source/blender/blenkernel/BKE_grease_pencil.hh

@@ -10,6 +10,7 @@
 #include "BLI_function_ref.hh"
 #include "BLI_map.hh"
 #include "BLI_math_vector.h"
+#include "BLI_math_vector_types.hh"
 #include "BLI_shared_cache.hh"
 #include "BLI_stack.hh"
 #include "BLI_string.h"
@@ -439,7 +440,13 @@ class GreasePencilRuntime {
 struct Main;
 struct Depsgraph;
 struct BoundBox;
+struct Scene;
+struct Object;
 
 void *BKE_grease_pencil_add(Main *bmain, const char *name);
+GreasePencil *BKE_grease_pencil_new_nomain();
 BoundBox *BKE_grease_pencil_boundbox_get(Object *ob);
 void BKE_grease_pencil_eval_geometry(Depsgraph *depsgraph, GreasePencil &grease_pencil);
+void BKE_grease_pencil_data_update(struct Depsgraph *depsgraph,
+                                   struct Scene *scene,
+                                   struct Object *object);

source/blender/blenkernel/intern/grease_pencil.cc

@@ -268,6 +268,13 @@ void *BKE_grease_pencil_add(Main *bmain, const char *name)
   return grease_pencil;
 }
 
+GreasePencil *BKE_grease_pencil_new_nomain()
+{
+  GreasePencil *grease_pencil = static_cast<GreasePencil *>(BKE_id_new_nomain(ID_GP, nullptr));
+  grease_pencil_init_data(&grease_pencil->id);
+  return grease_pencil;
+}
+
 BoundBox *BKE_grease_pencil_boundbox_get(Object *ob)
 {
   BLI_assert(ob->type == OB_GREASE_PENCIL);
@@ -309,6 +316,27 @@ BoundBox *BKE_grease_pencil_boundbox_get(Object *ob)
   return ob->runtime.bb;
 }
 
+void BKE_grease_pencil_data_update(struct Depsgraph *depsgraph, struct Scene *scene, Object *object)
+{
+  /* Free any evaluated data and restore original data. */
+  BKE_object_free_derived_caches(object);
+
+  GreasePencil *grease_pencil = static_cast<GreasePencil *>(object->data);
+  /* Evaluate modifiers. */
+  /* TODO. */
+
+  /* Assign evaluated object. */
+  /* TODO: Get eval from modifiers geometry set. */
+  GreasePencil *grease_pencil_eval = nullptr;
+  if (grease_pencil_eval == nullptr) {
+    grease_pencil_eval = BKE_grease_pencil_new_nomain();
+    BKE_object_eval_assign_data(object, &grease_pencil_eval->id, true);
+  }
+  else {
+    BKE_object_eval_assign_data(object, &grease_pencil_eval->id, false);
+  }
+}
+
 static void grease_pencil_drawing_calculate_fill_triangles(GreasePencilDrawing &drawing)
 {
   using namespace blender;

source/blender/blenkernel/intern/object_update.cc

@@ -32,6 +32,7 @@
 #include "BKE_gpencil_legacy.h"
 #include "BKE_gpencil_modifier_legacy.h"
 #include "BKE_grease_pencil.h"
+#include "BKE_grease_pencil.hh"
 #include "BKE_image.h"
 #include "BKE_key.h"
 #include "BKE_lattice.h"
@@ -198,7 +199,7 @@ void BKE_object_handle_data_update(Depsgraph *depsgraph, Scene *scene, Object *o
       BKE_volume_data_update(depsgraph, scene, ob);
       break;
     case OB_GREASE_PENCIL:
-      /* TODO: data update. */
+      BKE_grease_pencil_data_update(depsgraph, scene, ob);
       break;
   }
 

source/blender/editors/include/ED_grease_pencil_draw.h

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2023 Blender Foundation. */
+
+/** \file
+ * \ingroup editors
+ */
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void ED_operatortypes_grease_pencil_draw(void);
+
+#ifdef __cplusplus
+}
+#endif

source/blender/editors/object/object_modes.cc

@@ -82,6 +82,11 @@ static const char *object_mode_op_string(eObjectMode mode)
   if (mode == OB_MODE_EDIT_GPENCIL) {
     return "GPENCIL_OT_editmode_toggle";
   }
+  if (U.experimental.use_grease_pencil_version3) {
+    if (mode == OB_MODE_PAINT_GPENCIL) {
+      return "GREASE_PENCIL_OT_draw_mode_toggle";
+    }
+  }
   if (mode == OB_MODE_PAINT_GPENCIL) {
     return "GPENCIL_OT_paintmode_toggle";
   }

source/blender/editors/sculpt_paint/CMakeLists.txt

@@ -41,6 +41,7 @@ set(SRC
   curves_sculpt_slide.cc
   curves_sculpt_smooth.cc
   curves_sculpt_snake_hook.cc
+  grease_pencil_draw_ops.cc
   paint_canvas.cc
   paint_cursor.cc
   paint_curve.c

source/blender/editors/sculpt_paint/grease_pencil_draw_ops.cc

@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2023 Blender Foundation. */
+
+#include "BKE_context.h"
+#include "BKE_grease_pencil.hh"
+
+#include "DEG_depsgraph_query.h"
+
+#include "DNA_brush_types.h"
+#include "DNA_grease_pencil_types.h"
+
+#include "ED_grease_pencil_draw.h"
+#include "ED_object.h"
+
+#include "RNA_access.h"
+#include "RNA_define.h"
+#include "RNA_enum_types.h"
+
+#include "WM_api.h"
+#include "WM_message.h"
+#include "WM_toolsystem.h"
+
+#include "paint_intern.h"
+
+namespace blender::ed::sculpt_paint {
+
+
+/* -------------------------------------------------------------------- */
+/** \name Toggle Draw Mode
+ * \{ */
+
+static bool grease_pencil_poll(bContext *C)
+{
+  Object *object = CTX_data_active_object(C);
+  if (object == nullptr || object->type != OB_GREASE_PENCIL) {
+    return false;
+  }
+  return true;
+}
+
+static void grease_pencil_draw_mode_enter(bContext *C)
+{
+  Scene *scene = CTX_data_scene(C);
+  wmMsgBus *mbus = CTX_wm_message_bus(C);
+
+  Object *ob = CTX_data_active_object(C);
+  BKE_paint_ensure(scene->toolsettings, (Paint **)&scene->toolsettings->gp_paint);
+  GpPaint *grease_pencil_paint = scene->toolsettings->gp_paint;
+
+  ob->mode = OB_MODE_PAINT_GPENCIL;
+
+  /* Setup cursor color. BKE_paint_init() could be used, but creates an additional brush. */
+  Paint *paint = BKE_paint_get_active_from_paintmode(scene, PAINT_MODE_GPENCIL);
+  // copy_v3_v3_uchar(paint->paint_cursor_col, PAINT_CURSOR_GREASE_PENCIL);
+  // paint->paint_cursor_col[3] = 128;
+
+  // ED_paint_cursor_start(&grease_pencil_paint->paint, GREASE_PENCIL_mode_poll_view3d);
+  paint_init_pivot(ob, scene);
+
+  /* Necessary to change the object mode on the evaluated object. */
+  DEG_id_tag_update(&ob->id, ID_RECALC_COPY_ON_WRITE);
+  WM_msg_publish_rna_prop(mbus, &ob->id, ob, Object, mode);
+  WM_event_add_notifier(C, NC_SCENE | ND_MODE, nullptr);
+}
+
+static void grease_pencil_draw_mode_exit(bContext *C)
+{
+  Object *ob = CTX_data_active_object(C);
+  ob->mode = OB_MODE_OBJECT;
+}
+
+static int grease_pencil_draw_mode_toggle_exec(bContext *C, wmOperator *op)
+{
+  Object *ob = CTX_data_active_object(C);
+  wmMsgBus *mbus = CTX_wm_message_bus(C);
+
+  const bool is_mode_set = ob->mode == OB_MODE_PAINT_GPENCIL;
+
+  if (is_mode_set) {
+    if (!ED_object_mode_compat_set(C, ob, OB_MODE_PAINT_GPENCIL, op->reports)) {
+      return OPERATOR_CANCELLED;
+    }
+  }
+
+  if (is_mode_set) {
+    grease_pencil_draw_mode_exit(C);
+  }
+  else {
+    grease_pencil_draw_mode_enter(C);
+  }
+
+  WM_toolsystem_update_from_context_view3d(C);
+
+  /* Necessary to change the object mode on the evaluated object. */
+  DEG_id_tag_update(&ob->id, ID_RECALC_COPY_ON_WRITE);
+  WM_msg_publish_rna_prop(mbus, &ob->id, ob, Object, mode);
+  WM_event_add_notifier(C, NC_SCENE | ND_MODE, nullptr);
+  return OPERATOR_FINISHED;
+}
+
+static void GREASE_PENCIL_OT_draw_mode_toggle(wmOperatorType *ot)
+{
+  ot->name = "Grease Pencil Draw Mode Toggle";
+  ot->idname = "GREASE_PENCIL_OT_draw_mode_toggle";
+  ot->description = "Enter/Exit draw mode for grease pencil";
+
+  ot->exec = grease_pencil_draw_mode_toggle_exec;
+  ot->poll = grease_pencil_poll;
+
+  ot->flag = OPTYPE_UNDO | OPTYPE_REGISTER;
+}
+
+/** \} */
+
+}  // namespace blender::ed::sculpt_paint
+
+/* -------------------------------------------------------------------- */
+/** \name Registration
+ * \{ */
+
+void ED_operatortypes_grease_pencil_draw()
+{
+  using namespace blender::ed::sculpt_paint;
+  WM_operatortype_append(GREASE_PENCIL_OT_draw_mode_toggle);
+}
+
+/** \} */

source/blender/editors/sculpt_paint/paint_image.cc

@@ -818,6 +818,12 @@ static void paint_init_pivot_curves(Object *ob, float location[3])
   interp_v3_v3v3(location, bbox->vec[0], bbox->vec[6], 0.5f);
 }
 
+static void paint_init_pivot_grease_pencil(Object *ob, float location[3])
+{
+  const BoundBox *bbox = BKE_object_boundbox_get(ob);
+  interp_v3_v3v3(location, bbox->vec[0], bbox->vec[6], 0.5f);
+}
+
 void paint_init_pivot(Object *ob, Scene *scene)
 {
   UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
@@ -830,6 +836,9 @@ void paint_init_pivot(Object *ob, Scene *scene)
     case OB_CURVES:
       paint_init_pivot_curves(ob, location);
       break;
+    case OB_GREASE_PENCIL:
+      paint_init_pivot_grease_pencil(ob, location);
+      break;
     default:
       BLI_assert_unreachable();
       ups->last_stroke_valid = false;

source/blender/editors/space_api/spacetypes.c

@@ -34,6 +34,7 @@
 #include "ED_geometry.h"
 #include "ED_gizmo_library.h"
 #include "ED_gpencil.h"
+#include "ED_grease_pencil_draw.h"
 #include "ED_lattice.h"
 #include "ED_markers.h"
 #include "ED_mask.h"
@@ -91,6 +92,7 @@ void ED_spacetypes_init(void)
   ED_operatortypes_anim();
   ED_operatortypes_animchannels();
   ED_operatortypes_asset();
+  ED_operatortypes_grease_pencil_draw();
   ED_operatortypes_gpencil();
   ED_operatortypes_object();
   ED_operatortypes_lattice();

source/blender/editors/util/CMakeLists.txt

@@ -53,6 +53,7 @@ set(SRC
   ../include/ED_gizmo_library.h
   ../include/ED_gizmo_utils.h
   ../include/ED_gpencil.h
+  ../include/ED_grease_pencil_draw.h
   ../include/ED_image.h
   ../include/ED_info.h
   ../include/ED_keyframes_draw.h