Index: main.c
==================================================================
--- main.c
+++ main.c
@@ -35,11 +35,11 @@
   "PRAGMA APPLICATION_ID(1296388936);"
   "PRAGMA RECURSIVE_TRIGGERS(1);"
   "CREATE TABLE IF NOT EXISTS `USERCACHEINDEX`(`ID` INTEGER PRIMARY KEY, `NAME` TEXT, `TIME` INT);"
   "CREATE TABLE IF NOT EXISTS `USERCACHEDATA`(`ID` INTEGER PRIMARY KEY, `FILE` INT, `LEVEL` INT, `NAME` TEXT COLLATE NOCASE, `OFFSET` INT, `DATA` BLOB, `USERSTATE` BLOB);"
   "CREATE UNIQUE INDEX IF NOT EXISTS `USERCACHEDATA_I1` ON `USERCACHEDATA`(`FILE`, `LEVEL`);"
-  "CREATE TEMPORARY TABLE `PICTURES`(`ID` INTEGER PRIMARY KEY, `NAME` TEXT COLLATE NOCASE, `OFFSET` INT);"
+  "CREATE TEMPORARY TABLE `PICTURES`(`ID` INTEGER PRIMARY KEY, `NAME` TEXT COLLATE NOCASE, `OFFSET` INT, `DEPENDENT` INT);"
   "CREATE TEMPORARY TABLE `VARIABLES`(`ID` INTEGER PRIMARY KEY, `NAME` TEXT);"
   "COMMIT;"
 ;
 
 sqlite3*userdb;

Index: picture.c
==================================================================
--- picture.c
+++ picture.c
@@ -391,10 +391,14 @@
       pix+=pitch-picture_size;
     }
   }
   SDL_UnlockSurface(picts);
 }
+
+static void load_dependent_picture(FILE*fp,Uint16 img,int alt) {
+  //TODO
+}
 
 void load_pictures(void) {
   sqlite3_stmt*st=0;
   FILE*fp;
   Uint8 wantsize[32];
@@ -421,11 +425,11 @@
     if(i<2 || i>255) fatal("Invalid picture size %d\n",i);
     wantsize[nwantsize++]=i;
     v+=j;
   }
   if(n=sqlite3_exec(userdb,"BEGIN;",0,0,0)) fatal("SQL error (%d): %s\n",n,sqlite3_errmsg(userdb));
-  if(sqlite3_prepare_v2(userdb,"INSERT INTO `PICTURES`(`ID`,`NAME`,`OFFSET`) VALUES(?1,?2,?3);",-1,&st,0))
+  if(sqlite3_prepare_v2(userdb,"INSERT INTO `PICTURES`(`ID`,`NAME`,`OFFSET`,`DEPENDENT`) VALUES(?1,?2,?3,?4);",-1,&st,0))
    fatal("Unable to prepare SQL statement while loading pictures: %s\n",sqlite3_errmsg(userdb));
   nam=malloc(256);
   if(!nam) fatal("Allocation failed\n");
   n=0;
   memset(havesize,0,256*sizeof(Uint16));
@@ -434,17 +438,18 @@
     while(j=fgetc(fp)) {
       if(j==EOF) goto nomore1;
       if(i<255) nam[i++]=j;
     }
     nam[i]=0;
-    if(i>4 && !memcmp(".IMG",nam+i-4,4)) {
-      j=1;
+    if(i>4 && (!memcmp(".IMG",nam+i-4,4) || !memcmp(".DEP",nam+i-4,4))) {
+      if(nam[i-3]=='D') j=0; else j=1;
       if(n++==32768) fatal("Too many pictures\n");
       sqlite3_reset(st);
       sqlite3_bind_int(st,1,n);
       sqlite3_bind_text(st,2,nam,i-4,SQLITE_TRANSIENT);
       sqlite3_bind_int64(st,3,ftell(fp)+4);
+      sqlite3_bind_int(st,4,j^1);
       while((i=sqlite3_step(st))==SQLITE_ROW);
       if(i!=SQLITE_DONE) fatal("SQL error (%d): %s\n",i,sqlite3_errmsg(userdb));
     } else {
       j=0;
     }
@@ -473,23 +478,37 @@
     break;
   }
   if(!curpic) fatal("Allocation failed\n");
   picture_size=decide_picture_size(nwantsize,wantsize,havesize,n);
   if(main_options['x']) goto done;
-  if(sqlite3_prepare_v2(userdb,"SELECT `ID`, `OFFSET` FROM `PICTURES`;",-1,&st,0))
+  if(sqlite3_prepare_v2(userdb,"SELECT `ID`, `OFFSET` FROM `PICTURES` WHERE NOT `DEPENDENT`;",-1,&st,0))
    fatal("Unable to prepare SQL statement while loading pictures: %s\n",sqlite3_errmsg(userdb));
   optionquery[1]=Q_screenFlags;
   v=xrm_get_resource(resourcedb,optionquery,optionquery,2);
   i=v&&strchr(v,'h');
   picts=SDL_CreateRGBSurface((i?SDL_HWSURFACE:SDL_SWSURFACE)|SDL_SRCCOLORKEY,picture_size<<4,picture_size*((n+15)>>4),8,0,0,0,0);
   if(!picts) fatal("Error allocating surface for pictures: %s\n",SDL_GetError());
   init_palette();
   for(i=0;i<n;i++) {
-    if((j=sqlite3_step(st))!=SQLITE_ROW) fatal("SQL error (%d): %s\n",j,j==SQLITE_DONE?"Incorrect number of rows in a temporary table":sqlite3_errmsg(userdb));
+    if((j=sqlite3_step(st))!=SQLITE_ROW) {
+      if(j==SQLITE_DONE) break;
+      fatal("SQL error (%d): %s\n",j,sqlite3_errmsg(userdb));
+    }
     fseek(fp,sqlite3_column_int64(st,1),SEEK_SET);
     load_one_picture(fp,sqlite3_column_int(st,0),altImage);
   }
+  sqlite3_finalize(st);
+  if(sqlite3_prepare_v2(userdb,"SELECT `ID`, `OFFSET` FROM `PICTURES` WHERE `DEPENDENT`;",-1,&st,0))
+   fatal("Unable to prepare SQL statement while loading pictures: %s\n",sqlite3_errmsg(userdb));
+  for(i=0;i<n;i++) {
+    if((j=sqlite3_step(st))!=SQLITE_ROW) {
+      if(j==SQLITE_DONE) break;
+      fatal("SQL error (%d): %s\n",j,sqlite3_errmsg(userdb));
+    }
+    fseek(fp,sqlite3_column_int64(st,1)-4,SEEK_SET);
+    load_dependent_picture(fp,sqlite3_column_int(st,0),altImage);
+  }
   sqlite3_finalize(st);
   fclose(fp);
   SDL_SetColorKey(picts,SDL_SRCCOLORKEY|SDL_RLEACCEL,0);
 done:
   if(n=sqlite3_exec(userdb,"COMMIT;",0,0,0)) fatal("SQL error (%d): %s\n",n,sqlite3_errmsg(userdb));

Index: sql.doc
==================================================================
--- sql.doc
+++ sql.doc
@@ -121,11 +121,11 @@
   a new object of the correct class. DENSITY is read-only, but you can
   use ORDER BY DENSITY to sort in the stacking order of the objects.
   UP and DOWN are also read-only.
 
 CREATE TEMPORARY TABLE "PICTURES"("ID" INTEGER PRIMARY KEY, "NAME" TEXT
-COLLATE NOCASE, "OFFSET" INT);
+COLLATE NOCASE, "OFFSET" INT, "DEPENDENT" INT);
   List of all pictures available in this puzzle set.
 
 CREATE TABLE "USERCACHEDATA"("ID" INTEGER PRIMARY KEY, "FILE" INT,
 "LEVEL" INT, "NAME" TEXT COLLATE NOCASE, "OFFSET" INT, "DATA" BLOB,
 "USERSTATE" BLOB);