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).

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')
 

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);
 	}

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
 

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;

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.");

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);
-}
+}

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 */
 

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);

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;
+}

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);