scripts/startup/bl_ui/space_view3d.py

@@ -2303,6 +2303,16 @@ class VIEW3D_MT_volume_add(Menu):
                         icon='OUTLINER_DATA_VOLUME')
 
 
+class VIEW3D_MT_grease_pencil_add(Menu):
+    bl_idname = "VIEW3D_MT_grease_pencil_add"
+    bl_label = "Grease Pencil"
+
+    def draw(self, _context):
+        layout = self.layout
+        layout.operator("object.grease_pencil_add", text="Empty", icon='EMPTY_AXIS').type = 'EMPTY'
+        layout.operator("object.grease_pencil_add", text="Stroke", icon='STROKE').type = 'STROKE'
+
+
 class VIEW3D_MT_add(Menu):
     bl_label = "Add"
     bl_translation_context = i18n_contexts.operator_default
@@ -2328,7 +2338,14 @@ class VIEW3D_MT_add(Menu):
         if context.preferences.experimental.use_new_point_cloud_type:
             layout.operator("object.pointcloud_add", text="Point Cloud", icon='OUTLINER_OB_POINTCLOUD')
         layout.menu("VIEW3D_MT_volume_add", text="Volume", text_ctxt=i18n_contexts.id_id, icon='OUTLINER_OB_VOLUME')
-        layout.operator_menu_enum("object.gpencil_add", "type", text="Grease Pencil", icon='OUTLINER_OB_GREASEPENCIL')
+        if context.preferences.experimental.use_grease_pencil_version3:
+            layout.menu("VIEW3D_MT_grease_pencil_add", text="Grease Pencil", icon='OUTLINER_OB_GREASEPENCIL')
+        else:
+            layout.operator_menu_enum(
+                "object.gpencil_add",
+                "type",
+                text="Grease Pencil",
+                icon='OUTLINER_OB_GREASEPENCIL')
 
         layout.separator()
 
@@ -8188,6 +8205,7 @@ classes = (
     VIEW3D_MT_lightprobe_add,
     VIEW3D_MT_camera_add,
     VIEW3D_MT_volume_add,
+    VIEW3D_MT_grease_pencil_add,
     VIEW3D_MT_add,
     VIEW3D_MT_image_add,
     VIEW3D_MT_object,

source/blender/blenkernel/BKE_grease_pencil.hh

@@ -18,6 +18,13 @@
 #include "DNA_gpencil_legacy_types.h"
 #include "DNA_grease_pencil_types.h"
 
+struct Main;
+struct Depsgraph;
+struct BoundBox;
+struct Scene;
+struct Object;
+struct Material;
+
 namespace blender::bke {
 
 namespace greasepencil {
@@ -196,7 +203,6 @@ class Layer : public ::GreasePencilLayer {
    * \returns true on success.
    */
   bool insert_frame(int frame_number, const GreasePencilFrame &frame);
-  bool insert_frame(int frame_number, GreasePencilFrame &&frame);
 
   /**
    * Inserts the frame into the layer. If there exists a frame at \a frame_number already, it is
@@ -204,7 +210,6 @@ class Layer : public ::GreasePencilLayer {
    * \returns true on success.
    */
   bool overwrite_frame(int frame_number, const GreasePencilFrame &frame);
-  bool overwrite_frame(int frame_number, GreasePencilFrame &&frame);
 
   /**
    * Returns the sorted (start) frame numbers of the frames of this layer.
@@ -365,12 +370,6 @@ inline bool GreasePencil::has_active_layer() const
   return (this->active_layer != nullptr);
 }
 
-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);
@@ -378,5 +377,15 @@ void BKE_grease_pencil_data_update(struct Depsgraph *depsgraph,
                                    struct Scene *scene,
                                    struct Object *object);
 
+int BKE_grease_pencil_object_material_index_get_by_name(Object *ob, const char *name);
+Material *BKE_grease_pencil_object_material_new(Main *bmain,
+                                                Object *ob,
+                                                const char *name,
+                                                int *r_index);
+Material *BKE_grease_pencil_object_material_ensure_by_name(Main *bmain,
+                                                           Object *ob,
+                                                           const char *name,
+                                                           int *r_index);
+
 bool BKE_grease_pencil_references_cyclic_check(const GreasePencil *id_reference,
                                                const GreasePencil *grease_pencil);

source/blender/blenkernel/intern/grease_pencil.cc

@@ -14,6 +14,7 @@
 #include "BKE_idtype.h"
 #include "BKE_lib_id.h"
 #include "BKE_lib_query.h"
+#include "BKE_material.h"
 #include "BKE_object.h"
 
 #include "BLI_map.hh"
@@ -408,24 +409,12 @@ bool Layer::insert_frame(int frame_number, const GreasePencilFrame &frame)
   return this->frames_for_write().add(frame_number, frame);
 }
 
-bool Layer::insert_frame(int frame_number, GreasePencilFrame &&frame)
-{
-  this->tag_frames_map_changed();
-  return this->frames_for_write().add(frame_number, frame);
-}
-
 bool Layer::overwrite_frame(int frame_number, const GreasePencilFrame &frame)
 {
   this->tag_frames_map_changed();
   return this->frames_for_write().add_overwrite(frame_number, frame);
 }
 
-bool Layer::overwrite_frame(int frame_number, GreasePencilFrame &&frame)
-{
-  this->tag_frames_map_changed();
-  return this->frames_for_write().add_overwrite(frame_number, std::move(frame));
-}
-
 Span<int> Layer::sorted_keys() const
 {
   this->runtime->sorted_keys_cache_.ensure([&](Vector<int> &r_data) {
@@ -754,6 +743,56 @@ void BKE_grease_pencil_data_update(struct Depsgraph * /*depsgraph*/,
 
 /** \} */
 
+/* ------------------------------------------------------------------- */
+/** \name Grease Pencil material functions
+ * \{ */
+
+int BKE_grease_pencil_object_material_index_get_by_name(Object *ob, const char *name)
+{
+  short *totcol = BKE_object_material_len_p(ob);
+  Material *read_ma = NULL;
+  for (short i = 0; i < *totcol; i++) {
+    read_ma = BKE_object_material_get(ob, i + 1);
+    if (STREQ(name, read_ma->id.name + 2)) {
+      return i;
+    }
+  }
+
+  return -1;
+}
+
+Material *BKE_grease_pencil_object_material_new(Main *bmain,
+                                                Object *ob,
+                                                const char *name,
+                                                int *r_index)
+{
+  Material *ma = BKE_gpencil_material_add(bmain, name);
+  id_us_min(&ma->id); /* no users yet */
+
+  BKE_object_material_slot_add(bmain, ob);
+  BKE_object_material_assign(bmain, ob, ma, ob->totcol, BKE_MAT_ASSIGN_USERPREF);
+
+  if (r_index) {
+    *r_index = ob->actcol - 1;
+  }
+  return ma;
+}
+
+Material *BKE_grease_pencil_object_material_ensure_by_name(Main *bmain,
+                                                           Object *ob,
+                                                           const char *name,
+                                                           int *r_index)
+{
+  int index = BKE_grease_pencil_object_material_index_get_by_name(ob, name);
+  if (index != -1) {
+    *r_index = index;
+    return BKE_object_material_get(ob, index + 1);
+  }
+  return BKE_grease_pencil_object_material_new(bmain, ob, name, r_index);
+}
+
+/** \} */
+
 /* ------------------------------------------------------------------- */
 /** \name Grease Pencil reference functions
  * \{ */

source/blender/editors/CMakeLists.txt

@@ -15,6 +15,7 @@ if(WITH_BLENDER)
   add_subdirectory(geometry)
   add_subdirectory(gizmo_library)
   add_subdirectory(gpencil_legacy)
+  add_subdirectory(grease_pencil)
   add_subdirectory(interface)
   add_subdirectory(io)
   add_subdirectory(lattice)

source/blender/editors/grease_pencil/CMakeLists.txt

@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+set(INC
+  ../include
+  ../../blenkernel
+  ../../blenlib
+  ../../blentranslation
+  ../../depsgraph
+  ../../gpu
+  ../../imbuf
+  ../../makesdna
+  ../../makesrna
+  ../../windowmanager
+  ../../../../intern/guardedalloc
+  # RNA_prototypes.h
+  ${CMAKE_BINARY_DIR}/source/blender/makesrna
+)
+
+set(INC_SYS
+)
+
+set(SRC
+  intern/grease_pencil_add.cc
+)
+
+set(LIB
+  bf_blenkernel
+  bf_blenlib
+)
+
+blender_add_lib(bf_editor_grease_pencil "${SRC}" "${INC}" "${INC_SYS}" "${LIB}")
+add_dependencies(bf_editor_curves bf_rna)

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

@@ -0,0 +1,287 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2023 Blender Foundation. */
+
+/** \file
+ * \ingroup edgreasepencil
+ */
+
+#include <array>
+
+#include "BKE_curves.hh"
+#include "BKE_grease_pencil.hh"
+
+#include "BLI_math.h"
+#include "BLI_math_matrix.hh"
+
+#include "BLT_translation.h"
+
+#include "DNA_material_types.h"
+#include "DNA_scene_types.h"
+
+#include "ED_grease_pencil.h"
+
+namespace blender::ed::greasepencil {
+
+struct ColorTemplate {
+  const char *name;
+  float line[4];
+  float fill[4];
+  bool show_fill;
+};
+
+static const ColorTemplate gp_stroke_material_black = {
+    N_("Black"),
+    {0.0f, 0.0f, 0.0f, 1.0f},
+    {0.0f, 0.0f, 0.0f, 0.0f},
+    false,
+};
+
+static const ColorTemplate gp_stroke_material_white = {
+    N_("White"),
+    {1.0f, 1.0f, 1.0f, 1.0f},
+    {0.0f, 0.0f, 0.0f, 0.0f},
+    false,
+};
+
+static const ColorTemplate gp_stroke_material_red = {
+    N_("Red"),
+    {1.0f, 0.0f, 0.0f, 1.0f},
+    {0.0f, 0.0f, 0.0f, 0.0f},
+    false,
+};
+
+static const ColorTemplate gp_stroke_material_green = {
+    N_("Green"),
+    {0.0f, 1.0f, 0.0f, 1.0f},
+    {0.0f, 0.0f, 0.0f, 0.0f},
+    false,
+};
+
+static const ColorTemplate gp_stroke_material_blue = {
+    N_("Blue"),
+    {0.0f, 0.0f, 1.0f, 1.0f},
+    {0.0f, 0.0f, 0.0f, 0.0f},
+    false,
+};
+
+static const ColorTemplate gp_fill_material_grey = {
+    N_("Grey"),
+    {0.358f, 0.358f, 0.358f, 1.0f},
+    {0.5f, 0.5f, 0.5f, 1.0f},
+    true,
+};
+
+static std::array<float3, 175> stroke_positions({
+    float3(-1.281f, 0.0f, -0.315f), float3(-1.269f, 0.0f, -0.302f), float3(-1.261f, 0.0f, -0.293f),
+    float3(-1.251f, 0.0f, -0.282f), float3(-1.241f, 0.0f, -0.271f), float3(-1.23f, 0.0f, -0.259f),
+    float3(-1.219f, 0.0f, -0.247f), float3(-1.208f, 0.0f, -0.234f), float3(-1.196f, 0.0f, -0.221f),
+    float3(-1.184f, 0.0f, -0.208f), float3(-1.172f, 0.0f, -0.194f), float3(-1.159f, 0.0f, -0.18f),
+    float3(-1.147f, 0.0f, -0.165f), float3(-1.134f, 0.0f, -0.151f), float3(-1.121f, 0.0f, -0.136f),
+    float3(-1.108f, 0.0f, -0.121f), float3(-1.094f, 0.0f, -0.106f), float3(-1.08f, 0.0f, -0.091f),
+    float3(-1.066f, 0.0f, -0.076f), float3(-1.052f, 0.0f, -0.061f), float3(-1.037f, 0.0f, -0.047f),
+    float3(-1.022f, 0.0f, -0.032f), float3(-1.007f, 0.0f, -0.017f), float3(-0.991f, 0.0f, -0.003f),
+    float3(-0.975f, 0.0f, 0.012f),  float3(-0.959f, 0.0f, 0.027f),  float3(-0.942f, 0.0f, 0.041f),
+    float3(-0.926f, 0.0f, 0.056f),  float3(-0.909f, 0.0f, 0.071f),  float3(-0.893f, 0.0f, 0.086f),
+    float3(-0.876f, 0.0f, 0.1f),    float3(-0.859f, 0.0f, 0.115f),  float3(-0.842f, 0.0f, 0.129f),
+    float3(-0.824f, 0.0f, 0.144f),  float3(-0.807f, 0.0f, 0.158f),  float3(-0.79f, 0.0f, 0.172f),
+    float3(-0.773f, 0.0f, 0.186f),  float3(-0.755f, 0.0f, 0.199f),  float3(-0.738f, 0.0f, 0.212f),
+    float3(-0.721f, 0.0f, 0.224f),  float3(-0.703f, 0.0f, 0.236f),  float3(-0.686f, 0.0f, 0.248f),
+    float3(-0.67f, 0.0f, 0.26f),    float3(-0.653f, 0.0f, 0.27f),   float3(-0.637f, 0.0f, 0.28f),
+    float3(-0.621f, 0.0f, 0.29f),   float3(-0.605f, 0.0f, 0.298f),  float3(-0.589f, 0.0f, 0.306f),
+    float3(-0.574f, 0.0f, 0.313f),  float3(-0.559f, 0.0f, 0.319f),  float3(-0.544f, 0.0f, 0.325f),
+    float3(-0.53f, 0.0f, 0.331f),   float3(-0.516f, 0.0f, 0.336f),  float3(-0.503f, 0.0f, 0.34f),
+    float3(-0.489f, 0.0f, 0.344f),  float3(-0.477f, 0.0f, 0.347f),  float3(-0.464f, 0.0f, 0.35f),
+    float3(-0.452f, 0.0f, 0.352f),  float3(-0.44f, 0.0f, 0.354f),   float3(-0.429f, 0.0f, 0.355f),
+    float3(-0.418f, 0.0f, 0.355f),  float3(-0.407f, 0.0f, 0.355f),  float3(-0.397f, 0.0f, 0.354f),
+    float3(-0.387f, 0.0f, 0.353f),  float3(-0.378f, 0.0f, 0.351f),  float3(-0.368f, 0.0f, 0.348f),
+    float3(-0.36f, 0.0f, 0.344f),   float3(-0.351f, 0.0f, 0.34f),   float3(-0.344f, 0.0f, 0.336f),
+    float3(-0.336f, 0.0f, 0.33f),   float3(-0.329f, 0.0f, 0.324f),  float3(-0.322f, 0.0f, 0.318f),
+    float3(-0.316f, 0.0f, 0.31f),   float3(-0.311f, 0.0f, 0.303f),  float3(-0.306f, 0.0f, 0.294f),
+    float3(-0.301f, 0.0f, 0.285f),  float3(-0.297f, 0.0f, 0.275f),  float3(-0.293f, 0.0f, 0.264f),
+    float3(-0.29f, 0.0f, 0.253f),   float3(-0.288f, 0.0f, 0.241f),  float3(-0.286f, 0.0f, 0.229f),
+    float3(-0.285f, 0.0f, 0.216f),  float3(-0.284f, 0.0f, 0.202f),  float3(-0.283f, 0.0f, 0.188f),
+    float3(-0.283f, 0.0f, 0.173f),  float3(-0.284f, 0.0f, 0.158f),  float3(-0.285f, 0.0f, 0.142f),
+    float3(-0.286f, 0.0f, 0.125f),  float3(-0.288f, 0.0f, 0.108f),  float3(-0.29f, 0.0f, 0.091f),
+    float3(-0.293f, 0.0f, 0.073f),  float3(-0.295f, 0.0f, 0.054f),  float3(-0.298f, 0.0f, 0.035f),
+    float3(-0.302f, 0.0f, 0.016f),  float3(-0.305f, 0.0f, -0.004f), float3(-0.309f, 0.0f, -0.024f),
+    float3(-0.313f, 0.0f, -0.044f), float3(-0.317f, 0.0f, -0.065f), float3(-0.321f, 0.0f, -0.085f),
+    float3(-0.326f, 0.0f, -0.106f), float3(-0.33f, 0.0f, -0.127f),  float3(-0.335f, 0.0f, -0.148f),
+    float3(-0.339f, 0.0f, -0.168f), float3(-0.344f, 0.0f, -0.189f), float3(-0.348f, 0.0f, -0.21f),
+    float3(-0.353f, 0.0f, -0.23f),  float3(-0.357f, 0.0f, -0.25f),  float3(-0.361f, 0.0f, -0.27f),
+    float3(-0.365f, 0.0f, -0.29f),  float3(-0.369f, 0.0f, -0.309f), float3(-0.372f, 0.0f, -0.328f),
+    float3(-0.375f, 0.0f, -0.347f), float3(-0.377f, 0.0f, -0.365f), float3(-0.379f, 0.0f, -0.383f),
+    float3(-0.38f, 0.0f, -0.4f),    float3(-0.38f, 0.0f, -0.417f),  float3(-0.38f, 0.0f, -0.434f),
+    float3(-0.379f, 0.0f, -0.449f), float3(-0.377f, 0.0f, -0.464f), float3(-0.374f, 0.0f, -0.478f),
+    float3(-0.371f, 0.0f, -0.491f), float3(-0.366f, 0.0f, -0.503f), float3(-0.361f, 0.0f, -0.513f),
+    float3(-0.354f, 0.0f, -0.523f), float3(-0.347f, 0.0f, -0.531f), float3(-0.339f, 0.0f, -0.538f),
+    float3(-0.33f, 0.0f, -0.543f),  float3(-0.32f, 0.0f, -0.547f),  float3(-0.31f, 0.0f, -0.549f),
+    float3(-0.298f, 0.0f, -0.55f),  float3(-0.286f, 0.0f, -0.55f),  float3(-0.274f, 0.0f, -0.548f),
+    float3(-0.261f, 0.0f, -0.544f), float3(-0.247f, 0.0f, -0.539f), float3(-0.232f, 0.0f, -0.533f),
+    float3(-0.218f, 0.0f, -0.525f), float3(-0.202f, 0.0f, -0.515f), float3(-0.186f, 0.0f, -0.503f),
+    float3(-0.169f, 0.0f, -0.49f),  float3(-0.151f, 0.0f, -0.475f), float3(-0.132f, 0.0f, -0.458f),
+    float3(-0.112f, 0.0f, -0.44f),  float3(-0.091f, 0.0f, -0.42f),  float3(-0.069f, 0.0f, -0.398f),
+    float3(-0.045f, 0.0f, -0.375f), float3(-0.021f, 0.0f, -0.35f),  float3(0.005f, 0.0f, -0.324f),
+    float3(0.031f, 0.0f, -0.297f),  float3(0.06f, 0.0f, -0.268f),   float3(0.089f, 0.0f, -0.238f),
+    float3(0.12f, 0.0f, -0.207f),   float3(0.153f, 0.0f, -0.175f),  float3(0.187f, 0.0f, -0.14f),
+    float3(0.224f, 0.0f, -0.104f),  float3(0.262f, 0.0f, -0.067f),  float3(0.302f, 0.0f, -0.027f),
+    float3(0.344f, 0.0f, 0.014f),   float3(0.388f, 0.0f, 0.056f),   float3(0.434f, 0.0f, 0.1f),
+    float3(0.483f, 0.0f, 0.145f),   float3(0.533f, 0.0f, 0.191f),   float3(0.585f, 0.0f, 0.238f),
+    float3(0.637f, 0.0f, 0.284f),   float3(0.69f, 0.0f, 0.33f),     float3(0.746f, 0.0f, 0.376f),
+    float3(0.802f, 0.0f, 0.421f),   float3(0.859f, 0.0f, 0.464f),   float3(0.915f, 0.0f, 0.506f),
+    float3(0.97f, 0.0f, 0.545f),    float3(1.023f, 0.0f, 0.581f),   float3(1.075f, 0.0f, 0.614f),
+    float3(1.122f, 0.0f, 0.643f),   float3(1.169f, 0.0f, 0.671f),   float3(1.207f, 0.0f, 0.693f),
+    float3(1.264f, 0.0f, 0.725f),
+});
+
+static constexpr std::array<float, 175> stroke_radii({
+    0.038f, 0.069f, 0.089f, 0.112f, 0.134f, 0.155f, 0.175f, 0.194f, 0.211f, 0.227f, 0.242f, 0.256f,
+    0.268f, 0.28f,  0.29f,  0.299f, 0.307f, 0.315f, 0.322f, 0.329f, 0.335f, 0.341f, 0.346f, 0.351f,
+    0.355f, 0.36f,  0.364f, 0.368f, 0.371f, 0.373f, 0.376f, 0.377f, 0.378f, 0.379f, 0.379f, 0.379f,
+    0.38f,  0.38f,  0.381f, 0.382f, 0.384f, 0.386f, 0.388f, 0.39f,  0.393f, 0.396f, 0.399f, 0.403f,
+    0.407f, 0.411f, 0.415f, 0.42f,  0.425f, 0.431f, 0.437f, 0.443f, 0.45f,  0.457f, 0.464f, 0.471f,
+    0.479f, 0.487f, 0.495f, 0.503f, 0.512f, 0.52f,  0.528f, 0.537f, 0.545f, 0.553f, 0.562f, 0.57f,
+    0.579f, 0.588f, 0.597f, 0.606f, 0.615f, 0.625f, 0.635f, 0.644f, 0.654f, 0.664f, 0.675f, 0.685f,
+    0.696f, 0.707f, 0.718f, 0.729f, 0.74f,  0.751f, 0.761f, 0.772f, 0.782f, 0.793f, 0.804f, 0.815f,
+    0.828f, 0.843f, 0.86f,  0.879f, 0.897f, 0.915f, 0.932f, 0.947f, 0.962f, 0.974f, 0.985f, 0.995f,
+    1.004f, 1.011f, 1.018f, 1.024f, 1.029f, 1.033f, 1.036f, 1.037f, 1.037f, 1.035f, 1.032f, 1.029f,
+    1.026f, 1.023f, 1.021f, 1.019f, 1.017f, 1.016f, 1.016f, 1.016f, 1.016f, 1.017f, 1.017f, 1.018f,
+    1.017f, 1.017f, 1.016f, 1.015f, 1.013f, 1.009f, 1.005f, 0.998f, 0.99f,  0.98f,  0.968f, 0.955f,
+    0.939f, 0.923f, 0.908f, 0.895f, 0.882f, 0.87f,  0.858f, 0.844f, 0.828f, 0.81f,  0.79f,  0.769f,
+    0.747f, 0.724f, 0.7f,   0.676f, 0.651f, 0.625f, 0.599f, 0.573f, 0.546f, 0.516f, 0.483f, 0.446f,
+    0.407f, 0.365f, 0.322f, 0.28f,  0.236f, 0.202f, 0.155f,
+});
+
+static constexpr std::array<float, 175> stroke_opacities({
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+    1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+});
+
+static int add_material_from_template(Main &bmain, Object &ob, const ColorTemplate &pct)
+{
+  int index;
+  Material *ma = BKE_grease_pencil_object_material_ensure_by_name(
+      &bmain, &ob, DATA_(pct.name), &index);
+
+  copy_v4_v4(ma->gp_style->stroke_rgba, pct.line);
+  srgb_to_linearrgb_v4(ma->gp_style->stroke_rgba, ma->gp_style->stroke_rgba);
+
+  copy_v4_v4(ma->gp_style->fill_rgba, pct.fill);
+  srgb_to_linearrgb_v4(ma->gp_style->fill_rgba, ma->gp_style->fill_rgba);
+
+  if (pct.show_fill) {
+    ma->gp_style->flag |= GP_MATERIAL_FILL_SHOW;
+  }
+
+  return index;
+}
+
+static bke::CurvesGeometry create_drawing_data(const Span<float3> positions,
+                                               const Span<float> radii,
+                                               const Span<float> opacities,
+                                               const Span<int> offsets,
+                                               const Span<int> materials,
+                                               const Span<int> radii_factor,
+                                               const float4x4 &matrix)
+{
+  using namespace blender::bke;
+  CurvesGeometry curves(offsets.last(), offsets.size() - 1);
+  curves.offsets_for_write().copy_from(offsets);
+
+  curves.fill_curve_types(CURVE_TYPE_POLY);
+
+  MutableAttributeAccessor attributes = curves.attributes_for_write();
+  MutableSpan<float3> point_positions = curves.positions_for_write();
+  point_positions.copy_from(positions);
+
+  SpanAttributeWriter<float> point_radii = attributes.lookup_or_add_for_write_only_span<float>(
+      "radius", ATTR_DOMAIN_POINT);
+  point_radii.span.copy_from(radii);
+
+  SpanAttributeWriter<float> point_opacities = attributes.lookup_or_add_for_write_span<float>(
+      "opacity", ATTR_DOMAIN_POINT);
+  point_opacities.span.copy_from(opacities);
+
+  SpanAttributeWriter<bool> stroke_cyclic = attributes.lookup_or_add_for_write_span<bool>(
+      "cyclic", ATTR_DOMAIN_CURVE);
+  stroke_cyclic.span.fill(false);
+
+  SpanAttributeWriter<int> stroke_materials = attributes.lookup_or_add_for_write_span<int>(
+      "material_index", ATTR_DOMAIN_CURVE);
+  stroke_materials.span.copy_from(materials);
+
+  const OffsetIndices points_by_curve = curves.points_by_curve();
+  for (const int curve_i : curves.curves_range()) {
+    const IndexRange points = points_by_curve[curve_i];
+    for (const int point_i : points) {
+      point_positions[point_i] = math::transform_point(matrix, point_positions[point_i]);
+      point_radii.span[point_i] *= radii_factor[curve_i];
+    }
+  }
+
+  point_radii.finish();
+  point_opacities.finish();
+
+  stroke_cyclic.finish();
+  stroke_materials.finish();
+
+  return curves;
+}
+
+void create_blank(Main &bmain, Object &object, const int frame_numer)
+{
+  using namespace blender::bke::greasepencil;
+  GreasePencil &grease_pencil = *static_cast<GreasePencil *>(object.data);
+
+  int material_index = add_material_from_template(bmain, object, gp_stroke_material_black);
+  object.actcol = material_index + 1;
+
+  Layer &new_layer = grease_pencil.add_layer(grease_pencil.root_group.wrap(), "GP_Layer");
+  grease_pencil.active_layer = &new_layer;
+
+  grease_pencil.add_empty_drawings(1);
+
+  GreasePencilFrame frame{0, 0, BEZT_KEYTYPE_KEYFRAME};
+  new_layer.insert_frame(frame_numer, frame);
+}
+
+void create_stroke(Main &bmain, Object &object, float4x4 matrix, const int frame_numer)
+{
+  using namespace blender::bke::greasepencil;
+  GreasePencil &grease_pencil = *static_cast<GreasePencil *>(object.data);
+
+  int material_index = add_material_from_template(bmain, object, gp_stroke_material_black);
+  add_material_from_template(bmain, object, gp_stroke_material_black);
+  add_material_from_template(bmain, object, gp_stroke_material_white);
+  add_material_from_template(bmain, object, gp_stroke_material_red);
+  add_material_from_template(bmain, object, gp_stroke_material_green);
+  add_material_from_template(bmain, object, gp_stroke_material_blue);
+  add_material_from_template(bmain, object, gp_fill_material_grey);
+  object.actcol = material_index + 1;
+
+  Layer &layer_lines = grease_pencil.add_layer(grease_pencil.root_group.wrap(), "Lines");
+  Layer &layer_color = grease_pencil.add_layer(grease_pencil.root_group.wrap(), "Color");
+  grease_pencil.active_layer = &layer_lines;
+
+  grease_pencil.add_empty_drawings(2);
+
+  GreasePencilDrawing &drawing = *reinterpret_cast<GreasePencilDrawing *>(
+      grease_pencil.drawings_for_write()[1]);
+  drawing.geometry.wrap() = create_drawing_data(
+      stroke_positions, stroke_radii, stroke_opacities, {0, 175}, {material_index}, {75}, matrix);
+
+  GreasePencilFrame frame_lines{0, 0, BEZT_KEYTYPE_KEYFRAME};
+  GreasePencilFrame frame_color{1, 0, BEZT_KEYTYPE_KEYFRAME};
+  layer_lines.insert_frame(frame_numer, frame_lines);
+  layer_color.insert_frame(frame_numer, frame_color);
+}
+
+}  // namespace blender::ed::greasepencil

source/blender/editors/include/ED_grease_pencil.h

@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2023 Blender Foundation. */
+
+/** \file
+ * \ingroup editors
+ */
+
+#pragma once
+
+struct Main;
+struct Object;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#ifdef __cplusplus
+
+namespace blender::ed::greasepencil {
+
+void create_blank(Main &bmain, Object &object, int frame_numer);
+void create_stroke(Main &bmain, Object &object, float4x4 matrix, int frame_numer);
+
+}  // namespace blender::ed::greasepencil
+#endif

source/blender/editors/object/CMakeLists.txt

@@ -70,6 +70,7 @@ set(LIB
   bf_blenkernel
   bf_blenlib
   bf_editor_mesh
+  bf_editor_grease_pencil
   bf_render
   bf_windowmanager
 )

source/blender/editors/object/object_add.cc

@@ -105,6 +105,7 @@
 #include "ED_curve.h"
 #include "ED_curves.h"
 #include "ED_gpencil_legacy.h"
+#include "ED_grease_pencil.h"
 #include "ED_mball.h"
 #include "ED_mesh.h"
 #include "ED_node.h"
@@ -1306,7 +1307,7 @@ void OBJECT_OT_drop_named_image(wmOperatorType *ot)
 /** \} */
 
 /* -------------------------------------------------------------------- */
-/** \name Add Gpencil Operator
+/** \name Add Gpencil (legacy) Operator
  * \{ */
 
 static bool object_gpencil_add_poll(bContext *C)
@@ -1529,8 +1530,8 @@ static EnumPropertyItem rna_enum_gpencil_add_stroke_depth_order_items[] = {
 void OBJECT_OT_gpencil_add(wmOperatorType *ot)
 {
   /* identifiers */
-  ot->name = "Add Grease Pencil";
-  ot->description = "Add a Grease Pencil object to the scene";
+  ot->name = "Add Grease Pencil (legacy)";
+  ot->description = "Add a Grease Pencil (legacy) object to the scene";
   ot->idname = "OBJECT_OT_gpencil_add";
 
   /* api callbacks */
@@ -1576,6 +1577,109 @@ void OBJECT_OT_gpencil_add(wmOperatorType *ot)
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name Add Grease Pencil Operator
+ * \{ */
+
+static int object_grease_pencil_add_exec(bContext *C, wmOperator *op)
+{
+  using namespace blender::ed;
+  Main *bmain = CTX_data_main(C);
+  Scene *scene = CTX_data_scene(C);
+  /* TODO: For now, only support adding the 'Stroke' type. */
+  const int type = RNA_enum_get(op->ptr, "type");
+
+  ushort local_view_bits;
+  float loc[3], rot[3];
+
+  /* NOTE: We use 'Y' here (not 'Z'), as. */
+  WM_operator_view3d_unit_defaults(C, op);
+  if (!ED_object_add_generic_get_opts(
+          C, op, 'Y', loc, rot, nullptr, nullptr, &local_view_bits, nullptr))
+  {
+    return OPERATOR_CANCELLED;
+  }
+
+  const char *ob_name = nullptr;
+  switch (type) {
+    case GP_EMPTY: {
+      ob_name = CTX_DATA_(BLT_I18NCONTEXT_ID_GPENCIL, "GPencil");
+      break;
+    }
+    case GP_STROKE: {
+      ob_name = CTX_DATA_(BLT_I18NCONTEXT_ID_GPENCIL, "Stroke");
+      break;
+    }
+    case GP_MONKEY: {
+      ob_name = CTX_DATA_(BLT_I18NCONTEXT_ID_GPENCIL, "Suzanne");
+      break;
+    }
+    case GP_LRT_OBJECT:
+    case GP_LRT_SCENE:
+    case GP_LRT_COLLECTION: {
+      ob_name = CTX_DATA_(BLT_I18NCONTEXT_ID_GPENCIL, "LineArt");
+      break;
+    }
+    default: {
+      break;
+    }
+  }
+
+  Object *object = ED_object_add_type(
+      C, OB_GREASE_PENCIL, ob_name, loc, rot, false, local_view_bits);
+  GreasePencil &grease_pencil_id = *static_cast<GreasePencil *>(object->data);
+  switch (type) {
+    case GP_EMPTY: {
+      greasepencil::create_blank(*bmain, *object, scene->r.cfra);
+      break;
+    }
+    case GP_STROKE: {
+      const float radius = RNA_float_get(op->ptr, "radius");
+      const float3 scale(radius);
+
+      float4x4 mat;
+      ED_object_new_primitive_matrix(C, object, loc, rot, scale, mat.ptr());
+
+      greasepencil::create_stroke(*bmain, *object, mat, scene->r.cfra);
+      break;
+    }
+    case GP_MONKEY:
+    case GP_LRT_OBJECT:
+    case GP_LRT_SCENE:
+    case GP_LRT_COLLECTION: {
+      /* TODO. */
+      break;
+    }
+  }
+
+  DEG_id_tag_update(&grease_pencil_id.id, ID_RECALC_GEOMETRY);
+  WM_main_add_notifier(NC_GEOM | ND_DATA, &grease_pencil_id.id);
+
+  return OPERATOR_FINISHED;
+}
+
+void OBJECT_OT_grease_pencil_add(wmOperatorType *ot)
+{
+  /* identifiers */
+  ot->name = "Add Grease Pencil";
+  ot->description = "Add a Grease Pencil object to the scene";
+  ot->idname = "OBJECT_OT_grease_pencil_add";
+
+  /* api callbacks */
+  ot->exec = object_grease_pencil_add_exec;
+  ot->poll = ED_operator_objectmode;
+
+  /* flags */
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+  ot->prop = RNA_def_enum(ot->srna, "type", rna_enum_object_gpencil_type_items, 0, "Type", "");
+
+  ED_object_add_unit_props_radius(ot);
+  ED_object_add_generic_props(ot, false);
+}
+
+/** \} */
+
 /* -------------------------------------------------------------------- */
 /** \name Add Light Operator
  * \{ */

source/blender/editors/object/object_intern.h

@@ -119,6 +119,7 @@ void OBJECT_OT_empty_add(struct wmOperatorType *ot);
 void OBJECT_OT_lightprobe_add(struct wmOperatorType *ot);
 void OBJECT_OT_drop_named_image(struct wmOperatorType *ot);
 void OBJECT_OT_gpencil_add(struct wmOperatorType *ot);
+void OBJECT_OT_grease_pencil_add(struct wmOperatorType *ot);
 void OBJECT_OT_light_add(struct wmOperatorType *ot);
 void OBJECT_OT_effector_add(struct wmOperatorType *ot);
 void OBJECT_OT_camera_add(struct wmOperatorType *ot);

source/blender/editors/object/object_ops.c

@@ -90,6 +90,7 @@ void ED_operatortypes_object(void)
   WM_operatortype_append(OBJECT_OT_lightprobe_add);
   WM_operatortype_append(OBJECT_OT_drop_named_image);
   WM_operatortype_append(OBJECT_OT_gpencil_add);
+  WM_operatortype_append(OBJECT_OT_grease_pencil_add);
   WM_operatortype_append(OBJECT_OT_light_add);
   WM_operatortype_append(OBJECT_OT_camera_add);
   WM_operatortype_append(OBJECT_OT_speaker_add);