GPencil: Draw engine rewrite: Initial commit

This renames the `BKE_gpencil_*` as well as the `DNA_gpencil_types.h`
files to indicate that it's the legacy grease pencil.

@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */

@@ -0,0 +1,480 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */

@@ -0,0 +20,4 @@
+
+namespace blender::bke {
+
+namespace gpencil {

@@ -0,0 +70,4 @@
+  }
+
+ public:
+  class PreOrderRange {

@@ -0,0 +160,4 @@
+  LayerGroup &as_group();
+  Layer &as_layer();
+
+  int total_num_children() const

@@ -0,0 +197,4 @@
+  }
+
+ private:
+  void foreach_children_pre_order_recursive_(TreeNodeIterFn function)

@@ -0,0 +205,4 @@
+    }
+  }
+
+  void foreach_layer_pre_order_recursive_(LayerIterFn function)

@@ -0,0 +246,4 @@
+   * referenced drawings are discarded. If the frame is longer than the number of referenced
+   * drawings, then the last referenced drawing is held for the rest of the duration.
+   */
+  Map<int, int> frames_;

@@ -0,0 +294,4 @@
+    return frames_for_write().add_overwrite(frame_number, index);
+  }
+
+  Span<int> sorted_keys()

@@ -0,0 +307,4 @@
+    return sorted_keys_cache_.data().as_span();
+  }
+
+  void load_from_storage(GreasePencilLayer &node)

@@ -0,0 +317,4 @@
+  /**
+   * Return the index of the drawing at frame \a frame or -1 if there is no drawing.
+   */
+  int drawing_at(int frame)

@@ -0,0 +344,4 @@
+ public:
+  LayerGroup() : TreeNode(GREASE_PENCIL_LAYER_TREE_GROUP) {}
+  LayerGroup(StringRefNull name) : TreeNode(GREASE_PENCIL_LAYER_TREE_GROUP, name) {}
+  LayerGroup(const LayerGroup &other) : TreeNode(other)

@@ -0,0 +356,4 @@
+      }
+    }
+  }
+  LayerGroup(LayerGroup &&other) : TreeNode(std::move(other))

@@ -0,0 +461,4 @@
+  }
+
+ public:
+  void *batch_cache = nullptr;

@@ -200,6 +200,7 @@ typedef struct Main {
   ListBase pointclouds;
   ListBase volumes;
   ListBase simulations;
+  ListBase greasepencils;

@@ -1580,6 +1580,7 @@ GVArray CurvesGeometry::adapt_domain(const GVArray &varray,
 /** \name File reading/writing.
  * \{ */
 
+

@@ -0,0 +41,4 @@
+{
+  using namespace blender::bke;
+
+  // printf("grease_pencil_init_data\n");

@@ -0,0 +135,4 @@
+          reinterpret_cast<GreasePencilDrawingReference *>(drawing_or_ref);
+      BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, drawing_reference->id_reference, IDWALK_CB_USER);
+    }
+  }

@@ -0,0 +201,4 @@
+          reinterpret_cast<GreasePencilDrawingReference *>(drawing_or_ref);
+      BLO_read_id_address(reader, grease_pencil->id.lib, &drawing_reference->id_reference);
+    }
+  }

@@ -0,0 +217,4 @@
+          reinterpret_cast<GreasePencilDrawingReference *>(drawing_or_ref);
+      BLO_expand(expander, drawing_reference->id_reference);
+    }
+  }

@@ -0,0 +293,4 @@
+    float3 min(FLT_MAX);
+    float3 max(-FLT_MAX);
+
+    for (int i = 0; i < grease_pencil->drawing_array_size; i++) {

@@ -0,0 +301,4 @@
+          const blender::bke::CurvesGeometry &curves = drawing->geometry.wrap();
+
+          if (!curves.bounds_min_max(min, max)) {
+            min = float3(-1);

@@ -0,0 +16,4 @@
+
+namespace blender::bke::gpencil::convert {
+
+void legacy_gpencil_frame_to_curves_geometry(GreasePencilDrawing &drawing, bGPDframe &gpf)

@@ -0,0 +38,4 @@
+  EXPECT_EQ(grease_pencil.drawings().size(), 0);
+  EXPECT_EQ(grease_pencil.root_group().total_num_children(), 0);
+}
+

@@ -3936,7 +3950,6 @@ void BKE_object_minmax(Object *ob, float r_min[3], float r_max[3], const bool us
       changed = true;
       break;
     }
-

@@ -315,2 +320,4 @@
       BKE_volume_batch_cache_dirty_tag((struct Volume *)ob->data, BKE_VOLUME_BATCH_DIRTY_ALL);
       break;
+    case OB_GREASE_PENCIL:
+      /* TODO: tag batches. */

@@ -2514,2 +2516,4 @@
       break;
     }
+    case ID_GP:
+      break;

@@ -0,0 +31,4 @@
+  /** Instancing Data */
+  GPUVertBuf *vbo;
+  GPUVertBuf *vbo_col;
+  /** Indices in material order, then stroke order with fill first.

@@ -0,0 +38,4 @@
+  /** Batches */
+  GPUBatch *geom_batch;
+  /** Stroke lines only */
+  GPUBatch *lines_batch;

@@ -0,0 +66,4 @@
+   * The stroke data for this drawing.
+   */
+  CurvesGeometry geometry;
+#ifdef __cplusplus

@@ -6525,1 +6525,4 @@
 
+  prop = RNA_def_property(srna, "use_grease_pencil_version3", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "use_grease_pencil_version3", 1);
+  RNA_def_property_ui_text(prop, "Grease Pencil 3.0", "Enable the new grease pencil 3.0 codebase");

@@ -0,0 +252,4 @@
+   */
+  float tint_color[4];
+  /**
+   * Layer transfrom.

@@ -0,0 +219,4 @@
+   * Adds a layer at the end of this group and returns it.
+   */
+  Layer &add_layer(Layer &layer);
+  Layer &add_layer(Layer &&layer);

@@ -0,0 +300,4 @@
+
+class GreasePencilRuntime {
+ public:
+  mutable SharedCache<Vector<greasepencil::Layer *>> layer_cache_;

@@ -0,0 +323,4 @@
+  void ensure_layer_cache() const;
+
+  void load_layer_tree_from_storage(GreasePencilLayerTreeStorage &storage);
+  void save_layer_tree_to_storage(GreasePencilLayerTreeStorage &storage);

@@ -0,0 +328,4 @@
+  void tag_layer_tree_topology_changed();
+
+ public:
+  void *batch_cache = nullptr;

@@ -0,0 +155,4 @@
+  BLO_write_id_struct(writer, GreasePencil, id_address, &grease_pencil->id);
+  BKE_id_blend_write(writer, &grease_pencil->id);
+
+  /* Write drawings. */

@@ -0,0 +424,4 @@
+Span<int> Layer::sorted_keys() const
+{
+  this->sorted_keys_cache_.ensure([&](Vector<int> &r_data) {
+    r_data.clear_and_shrink();

@@ -0,0 +431,4 @@
+    }
+    std::sort(r_data.begin(), r_data.end());
+  });
+  return this->sorted_keys_cache_.data().as_span();

@@ -0,0 +482,4 @@
+
+void LayerGroup::add_group(LayerGroup &&group)
+{
+  this->children.append(std::make_unique<LayerGroup>(group));

@@ -0,0 +594,4 @@
+GreasePencilRuntime::GreasePencilRuntime(const GreasePencilRuntime &other)
+    : root_group_(other.root_group_), active_layer_index_(other.active_layer_index_)
+{
+  /* We cannot copy this cache, because the pointers in that cache become invalid. */

@@ -0,0 +956,4 @@
+{
+  using namespace blender;
+  const bke::GreasePencilDrawingRuntime &runtime = *this->runtime;
+  runtime.triangles_cache.ensure([&](Vector<uint3> &cache) {

@@ -0,0 +964,4 @@
+    const offset_indices::OffsetIndices<int> points_by_curve = curves.points_by_curve();
+
+    int total_triangles = 0;
+    for (int curve_i : curves.curves_range()) {

@@ -0,0 +965,4 @@
+
+    int total_triangles = 0;
+    for (int curve_i : curves.curves_range()) {
+      IndexRange points = points_by_curve[curve_i];

@@ -0,0 +984,4 @@
+      const int num_trinagles = points.size() - 2;
+
+      uint(*tris)[3] = static_cast<uint(*)[3]>(
+          BLI_memarena_alloc(pf_arena, sizeof(*tris) * size_t(num_trinagles)));

@@ -0,0 +1034,4 @@
+/** \name Grease Pencil data-block API
+ * \{ */
+
+static void grease_pencil_grow_drawing_array_by(GreasePencil &self, const int add_capacity)

@@ -0,0 +1073,4 @@
+                                                         this->drawing_array_size};
+}
+
+void GreasePencil::add_empty_drawings(int n)

@@ -0,0 +1081,4 @@
+  grease_pencil_grow_drawing_array_by(*this, n);
+  MutableSpan<GreasePencilDrawingBase *> new_drawings = this->drawings_for_write().drop_front(
+      prev_size);
+  for (const int i : IndexRange(new_drawings.size())) {

@@ -0,0 +1091,4 @@
+  }
+}
+
+void GreasePencil::remove_drawing(int index_to_remove)

@@ -0,0 +1096,4 @@
+  using namespace blender::bke::greasepencil;
+  /* In order to not change the indices of the drawings, we do the following to the drawing to be
+   * removed:
+   *  - If the drawing (A) is not the last one:

@@ -0,0 +1230,4 @@
+        GreasePencilDrawing *drawing = reinterpret_cast<GreasePencilDrawing *>(drawing_base);
+        drawing->geometry.wrap().blend_read(*reader);
+        /* Initialize runtime data. */
+        drawing->geometry.runtime = MEM_new<blender::bke::CurvesGeometryRuntime>(__func__);

@@ -0,0 +1233,4 @@
+        drawing->geometry.runtime = MEM_new<blender::bke::CurvesGeometryRuntime>(__func__);
+        drawing->geometry.wrap().update_curve_types();
+        drawing->runtime = MEM_new<blender::bke::GreasePencilDrawingRuntime>(__func__);
+        drawing->runtime->triangles_cache.tag_dirty();

@@ -0,0 +1281,4 @@
+        drawing->geometry.wrap().~CurvesGeometry();
+        MEM_delete(drawing->runtime);
+        drawing->runtime = nullptr;
+        MEM_freeN(drawing);

@@ -0,0 +195,4 @@
+  int total_points_num = 0;
+  int total_triangles_num = 0;
+  int v = 0;
+  Vector<Vector<int>> verts_start_offsets_per_visible_drawing;

@@ -0,0 +197,4 @@
+  int v = 0;
+  Vector<Vector<int>> verts_start_offsets_per_visible_drawing;
+  Vector<Vector<int>> tris_start_offsets_per_visible_drawing;
+  grease_pencil.foreach_visible_drawing(cfra, [&](GreasePencilDrawing &drawing) {

@@ -0,0 +205,4 @@
+    Vector<int> tris_start_offsets(curves.curves_num());
+
+    /* Calculate the vertex and triangle offsets for all the curves. */
+    int t = 0;

@@ -0,0 +221,4 @@
+      }
+
+      verts_start_offsets[curve_i] = v;
+      v += 1 + points.size() + (is_cyclic ? 1 : 0) + 1;

@@ -0,0 +271,4 @@
+    const offset_indices::OffsetIndices<int> points_by_curve = curves.points_by_curve();
+    const Span<float3> positions = curves.positions();
+    const VArray<bool> cyclic = curves.cyclic();
+    const VArray<float> radii = attributes.lookup_or_default<float>(

@@ -0,0 +283,4 @@
+        "material_index", ATTR_DOMAIN_CURVE, -1).varray;
+    const Span<uint3> triangles = drawing.triangles();
+    const Span<int> verts_start_offsets =
+        verts_start_offsets_per_visible_drawing[drawing_i].as_span();

@@ -688,6 +688,9 @@ static bool ED_object_editmode_load_free_ex(Main *bmain,
   else if (obedit->type == OB_CURVES) {
     /* Curves don't have specific edit mode data, so pass. */
   }
+  else if (obedit->type == OB_GREASE_PENCIL) {

@@ -0,0 +44,4 @@
+    Scene *scene = CTX_data_scene(&C);
+    ARegion *region = CTX_wm_region(&C);
+    Object *obact = CTX_data_active_object(&C);
+    Object *ob_eval = DEG_get_evaluated_object(depsgraph, obact);

@@ -0,0 +109,4 @@
+  curves.offsets_for_write()[num_old_curves] = num_old_points;
+  curves.offsets_for_write()[num_old_curves + 1] = num_old_points + stroke_points.size();
+
+  const offset_indices::OffsetIndices<int> points_by_curve = curves.points_by_curve();

@@ -0,0 +82,4 @@
+  /**
+   * Number of users of this drawing in the layer tree.
+   */
+  int32_t user_count;

@@ -0,0 +109,4 @@
+  /**
+   * A buffer for a single stroke while drawing.
+   */
+  blender::Span<blender::bke::StrokePoint> stroke_buffer();

@@ -0,0 +110,4 @@
+   * A buffer for a single stroke while drawing.
+   */
+  blender::Span<blender::bke::StrokePoint> stroke_buffer();
+  bool has_stroke_buffer();

@@ -0,0 +180,4 @@
+  struct GreasePencilLayerMask *next, *prev;
+  /**
+   * The name of the layer that is the mask.
+   * \note Null-terminated.

@@ -0,0 +247,4 @@
+  /**
+   * List of `GreasePencilLayerMask`. Only used for storage in the .blend file.
+   */
+  ListBase masks_storage;

@@ -0,0 +406,4 @@
+  struct AnimData *adt;
+
+  /**
+   * An array of pointers to drawings. The drawing can own it's data or reference it from another

@@ -0,0 +414,4 @@
+  int drawing_array_size;
+  char _pad[4];
+#ifdef __cplusplus
+  void read_drawing_array(BlendDataReader *reader);

@@ -0,0 +446,4 @@
+   */
+  GreasePencilRuntimeHandle *runtime;
+#ifdef __cplusplus
+  blender::Span<GreasePencilDrawingBase *> drawings() const;

@@ -0,0 +449,4 @@
+  blender::Span<GreasePencilDrawingBase *> drawings() const;
+  blender::MutableSpan<GreasePencilDrawingBase *> drawings_for_write();
+  void add_empty_drawings(int n);
+  void remove_drawing(int index);

@@ -0,0 +117,4 @@
+   *
+   *           | | | | | | | | | | |1|1|1|1|1|1|1|
+   *    Time:  |0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|...
+   *    Frame: [#0      ][#1      ]    [#2    ]

@@ -0,0 +151,4 @@
+    }
+  }
+
+  radii.finish();