
       SEQ_transform_translate_sequence(scene, seq, delta);
-      SEQ_time_update_sequence(scene, seqbase, seq);
       SEQ_relations_invalidate_cache_preprocessed(scene, seq);
     }
   }