Geometry Nodes: transfer corner and point attributes in Point Distribute node

If the mesh has any corner or point attributes (e.g. vertex weights or
uv maps), those attributes will now be available on the generated points
as well.

Other domains can be supported as well. I just did not implement those yet,
because we don't have a use case for them.

Differential Revision: https://developer.blender.org/D10114

1 files changed, 94 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_attribute_math.hh b/source/blender/blenkernel/BKE_attribute_math.hh
new file mode 100644
index 00000000000..b8bb2048d9d
--- /dev/null
+++ b/source/blender/blenkernel/BKE_attribute_math.hh
@@ -0,0 +1,94 @@
+/*
+ * 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 "BLI_color.hh"
+#include "BLI_float2.hh"
+#include "BLI_float3.hh"
+#include "DNA_customdata_types.h"
+
+namespace blender::attribute_math {
+
+/**
+ * Utility function that simplifies calling a templated function based on a custom data type.
+ */
+template<typename Func>
+void convert_to_static_type(const CustomDataType data_type, const Func &func)
+{
+  switch (data_type) {
+    case CD_PROP_FLOAT:
+      func(float());
+      break;
+    case CD_PROP_FLOAT2:
+      func(float2());
+      break;
+    case CD_PROP_FLOAT3:
+      func(float3());
+      break;
+    case CD_PROP_INT32:
+      func(int());
+      break;
+    case CD_PROP_BOOL:
+      func(bool());
+      break;
+    case CD_PROP_COLOR:
+      func(Color4f());
+      break;
+    default:
+      BLI_assert(false);
+      break;
+  }
+}
+
+/* Interpolate between three values. */
+template<typename T> T mix3(const float3 &weights, const T &v0, const T &v1, const T &v2);
+
+template<> inline bool mix3(const float3 &weights, const bool &v0, const bool &v1, const bool &v2)
+{
+  return (weights.x * v0 + weights.y * v1 + weights.z * v2) >= 0.5f;
+}
+
+template<> inline int mix3(const float3 &weights, const int &v0, const int &v1, const int &v2)
+{
+  return static_cast<int>(weights.x * v0 + weights.y * v1 + weights.z * v2);
+}
+
+template<>
+inline float mix3(const float3 &weights, const float &v0, const float &v1, const float &v2)
+{
+  return weights.x * v0 + weights.y * v1 + weights.z * v2;
+}
+
+template<>
+inline float2 mix3(const float3 &weights, const float2 &v0, const float2 &v1, const float2 &v2)
+{
+  return weights.x * v0 + weights.y * v1 + weights.z * v2;
+}
+
+template<>
+inline float3 mix3(const float3 &weights, const float3 &v0, const float3 &v1, const float3 &v2)
+{
+  return weights.x * v0 + weights.y * v1 + weights.z * v2;
+}
+
+template<>
+inline Color4f mix3(const float3 &weights, const Color4f &v0, const Color4f &v1, const Color4f &v2)
+{
+  Color4f result;
+  interp_v4_v4v4v4(result, v0, v1, v2, weights);
+  return result;
+}
+
+}  // namespace blender::attribute_math