Basic Alembic support

All in all, this patch adds an Alembic importer, an Alembic exporter,
and a new CacheFile data block which, for now, wraps around an Alembic
archive. This data block is made available through a new modifier ("Mesh
Sequence Cache") as well as a new constraint ("Transform Cache") to
somewhat properly support respectively geometric and transformation data
streaming from alembic caches.

A more in-depth documentation is to be found on the wiki, as well as a
 guide to compile alembic: https://wiki.blender.org/index.php/
User:Kevindietrich/AlembicBasicIo.

Many thanks to everyone involved in this little project, and huge shout
out to "cgstrive" for the thorough testings with Maya, 3ds Max, Houdini
and Realflow as well as @fjuhec, @jensverwiebe and @jasperge for the
custom builds and compile fixes.

Reviewers: sergey, campbellbarton, mont29

Reviewed By: sergey, campbellbarton, mont29

Differential Revision: https://developer.blender.org/D2060

3 files changed, 71 insertions, 0 deletions

diff --git a/source/blender/blenloader/CMakeLists.txt b/source/blender/blenloader/CMakeLists.txt
index 479d3a15e6c..8cb9ef837b2 100644
--- a/source/blender/blenloader/CMakeLists.txt
+++ b/source/blender/blenloader/CMakeLists.txt
@@ -77,6 +77,13 @@ if(WITH_CODEC_FFMPEG)
 	add_definitions(-DWITH_FFMPEG)
 endif()
 
+if(WITH_ALEMBIC)
+	list(APPEND INC
+		../alembic
+	)
+	add_definitions(-DWITH_ALEMBIC)
+endif()
+
 blender_add_lib(bf_blenloader "${SRC}" "${INC}" "${INC_SYS}")
 
 # needed so writefile.c can use dna_type_offsets.h
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 52ca8520b46..eb94c91389c 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -59,6 +59,7 @@
 #include "DNA_actuator_types.h"
 #include "DNA_brush_types.h"
 #include "DNA_camera_types.h"
+#include "DNA_cachefile_types.h"
 #include "DNA_cloth_types.h"
 #include "DNA_controller_types.h"
 #include "DNA_constraint_types.h"
@@ -114,6 +115,7 @@
 #include "BKE_action.h"
 #include "BKE_armature.h"
 #include "BKE_brush.h"
+#include "BKE_cachefile.h"
 #include "BKE_cloth.h"
 #include "BKE_constraint.h"
 #include "BKE_context.h"
@@ -2691,6 +2693,36 @@ static void direct_link_animdata(FileData *fd, AnimData *adt)
 	adt->actstrip = newdataadr(fd, adt->actstrip);
 }	
 
+/* ************ READ CACHEFILES *************** */
+
+static void lib_link_cachefiles(FileData *fd, Main *bmain)
+{
+	CacheFile *cache_file;
+
+	/* only link ID pointers */
+	for (cache_file = bmain->cachefiles.first; cache_file; cache_file = cache_file->id.next) {
+		if (cache_file->id.tag & LIB_TAG_NEED_LINK) {
+			cache_file->id.tag &= ~LIB_TAG_NEED_LINK;
+		}
+
+		BLI_listbase_clear(&cache_file->object_paths);
+		cache_file->handle = NULL;
+
+		if (cache_file->adt) {
+			lib_link_animdata(fd, &cache_file->id, cache_file->adt);
+		}
+	}
+}
+
+static void direct_link_cachefile(FileData *fd, CacheFile *cache_file)
+{
+	cache_file->handle = NULL;
+
+	/* relink animdata */
+	cache_file->adt = newdataadr(fd, cache_file->adt);
+	direct_link_animdata(fd, cache_file->adt);
+}
+
 /* ************ READ MOTION PATHS *************** */
 
 /* direct data for cache */
@@ -7912,6 +7944,7 @@ static const char *dataname(short id_code)
 		case ID_MC: return "Data from MC";
 		case ID_MSK: return "Data from MSK";
 		case ID_LS: return "Data from LS";
+		case ID_CF: return "Data from CF";
 	}
 	return "Data from Lib Block";
 	
@@ -8163,6 +8196,9 @@ static BHead *read_libblock(FileData *fd, Main *main, BHead *bhead, const short
 		case ID_PC:
 			direct_link_paint_curve(fd, (PaintCurve *)id);
 			break;
+		case ID_CF:
+			direct_link_cachefile(fd, (CacheFile *)id);
+			break;
 	}
 	
 	oldnewmap_free_unused(fd->datamap);
@@ -8356,6 +8392,7 @@ static void lib_link_all(FileData *fd, Main *main)
 	lib_link_mask(fd, main);
 	lib_link_linestyle(fd, main);
 	lib_link_gpencil(fd, main);
+	lib_link_cachefiles(fd, main);
 
 	lib_link_mesh(fd, main);		/* as last: tpage images with users at zero */
 	
@@ -9462,6 +9499,13 @@ static void expand_camera(FileData *fd, Main *mainvar, Camera *ca)
 		expand_animdata(fd, mainvar, ca->adt);
 }
 
+static void expand_cachefile(FileData *fd, Main *mainvar, CacheFile *cache_file)
+{
+	if (cache_file->adt) {
+		expand_animdata(fd, mainvar, cache_file->adt);
+	}
+}
+
 static void expand_speaker(FileData *fd, Main *mainvar, Speaker *spk)
 {
 	expand_doit(fd, mainvar, spk->sound);
@@ -9657,6 +9701,9 @@ void BLO_expand_main(void *fdhandle, Main *mainvar)
 					case ID_GD:
 						expand_gpencil(fd, mainvar, (bGPdata *)id);
 						break;
+					case ID_CF:
+						expand_cachefile(fd, mainvar, (CacheFile *)id);
+						break;
 					}
 					
 					do_it = true;
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index fb31cd227ba..b6a54715763 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -107,6 +107,7 @@
 #include "DNA_armature_types.h"
 #include "DNA_actuator_types.h"
 #include "DNA_brush_types.h"
+#include "DNA_cachefile_types.h"
 #include "DNA_camera_types.h"
 #include "DNA_cloth_types.h"
 #include "DNA_constraint_types.h"
@@ -3882,6 +3883,21 @@ static void write_linestyles(WriteData *wd, ListBase *idbase)
 	}
 }
 
+static void write_cachefiles(WriteData *wd, ListBase *idbase)
+{
+	CacheFile *cache_file;
+
+	for (cache_file = idbase->first; cache_file; cache_file = cache_file->id.next) {
+		if (cache_file->id.us > 0 || wd->current) {
+			writestruct(wd, ID_CF, CacheFile, 1, cache_file);
+
+			if (cache_file->adt) {
+				write_animdata(wd, cache_file->adt);
+			}
+		}
+	}
+}
+
 /* Keep it last of write_foodata functions. */
 static void write_libraries(WriteData *wd, Main *main)
 {
@@ -4079,6 +4095,7 @@ static bool write_file_handle(
 	write_paintcurves(wd, &mainvar->paintcurves);
 	write_gpencils(wd, &mainvar->gpencil);
 	write_linestyles(wd, &mainvar->linestyle);
+	write_cachefiles(wd, &mainvar->cachefiles);
 	write_libraries(wd,  mainvar->next);
 
 	/* So changes above don't cause a 'DNA1' to be detected as changed on undo. */