Cleanup: Move attribute code to attribute header

This code in the geometry set header was not directly related to
geometry sets, it makes more sense in the attribute access header.
This makes it clearer that code for geometry components uses attribute
code, rather than the other way around. It also allows adding more
functionality to `BKE_attribute_access.hh` that depends on these things
without including `BKE_geometry_set.hh` there.

source/blender/blenkernel/BKE_attribute_access.hh

@@ -27,6 +27,80 @@
 #include "BLI_color.hh"
 #include "BLI_float2.hh"
 #include "BLI_float3.hh"
+#include "BLI_function_ref.hh"
+
+/**
+ * Contains information about an attribute in a geometry component.
+ * More information can be added in the future. E.g. whether the attribute is builtin and how it is
+ * stored (uv map, vertex group, ...).
+ */
+struct AttributeMetaData {
+  AttributeDomain domain;
+  CustomDataType data_type;
+};
+
+/**
+ * Base class for the attribute intializer types described below.
+ */
+struct AttributeInit {
+  enum class Type {
+    Default,
+    VArray,
+    MoveArray,
+  };
+  Type type;
+  AttributeInit(const Type type) : type(type)
+  {
+  }
+};
+
+/**
+ * Create an attribute using the default value for the data type.
+ * The default values may depend on the attribute provider implementation.
+ */
+struct AttributeInitDefault : public AttributeInit {
+  AttributeInitDefault() : AttributeInit(Type::Default)
+  {
+  }
+};
+
+/**
+ * Create an attribute by copying data from an existing virtual array. The virtual array
+ * must have the same type as the newly created attribute.
+ *
+ * Note that this can be used to fill the new attribute with the default
+ */
+struct AttributeInitVArray : public AttributeInit {
+  const blender::fn::GVArray *varray;
+
+  AttributeInitVArray(const blender::fn::GVArray *varray)
+      : AttributeInit(Type::VArray), varray(varray)
+  {
+  }
+};
+
+/**
+ * Create an attribute with a by passing ownership of a pre-allocated contiguous array of data.
+ * Sometimes data is created before a geometry component is available. In that case, it's
+ * preferable to move data directly to the created attribute to avoid a new allocation and a copy.
+ *
+ * Note that this will only have a benefit for attributes that are stored directly as contiguous
+ * arrays, so not for some built-in attributes.
+ *
+ * The array must be allocated with MEM_*, since `attribute_try_create` will free the array if it
+ * can't be used directly, and that is generally how Blender expects custom data to be allocated.
+ */
+struct AttributeInitMove : public AttributeInit {
+  void *data = nullptr;
+
+  AttributeInitMove(void *data) : AttributeInit(Type::MoveArray), data(data)
+  {
+  }
+};
+
+/* Returns false when the iteration should be stopped. */
+using AttributeForeachCallback = blender::FunctionRef<bool(blender::StringRefNull attribute_name,
+                                                           const AttributeMetaData &meta_data)>;
 
 namespace blender::bke {
 

source/blender/blenkernel/BKE_geometry_set.hh

@@ -25,7 +25,6 @@
 
 #include "BLI_float3.hh"
 #include "BLI_float4x4.hh"
-#include "BLI_function_ref.hh"
 #include "BLI_hash.hh"
 #include "BLI_map.hh"
 #include "BLI_set.hh"
@@ -57,79 +56,6 @@ class ComponentAttributeProviders;
 
 class GeometryComponent;
 
-/**
- * Contains information about an attribute in a geometry component.
- * More information can be added in the future. E.g. whether the attribute is builtin and how it is
- * stored (uv map, vertex group, ...).
- */
-struct AttributeMetaData {
-  AttributeDomain domain;
-  CustomDataType data_type;
-};
-
-/* Returns false when the iteration should be stopped. */
-using AttributeForeachCallback = blender::FunctionRef<bool(blender::StringRefNull attribute_name,
-                                                           const AttributeMetaData &meta_data)>;
-
-/**
- * Base class for the attribute intializer types described below.
- */
-struct AttributeInit {
-  enum class Type {
-    Default,
-    VArray,
-    MoveArray,
-  };
-  Type type;
-  AttributeInit(const Type type) : type(type)
-  {
-  }
-};
-
-/**
- * Create an attribute using the default value for the data type.
- * The default values may depend on the attribute provider implementation.
- */
-struct AttributeInitDefault : public AttributeInit {
-  AttributeInitDefault() : AttributeInit(Type::Default)
-  {
-  }
-};
-
-/**
- * Create an attribute by copying data from an existing virtual array. The virtual array
- * must have the same type as the newly created attribute.
- *
- * Note that this can be used to fill the new attribute with the default
- */
-struct AttributeInitVArray : public AttributeInit {
-  const blender::fn::GVArray *varray;
-
-  AttributeInitVArray(const blender::fn::GVArray *varray)
-      : AttributeInit(Type::VArray), varray(varray)
-  {
-  }
-};
-
-/**
- * Create an attribute with a by passing ownership of a pre-allocated contiguous array of data.
- * Sometimes data is created before a geometry component is available. In that case, it's
- * preferable to move data directly to the created attribute to avoid a new allocation and a copy.
- *
- * Note that this will only have a benefit for attributes that are stored directly as contiguous
- * arrays, so not for some built-in attributes.
- *
- * The array must be allocated with MEM_*, since `attribute_try_create` will free the array if it
- * can't be used directly, and that is generally how Blender expects custom data to be allocated.
- */
-struct AttributeInitMove : public AttributeInit {
-  void *data = nullptr;
-
-  AttributeInitMove(void *data) : AttributeInit(Type::MoveArray), data(data)
-  {
-  }
-};
-
 /**
  * This is the base class for specialized geometry component types.
  */