VSE: New iterator design

This iterator design provides means to create simple and flexible API
to query and work with collection of strips. It should be used in cases
when conditions require multiple stages of recursive iteration of all
strips or similar complex scenarios.

Quick API overview:
Basic queries are standalone functions that return SeqCollection
Use SEQ_collection_create() and SEQ_collection_free() to construct
such query functions.
Use these functions to get strips of known conditions, like selected
strips, movie strips, muted strips and so on.

Use SEQ_reference_query() when querying strips with relation to
some reference strip. For example to get its effects, strips that have
same type or use same input file and so on.
These aren't standalone functions because often you need to query strips
relative to each strip in collection.

Use SEQ_collection_expand() to query strips relative to each strip
in collection. These will be merged to original collection.

Use SEQ_collection_merge() to merge 2 collections

To iterate collection elements use macro SEQ_ITERATOR_FOREACH()

This API is quite specific, but I think it is best suited for tasks
that are usualy solved in sequencer codebase.

Old sequencer iterator has been completely removed.
SEQ_ALL_BEGIN and SEQ_ALL_END macros re-use new iterator design.

As initial use for this iterator select_grouped_effect_link()
function has been rewritten. It was not only broken, but also it used
DNA fields to aid iterating strips.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D10337

1 files changed, 59 insertions, 48 deletions

diff --git a/source/blender/editors/space_sequencer/sequencer_select.c b/source/blender/editors/space_sequencer/sequencer_select.c
index a9f8a70d61e..ec5ec5c8ce0 100644
--- a/source/blender/editors/space_sequencer/sequencer_select.c
+++ b/source/blender/editors/space_sequencer/sequencer_select.c
@@ -26,7 +26,6 @@
 #include <string.h>
 
 #include "BLI_blenlib.h"
-#include "BLI_ghash.h"
 #include "BLI_math.h"
 #include "BLI_utildefines.h"
 
@@ -1622,64 +1621,76 @@ static bool select_grouped_time_overlap(Editing *ed, Sequence *actseq)
   return changed;
 }
 
-static bool select_grouped_effect_link(Editing *ed, Sequence *actseq, const int channel)
+/* Query all effect strips that are directly or indirectly connected to seq_reference. */
+void query_strip_effect_chain(Sequence *seq_reference,
+                              ListBase *seqbase,
+                              SeqCollection *collection)
 {
-  bool changed = false;
-  const bool is_audio = ((actseq->type == SEQ_TYPE_META) || SEQ_IS_SOUND(actseq));
-  int startdisp = actseq->startdisp;
-  int enddisp = actseq->enddisp;
-  int machine = actseq->machine;
-  SeqIterator iter;
-
-  LISTBASE_FOREACH (Sequence *, seq, SEQ_active_seqbase_get(ed)) {
-    seq->tmp = NULL;
+  if (!SEQ_collection_append_strip(seq_reference, collection)) {
+    return; /* Strip is already in set, so all effects connected to it are as well. */
   }
 
-  actseq->tmp = POINTER_FROM_INT(true);
-
-  Sequence *seq = NULL;
-  for (SEQ_iterator_begin(ed, &iter, true); iter.valid; SEQ_iterator_next(&iter)) {
-    seq = iter.seq;
+  /* Find all strips that seq_reference is connected to. */
+  if (seq_reference->type & SEQ_TYPE_EFFECT) {
+    if (seq_reference->seq1) {
+      query_strip_effect_chain(seq_reference->seq1, seqbase, collection);
+    }
+    if (seq_reference->seq2) {
+      query_strip_effect_chain(seq_reference->seq2, seqbase, collection);
+    }
+    if (seq_reference->seq3) {
+      query_strip_effect_chain(seq_reference->seq3, seqbase, collection);
+    }
+  }
 
-    /* Ignore all seqs already selected. */
-    /* Ignore all seqs not sharing some time with active one. */
-    /* Ignore all seqs of incompatible types (audio vs video). */
-    if (!SEQ_CHANNEL_CHECK(seq, channel) || (seq->flag & SELECT) || (seq->startdisp >= enddisp) ||
-        (seq->enddisp < startdisp) || (!is_audio && SEQ_IS_SOUND(seq)) ||
-        (is_audio && !((seq->type == SEQ_TYPE_META) || SEQ_IS_SOUND(seq)))) {
-      continue;
+  /* Find all strips connected to seq_reference. */
+  LISTBASE_FOREACH (Sequence *, seq_test, seqbase) {
+    if (seq_test->seq1 == seq_reference || seq_test->seq2 == seq_reference ||
+        seq_test->seq3 == seq_reference) {
+      query_strip_effect_chain(seq_test, seqbase, collection);
     }
+  }
+}
 
-    /* If the seq is an effect one, we need extra checking. */
-    if (SEQ_IS_EFFECT(seq) && ((seq->seq1 && seq->seq1->tmp) || (seq->seq2 && seq->seq2->tmp) ||
-                               (seq->seq3 && seq->seq3->tmp))) {
-      if (startdisp > seq->startdisp) {
-        startdisp = seq->startdisp;
-      }
-      if (enddisp < seq->enddisp) {
-        enddisp = seq->enddisp;
-      }
-      if (machine < seq->machine) {
-        machine = seq->machine;
-      }
+/* Query strips that are in lower channel and intersect in time with seq_reference. */
+static void query_lower_channel_strips(Sequence *seq_reference,
+                                       ListBase *seqbase,
+                                       SeqCollection *collection)
+{
+  LISTBASE_FOREACH (Sequence *, seq_test, seqbase) {
+    if (seq_test->machine > seq_reference->machine) {
+      continue; /* Not lower channel. */
+    }
+    if (seq_test->enddisp <= seq_reference->startdisp ||
+        seq_test->startdisp >= seq_reference->enddisp) {
+      continue; /* Not intersecting in time. */
+    }
+    SEQ_collection_append_strip(seq_test, collection);
+  }
+}
 
-      seq->tmp = POINTER_FROM_INT(true);
+/* Select all strips within time range and with lower channel of initial selection. Then select
+ * effect chains of these strips. */
+static bool select_grouped_effect_link(Editing *ed, Sequence *actseq, const int channel)
+{
+  ListBase *seqbase = SEQ_active_seqbase_get(ed);
 
-      seq->flag |= SELECT;
-      changed = true;
+  /* Get collection of strips. */
+  SeqCollection *collection = SEQ_query_selected_strips(seqbase);
+  const int selected_strip_count = BLI_gset_len(collection->set);
+  SEQ_collection_expand(seqbase, collection, query_lower_channel_strips);
+  SEQ_collection_expand(seqbase, collection, query_strip_effect_chain);
 
-      /* Unfortunately, we must restart checks from the beginning. */
-      SEQ_iterator_end(&iter);
-      SEQ_iterator_begin(ed, &iter, true);
-    }
+  /* Check if other strips will be affected. */
+  const bool changed = BLI_gset_len(collection->set) > selected_strip_count;
 
-    /* Video strips below active one, or any strip for audio (order doesn't matter here). */
-    else if (seq->machine < machine || is_audio) {
-      seq->flag |= SELECT;
-      changed = true;
-    }
+  /* Actual logic. */
+  Sequence *seq;
+  SEQ_ITERATOR_FOREACH (seq, collection) {
+    seq->flag |= SELECT;
   }
-  SEQ_iterator_end(&iter);
+
+  SEQ_collection_free(collection);
 
   return changed;
 }