Geometry Nodes: Add simple subdivision surface node

Add the Simple subdivision option to Geometry nodes, as a new node
instead of part of the existing subdivision node because of future
backend changes to the Simple option. (See T85584)

https://developer.blender.org/D10409

6 files changed, 117 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index 7984bbc980a..77d850ec2f6 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -1372,6 +1372,7 @@ int ntreeTexExecTree(struct bNodeTree *ntree,
 #define GEO_NODE_VOLUME_TO_MESH 1026
 #define GEO_NODE_ATTRIBUTE_COMBINE_XYZ 1027
 #define GEO_NODE_ATTRIBUTE_SEPARATE_XYZ 1028
+#define GEO_NODE_SUBDIVISION_SURFACE_SIMPLE 1029
 
 /** \} */
 
diff --git a/source/blender/blenkernel/intern/node.cc b/source/blender/blenkernel/intern/node.cc
index 248d2776678..228d3e0d825 100644
--- a/source/blender/blenkernel/intern/node.cc
+++ b/source/blender/blenkernel/intern/node.cc
@@ -4794,6 +4794,7 @@ static void registerGeometryNodes()
   register_node_type_geo_points_to_volume();
   register_node_type_geo_sample_texture();
   register_node_type_geo_subdivision_surface();
+  register_node_type_geo_subdivision_surface_simple();
   register_node_type_geo_transform();
   register_node_type_geo_triangulate();
   register_node_type_geo_volume_to_mesh();
diff --git a/source/blender/nodes/CMakeLists.txt b/source/blender/nodes/CMakeLists.txt
index 94b6148ff9b..c9eb0c43bba 100644
--- a/source/blender/nodes/CMakeLists.txt
+++ b/source/blender/nodes/CMakeLists.txt
@@ -168,6 +168,7 @@ set(SRC
   geometry/nodes/node_geo_point_translate.cc
   geometry/nodes/node_geo_points_to_volume.cc
   geometry/nodes/node_geo_subdivision_surface.cc
+  geometry/nodes/node_geo_subdivision_surface_simple.cc
   geometry/nodes/node_geo_transform.cc
   geometry/nodes/node_geo_triangulate.cc
   geometry/nodes/node_geo_volume_to_mesh.cc
diff --git a/source/blender/nodes/NOD_geometry.h b/source/blender/nodes/NOD_geometry.h
index 8980855fd51..3ee8067e81a 100644
--- a/source/blender/nodes/NOD_geometry.h
+++ b/source/blender/nodes/NOD_geometry.h
@@ -52,6 +52,7 @@ void register_node_type_geo_point_translate(void);
 void register_node_type_geo_points_to_volume(void);
 void register_node_type_geo_sample_texture(void);
 void register_node_type_geo_subdivision_surface(void);
+void register_node_type_geo_subdivision_surface_simple(void);
 void register_node_type_geo_transform(void);
 void register_node_type_geo_triangulate(void);
 void register_node_type_geo_volume_to_mesh(void);
diff --git a/source/blender/nodes/NOD_static_types.h b/source/blender/nodes/NOD_static_types.h
index 15f078cebf2..962ad70eda4 100644
--- a/source/blender/nodes/NOD_static_types.h
+++ b/source/blender/nodes/NOD_static_types.h
@@ -297,6 +297,7 @@ DefNode(GeometryNode, GEO_NODE_ATTRIBUTE_PROXIMITY, def_geo_attribute_proximity,
 DefNode(GeometryNode, GEO_NODE_VOLUME_TO_MESH, def_geo_volume_to_mesh, "VOLUME_TO_MESH", VolumeToMesh, "Volume to Mesh", "")
 DefNode(GeometryNode, GEO_NODE_ATTRIBUTE_COMBINE_XYZ, def_geo_attribute_combine_xyz, "ATTRIBUTE_COMBINE_XYZ", AttributeCombineXYZ, "Attribute Combine XYZ", "")
 DefNode(GeometryNode, GEO_NODE_ATTRIBUTE_SEPARATE_XYZ, def_geo_attribute_separate_xyz, "ATTRIBUTE_SEPARATE_XYZ", AttributeSeparateXYZ, "Attribute Separate XYZ", "")
+DefNode(GeometryNode, GEO_NODE_SUBDIVISION_SURFACE_SIMPLE, 0, "SUBDIVISION_SURFACE_SIMPLE", SubdivisionSurfaceSimple, "Simple Subdivision Surface", "")
 
 /* undefine macros */
 #undef DefNode
diff --git a/source/blender/nodes/geometry/nodes/node_geo_subdivision_surface_simple.cc b/source/blender/nodes/geometry/nodes/node_geo_subdivision_surface_simple.cc
new file mode 100644
index 00000000000..f6ea68fb63f
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_subdivision_surface_simple.cc
@@ -0,0 +1,112 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "BKE_mesh.h"
+#include "BKE_subdiv.h"
+#include "BKE_subdiv_mesh.h"
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "node_geometry_util.hh"
+
+static bNodeSocketTemplate geo_node_subdivision_surface_simple_in[] = {
+    {SOCK_GEOMETRY, N_("Geometry")},
+    {SOCK_INT, N_("Level"), 1, 0, 0, 0, 0, 6},
+    {-1, ""},
+};
+
+static bNodeSocketTemplate geo_node_subdivision_surface_simple_out[] = {
+    {SOCK_GEOMETRY, N_("Geometry")},
+    {-1, ""},
+};
+
+namespace blender::nodes {
+
+static void geo_node_subdivision_surface_simple_exec(GeoNodeExecParams params)
+{
+  GeometrySet geometry_set = params.extract_input<GeometrySet>("Geometry");
+
+  if (!geometry_set.has_mesh()) {
+    params.set_output("Geometry", geometry_set);
+    return;
+  }
+
+#ifndef WITH_OPENSUBDIV
+  params.error_message_add(NodeWarningType::Error,
+                           "Disabled, Blender was built without OpenSubdiv");
+  params.set_output("Geometry", std::move(geometry_set));
+  return;
+#endif
+
+  /* See CCGSUBSURF_LEVEL_MAX for max limit. */
+  const int subdiv_level = clamp_i(params.extract_input<int>("Level"), 0, 11);
+
+  if (subdiv_level == 0) {
+    params.set_output("Geometry", std::move(geometry_set));
+    return;
+  }
+
+  const Mesh *mesh_in = geometry_set.get_mesh_for_read();
+
+  /* Initialize mesh settings. */
+  SubdivToMeshSettings mesh_settings;
+  mesh_settings.resolution = (1 << subdiv_level) + 1;
+  mesh_settings.use_optimal_display = false;
+
+  /* Initialize subdivision settings. */
+  SubdivSettings subdiv_settings = {0};
+  subdiv_settings.is_simple = true;
+  subdiv_settings.is_adaptive = false;
+  subdiv_settings.use_creases = false;
+  subdiv_settings.level = 1;
+
+  /* Apply subdivision from mesh. */
+  Subdiv *subdiv = BKE_subdiv_update_from_mesh(nullptr, &subdiv_settings, mesh_in);
+
+  /* In case of bad topology, skip to input mesh. */
+  if (subdiv == nullptr) {
+    params.set_output("Geometry", std::move(geometry_set));
+    return;
+  }
+
+  Mesh *mesh_out = BKE_subdiv_to_mesh(subdiv, &mesh_settings, mesh_in);
+  BKE_mesh_calc_normals(mesh_out);
+
+  geometry_set.replace_mesh(mesh_out);
+
+  BKE_subdiv_free(subdiv);
+
+  params.set_output("Geometry", std::move(geometry_set));
+}
+}  // namespace blender::nodes
+
+void register_node_type_geo_subdivision_surface_simple()
+{
+  static bNodeType ntype;
+
+  geo_node_type_base(&ntype,
+                     GEO_NODE_SUBDIVISION_SURFACE_SIMPLE,
+                     "Simple Subdivision Surface",
+                     NODE_CLASS_GEOMETRY,
+                     0);
+  node_type_socket_templates(
+      &ntype, geo_node_subdivision_surface_simple_in, geo_node_subdivision_surface_simple_out);
+  ntype.geometry_node_execute = blender::nodes::geo_node_subdivision_surface_simple_exec;
+  nodeRegisterType(&ntype);
+}