1 files changed, 83 insertions, 1 deletions

diff --git a/source/blender/blenkernel/BKE_attribute_accessor.hh b/source/blender/blenkernel/BKE_attribute_accessor.hh
index 3cf2fd4f865..0905f81d472 100644
--- a/source/blender/blenkernel/BKE_attribute_accessor.hh
+++ b/source/blender/blenkernel/BKE_attribute_accessor.hh
@@ -39,7 +39,7 @@ class ReadAttribute {
   {
   }
 
-  virtual ~ReadAttribute() = default;
+  virtual ~ReadAttribute();
 
   AttributeDomain domain() const
   {
@@ -67,7 +67,54 @@ class ReadAttribute {
   virtual void get_internal(const int64_t index, void *r_value) const = 0;
 };
 
+class WriteAttribute {
+ protected:
+  const AttributeDomain domain_;
+  const CPPType &cpp_type_;
+  const int64_t size_;
+
+ public:
+  WriteAttribute(AttributeDomain domain, const CPPType &cpp_type, const int64_t size)
+      : domain_(domain), cpp_type_(cpp_type), size_(size)
+  {
+  }
+
+  virtual ~WriteAttribute();
+
+  AttributeDomain domain() const
+  {
+    return domain_;
+  }
+
+  const CPPType &cpp_type() const
+  {
+    return cpp_type_;
+  }
+
+  int64_t size() const
+  {
+    return size_;
+  }
+
+  void get(const int64_t index, void *r_value) const
+  {
+    BLI_assert(index < size_);
+    this->get_internal(index, r_value);
+  }
+
+  void set(const int64_t index, const void *value)
+  {
+    BLI_assert(index < size_);
+    this->set_internal(index, value);
+  }
+
+ protected:
+  virtual void get_internal(const int64_t index, void *r_value) const = 0;
+  virtual void set_internal(const int64_t index, const void *value) = 0;
+};
+
 using ReadAttributePtr = std::unique_ptr<ReadAttribute>;
+using WriteAttributePtr = std::unique_ptr<WriteAttribute>;
 
 template<typename T> class TypedReadAttribute {
  private:
@@ -95,11 +142,46 @@ template<typename T> class TypedReadAttribute {
   }
 };
 
+template<typename T> class TypedWriteAttribute {
+ private:
+  WriteAttributePtr attribute_;
+
+ public:
+  TypedWriteAttribute(WriteAttributePtr attribute) : attribute_(std::move(attribute))
+  {
+    BLI_assert(attribute_);
+    BLI_assert(attribute_->cpp_type().is<T>());
+  }
+
+  int64_t size() const
+  {
+    return attribute_->size();
+  }
+
+  T operator[](const int64_t index) const
+  {
+    BLI_assert(index < attribute_->size());
+    T value;
+    value.~T();
+    attribute_->get(index, &value);
+    return value;
+  }
+
+  void set(const int64_t index, const T &value)
+  {
+    attribute_->set(index, &value);
+  }
+};
+
 using FloatReadAttribute = TypedReadAttribute<float>;
 using Float3ReadAttribute = TypedReadAttribute<float3>;
+using FloatWriteAttribute = TypedWriteAttribute<float>;
+using Float3WriteAttribute = TypedWriteAttribute<float3>;
 
 ReadAttributePtr mesh_attribute_get_for_read(const MeshComponent &mesh_component,
                                              const StringRef attribute_name);
+std::optional<WriteAttributePtr> mesh_attribute_get_for_write(MeshComponent &mesh_component,
+                                                              const StringRef attribute_name);
 
 ReadAttributePtr mesh_attribute_adapt_domain(const MeshComponent &mesh_component,
                                              ReadAttributePtr attribute,