Separate Operator

@@ -28,8 +29,11 @@
 
 #include "DEG_depsgraph.hh"
 
+#include "DNA_material_types.h"

@@ -37,6 +41,7 @@
 #include "UI_resources.hh"
 
 namespace blender::ed::greasepencil {
+static void remove_unused_materials(Object *object_src, Main *bmain);

@@ -1643,0 +1653,4 @@
+  /* Selected Points/Strokes */
+  SELECTED = 0,
+  /* By Material */
+  MATERIAL,

@@ -1643,0 +1699,4 @@
+}
+
+static bke::greasepencil::Layer &get_layer_dst(const int layer_index,
+                                               GreasePencil &grease_pencil_src,

@@ -1643,0 +1719,4 @@
+  const bke::AttributeAccessor src_attributes = grease_pencil_src.attributes();
+  bke::MutableAttributeAccessor dst_attributes = grease_pencil_dst.attributes_for_write();
+
+  bke::gather_attributes(src_attributes,

@@ -1643,0 +1737,4 @@
+                                            Object *object_src)
+{
+  using namespace bke::greasepencil;
+  bool result = false;

@@ -1643,0 +1752,4 @@
+    bke::CurvesGeometry &curves_src = info.drawing.strokes_for_write();
+    IndexMaskMemory memory;
+    IndexMask selected_points = ed::curves::retrieve_selected_points(curves_src, memory);
+

@@ -1643,0 +1759,4 @@
+
+    /* Insert Keyframe at current frame/layer */
+    Layer &layer_dst = get_layer_dst(info.layer_index, grease_pencil_src, grease_pencil_dst);
+    grease_pencil_dst.insert_blank_frame(layer_dst, info.frame_number, 0, BEZT_KEYTYPE_KEYFRAME);

@@ -1643,0 +1767,4 @@
+    /* Copy selected points/strokes to new CurvesGeometry. */
+    const bke::AnonymousAttributePropagationInfo propagation_info{};
+    drawing_dst->strokes_for_write() = bke::curves_copy_point_selection(
+        curves_src, selected_points, propagation_info);

@@ -1643,0 +1822,4 @@
+    Object *object_dst = duplicate_grease_pencil_object(
+        bmain, scene, view_layer, base_prev, grease_pencil_src);
+    GreasePencil &grease_pencil_dst = *static_cast<GreasePencil *>(object_dst->data);
+    /* Create Layer. */

@@ -1643,0 +1834,4 @@
+      /* Select all strokes */
+      IndexMaskMemory memory;
+      IndexMask strokes = retrieve_editable_strokes(
+          *static_cast<Object *>(object_src), info.drawing, memory);

@@ -1643,0 +1836,4 @@
+      IndexMask strokes = retrieve_editable_strokes(
+          *static_cast<Object *>(object_src), info.drawing, memory);
+
+      if (!strokes.is_empty()) {

@@ -1643,0 +1877,4 @@
+  return result;
+}
+
+static bool grease_pencil_separate_material(bContext *C,

@@ -1643,0 +1884,4 @@
+                                            Base *base_prev,
+                                            Object *object_src)
+{
+

@@ -1643,0 +1893,4 @@
+
+  /* Create a new object for each material. */
+  for (const int mat_i : IndexRange(object_src->totcol)) {
+

@@ -1643,0 +1912,4 @@
+    const Array<MutableDrawingInfo> drawings_src = retrieve_editable_drawings(*scene,
+                                                                              grease_pencil_src);
+    threading::parallel_for_each(drawings_src, [&](const MutableDrawingInfo &info) {
+      /* Get geometry of current drawing. */

@@ -1643,0 +1918,4 @@
+      IndexMask strokes = retrieve_editable_strokes_by_material(
+          *static_cast<Object *>(object_src), info.drawing, memory, mat_i);
+
+      if (!strokes.is_empty()) {

@@ -1643,0 +1924,4 @@
+
+        /* Insert Keyframe at current frame/layer */
+        Layer &layer_dst = get_layer_dst(info.layer_index, grease_pencil_src, grease_pencil_dst);
+        grease_pencil_dst.insert_blank_frame(

@@ -1643,0 +1961,4 @@
+
+static int grease_pencil_separate_exec(bContext *C, wmOperator *op)
+{
+  using namespace blender;

@@ -1643,0 +1975,4 @@
+  bool has_selection = false;
+
+  /* Cancel if nothing selected. */
+  if ((mode == SeparateMode::SELECTED)) {

@@ -1643,0 +1978,4 @@
+  if ((mode == SeparateMode::SELECTED)) {
+    const Array<MutableDrawingInfo> drawings = retrieve_editable_drawings(*scene,
+                                                                          grease_pencil_src);
+    threading::parallel_for_each(drawings, [&](const MutableDrawingInfo &info) {

@@ -1643,0 +2026,4 @@
+  WM_cursor_wait(false);
+
+  if (changed) {
+

@@ -373,0 +425,4 @@
+        if (material_index == mat_i) {
+          return editable_material_indices.contains(material_index);
+        }
+        else {

@@ -1643,0 +1712,4 @@
+  src_to_dst_layer.append(layer_index);
+  bke::gather_attributes(grease_pencil_src.attributes(),
+                         bke::AttrDomain::Layer,
+                         {},

@@ -1643,0 +1757,4 @@
+    drawing_dst->strokes_for_write() = bke::curves_copy_point_selection(
+        curves_src, selected_points, {});
+
+    /* Delete selected points from current drawing. */

@@ -1643,0 +1782,4 @@
+    DEG_id_tag_update(&grease_pencil_dst.id, ID_RECALC_GEOMETRY);
+    WM_event_add_notifier(&C, NC_OBJECT | ND_DRAW, &grease_pencil_dst);
+
+    /* Remove unused material slots from source object. */

@@ -1643,0 +1802,4 @@
+
+  /* Create a new object for each layer. */
+  for (const Layer *layer_src : grease_pencil_src.layers()) {
+

@@ -1643,0 +1819,4 @@
+    for (const MutableDrawingInfo &info : drawings_src) {
+      bke::CurvesGeometry &curves_src = info.drawing.strokes_for_write();
+      IndexMaskMemory memory;
+      const IndexMask strokes = retrieve_editable_strokes(object_src, info.drawing, memory);

@@ -1643,0 +1831,4 @@
+      /* Copy strokes to new CurvesGeometry. */
+      Drawing *drawing_dst = grease_pencil_dst.get_editable_drawing_at(&layer_dst,
+                                                                       info.frame_number);
+      const bke::AnonymousAttributePropagationInfo propagation_info{};

@@ -1643,0 +1876,4 @@
+
+  /* Create a new object for each material. */
+  for (const int mat_i : IndexRange(object_src.totcol)) {
+    if (mat_i == 0) {

@@ -1643,0 +1898,4 @@
+      IndexMaskMemory memory;
+      const IndexMask strokes = retrieve_editable_strokes_by_material(
+          *static_cast<Object *>(&object_src), info.drawing, memory, mat_i);
+

@@ -1643,0 +1932,4 @@
+  }
+
+  if (changed) {
+    /* Remove unused material slots from source object. */

@@ -1777,0 +1895,4 @@
+  };
+
+  if (changed) {
+

@@ -1777,0 +1996,4 @@
+
+  /* Create a new object for each material. */
+  for (const int mat_i : IndexRange(object_src.totcol).drop_front(1)) {
+

@@ -373,0 +396,4 @@
+IndexMask retrieve_editable_strokes_by_material(Object &object,
+                                                const bke::greasepencil::Drawing &drawing,
+                                                IndexMaskMemory &memory,
+                                                const int &mat_i)

@@ -1777,0 +1826,4 @@
+  return object_dst;
+}
+
+static bke::greasepencil::Layer &get_layer_dst(const int layer_index,

@@ -1777,0 +1844,4 @@
+  bke::gather_attributes(grease_pencil_src.attributes(),
+                         bke::AttrDomain::Layer,
+                         {},
+                         {".layers"},

@@ -1777,0 +1927,4 @@
+
+  /* Create a new object for each layer. */
+  for (const Layer *layer_src : grease_pencil_src.layers()) {
+    if (layer_src->is_selected() || layer_src->is_locked()) {

@@ -1801,0 +2094,4 @@
+                                                                            grease_pencil_src);
+      has_selection = std::any_of(
+          drawings.begin(), drawings.end(), [&](const MutableDrawingInfo &info) {
+            return ed::curves::has_anything_selected(info.drawing.strokes());

@@ -4419,3 +4419,3 @@
         op_menu("GPENCIL_MT_layer_active", {"type": 'Y', "value": 'PRESS'}),
         # Merge Layer
-        ("gpencil.layer_merge", {"type": 'M', "value": 'PRESS', "shift": True, "ctrl": True}, None),
+        ("gpencil.layer_merge", {"type": 'M', "value": 'PRESS', "shift": True, "ctrl": True}, None),      

@@ -5800,2 +5800,4 @@
         layout.menu("VIEW3D_MT_mirror")
 
+        layout.separator()
+        

@@ -5802,0 +5802,4 @@
+        layout.separator()
+        
+        layout.operator_menu_enum("grease_pencil.separate", "mode", text="Separate")
+        

@@ -1801,0 +1863,4 @@
+  }
+
+  /* Transfer Layer attributes. */
+  bke::gather_attributes(grease_pencil_src.attributes(),

@@ -1801,0 +1909,4 @@
+                                                                      info.frame_number);
+    drawing_dst.strokes_for_write() = bke::curves_copy_point_selection(
+        curves_src, selected_points, {});
+    curves_src.remove_points(selected_points, {});

@@ -1801,0 +2083,4 @@
+
+  const SeparateMode mode = SeparateMode(RNA_enum_get(op->ptr, "mode"));
+  bool changed = false;
+  bool has_selection = false;

@@ -1801,0 +1915,4 @@
+    drawing_dst.tag_topology_changed();
+
+    changed = true;
+  };

@@ -1801,0 +1992,4 @@
+      drawing_dst.tag_topology_changed();
+
+      changed = true;
+    };

@@ -1801,0 +2059,4 @@
+      WM_event_add_notifier(&C, NC_OBJECT | ND_DRAW, &grease_pencil_dst);
+
+      changed = true;
+    };

@@ -1801,0 +1931,4 @@
+    DEG_id_tag_update(&grease_pencil_dst.id, ID_RECALC_GEOMETRY);
+    WM_event_add_notifier(&C, NC_OBJECT | ND_DRAW, &grease_pencil_dst);
+
+    remove_unused_materials(&bmain, &object_src);

@@ -1801,0 +1948,4 @@
+
+  GreasePencil &grease_pencil_src = *static_cast<GreasePencil *>(object_src.data);
+
+  /* Create a new object for each layer. */

@@ -1801,0 +1950,4 @@
+
+  /* Create a new object for each layer. */
+  for (const Layer *layer_src : grease_pencil_src.layers()) {
+    if (layer_src->is_selected() || layer_src->is_locked()) {

@@ -1696,0 +1745,4 @@
+  return object_dst;
+}
+
+static bke::greasepencil::Layer &find_or_create_layer_by_name(

@@ -1696,0 +1752,4 @@
+
+  const Layer *layer_src = grease_pencil_src.layers().get(layer_index, layer_src);
+
+  for (Layer *layer : grease_pencil_dst.layers_for_write()) {

@@ -224,6 +224,29 @@ Array<MutableDrawingInfo> retrieve_editable_drawings(const Scene &scene,
   return editable_drawings.as_span();
 }
 
+Array<MutableDrawingInfo> retrieve_editable_drawings_by_layer(

@@ -318,0 +341,4 @@
+IndexMask retrieve_editable_strokes_by_material(Object &object,
+                                                const bke::greasepencil::Drawing &drawing,
+                                                IndexMaskMemory &memory,
+                                                const int mat_i)