From dc248316938e3667ebf7f218da86da6bd89f6071 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Wed, 18 Dec 2019 20:53:28 +0100
Subject: [PATCH] MeshTools: we know the final size beforehand.

---
 src/Magnum/MeshTools/Subdivide.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/Magnum/MeshTools/Subdivide.h b/src/Magnum/MeshTools/Subdivide.h
index 5cfc614f4..ce09d1b98 100644
--- a/src/Magnum/MeshTools/Subdivide.h
+++ b/src/Magnum/MeshTools/Subdivide.h
@@ -49,10 +49,13 @@ duplicate vertices in the mesh is up to user.
 template<class Vertex, class Interpolator> void subdivide(std::vector<UnsignedInt>& indices, std::vector<Vertex>& vertices, Interpolator interpolator) {
     CORRADE_ASSERT(!(indices.size()%3), "MeshTools::subdivide(): index count is not divisible by 3!", );
 
-    std::size_t indexCount = indices.size();
+    /* For each triangle it'll generate three new vertices and three more
+       triangles */
     indices.reserve(indices.size()*4);
+    vertices.reserve(vertices.size() + indices.size());
 
     /* Subdivide each face to four new */
+    std::size_t indexCount = indices.size();
     for(std::size_t i = 0; i != indexCount; i += 3) {
         /* Interpolate each side */
         UnsignedInt newVertices[3];