Cleanup: move Alembic, AVI, Collada, and USD to `source/blender/io`

This moves the `alembic`, `avi`, `collada`, and `usd` modules into a common
`io` directory.

This also cleans up some `#include "../../{somedir}/{somefile}.h"` by
adding `../../io/{somedir}` to `CMakeLists.txt` and then just using
`#include "{somefile}.h"`.

No functional changes.

1 files changed, 81 insertions, 0 deletions

diff --git a/source/blender/io/usd/intern/usd_writer_metaball.cc b/source/blender/io/usd/intern/usd_writer_metaball.cc
new file mode 100644
index 00000000000..25b216d20f3
--- /dev/null
+++ b/source/blender/io/usd/intern/usd_writer_metaball.cc
@@ -0,0 +1,81 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+#include "usd_writer_metaball.h"
+#include "usd_hierarchy_iterator.h"
+
+#include <pxr/usd/usdGeom/mesh.h>
+#include <pxr/usd/usdShade/material.h>
+#include <pxr/usd/usdShade/materialBindingAPI.h>
+
+extern "C" {
+#include "BLI_assert.h"
+
+#include "BKE_displist.h"
+#include "BKE_lib_id.h"
+#include "BKE_mball.h"
+#include "BKE_mesh.h"
+#include "BKE_object.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_meta_types.h"
+}
+
+namespace USD {
+
+USDMetaballWriter::USDMetaballWriter(const USDExporterContext &ctx) : USDGenericMeshWriter(ctx)
+{
+}
+
+bool USDMetaballWriter::is_supported(const HierarchyContext *context) const
+{
+  Scene *scene = DEG_get_input_scene(usd_export_context_.depsgraph);
+  return is_basis_ball(scene, context->object) && USDGenericMeshWriter::is_supported(context);
+}
+
+bool USDMetaballWriter::check_is_animated(const HierarchyContext & /*context*/) const
+{
+  /* We assume that metaballs are always animated, as the current object may
+   * not be animated but another ball in the same group may be. */
+  return true;
+}
+
+Mesh *USDMetaballWriter::get_export_mesh(Object *object_eval, bool &r_needsfree)
+{
+  Mesh *mesh_eval = BKE_object_get_evaluated_mesh(object_eval);
+  if (mesh_eval != nullptr) {
+    /* Mesh_eval only exists when generative modifiers are in use. */
+    r_needsfree = false;
+    return mesh_eval;
+  }
+  r_needsfree = true;
+  return BKE_mesh_new_from_object(usd_export_context_.depsgraph, object_eval, false);
+}
+
+void USDMetaballWriter::free_export_mesh(Mesh *mesh)
+{
+  BKE_id_free(nullptr, mesh);
+}
+
+bool USDMetaballWriter::is_basis_ball(Scene *scene, Object *ob) const
+{
+  Object *basis_ob = BKE_mball_basis_find(scene, ob);
+  return ob == basis_ob;
+}
+
+}  // namespace USD