blend file thumbnailing

- uses same thumbnail system as image browser
- blend files show thumbnails in ubuntu/gnome (freedesktop spec)
- 128x128 images are embedded into the blend file header, a simple loader avoids reading the entire blend file to extract it when generating thumbnails in the file selector.
  When the image browser reads a directory it loads images and creates thumbnails, blend files embedded images are treated just like loading an image.
- the thumbnail is created from the camera view in solid mode. (no camera == no thumbnal).
- readfile/writefile.c: had to use the 'TEST' code name to save thumbnails, anything else would segfault older blender versions on load. (its not used elsewhere).

1 files changed, 3 insertions, 1 deletions

diff --git a/source/blender/blenloader/BLO_writefile.h b/source/blender/blenloader/BLO_writefile.h
index a95e5867c7e..182c582cc0f 100644
--- a/source/blender/blenloader/BLO_writefile.h
+++ b/source/blender/blenloader/BLO_writefile.h
@@ -35,10 +35,12 @@ struct MemFile;
 struct Main;
 struct ReportList;
 
-extern int BLO_write_file(struct Main *mainvar, char *dir, int write_flags, struct ReportList *reports);
+extern int BLO_write_file(struct Main *mainvar, char *dir, int write_flags, struct ReportList *reports, int *thumb);
 extern int BLO_write_file_mem(struct Main *mainvar, struct MemFile *compare, struct MemFile *current, 
 							  int write_flags, struct ReportList *reports);
 extern int BLO_write_runtime(struct Main *mainvar, char *file, char *exename, struct ReportList *reports);
 
+#define BLEN_THUMB_SIZE 128
+
 #endif