Geometry Nodes: Use common utility for copying attribute data

Attribute copying often uses identical logic for copying selected
elements or copying with an index map. Instead of reimplementing
this in each file, use the common implementation in the array_utils
namespace. This makes the commonality more obvious, gives improved
performance (this implementation is multithreaded), reduces binary
size (I observed a 173KB reduction), and probably reduces compile time.

2 files changed, 9 insertions, 29 deletions

diff --git a/source/blender/blenkernel/intern/curves_geometry.cc b/source/blender/blenkernel/intern/curves_geometry.cc
index 29f8d62545f..d65c31139fc 100644
--- a/source/blender/blenkernel/intern/curves_geometry.cc
+++ b/source/blender/blenkernel/intern/curves_geometry.cc
@@ -9,6 +9,7 @@
 
 #include "MEM_guardedalloc.h"
 
+#include "BLI_array_utils.hh"
 #include "BLI_bounds.hh"
 #include "BLI_index_mask_ops.hh"
 #include "BLI_length_parameterize.hh"
@@ -1111,21 +1112,11 @@ static void copy_between_buffers(const CPPType &type,
                         src_range.size());
 }
 
-template<typename T>
-static void copy_with_map(const Span<T> src, const Span<int> map, MutableSpan<T> dst)
-{
-  threading::parallel_for(map.index_range(), 1024, [&](const IndexRange range) {
-    for (const int i : range) {
-      dst[i] = src[map[i]];
-    }
-  });
-}
-
 static void copy_with_map(const GSpan src, const Span<int> map, GMutableSpan dst)
 {
   attribute_math::convert_to_static_type(src.type(), [&](auto dummy) {
     using T = decltype(dummy);
-    copy_with_map(src.typed<T>(), map, dst.typed<T>());
+    array_utils::gather(src.typed<T>(), map, dst.typed<T>());
   });
 }
 
diff --git a/source/blender/blenkernel/intern/instances.cc b/source/blender/blenkernel/intern/instances.cc
index 2f8acf477e2..4675562e927 100644
--- a/source/blender/blenkernel/intern/instances.cc
+++ b/source/blender/blenkernel/intern/instances.cc
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */
 
+#include "BLI_array_utils.hh"
 #include "BLI_cpp_type_make.hh"
 #include "BLI_rand.hh"
 #include "BLI_task.hh"
@@ -107,18 +108,6 @@ blender::Span<InstanceReference> Instances::references() const
   return references_;
 }
 
-template<typename T>
-static void copy_data_based_on_mask(Span<T> src, MutableSpan<T> dst, IndexMask mask)
-{
-  BLI_assert(src.data() != dst.data());
-  using namespace blender;
-  threading::parallel_for(mask.index_range(), 1024, [&](IndexRange range) {
-    for (const int i : range) {
-      dst[i] = src[mask[i]];
-    }
-  });
-}
-
 void Instances::remove(const IndexMask mask)
 {
   using namespace blender;
@@ -129,11 +118,14 @@ void Instances::remove(const IndexMask mask)
     return;
   }
 
+  const Span<int> old_handles = this->reference_handles();
   Vector<int> new_handles(mask.size());
-  copy_data_based_on_mask<int>(this->reference_handles(), new_handles, mask);
+  array_utils::gather(old_handles, mask.indices(), new_handles.as_mutable_span());
   reference_handles_ = std::move(new_handles);
+
+  const Span<float4x4> old_tansforms = this->transforms();
   Vector<float4x4> new_transforms(mask.size());
-  copy_data_based_on_mask<float4x4>(this->transforms(), new_transforms, mask);
+  array_utils::gather(old_tansforms, mask.indices(), new_transforms.as_mutable_span());
   transforms_ = std::move(new_transforms);
 
   const bke::CustomDataAttributes &src_attributes = attributes_;
@@ -150,11 +142,8 @@ void Instances::remove(const IndexMask mask)
         GSpan src = *src_attributes.get_for_read(id);
         dst_attributes.create(id, meta_data.data_type);
         GMutableSpan dst = *dst_attributes.get_for_write(id);
+        array_utils::gather(src, mask.indices(), dst);
 
-        attribute_math::convert_to_static_type(src.type(), [&](auto dummy) {
-          using T = decltype(dummy);
-          copy_data_based_on_mask<T>(src.typed<T>(), dst.typed<T>(), mask);
-        });
         return true;
       },
       ATTR_DOMAIN_INSTANCE);