source/blender/blenkernel/BKE_grease_pencil.cpp

@@ -1,6 +0,0 @@
-#include "BKE_grease_pencil.hh"
-
-Span<GreasePencilDrawing> blender::bke::GreasePencil::drawings() const
-{
-  return Span<GreasePencilDrawing>{this->drawing_array, this->drawing_array_size};
-}

source/blender/blenkernel/BKE_grease_pencil.hh

@@ -8,6 +8,7 @@
  */
 
 #include "BLI_map.hh"
+#include "DNA_gpencil_legacy_types.h"
 #include "DNA_grease_pencil_types.h"
 
 namespace blender::bke {
@@ -17,6 +18,11 @@ class GreasePencilLayerRuntime {
   Map<int, int> frames;
 };
 
+namespace gpencil::convert {
+
+CurvesGeometry &legacy_gpencil_frame_to_curves_geometry(bGPDframe &gpf);
+
+}  // namespace gpencil::convert
 
 }  // namespace blender::bke
 

source/blender/blenkernel/CMakeLists.txt

@@ -148,6 +148,7 @@ set(SRC
   intern/gpencil_geom_legacy.cc
   intern/gpencil_modifier_legacy.c
   intern/gpencil_update_cache_legacy.c
+  intern/grease_pencil_convert_legacy.cc
   intern/grease_pencil.cc
   intern/icons.cc
   intern/icons_rasterize.c
@@ -389,6 +390,7 @@ set(SRC
   BKE_gpencil_geom_legacy.h
   BKE_gpencil_modifier_legacy.h
   BKE_gpencil_update_cache_legacy.h
+  BKE_grease_pencil.hh
   BKE_icons.h
   BKE_idprop.h
   BKE_idprop.hh

source/blender/blenkernel/intern/grease_pencil_convert_legacy.cc

@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup bke
+ */
+
+#include "BKE_curves.hh"
+#include "BKE_grease_pencil.hh"
+
+#include "BLI_listbase.h"
+#include "BLI_math_vector_types.hh"
+#include "BLI_vector.hh"
+
+#include "DNA_gpencil_legacy_types.h"
+#include "DNA_grease_pencil_types.h"
+
+namespace blender::bke::gpencil::convert {
+
+CurvesGeometry &legacy_gpencil_frame_to_curves_geometry(bGPDframe &gpf)
+{
+  /* Get the number of points, number of strokes and the offsets for each stroke. */
+  Vector<int> offsets;
+  offsets.append(0);
+  int num_strokes = 0;
+  int num_points = 0;
+  LISTBASE_FOREACH (bGPDstroke *, gps, &gpf.strokes) {
+    num_points += gps->totpoints;
+    offsets.append(num_points);
+    num_strokes++;
+  }
+
+  /* Create a new CurvesGeometry. */
+  CurvesGeometry curves{num_points, num_strokes};
+  curves.offsets_for_write().copy_from(offsets);
+  OffsetIndices<int> points_by_curve = curves.points_by_curve();
+  MutableAttributeAccessor attributes = curves.attributes_for_write();
+
+  /* All strokes are poly curves. */
+  curves.curve_types_for_write().fill(CURVE_TYPE_POLY);
+
+  /* Point Attributes. */
+  MutableSpan<float3> positions = curves.positions_for_write();
+  MutableSpan<float> radii =
+      attributes.lookup_or_add_for_write_span<float>("radius", ATTR_DOMAIN_POINT).span;
+  MutableSpan<float> opacities =
+      attributes.lookup_or_add_for_write_span<float>("opacity", ATTR_DOMAIN_POINT).span;
+  MutableSpan<bool> selection =
+      attributes.lookup_or_add_for_write_span<bool>(".selection", ATTR_DOMAIN_POINT).span;
+
+  /* Curve Attributes. */
+  MutableSpan<bool> curve_cyclic =
+      attributes.lookup_or_add_for_write_span<bool>("cyclic", ATTR_DOMAIN_CURVE).span;
+  MutableSpan<int> curve_materials =
+      attributes.lookup_or_add_for_write_span<int>("material_index", ATTR_DOMAIN_CURVE).span;
+
+  int i = 0;
+  LISTBASE_FOREACH_INDEX (bGPDstroke *, gps, &gpf.strokes, i) {
+    /* Write curve attributes. */
+    curve_cyclic[i] = (gps->flag & GP_STROKE_CYCLIC) != 0;
+    curve_materials[i] = gps->mat_nr;
+
+    /* Write point attributes. */
+    IndexRange curve_points = points_by_curve[i];
+    Span<bGPDspoint> stroke_points{gps->points, gps->totpoints};
+
+    MutableSpan<float3> curve_positions = positions.slice(curve_points);
+    MutableSpan<float> curve_radii = radii.slice(curve_points);
+    MutableSpan<float> curve_opacities = opacities.slice(curve_points);
+    MutableSpan<bool> curve_selections = selection.slice(curve_points);
+
+    for (const int j : stroke_points.index_range()) {
+      const bGPDspoint &pt = stroke_points[j];
+      curve_positions[j] = float3(pt.x, pt.y, pt.z);
+      curve_radii[j] = pt.pressure;
+      curve_opacities[j] = pt.strength;
+      curve_selections[j] = (pt.flag & GP_SPOINT_SELECT) != 0;
+    }
+  }
+
+  return curves;
+}
+
+}  // namespace blender::bke::gpencil::convert