Geometry Nodes: Curve Primitive Bezier Segment

Creates a Curve with 1 Bezier Spline from four positions (start,
start handle, end handle, end) and a resolution. The handles are
aligned and mirrored automatically. An "Offset" mode is also included
to allow specifying the handles relative to the control points.

The default settings recreate the existing default Bezier Curve in the
3D viewport add menu.

Differential Revision: https://developer.blender.org/D11648

1 files changed, 149 insertions, 0 deletions

diff --git a/source/blender/nodes/geometry/nodes/node_geo_curve_primitive_bezier_segment.cc b/source/blender/nodes/geometry/nodes/node_geo_curve_primitive_bezier_segment.cc
new file mode 100644
index 00000000000..e167219ea6b
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_curve_primitive_bezier_segment.cc
@@ -0,0 +1,149 @@
+/*
+ * 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 "UI_interface.h"
+#include "UI_resources.h"
+
+#include "node_geometry_util.hh"
+
+static bNodeSocketTemplate geo_node_curve_primitive_bezier_segment_in[] = {
+    {SOCK_INT, N_("Resolution"), 16.0f, 0.0f, 0.0f, 0.0f, 1, 256, PROP_UNSIGNED},
+    {SOCK_VECTOR, N_("Start"), -1.0f, 0.0f, 0.0f, 0.0f, -FLT_MAX, FLT_MAX, PROP_TRANSLATION},
+    {SOCK_VECTOR,
+     N_("Start Handle"),
+     -0.5f,
+     0.5f,
+     0.0f,
+     0.0f,
+     -FLT_MAX,
+     FLT_MAX,
+     PROP_TRANSLATION},
+    {SOCK_VECTOR, N_("End Handle"), 0.0f, 0.0f, 0.0f, 0.0f, -FLT_MAX, FLT_MAX, PROP_TRANSLATION},
+    {SOCK_VECTOR, N_("End"), 1.0f, 0.0f, 0.0f, 0.0f, -FLT_MAX, FLT_MAX, PROP_TRANSLATION},
+    {-1, ""},
+};
+
+static bNodeSocketTemplate geo_node_curve_primitive_bezier_segment_out[] = {
+    {SOCK_GEOMETRY, N_("Curve")},
+    {-1, ""},
+};
+static void geo_node_curve_primitive_bezier_segment_layout(uiLayout *layout,
+                                                           bContext *UNUSED(C),
+                                                           PointerRNA *ptr)
+{
+  uiItemR(layout, ptr, "mode", UI_ITEM_R_EXPAND, nullptr, ICON_NONE);
+}
+
+namespace blender::nodes {
+
+static void geo_node_curve_primitive_bezier_segment_init(bNodeTree *UNUSED(tree), bNode *node)
+{
+  NodeGeometryCurvePrimitiveBezierSegment *data = (NodeGeometryCurvePrimitiveBezierSegment *)
+      MEM_callocN(sizeof(NodeGeometryCurvePrimitiveBezierSegment), __func__);
+
+  data->mode = GEO_NODE_CURVE_PRIMITIVE_BEZIER_SEGMENT_POSITION;
+  node->storage = data;
+}
+
+static std::unique_ptr<CurveEval> create_bezier_segment_curve(
+    const float3 start,
+    const float3 start_handle_right,
+    const float3 end,
+    const float3 end_handle_left,
+    const int resolution,
+    const GeometryNodeCurvePrimitiveBezierSegmentMode mode)
+{
+  std::unique_ptr<CurveEval> curve = std::make_unique<CurveEval>();
+  std::unique_ptr<BezierSpline> spline = std::make_unique<BezierSpline>();
+
+  if (mode == GEO_NODE_CURVE_PRIMITIVE_BEZIER_SEGMENT_POSITION) {
+    spline->add_point(start,
+                      BezierSpline::HandleType::Align,
+                      start - (start_handle_right - start) * -1.0f,
+                      BezierSpline::HandleType::Align,
+                      start_handle_right,
+                      1.0f,
+                      0.0f);
+    spline->add_point(end,
+                      BezierSpline::HandleType::Align,
+                      end_handle_left,
+                      BezierSpline::HandleType::Align,
+                      end - (end_handle_left - end) * -1.0f,
+                      1.0f,
+                      0.0f);
+  }
+  else {
+    spline->add_point(start,
+                      BezierSpline::HandleType::Align,
+                      start - start_handle_right,
+                      BezierSpline::HandleType::Align,
+                      start + start_handle_right,
+                      1.0f,
+                      0.0f);
+    spline->add_point(end,
+                      BezierSpline::HandleType::Align,
+                      end + end_handle_left,
+                      BezierSpline::HandleType::Align,
+                      end - end_handle_left,
+                      1.0f,
+                      0.0f);
+  }
+
+  spline->set_resolution(resolution);
+  spline->attributes.reallocate(spline->size());
+  curve->add_spline(std::move(spline));
+  curve->attributes.reallocate(curve->splines().size());
+  return curve;
+}
+
+static void geo_node_curve_primitive_bezier_segment_exec(GeoNodeExecParams params)
+{
+  const NodeGeometryCurvePrimitiveBezierSegment *node_storage =
+      (NodeGeometryCurvePrimitiveBezierSegment *)params.node().storage;
+  const GeometryNodeCurvePrimitiveBezierSegmentMode mode =
+      (const GeometryNodeCurvePrimitiveBezierSegmentMode)node_storage->mode;
+
+  std::unique_ptr<CurveEval> curve = create_bezier_segment_curve(
+      params.extract_input<float3>("Start"),
+      params.extract_input<float3>("Start Handle"),
+      params.extract_input<float3>("End"),
+      params.extract_input<float3>("End Handle"),
+      std::max(params.extract_input<int>("Resolution"), 1),
+      mode);
+  params.set_output("Curve", GeometrySet::create_with_curve(curve.release()));
+}
+
+}  // namespace blender::nodes
+
+void register_node_type_geo_curve_primitive_bezier_segment()
+{
+  static bNodeType ntype;
+  geo_node_type_base(
+      &ntype, GEO_NODE_CURVE_PRIMITIVE_BEZIER_SEGMENT, "Bezier Segment", NODE_CLASS_GEOMETRY, 0);
+  node_type_socket_templates(&ntype,
+                             geo_node_curve_primitive_bezier_segment_in,
+                             geo_node_curve_primitive_bezier_segment_out);
+  node_type_init(&ntype, blender::nodes::geo_node_curve_primitive_bezier_segment_init);
+  node_type_storage(&ntype,
+                    "NodeGeometryCurvePrimitiveBezierSegment",
+                    node_free_standard_storage,
+                    node_copy_standard_storage);
+  ntype.draw_buttons = geo_node_curve_primitive_bezier_segment_layout;
+  ntype.geometry_node_execute = blender::nodes::geo_node_curve_primitive_bezier_segment_exec;
+  nodeRegisterType(&ntype);
+}