1 files changed, 122 insertions, 0 deletions
diff --git a/source/blender/nodes/geometry/nodes/node_geo_collapse.cc b/source/blender/nodes/geometry/nodes/node_geo_collapse.cc
new file mode 100644
index 00000000000..c13ab362f17
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_collapse.cc
@@ -0,0 +1,122 @@
+/*
+ * 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 "BKE_mesh.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "bmesh.h"
+#include "bmesh_tools.h"
+
+#include "node_geometry_util.hh"
+
+static bNodeSocketTemplate geo_node_collapse_in[] = {
+    {SOCK_GEOMETRY, N_("Geometry")},
+    {SOCK_FLOAT, N_("Factor"), 1.0f, 0.0f, 0.0f, 0.0f, 0, 1.0f, PROP_FACTOR},
+    {SOCK_STRING, N_("Selection")},
+    {-1, ""},
+};
+
+static bNodeSocketTemplate geo_node_collapse_out[] = {
+    {SOCK_GEOMETRY, N_("Geometry")},
+    {-1, ""},
+};
+
+static void geo_node_collapse_layout(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
+{
+  uiLayoutSetPropSep(layout, true);
+  uiLayoutSetPropDecorate(layout, false);
+  uiItemR(layout, ptr, "symmetry_axis", 0, nullptr, ICON_NONE);
+}
+
+static void geo_node_collapse_init(bNodeTree *UNUSED(tree), bNode *node)
+{
+  NodeGeometryCollapse *node_storage = (NodeGeometryCollapse *)MEM_callocN(
+      sizeof(NodeGeometryCollapse), __func__);
+
+  node->storage = node_storage;
+  node_storage->symmetry_axis = GEO_NODE_COLLAPSE_SYMMETRY_AXIS_NONE;
+}
+
+namespace blender::nodes {
+
+static Mesh *collapse_mesh(const float factor,
+                           const VArray<float> &selection,
+                           const bool triangulate,
+                           const int symmetry_axis,
+                           const Mesh *mesh)
+{
+  const BMeshCreateParams bmesh_create_params = {0};
+  const BMeshFromMeshParams bmesh_from_mesh_params = {
+      true, 0, 0, 0, {CD_MASK_ORIGINDEX, CD_MASK_ORIGINDEX, CD_MASK_ORIGINDEX}};
+  BMesh *bm = BKE_mesh_to_bmesh_ex(mesh, &bmesh_create_params, &bmesh_from_mesh_params);
+
+  const float symmetry_eps = 0.00002f;
+  Array<float> mask(selection.size());
+  selection.materialize(mask);
+
+  BM_mesh_decimate_collapse(
+      bm, factor, mask.data(), 1.0f, triangulate, symmetry_axis, symmetry_eps);
+  Mesh *result = BKE_mesh_from_bmesh_for_eval_nomain(bm, NULL, mesh);
+  BM_mesh_free(bm);
+
+  result->runtime.cd_dirty_vert |= CD_MASK_NORMAL;
+  return result;
+}
+
+static void geo_node_collapse_exec(GeoNodeExecParams params)
+{
+  GeometrySet geometry_set = params.extract_input<GeometrySet>("Geometry");
+  const float factor = params.extract_input<float>("Factor");
+
+  if (factor < 1.0f && geometry_set.has_mesh()) {
+    MeshComponent &mesh_component = geometry_set.get_component_for_write<MeshComponent>();
+
+    const float default_factor = 1.0f;
+    GVArray_Typed<float> selection_attribute = params.get_input_attribute<float>(
+        "Selection", mesh_component, ATTR_DOMAIN_POINT, default_factor);
+    // VArray<float> selection(selection_attribute.to);
+    const Mesh *input_mesh = mesh_component.get_for_read();
+
+    const bNode &node = params.node();
+    const NodeGeometryCollapse &node_storage = *(NodeGeometryCollapse *)node.storage;
+    Mesh *result = collapse_mesh(
+        factor, selection_attribute, false, node_storage.symmetry_axis, input_mesh);
+    geometry_set.replace_mesh(result);
+  }
+
+  params.set_output("Geometry", std::move(geometry_set));
+}
+}  // namespace blender::nodes
+
+void register_node_type_geo_collapse()
+{
+  static bNodeType ntype;
+
+  geo_node_type_base(&ntype, GEO_NODE_COLLAPSE, "Collapse", NODE_CLASS_GEOMETRY, 0);
+  node_type_socket_templates(&ntype, geo_node_collapse_in, geo_node_collapse_out);
+  node_type_storage(
+      &ntype, "NodeGeometryCollapse", node_free_standard_storage, node_copy_standard_storage);
+  node_type_init(&ntype, geo_node_collapse_init);
+  ntype.geometry_node_execute = blender::nodes::geo_node_collapse_exec;
+  ntype.draw_buttons = geo_node_collapse_layout;
+  ntype.width = 180;
+  nodeRegisterType(&ntype);
+}