message: gltfpack: Improve statistics output for instancing
  We now separately print mesh stats followed by draw stats, that include
  the draw count, instance count and cumulative triangle count.
diff: @@ -73,23 +73,29 @@ static void finalizeBufferViews(std::string& json, std::vector<BufferView>& view
  static void printMeshStats(const std::vector<Mesh>& meshes, const char* name)
  {
  - size_t triangles = 0;
  - size_t vertices = 0;
  - size_t instanced = 0;
  + size_t mesh_triangles = 0;
  + size_t mesh_vertices = 0;
  + size_t total_triangles = 0;
  + size_t total_instances = 0;
  + size_t total_draws = 0;
  for (size_t i = 0; i < meshes.size(); ++i)
  {
  const Mesh& mesh = meshes[i];
  - triangles += mesh.indices.size() / 3;
  - vertices += mesh.streams.empty() ? 0 : mesh.streams[0].data.size();
  + mesh_triangles += mesh.indices.size() / 3;
  + mesh_vertices += mesh.streams.empty() ? 0 : mesh.streams[0].data.size();
  size_t instances = std::max(size_t(1), mesh.nodes.size() + mesh.instances.size());
  - instanced += mesh.indices.size() / 3 * instances;
  + total_triangles += mesh.indices.size() / 3 * instances;
  + total_instances += instances;
  + total_draws += std::max(size_t(1), mesh.nodes.size());
  }
  - printf("%s: %d triangles (%lld instanced), %d vertices\n", name, int(triangles), (long long)instanced, int(vertices));
  + printf("%s: %d meshes (%d triangles, %d vertices); %d draw calls (%d instances, %lld triangles)\n", name,
  + int(meshes.size()), int(mesh_triangles), int(mesh_vertices),
  + int(total_draws), int(total_instances), (long long)total_triangles);
  }
  static void printSceneStats(const std::vector<BufferView>& views, const std::vector<Mesh>& meshes, size_t node_offset, size_t mesh_offset, size_t material_offset, size_t json_size, size_t bin_size)
  