[Bf-blender-cvs] [21d4c9e] temp-cycles-microdisplacement: Fix performance regression during mesh sync

[Mai Lavelle]

Commit: 21d4c9e649cc7f2e721938cd0534a5a28cc9ba51
Author: Mai Lavelle
Date:   Sun Jul 10 19:04:36 2016 -0400
Branches: temp-cycles-microdisplacement
https://developer.blender.org/rB21d4c9e649cc7f2e721938cd0534a5a28cc9ba51

Fix performance regression during mesh sync

The switch from std::vector to ccl::array in Mesh caused quite a big slowdown
during mesh sync. Using a quick fix for now. Proper thing to do would be to
avoid most memory allocation in subd code.

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

M	intern/cycles/subd/subd_dice.cpp

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

diff --git a/intern/cycles/subd/subd_dice.cpp b/intern/cycles/subd/subd_dice.cpp
index d99050c..f2d44d7 100644
--- a/intern/cycles/subd/subd_dice.cpp
+++ b/intern/cycles/subd/subd_dice.cpp
@@ -48,6 +48,11 @@ void EdgeDice::reserve(int num_verts)
 	vert_offset = mesh->verts.size();
 	tri_offset = mesh->num_triangles();
 
+	/* todo: optimize so we can reserve in advance, this is like push_back_slow() */
+	if(vert_offset + num_verts > mesh->verts.capacity()) {
+		mesh->reserve_mesh(size_t((vert_offset + num_verts) * 1.2), mesh->num_triangles());
+	}
+
 	mesh->resize_mesh(vert_offset + num_verts, tri_offset);
 
 	Attribute *attr_vN = mesh->attributes.add(ATTR_STD_VERTEX_NORMAL);