[Bf-blender-cvs] [146f6a827ba] functions-experimental-refactor: add utility to destruct and reorder attribute arrays

[Jacques Lucke]

Commit: 146f6a827ba7dfbe21eb5722c56f7ca01a511210
Author: Jacques Lucke
Date:   Sun Nov 3 13:08:35 2019 +0100
Branches: functions-experimental-refactor
https://developer.blender.org/rB146f6a827ba7dfbe21eb5722c56f7ca01a511210

add utility to destruct and reorder attribute arrays

===================================================================

M	source/blender/functions2/FN_attributes_ref.h
M	source/blender/functions2/intern/attributes_ref.cc

===================================================================

diff --git a/source/blender/functions2/FN_attributes_ref.h b/source/blender/functions2/FN_attributes_ref.h
index 1fb6c03ffe9..9889da37f08 100644
--- a/source/blender/functions2/FN_attributes_ref.h
+++ b/source/blender/functions2/FN_attributes_ref.h
@@ -164,11 +164,11 @@ class AttributesRef {
     return *m_info;
   }
 
-  void *get(uint index) const
+  GenericMutableArrayRef get(uint index) const
   {
-    void *ptr = m_buffers[index];
-    uint size = m_info->type_of(index).size();
-    return POINTER_OFFSET(ptr, m_range.start() * size);
+    const CPPType &type = m_info->type_of(index);
+    void *ptr = POINTER_OFFSET(m_buffers[index], type.size() * m_range.start());
+    return GenericMutableArrayRef(m_info->type_of(index), ptr, m_range.size());
   }
 
   template<typename T> MutableArrayRef<T> get(uint index) const
@@ -207,6 +207,8 @@ class AttributesRef {
   {
     return this->slice(0, n);
   }
+
+  void destruct_and_reorder(ArrayRef<uint> sorted_indices_to_destruct);
 };
 
 class AttributesRefGroup {
diff --git a/source/blender/functions2/intern/attributes_ref.cc b/source/blender/functions2/intern/attributes_ref.cc
index 87182abf857..deedc7b969a 100644
--- a/source/blender/functions2/intern/attributes_ref.cc
+++ b/source/blender/functions2/intern/attributes_ref.cc
@@ -25,6 +25,36 @@ AttributesInfo::AttributesInfo(const AttributesInfoBuilder &builder)
   }
 }
 
+void AttributesRef::destruct_and_reorder(ArrayRef<uint> indices)
+{
+#ifdef DEBUG
+  BLI_assert(indices.size() <= m_range.size());
+  BLI_assert(indices.size() == 0 || indices.last() < m_range.size());
+  for (uint i = 1; i < indices.size(); i++) {
+    BLI_assert(indices[i - 1] < indices[i]);
+  }
+#endif
+
+  for (uint attribute_index : m_info->indices()) {
+    GenericMutableArrayRef array = this->get(attribute_index);
+    const CPPType &type = m_info->type_of(attribute_index);
+
+    array.destruct_indices(indices);
+
+    for (uint i = 0; i < indices.size(); i++) {
+      uint last_index = m_range.size() - 1 - i;
+      uint index_to_remove = indices[indices.size() - 1 - i];
+      if (index_to_remove == last_index) {
+        /* Do nothing. It has been destructed before. */
+      }
+      else {
+        /* Relocate last undestructed value. */
+        type.relocate_to_uninitialized(array[last_index], array[index_to_remove]);
+      }
+    }
+  }
+}
+
 AttributesRefGroup::AttributesRefGroup(const AttributesInfo &info,
                                        Vector<ArrayRef<void *>> buffers,
                                        Vector<IndexRange> ranges)