Geometry Nodes: Curve Length Node

This commit adds a node that outputs the total length of all
evalauted curve splines in a geometry set as a float value.

Differential Revision: https://developer.blender.org/D11459

7 files changed, 64 insertions, 0 deletions

diff --git a/release/scripts/startup/nodeitems_builtins.py b/release/scripts/startup/nodeitems_builtins.py
index d4c21bf5a23..5e245d81de4 100644
--- a/release/scripts/startup/nodeitems_builtins.py
+++ b/release/scripts/startup/nodeitems_builtins.py
@@ -504,6 +504,7 @@ geometry_node_categories = [
         NodeItem("GeometryNodeCurveToMesh"),
         NodeItem("GeometryNodeCurveResample"),
         NodeItem("GeometryNodeMeshToCurve"),
+        NodeItem("GeometryNodeCurveLength"),
     ]),
     GeometryNodeCategory("GEO_GEOMETRY", "Geometry", items=[
         NodeItem("GeometryNodeBoundBox"),
diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index 00111910d66..380e75f0924 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -1431,6 +1431,7 @@ int ntreeTexExecTree(struct bNodeTree *ntree,
 #define GEO_NODE_MATERIAL_REPLACE 1051
 #define GEO_NODE_MESH_TO_CURVE 1052
 #define GEO_NODE_DELETE_GEOMETRY 1053
+#define GEO_NODE_CURVE_LENGTH 1054
 
 /** \} */
 
diff --git a/source/blender/blenkernel/intern/node.cc b/source/blender/blenkernel/intern/node.cc
index 0923917aa55..2a509fd7df4 100644
--- a/source/blender/blenkernel/intern/node.cc
+++ b/source/blender/blenkernel/intern/node.cc
@@ -5050,6 +5050,7 @@ static void registerGeometryNodes()
   register_node_type_geo_boolean();
   register_node_type_geo_bounding_box();
   register_node_type_geo_collection_info();
+  register_node_type_geo_curve_length();
   register_node_type_geo_curve_to_mesh();
   register_node_type_geo_curve_resample();
   register_node_type_geo_delete_geometry();
diff --git a/source/blender/nodes/CMakeLists.txt b/source/blender/nodes/CMakeLists.txt
index 6ecf46647a0..8baa891df5c 100644
--- a/source/blender/nodes/CMakeLists.txt
+++ b/source/blender/nodes/CMakeLists.txt
@@ -162,6 +162,7 @@ set(SRC
   geometry/nodes/node_geo_bounding_box.cc
   geometry/nodes/node_geo_collection_info.cc
   geometry/nodes/node_geo_common.cc
+  geometry/nodes/node_geo_curve_length.cc  
   geometry/nodes/node_geo_curve_to_mesh.cc
   geometry/nodes/node_geo_curve_resample.cc
   geometry/nodes/node_geo_delete_geometry.cc
diff --git a/source/blender/nodes/NOD_geometry.h b/source/blender/nodes/NOD_geometry.h
index 30b039bca40..3c43b53da5a 100644
--- a/source/blender/nodes/NOD_geometry.h
+++ b/source/blender/nodes/NOD_geometry.h
@@ -50,6 +50,7 @@ void register_node_type_geo_attribute_remove(void);
 void register_node_type_geo_boolean(void);
 void register_node_type_geo_bounding_box(void);
 void register_node_type_geo_collection_info(void);
+void register_node_type_geo_curve_length(void);
 void register_node_type_geo_curve_to_mesh(void);
 void register_node_type_geo_curve_resample(void);
 void register_node_type_geo_delete_geometry(void);
diff --git a/source/blender/nodes/NOD_static_types.h b/source/blender/nodes/NOD_static_types.h
index 081525ffb5b..19b671de49d 100644
--- a/source/blender/nodes/NOD_static_types.h
+++ b/source/blender/nodes/NOD_static_types.h
@@ -289,6 +289,7 @@ DefNode(GeometryNode, GEO_NODE_ATTRIBUTE_VECTOR_ROTATE, def_geo_attribute_vector
 DefNode(GeometryNode, GEO_NODE_BOOLEAN, def_geo_boolean, "BOOLEAN", Boolean, "Boolean", "")
 DefNode(GeometryNode, GEO_NODE_BOUNDING_BOX, 0, "BOUNDING_BOX", BoundBox, "Bounding Box", "")
 DefNode(GeometryNode, GEO_NODE_COLLECTION_INFO, def_geo_collection_info, "COLLECTION_INFO", CollectionInfo, "Collection Info", "")
+DefNode(GeometryNode, GEO_NODE_CURVE_LENGTH, 0, "CURVE_LENGTH", CurveLength, "Curve Length", "")
 DefNode(GeometryNode, GEO_NODE_CURVE_RESAMPLE, def_geo_curve_resample, "CURVE_RESAMPLE", CurveResample, "Resample Curve", "")
 DefNode(GeometryNode, GEO_NODE_CURVE_TO_MESH, 0, "CURVE_TO_MESH", CurveToMesh, "Curve to Mesh", "")
 DefNode(GeometryNode, GEO_NODE_DELETE_GEOMETRY, 0, "DELETE_GEOMETRY", DeleteGeometry, "Delete Geometry", "")
diff --git a/source/blender/nodes/geometry/nodes/node_geo_curve_length.cc b/source/blender/nodes/geometry/nodes/node_geo_curve_length.cc
new file mode 100644
index 00000000000..306085e3b75
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_curve_length.cc
@@ -0,0 +1,58 @@
+/*
+ * 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_spline.hh"
+#include "node_geometry_util.hh"
+
+static bNodeSocketTemplate geo_node_curve_length_in[] = {
+    {SOCK_GEOMETRY, N_("Curve")},
+    {-1, ""},
+};
+
+static bNodeSocketTemplate geo_node_curve_length_out[] = {
+    {SOCK_FLOAT, N_("Length")},
+    {-1, ""},
+};
+
+namespace blender::nodes {
+
+static void geo_node_curve_length_exec(GeoNodeExecParams params)
+{
+  GeometrySet curve_set = params.extract_input<GeometrySet>("Curve");
+  curve_set = bke::geometry_set_realize_instances(curve_set);
+  if (!curve_set.has_curve()) {
+    params.set_output("Length", 0.0f);
+    return;
+  }
+  const CurveEval &curve = *curve_set.get_curve_for_read();
+  float length = 0.0f;
+  for (const SplinePtr &spline : curve.splines()) {
+    length += spline->length();
+  }
+  params.set_output("Length", length);
+}
+
+}  // namespace blender::nodes
+
+void register_node_type_geo_curve_length()
+{
+  static bNodeType ntype;
+
+  geo_node_type_base(&ntype, GEO_NODE_CURVE_LENGTH, "Curve Length", NODE_CLASS_GEOMETRY, 0);
+  node_type_socket_templates(&ntype, geo_node_curve_length_in, geo_node_curve_length_out);
+  ntype.geometry_node_execute = blender::nodes::geo_node_curve_length_exec;
+  nodeRegisterType(&ntype);
+}