From fc767502dc7dce4ff92d239abbcc49a68fe45e02 Mon Sep 17 00:00:00 2001
From: Brecht Van Lommel <brecht@blender.org>
Date: Wed, 7 Oct 2020 16:39:51 +0200
Subject: Python API: add volume.grids.save(filepath) to save grids and
 metadata to disk

Particularly useful now that we can dynamically generate volume using
modifiers. Not exposed in the user interface currently, but it can be used
by add-ons that need to export an entire scene including volumes.
---
 source/blender/blenkernel/BKE_volume.h      |  7 ++++++
 source/blender/blenkernel/intern/volume.cc  | 37 ++++++++++++++++++++++++++++-
 source/blender/makesrna/intern/rna_volume.c |  8 +++++++
 3 files changed, 51 insertions(+), 1 deletion(-)

(limited to 'source/blender')

diff --git a/source/blender/blenkernel/BKE_volume.h b/source/blender/blenkernel/BKE_volume.h
index 738042cc3c0..e199a113410 100644
--- a/source/blender/blenkernel/BKE_volume.h
+++ b/source/blender/blenkernel/BKE_volume.h
@@ -30,6 +30,7 @@ struct BoundBox;
 struct Depsgraph;
 struct Main;
 struct Object;
+struct ReportList;
 struct Scene;
 struct Volume;
 struct VolumeGridVector;
@@ -143,6 +144,12 @@ struct VolumeGrid *BKE_volume_grid_add(struct Volume *volume,
                                        VolumeGridType type);
 void BKE_volume_grid_remove(struct Volume *volume, struct VolumeGrid *grid);
 
+/* File Save */
+bool BKE_volume_save(struct Volume *volume,
+                     struct Main *bmain,
+                     struct ReportList *reports,
+                     const char *filename);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/blenkernel/intern/volume.cc b/source/blender/blenkernel/intern/volume.cc
index 7e895e0ba7a..87c45753393 100644
--- a/source/blender/blenkernel/intern/volume.cc
+++ b/source/blender/blenkernel/intern/volume.cc
@@ -44,6 +44,7 @@
 #include "BKE_modifier.h"
 #include "BKE_object.h"
 #include "BKE_packedFile.h"
+#include "BKE_report.h"
 #include "BKE_scene.h"
 #include "BKE_volume.h"
 
@@ -401,7 +402,7 @@ struct VolumeGrid {
  * the actual grids are always saved in a VDB file. */
 
 struct VolumeGridVector : public std::list<VolumeGrid> {
-  VolumeGridVector()
+  VolumeGridVector() : metadata(new openvdb::MetaMap())
   {
     filepath[0] = '\0';
   }
@@ -803,6 +804,40 @@ void BKE_volume_unload(Volume *volume)
 #endif
 }
 
+/* File Save */
+
+bool BKE_volume_save(Volume *volume, Main *bmain, ReportList *reports, const char *filepath)
+{
+#ifdef WITH_OPENVDB
+  if (!BKE_volume_load(volume, bmain)) {
+    BKE_reportf(reports, RPT_ERROR, "Could not load volume for writing");
+    return false;
+  }
+
+  VolumeGridVector &grids = *volume->runtime.grids;
+  openvdb::GridCPtrVec vdb_grids;
+
+  for (VolumeGrid &grid : grids) {
+    vdb_grids.push_back(BKE_volume_grid_openvdb_for_read(volume, &grid));
+  }
+
+  try {
+    openvdb::io::File file(filepath);
+    file.write(vdb_grids, *grids.metadata);
+    file.close();
+  }
+  catch (const openvdb::IoError &e) {
+    BKE_reportf(reports, RPT_ERROR, "Could not write volume: %s", e.what());
+    return false;
+  }
+
+  return true;
+#else
+  UNUSED_VARS(volume, bmain, reports, filepath);
+  return false;
+#endif
+}
+
 BoundBox *BKE_volume_boundbox_get(Object *ob)
 {
   BLI_assert(ob->type == OB_VOLUME);
diff --git a/source/blender/makesrna/intern/rna_volume.c b/source/blender/makesrna/intern/rna_volume.c
index 8a5e25c52fb..7f3941e29b8 100644
--- a/source/blender/makesrna/intern/rna_volume.c
+++ b/source/blender/makesrna/intern/rna_volume.c
@@ -343,6 +343,14 @@ static void rna_def_volume_grids(BlenderRNA *brna, PropertyRNA *cprop)
 
   func = RNA_def_function(srna, "unload", "BKE_volume_unload");
   RNA_def_function_ui_description(func, "Unload all grid and voxel data from memory");
+
+  func = RNA_def_function(srna, "save", "BKE_volume_save");
+  RNA_def_function_ui_description(func, "Save grids and metadata to file");
+  RNA_def_function_flag(func, FUNC_USE_MAIN | FUNC_USE_REPORTS);
+  parm = RNA_def_string_file_path(func, "filepath", NULL, 0, "", "File path to save to");
+  RNA_def_parameter_flags(parm, 0, PARM_REQUIRED);
+  parm = RNA_def_boolean(func, "success", 0, "", "True if grid list was successfully loaded");
+  RNA_def_function_return(func, parm);
 }
 
 static void rna_def_volume_display(BlenderRNA *brna)
-- 
cgit v1.2.3