Geometry: Avoid unnecessary initialization when resizing data arrays

When resizing mesh and curves attribute storage, avoid initializing the
new memory for basic types. Also, avoid skipping "no free" layers; all
layers should be reallocated to the new size since they may be accessed.

The semantics introduced in 25237d2625078c6d1 are essential for this
change, because otherwise we don't have a way to construct non-trivial
types in the new memory.

In a basic test of the extrude node, I observed a performance
improvement of about 30%, from 55ms to 42ms.

Differential Revision: https://developer.blender.org/D15818

1 files changed, 2 insertions, 2 deletions

diff --git a/source/blender/blenkernel/intern/curves_geometry.cc b/source/blender/blenkernel/intern/curves_geometry.cc
index 35b209179d3..d192c10912f 100644
--- a/source/blender/blenkernel/intern/curves_geometry.cc
+++ b/source/blender/blenkernel/intern/curves_geometry.cc
@@ -963,11 +963,11 @@ void CurvesGeometry::ensure_can_interpolate_to_evaluated() const
 void CurvesGeometry::resize(const int points_num, const int curves_num)
 {
   if (points_num != this->point_num) {
-    CustomData_realloc(&this->point_data, points_num);
+    CustomData_realloc(&this->point_data, this->points_num(), points_num);
     this->point_num = points_num;
   }
   if (curves_num != this->curve_num) {
-    CustomData_realloc(&this->curve_data, curves_num);
+    CustomData_realloc(&this->curve_data, this->curves_num(), curves_num);
     this->curve_num = curves_num;
     this->curve_offsets = (int *)MEM_reallocN(this->curve_offsets, sizeof(int) * (curves_num + 1));
   }