GPv3: Port frame_clean_duplicate operator

Port the `frame_clean_duplicate` operator to GPv3.
Resolves #114182.

Pull Request: https://projects.blender.org/blender/blender/pulls/116655

scripts/startup/bl_ui/space_view3d.py

@@ -6084,6 +6084,7 @@ class VIEW3D_MT_edit_greasepencil_cleanup(Menu):
         layout = self.layout
 
         layout.operator("grease_pencil.clean_loose")
+        layout.operator("grease_pencil.frame_clean_duplicate")
 
         if ob.mode != 'PAINT_GREASE_PENCIL':
             layout.operator("grease_pencil.stroke_merge_by_distance", text="Merge by Distance")

source/blender/editors/grease_pencil/intern/grease_pencil_frames.cc

@@ -6,6 +6,7 @@
  * \ingroup edgreasepencil
  */
 
+#include "BKE_curves.hh"
 #include "BLI_map.hh"
 #include "BLI_math_vector_types.hh"
 #include "BLI_utildefines.h"
@@ -413,6 +414,162 @@ static int insert_blank_frame_exec(bContext *C, wmOperator *op)
   return OPERATOR_FINISHED;
 }
 
+static bool attributes_varrays_not_equal(const bke::GAttributeReader &attrs_a,
+                                         const bke::GAttributeReader &attrs_b)
+{
+  return (attrs_a.varray.size() != attrs_b.varray.size() ||
+          attrs_a.varray.type() != attrs_b.varray.type());
+}
+
+static bool attributes_varrays_span_data_equal(const bke::GAttributeReader &attrs_a,
+                                               const bke::GAttributeReader &attrs_b)
+{
+  if (attrs_a.varray.is_span() && attrs_b.varray.is_span()) {
+    const GSpan attrs_span_a = attrs_a.varray.get_internal_span();
+    const GSpan attrs_span_b = attrs_b.varray.get_internal_span();
+
+    if (attrs_span_a.data() == attrs_span_b.data()) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+template<typename T>
+static bool attributes_elements_are_equal(const VArray<T> &attributes_a,
+                                          const VArray<T> &attributes_b)
+{
+  const std::optional<T> value_a = attributes_a.get_if_single();
+  const std::optional<T> value_b = attributes_b.get_if_single();
+  if (value_a.has_value() && value_b.has_value()) {
+    return value_a.value() == value_b.value();
+  }
+
+  const VArraySpan attrs_span_a = attributes_a;
+  const VArraySpan attrs_span_b = attributes_b;
+
+  return std::equal(
+      attrs_span_a.begin(), attrs_span_a.end(), attrs_span_b.begin(), attrs_span_b.end());
+}
+
+static bool curves_geometry_is_equal(const bke::CurvesGeometry &curves_a,
+                                     const bke::CurvesGeometry &curves_b)
+{
+  using namespace blender::bke;
+
+  if (curves_a.points_num() == 0 && curves_b.points_num() == 0) {
+    return true;
+  }
+
+  if (curves_a.curves_num() != curves_b.curves_num() ||
+      curves_a.points_num() != curves_b.points_num() || curves_a.offsets() != curves_b.offsets())
+  {
+    return false;
+  }
+
+  const AttributeAccessor attributes_a = curves_a.attributes();
+  const AttributeAccessor attributes_b = curves_b.attributes();
+
+  const Set<AttributeIDRef> ids_a = attributes_a.all_ids();
+  const Set<AttributeIDRef> ids_b = attributes_b.all_ids();
+  if (ids_a != ids_b) {
+    return false;
+  }
+
+  for (const AttributeIDRef &id : ids_a) {
+    GAttributeReader attrs_a = attributes_a.lookup(id);
+    GAttributeReader attrs_b = attributes_b.lookup(id);
+
+    if (attributes_varrays_not_equal(attrs_a, attrs_b)) {
+      return false;
+    }
+
+    if (attributes_varrays_span_data_equal(attrs_a, attrs_b)) {
+      return true;
+    }
+
+    bool attributes_are_equal = true;
+
+    attribute_math::convert_to_static_type(attrs_a.varray.type(), [&](auto dummy) {
+      using T = decltype(dummy);
+
+      const VArray attributes_a = attrs_a.varray.typed<T>();
+      const VArray attributes_b = attrs_b.varray.typed<T>();
+
+      attributes_are_equal = attributes_elements_are_equal(attributes_a, attributes_b);
+    });
+
+    if (!attributes_are_equal) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+static int frame_clean_duplicate_exec(bContext *C, wmOperator *op)
+{
+  using namespace blender::bke::greasepencil;
+  Object *object = CTX_data_active_object(C);
+  GreasePencil &grease_pencil = *static_cast<GreasePencil *>(object->data);
+  const bool selected = RNA_boolean_get(op->ptr, "selected");
+
+  bool changed = false;
+
+  for (Layer *layer : grease_pencil.layers_for_write()) {
+    if (!layer->is_editable()) {
+      continue;
+    }
+
+    Vector<int> start_frame_numbers;
+    for (const FramesMapKeyT key : layer->sorted_keys()) {
+      const GreasePencilFrame *frame = layer->frames().lookup_ptr(key);
+      if (selected && !frame->is_selected()) {
+        continue;
+      }
+      if (frame->is_end()) {
+        continue;
+      }
+      start_frame_numbers.append(int(key));
+    }
+
+    Vector<int> frame_numbers_to_delete;
+    for (const int i : start_frame_numbers.index_range().drop_back(1)) {
+      const int current = start_frame_numbers[i];
+      const int next = start_frame_numbers[i + 1];
+
+      Drawing *drawing = grease_pencil.get_drawing_at(*layer, current);
+      Drawing *drawing_next = grease_pencil.get_drawing_at(*layer, next);
+
+      if (!drawing || !drawing_next) {
+        continue;
+      }
+
+      bke::CurvesGeometry &curves = drawing->strokes_for_write();
+      bke::CurvesGeometry &curves_next = drawing_next->strokes_for_write();
+
+      if (!curves_geometry_is_equal(curves, curves_next)) {
+        continue;
+      }
+
+      frame_numbers_to_delete.append(next);
+    }
+
+    grease_pencil.remove_frames(*layer, frame_numbers_to_delete.as_span());
+
+    changed = true;
+  }
+
+  if (changed) {
+    DEG_id_tag_update(&grease_pencil.id, ID_RECALC_GEOMETRY);
+    WM_event_add_notifier(C, NC_GEOM | ND_DATA, &grease_pencil);
+    WM_event_add_notifier(C, NC_GPENCIL | NA_EDITED, nullptr);
+  }
+
+  return OPERATOR_FINISHED;
+}
+
 static void GREASE_PENCIL_OT_insert_blank_frame(wmOperatorType *ot)
 {
   PropertyRNA *prop;
@@ -435,6 +592,27 @@ static void GREASE_PENCIL_OT_insert_blank_frame(wmOperatorType *ot)
   RNA_def_int(ot->srna, "duration", 0, 0, MAXFRAME, "Duration", "", 0, 100);
 }
 
+static void GREASE_PENCIL_OT_frame_clean_duplicate(wmOperatorType *ot)
+{
+  PropertyRNA *prop;
+
+  /* identifiers */
+  ot->name = "Delete Duplicate Frames";
+  ot->idname = "GREASE_PENCIL_OT_frame_clean_duplicate";
+  ot->description = "Remove any keyframe that is a duplicate of the previous one";
+
+  /* callbacks */
+  ot->exec = frame_clean_duplicate_exec;
+  ot->poll = active_grease_pencil_poll;
+
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+  /* properties */
+  prop = RNA_def_boolean(
+      ot->srna, "selected", false, "Selected", "Only delete selected keyframes");
+  RNA_def_property_flag(prop, PROP_SKIP_SAVE);
+}
+
 bool grease_pencil_copy_keyframes(bAnimContext *ac, KeyframeClipboard &clipboard)
 {
   using namespace bke::greasepencil;
@@ -635,4 +813,5 @@ void ED_operatortypes_grease_pencil_frames()
 {
   using namespace blender::ed::greasepencil;
   WM_operatortype_append(GREASE_PENCIL_OT_insert_blank_frame);
+  WM_operatortype_append(GREASE_PENCIL_OT_frame_clean_duplicate);
 }