Messages about figures that don’t exist are treated as requests for empty figures. Typically, they shouldn’t be present unless they are programmed into \setbox-like commands. tex4ht-c identifies in the .lg file the empty figures it finds.
The messages in the “.lg” file look like ‘--- empty picture --- aa.idv[1] ---’.
<..identify the empty pictures..>
{ struct empty_pic_struct *last;
last = empty_pic = (struct empty_pic_struct *) 0;
while( TRUE ) {
status = scan_str("--- empty picture --- ", TRUE, lg_file);
status = scan_until_str( ".idv[" , 1, status, lg_file);
status = scan_until_end_str("] ---", 1, status, lg_file);
if( status ){ <.add empty pic.> }
if ( eoln_ch == EOF ){ break; }
}
<.add empty pic.>
last->next = (struct empty_pic_struct *) 0;
last->n = 100000;
}
-_-_-
<..add empty pic..>
if( last == (struct empty_pic_struct *) 0 ){
last = empty_pic = (struct empty_pic_struct *)
m_alloc(struct empty_pic_struct, (int) 1);
} else {
last = last->next = (struct empty_pic_struct *)
m_alloc(struct empty_pic_struct, (int) 1);
}
last->next = (struct empty_pic_struct *) 0;
last->n = get_long_int(match[1]);
-_-_-
<..main’s vars..>
struct empty_pic_struct *empty_pic;
-_-_-
<..defines..>+
struct empty_pic_struct{
long int n;
struct empty_pic_struct *next;
};
-_-_-
The list of empty pictures is stored in ‘emptypic’.