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, 13 insertions, 8 deletions

diff --git a/source/blender/sequencer/intern/effects.c b/source/blender/sequencer/intern/effects.c
index d9d21ee3b05..0e5e56908b0 100644
--- a/source/blender/sequencer/intern/effects.c
+++ b/source/blender/sequencer/intern/effects.c
@@ -49,6 +49,7 @@
 #include "SEQ_proxy.h"
 #include "SEQ_relations.h"
 #include "SEQ_render.h"
+#include "SEQ_time.h"
 #include "SEQ_utils.h"
 
 #include "BLF_api.h"
@@ -2431,7 +2432,7 @@ static ImBuf *do_multicam(const SeqRenderData *context,
   if (!ed) {
     return NULL;
   }
-  ListBase *seqbasep = SEQ_get_seqbase_by_seq(&ed->seqbase, seq);
+  ListBase *seqbasep = SEQ_get_seqbase_by_seq(context->scene, seq);
   ListBase *channels = SEQ_get_channels_by_seq(&ed->seqbase, &ed->channels, seq);
   if (!seqbasep) {
     return NULL;
@@ -2467,13 +2468,15 @@ static ImBuf *do_adjustment_impl(const SeqRenderData *context, Sequence *seq, fl
 
   ed = context->scene->ed;
 
-  ListBase *seqbasep = SEQ_get_seqbase_by_seq(&ed->seqbase, seq);
+  ListBase *seqbasep = SEQ_get_seqbase_by_seq(context->scene, seq);
   ListBase *channels = SEQ_get_channels_by_seq(&ed->seqbase, &ed->channels, seq);
 
   /* Clamp timeline_frame to strip range so it behaves as if it had "still frame" offset (last
    * frame is static after end of strip). This is how most strips behave. This way transition
    * effects that doesn't overlap or speed effect can't fail rendering outside of strip range. */
-  timeline_frame = clamp_i(timeline_frame, seq->startdisp, seq->enddisp - 1);
+  timeline_frame = clamp_i(timeline_frame,
+                           SEQ_time_left_handle_frame_get(seq),
+                           SEQ_time_right_handle_frame_get(seq) - 1);
 
   if (seq->machine > 1) {
     i = seq_render_give_ibuf_seqbase(
@@ -2583,7 +2586,7 @@ static int early_out_speed(Sequence *UNUSED(seq), float UNUSED(fac))
 static int seq_effect_speed_get_strip_content_length(const Sequence *seq)
 {
   if ((seq->type & SEQ_TYPE_EFFECT) != 0 && SEQ_effect_get_num_inputs(seq->type) == 0) {
-    return seq->enddisp - seq->startdisp;
+    return SEQ_time_right_handle_frame_get(seq) - SEQ_time_left_handle_frame_get(seq);
   }
 
   return seq->len;
@@ -2610,13 +2613,14 @@ void seq_effect_speed_rebuild_map(Scene *scene, Sequence *seq)
     MEM_freeN(v->frameMap);
   }
 
-  const int effect_strip_length = seq->enddisp - seq->startdisp;
+  const int effect_strip_length = SEQ_time_right_handle_frame_get(seq) -
+                                  SEQ_time_left_handle_frame_get(seq);
   v->frameMap = MEM_mallocN(sizeof(float) * effect_strip_length, __func__);
   v->frameMap[0] = 0.0f;
 
   float target_frame = 0;
   for (int frame_index = 1; frame_index < effect_strip_length; frame_index++) {
-    target_frame += evaluate_fcurve(fcu, seq->startdisp + frame_index);
+    target_frame += evaluate_fcurve(fcu, SEQ_time_left_handle_frame_get(seq) + frame_index);
     CLAMP(target_frame, 0, seq->seq1->len);
     v->frameMap[frame_index] = target_frame;
   }
@@ -2652,7 +2656,8 @@ float seq_speed_effect_target_frame_get(Scene *scene,
       /* Only right handle controls effect speed! */
       const float target_content_length = seq_effect_speed_get_strip_content_length(source) -
                                           source->startofs;
-      const float speed_effetct_length = seq_speed->enddisp - seq_speed->startdisp;
+      const float speed_effetct_length = SEQ_time_right_handle_frame_get(seq_speed) -
+                                         SEQ_time_left_handle_frame_get(seq_speed);
       const float ratio = frame_index / speed_effetct_length;
       target_frame = target_content_length * ratio;
       break;
@@ -3509,7 +3514,7 @@ static void get_default_fac_noop(Sequence *UNUSED(seq), float UNUSED(timeline_fr
 
 static void get_default_fac_fade(Sequence *seq, float timeline_frame, float *fac)
 {
-  *fac = (float)(timeline_frame - seq->startdisp);
+  *fac = (float)(timeline_frame - SEQ_time_left_handle_frame_get(seq));
   *fac /= seq->len;
 }