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).

10 files changed, 230 insertions, 27 deletions

diff --git a/source/blender/blenkernel/BKE_utildefines.h b/source/blender/blenkernel/BKE_utildefines.h
index 73323c5a960..925b1d7171a 100644
--- a/source/blender/blenkernel/BKE_utildefines.h
+++ b/source/blender/blenkernel/BKE_utildefines.h
@@ -166,7 +166,7 @@
 #define IMAG MAKE_ID('I','M','A','G')
 
 #define DNA1 MAKE_ID('D','N','A','1')
-#define TEST MAKE_ID('T','E','S','T')
+#define TEST MAKE_ID('T','E','S','T') /* used as preview between 'REND' and 'GLOB' */
 #define REND MAKE_ID('R','E','N','D')
 #define USER MAKE_ID('U','S','E','R')
 
diff --git a/source/blender/blenkernel/intern/blender.c b/source/blender/blenkernel/intern/blender.c
index 5d12675952c..046b8de2431 100644
--- a/source/blender/blenkernel/intern/blender.c
+++ b/source/blender/blenkernel/intern/blender.c
@@ -534,7 +534,7 @@ void BKE_write_undo(bContext *C, char *name)
 		sprintf(numstr, "%d.blend", counter);
 		BLI_make_file_string("/", tstr, btempdir, numstr);
 	
-		success= BLO_write_file(CTX_data_main(C), tstr, G.fileflags, NULL);
+		success= BLO_write_file(CTX_data_main(C), tstr, G.fileflags, NULL, NULL);
 		
 		strcpy(curundo->str, tstr);
 	}
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
 
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 381fc868a0d..8dbf2682bb6 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -10971,7 +10971,7 @@ BlendFileData *blo_read_file_internal(FileData *fd, const char *filename)
 		switch(bhead->code) {
 		case DATA:
 		case DNA1:
-		case TEST:
+		case TEST: /* used as preview since 2.5x */
 		case REND:
 			bhead = blo_nextbhead(fd, bhead);
 			break;
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index 5f2ee73e129..35fda1d8aa7 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -62,6 +62,7 @@ Any case: direct data is ALWAYS after the lib block
 	- write library block
 	- per LibBlock
 		- write the ID of LibBlock
+- write TEST (128x128, blend file preview, optional)
 - write FileGlobal (some global vars)
 - write SDNA
 - write USER if filename is ~/.B.blend
@@ -2390,9 +2391,19 @@ static void write_global(WriteData *wd, int fileflags, Main *mainvar)
 	writestruct(wd, GLOB, "FileGlobal", 1, &fg);
 }
 
+/* preview image, first 2 values are width and height
+ * second are an RGBA image (unsigned char)
+ * note, this uses 'TEST' since new types will segfault on file load for older blender versions.
+ */
+static void write_thumb(WriteData *wd, int *img)
+{
+	if(img)
+		writedata(wd, TEST, (2 + img[0] * img[1]) * sizeof(int), img);
+}
+
 /* if MemFile * there's filesave to memory */
 static int write_file_handle(Main *mainvar, int handle, MemFile *compare, MemFile *current, 
-							 int write_user_block, int write_flags)
+							 int write_user_block, int write_flags, int *thumb)
 {
 	BHead bhead;
 	ListBase mainlist;
@@ -2407,6 +2418,7 @@ static int write_file_handle(Main *mainvar, int handle, MemFile *compare, MemFil
 	mywrite(wd, buf, 12);
 
 	write_renderinfo(wd, mainvar);
+	write_thumb(wd, thumb);
 	write_global(wd, write_flags, mainvar);
 
 	/* no UI save in undo */
@@ -2458,7 +2470,7 @@ static int write_file_handle(Main *mainvar, int handle, MemFile *compare, MemFil
 }
 
 /* return: success (1) */
-int BLO_write_file(Main *mainvar, char *dir, int write_flags, ReportList *reports)
+int BLO_write_file(Main *mainvar, char *dir, int write_flags, ReportList *reports, int *thumb)
 {
 	char userfilename[FILE_MAXDIR+FILE_MAXFILE];
 	char tempname[FILE_MAXDIR+FILE_MAXFILE+1];
@@ -2497,7 +2509,7 @@ int BLO_write_file(Main *mainvar, char *dir, int write_flags, ReportList *report
 		makeFilesRelative(dir, NULL); /* note, making relative to something OTHER then G.sce */
 
 	/* actual file writing */
-	err= write_file_handle(mainvar, file, NULL,NULL, write_user_block, write_flags);
+	err= write_file_handle(mainvar, file, NULL,NULL, write_user_block, write_flags, thumb);
 	close(file);
 
 	/* rename/compress */
@@ -2550,7 +2562,7 @@ int BLO_write_file_mem(Main *mainvar, MemFile *compare, MemFile *current, int wr
 {
 	int err;
 
-	err= write_file_handle(mainvar, 0, compare, current, 0, write_flags);
+	err= write_file_handle(mainvar, 0, compare, current, 0, write_flags, NULL);
 	
 	if(err==0) return 1;
 	return 0;
@@ -2646,7 +2658,7 @@ int BLO_write_runtime(Main *mainvar, char *file, char *exename, ReportList *repo
 	outfd= open(gamename, O_BINARY|O_WRONLY|O_CREAT|O_TRUNC, 0777);
 	if (outfd != -1) {
 
-		write_file_handle(mainvar, outfd, NULL,NULL, 0, G.fileflags);
+		write_file_handle(mainvar, outfd, NULL,NULL, 0, G.fileflags, NULL);
 
 		if (write(outfd, " ", 1) != 1) {
 			BKE_report(reports, RPT_ERROR, "Unable to write to output file.");
@@ -2732,7 +2744,7 @@ int BLO_write_runtime(Main *mainvar, char *file, char *exename, ReportList *repo
 
 	datastart= lseek(outfd, 0, SEEK_CUR);
 
-	write_file_handle(mainvar, outfd, NULL,NULL, 0, G.fileflags);
+	write_file_handle(mainvar, outfd, NULL,NULL, 0, G.fileflags, NULL);
 
 	if (!handle_write_msb_int(outfd, datastart) || (write(outfd, "BRUNTIME", 8)!=8)) {
 		BKE_report(reports, RPT_ERROR, "Unable to write to output file.");
diff --git a/source/blender/editors/space_file/filelist.c b/source/blender/editors/space_file/filelist.c
index ebe42219f01..dd23c6b64b2 100644
--- a/source/blender/editors/space_file/filelist.c
+++ b/source/blender/editors/space_file/filelist.c
@@ -1280,6 +1280,8 @@ static void thumbnails_startjob(void *tjv, short *stop, short *do_update)
 	while ( (*stop==0) && (limg) ) {
 		if ( limg->flags & IMAGEFILE ) {
 			limg->img = IMB_thumb_manage(limg->path, THB_NORMAL, THB_SOURCE_IMAGE);
+		} else if ( limg->flags & BLENDERFILE ) {
+			limg->img = IMB_thumb_manage(limg->path, THB_NORMAL, THB_SOURCE_BLEND);
 		} else if ( limg->flags & MOVIEFILE ) {
 			limg->img = IMB_thumb_manage(limg->path, THB_NORMAL, THB_SOURCE_MOVIE);
 			if (!limg->img) {
@@ -1334,7 +1336,7 @@ void thumbnails_start(struct FileList* filelist, const struct bContext* C)
 	tj->filelist = filelist;
 	for (idx = 0; idx < filelist->numfiles;idx++) {
 		if (!filelist->filelist[idx].image) {
-			if ( (filelist->filelist[idx].flags & IMAGEFILE) || (filelist->filelist[idx].flags & MOVIEFILE) ) {
+			if ( (filelist->filelist[idx].flags & (IMAGEFILE|MOVIEFILE|BLENDERFILE)) ) {
 				FileImage* limg = MEM_callocN(sizeof(struct FileImage), "loadimage");
 				BLI_strncpy(limg->path, filelist->filelist[idx].path, FILE_MAX);
 				limg->index= idx;
@@ -1364,4 +1366,4 @@ void thumbnails_stop(struct FileList* filelist, const struct bContext* C)
 int thumbnails_running(struct FileList* filelist, const struct bContext* C)
 {
 	return WM_jobs_test(CTX_wm_manager(C), filelist);
-}
\ No newline at end of file
+}
diff --git a/source/blender/imbuf/IMB_thumbs.h b/source/blender/imbuf/IMB_thumbs.h
index c7e39b9e0d7..ecb0ba8abd1 100644
--- a/source/blender/imbuf/IMB_thumbs.h
+++ b/source/blender/imbuf/IMB_thumbs.h
@@ -50,13 +50,14 @@ typedef enum ThumbSize {
 
 typedef enum ThumbSource {
 	THB_SOURCE_IMAGE,
-	THB_SOURCE_MOVIE
+	THB_SOURCE_MOVIE,
+	THB_SOURCE_BLEND
 } ThumbSource;
 
 // IB_metadata
 
 /* create thumbnail for file and returns new imbuf for thumbnail */
-ImBuf* IMB_thumb_create(const char* path, ThumbSize size, ThumbSource source);
+ImBuf* IMB_thumb_create(const char* path, ThumbSize size, ThumbSource source, ImBuf *ibuf);
 
 /* read thumbnail for file and returns new imbuf for thumbnail */
 ImBuf* IMB_thumb_read(const char* path, ThumbSize size);
@@ -70,6 +71,8 @@ ImBuf* IMB_thumb_manage(const char* path, ThumbSize size, ThumbSource source);
 /* create the necessary dirs to store the thumbnails */
 void IMB_thumb_makedirs();
 
+/* special function for loading a thumbnail embedded into a blend file */
+ImBuf *IMB_loadblend_thumb(const char *path);
 
 #endif /* _IMB_THUMBS_H */
 
diff --git a/source/blender/imbuf/intern/thumbs.c b/source/blender/imbuf/intern/thumbs.c
index 45fbf49dbbd..8c75f5ab1ab 100644
--- a/source/blender/imbuf/intern/thumbs.c
+++ b/source/blender/imbuf/intern/thumbs.c
@@ -241,9 +241,8 @@ void IMB_thumb_makedirs()
 }
 
 /* create thumbnail for file and returns new imbuf for thumbnail */
-ImBuf* IMB_thumb_create(const char* path, ThumbSize size, ThumbSource source)
+ImBuf* IMB_thumb_create(const char* path, ThumbSize size, ThumbSource source, ImBuf *img)
 {
-	ImBuf *img = 0;
 	char uri[URI_MAX];
 	char desc[URI_MAX+22];
 	char tpath[FILE_MAX];
@@ -285,8 +284,18 @@ ImBuf* IMB_thumb_create(const char* path, ThumbSize size, ThumbSource source)
 			img = IMB_allocImBuf(0,0,32, IB_rect | IB_metadata, 0);
 			if (!img) return 0;
 		} else {
-			if (THB_SOURCE_IMAGE == source) {
-				img = IMB_loadiffname(path, IB_rect | IB_metadata);
+			if (THB_SOURCE_IMAGE == source || THB_SOURCE_BLEND == source) {
+				
+				/* only load if we didnt give an image */
+				if(img==NULL) {
+					if(THB_SOURCE_BLEND == source) {
+						img = IMB_loadblend_thumb(path);
+					}
+					else {
+						img = IMB_loadiffname(path, IB_rect | IB_metadata);
+					}
+				}
+
 				if (img != NULL) {
 					stat(path, &info);
 					sprintf(mtime, "%ld", info.st_mtime);
@@ -425,10 +434,10 @@ ImBuf* IMB_thumb_manage(const char* path, ThumbSize size, ThumbSource source)
 						IMB_thumb_delete(path, THB_NORMAL);
 						IMB_thumb_delete(path, THB_LARGE);
 						IMB_thumb_delete(path, THB_FAIL);
-						img = IMB_thumb_create(path, size, source);
+						img = IMB_thumb_create(path, size, source, NULL);
 						if(!img){
 							/* thumb creation failed, write fail thumb */
-							img = IMB_thumb_create(path, THB_FAIL, source);
+							img = IMB_thumb_create(path, THB_FAIL, source, NULL);
 							if (img) {
 								/* we don't need failed thumb anymore */
 								IMB_freeImBuf(img);
@@ -438,10 +447,10 @@ ImBuf* IMB_thumb_manage(const char* path, ThumbSize size, ThumbSource source)
 					}
 				}
 			} else {
-				img = IMB_thumb_create(path, size, source);
+				img = IMB_thumb_create(path, size, source, NULL);
 				if(!img){
 					/* thumb creation failed, write fail thumb */
-					img = IMB_thumb_create(path, THB_FAIL, source);
+					img = IMB_thumb_create(path, THB_FAIL, source, NULL);
 					if (img) {
 						/* we don't need failed thumb anymore */
 						IMB_freeImBuf(img);
diff --git a/source/blender/imbuf/intern/thumbs_blend.c b/source/blender/imbuf/intern/thumbs_blend.c
new file mode 100644
index 00000000000..f38975f1da1
--- /dev/null
+++ b/source/blender/imbuf/intern/thumbs_blend.c
@@ -0,0 +1,122 @@
+/**
+ * $Id:
+ *
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * 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.
+ *
+ * Contributor(s): Campbell Barton.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#include <string.h>
+
+#include "zlib.h"
+
+#include "BKE_utildefines.h"
+#include "BKE_global.h"
+
+#include "IMB_imbuf_types.h"
+#include "IMB_imbuf.h"
+#include "IMB_thumbs.h"
+
+#include "MEM_guardedalloc.h"
+
+ImBuf *IMB_loadblend_thumb(const char *path)
+{
+	char buf[8];
+	int code= 0;
+	char endian, pointer_size;
+	char endian_switch;
+	int len, im_len, x, y;
+	int *rect= NULL;
+
+	gzFile gzfile;
+	
+	ImBuf *img;
+	
+	/* not necessarily a gzip */
+	gzfile = gzopen(path, "rb");
+
+	if (NULL == gzfile ) {
+		return NULL;
+	}
+	
+	/* read the blend file header */
+	if(gzread(gzfile, buf, 8) < 8)		goto thumb_error;
+	if(strncmp(buf, "BLENDER", 7))		goto thumb_error;
+	
+	if(buf[7]=='-')						pointer_size= 8;
+	else if(buf[7]=='_')				pointer_size= 4;
+	else								goto thumb_error;
+	
+	/* read the next 4 bytes, only need the first char, ignore the version */
+	/* endian and vertsion (ignored) */
+	if(gzread(gzfile, buf, 4) < 4)		goto thumb_error;
+	
+	if(buf[0]=='V')						endian= B_ENDIAN; /* big: PPC */
+	else if(buf[0]=='v')				endian= L_ENDIAN; /* little: x86 */
+	else								goto thumb_error;
+
+	while(gzread(gzfile, &code, 4) == 4) {
+		endian_switch = ((ENDIAN_ORDER != endian)) ? 1 : 0;
+		
+		if(gzread(gzfile, buf, 4) < 4)		goto thumb_error;
+		len = *( (int *)((void *)buf) );
+		if(endian_switch) SWITCH_INT(len);
+		
+		/* finally read the rest of the bhead struct, pointer and 2 ints */
+		if(gzread(gzfile, buf, pointer_size) < pointer_size)	goto thumb_error;
+		if(gzread(gzfile, buf, 8) < 8)	goto thumb_error;
+		/* we dont actually care whats in the bhead */
+		
+		if (code==REND) {
+			gzseek(gzfile, len, SEEK_CUR); /* skip to the next */
+		}
+		else {
+			break;
+		}
+	}
+	
+	/* using 'TEST' since new names segfault when loading in old blenders */
+	if(code != TEST)					goto thumb_error;
+	
+	/* finally malloc and read the data */
+	rect= MEM_mallocN(len, "imb_loadblend_thumb");
+
+	if(gzread(gzfile, rect, len) < len)	goto thumb_error;
+
+	/* read ok! */
+	gzclose(gzfile);
+	
+	x= rect[0];	y= rect[1];
+	if(endian_switch) { SWITCH_INT(x); SWITCH_INT(y); }
+
+	im_len = x * y * sizeof(int);
+
+	img = IMB_allocImBuf(x, y, 32, IB_rect | IB_metadata, 0);
+
+	memcpy(img->rect, rect + 2, im_len);
+
+	MEM_freeN(rect);
+	
+	return img;	
+
+thumb_error:
+	gzclose(gzfile);
+	if(rect) MEM_freeN(rect);
+	return NULL;
+}
diff --git a/source/blender/windowmanager/intern/wm_files.c b/source/blender/windowmanager/intern/wm_files.c
index c981836a8ed..91ebb5d6fb4 100644
--- a/source/blender/windowmanager/intern/wm_files.c
+++ b/source/blender/windowmanager/intern/wm_files.c
@@ -77,10 +77,15 @@
 
 #include "RNA_access.h"
 
+#include "IMB_imbuf.h"
+#include "IMB_imbuf_types.h"
+#include "IMB_thumbs.h"
+
 #include "ED_datafiles.h"
 #include "ED_object.h"
 #include "ED_screen.h"
 #include "ED_sculpt.h"
+#include "ED_view3d.h"
 #include "ED_util.h"
 
 #include "GHOST_C-api.h"
@@ -486,12 +491,53 @@ static void do_history(char *name, ReportList *reports)
 		BKE_report(reports, RPT_ERROR, "Unable to make version backup");
 }
 
+/* writes a thumbnail for a blendfile */
+static void writeThumb(const char *path, Scene *scene, int **thumb_pt)
+{
+	/* will be scaled down, but gives some nice oversampling */
+	ImBuf *ibuf;
+	int *thumb;
+
+	*thumb_pt= NULL;
+	
+	if(G.background || scene->camera==NULL)
+		return;
+	
+	thumb = MEM_mallocN(((2 + (BLEN_THUMB_SIZE * BLEN_THUMB_SIZE))) * sizeof(int), "write_file thumb");
+	
+	/* gets scaled to BLEN_THUMB_SIZE */
+	ibuf= ED_view3d_draw_offscreen_imbuf_simple(scene, BLEN_THUMB_SIZE * 2, BLEN_THUMB_SIZE * 2, OB_SOLID);
+	
+	if(ibuf) {		
+		
+		/* dirty oversampling */
+		IMB_scaleImBuf(ibuf, BLEN_THUMB_SIZE, BLEN_THUMB_SIZE);
+		
+		/* first write into thumb buffer */
+		thumb[0] = BLEN_THUMB_SIZE;
+		thumb[1] = BLEN_THUMB_SIZE;
+		memcpy(thumb + 2, ibuf->rect, BLEN_THUMB_SIZE * BLEN_THUMB_SIZE * sizeof(int));
+		
+		/* the image is scaled here */
+		ibuf= IMB_thumb_create(path, THB_NORMAL, THB_SOURCE_BLEND, ibuf);
+	}
+
+	if (ibuf) {		
+		IMB_freeImBuf(ibuf);
+	}
+	
+	/* must be freed by caller */
+	*thumb_pt= thumb;
+}
+
 int WM_write_file(bContext *C, char *target, int fileflags, ReportList *reports)
 {
 	Library *li;
 	int len;
 	char di[FILE_MAX];
-	
+
+	int *thumb= NULL;
+
 	len = strlen(target);
 	
 	if (len == 0) {
@@ -532,7 +578,10 @@ int WM_write_file(bContext *C, char *target, int fileflags, ReportList *reports)
 
 	do_history(di, reports);
 	
-	if (BLO_write_file(CTX_data_main(C), di, fileflags, reports)) {
+	/* blend file thumbnail */
+	writeThumb(di, CTX_data_scene(C), &thumb);
+
+	if (BLO_write_file(CTX_data_main(C), di, fileflags, reports, thumb)) {
 		strcpy(G.sce, di);
 		G.relbase_valid = 1;
 		strcpy(G.main->name, di);	/* is guaranteed current file */
@@ -546,7 +595,11 @@ int WM_write_file(bContext *C, char *target, int fileflags, ReportList *reports)
 		else G.fileflags &= ~G_FILE_AUTOPLAY;
 
 		writeBlog();
-	} else {
+
+		if(thumb) MEM_freeN(thumb);
+	}
+	else {
+		if(thumb) MEM_freeN(thumb);
 		return -1;
 	}
 
@@ -571,7 +624,7 @@ int WM_write_homefile(bContext *C, wmOperator *op)
 	/*  force save as regular blend file */
 	fileflags = G.fileflags & ~(G_FILE_COMPRESS | G_FILE_AUTOPLAY | G_FILE_LOCK | G_FILE_SIGN);
 
-	BLO_write_file(CTX_data_main(C), tstr, fileflags, op->reports);
+	BLO_write_file(CTX_data_main(C), tstr, fileflags, op->reports, NULL);
 	
 	G.save_over= 0;
 	
@@ -640,7 +693,7 @@ void wm_autosave_timer(const bContext *C, wmWindowManager *wm, wmTimer *wt)
 	fileflags = G.fileflags & ~(G_FILE_COMPRESS|G_FILE_AUTOPLAY |G_FILE_LOCK|G_FILE_SIGN);
 
 	/* no error reporting to console */
-	BLO_write_file(CTX_data_main(C), filename, fileflags, NULL);
+	BLO_write_file(CTX_data_main(C), filename, fileflags, NULL, NULL);
 
 	/* do timer after file write, just in case file write takes a long time */
 	wm->autosavetimer= WM_event_add_timer(wm, NULL, TIMERAUTOSAVE, U.savetime*60.0);