Free Hero Mesh

  .xBestIndex=vt1_playfield_index,
  .xColumn=vt1_playfield_column,
  .xFilter=vt1_playfield_filter,
  .xNext=vt1_playfield_next,
);

static int vt1_levels_connect(sqlite3*db,void*aux,int argc,const char*const*argv,sqlite3_vtab**vt,char**err) {
  if(levels_schema) goto declare;
  //TODO: Add columns specific to a puzzle set.
  levels_schema=sqlite3_mprintf("CREATE TEMPORARY TABLE `LEVELS`"
   "(`ID` INTEGER PRIMARY KEY, `ORD` INT, `CODE` INT, `WIDTH` INT, `HEIGHT` INT, `TITLE` BLOB, `SOLVED` INT, `SOLVABLE` INT);");
  if(!levels_schema) fatal("Allocation failed\n");
  declare:
  sqlite3_declare_vtab(db,levels_schema);
  *vt=sqlite3_malloc(sizeof(sqlite3_vtab));
  return *vt?SQLITE_OK:SQLITE_NOMEM;
}

static int vt1_levels_open(sqlite3_vtab*vt,sqlite3_vtab_cursor**cur) {
  //TODO: Add columns specific to a puzzle set.
  sqlite3_stmt*st1;
  sqlite3_stmt*st2;
  const unsigned char*d;
  unsigned char*p;
  int i,j;
  long n;
  int txn=sqlite3_get_autocommit(userdb)?sqlite3_exec(userdb,"BEGIN;",0,0,0):1;
  if(!levels_schema) return SQLITE_CORRUPT_VTAB;
  if(screen) set_cursor(XC_coffee_mug);
  fprintf(stderr,"Loading level index...\n");
  fprintf(stderr,"Loading level table...\n");
  if(sqlite3_exec(userdb,levels_schema,0,0,0)) {
    err: fatal("SQL error while loading LEVELS table: %s\n",sqlite3_errmsg(userdb));
  }
  sqlite3_free(levels_schema);
  levels_schema=0;
  if(sqlite3_prepare_v2(userdb,"SELECT `LEVEL`, IFNULL(`DATA`,READ_LUMP_AT(`OFFSET`,?1)), `USERSTATE` FROM `USERCACHEDATA`"
   " WHERE `FILE` = LEVEL_CACHEID() AND `LEVEL` NOT NULL AND `LEVEL` >= 0 ORDER BY `LEVEL`;",-1,&st1,0))
   goto err;
  // ?1=ID, ?2=CODE, ?3=WIDTH, ?4=HEIGHT, ?5=TITLE, ?6=SOLVED, ?7=SOLVABLE
  if(sqlite3_prepare_v3(userdb,"INSERT INTO `LEVELS` VALUES(?1,NULL,?2,?3,?4,?5,?6,?7);",-1,SQLITE_PREPARE_NO_VTAB,&st2,0))
   goto err;
  sqlite3_bind_pointer(st1,1,levelfp,"http://zzo38computer.org/fossil/heromesh.ui#FILE_ptr",0);