H. G. Muller wrote on Sun, Oct 14, 2018 08:24 PM UTC:
Well, WinBoard uses asterisk for non-space in FENs, and I was planning to do that here too, rendering the corresponding squares as transparent. But for combining two pieces there are still plenty other characters available. The current version of my renderer (fen2.cgi) uses parentheses to enclose piece names for which no dressed-letter ID is available. I could easily switch that to braces, I have no preference in that respect. I don't think it is a good idea to use the same enclosing for full piece names and IDs, though. Infix notation is unambiguous enough.
I have now made it such that a 1x1 FEN always uses fully transparent background, so that it can be used as a piece in other drawing routines (such as the Interactive Diagram). That means the CGI argument p=... has become somewhat redundant; to get a bishop (which before required p=wbishop) now can simply be done by f=B. That means that the piece-combining also works, f=N-Q would give you an Amazon, and f=_Q an inverted Queen. I think I will keep the p=filename argument, but implement it to do the same as f=(filename), i.e. slam parentheses (or braces) around it, and then treat it as FEN.
It might also be worthwile to have a way to add board markers. Perhaps as a second 'color FEN' through the argument m=, where each letter then indicates a color (and perhaps a shape) to be drawn over the corresponding square.
Well, WinBoard uses asterisk for non-space in FENs, and I was planning to do that here too, rendering the corresponding squares as transparent. But for combining two pieces there are still plenty other characters available. The current version of my renderer (fen2.cgi) uses parentheses to enclose piece names for which no dressed-letter ID is available. I could easily switch that to braces, I have no preference in that respect. I don't think it is a good idea to use the same enclosing for full piece names and IDs, though. Infix notation is unambiguous enough.
I have now made it such that a 1x1 FEN always uses fully transparent background, so that it can be used as a piece in other drawing routines (such as the Interactive Diagram). That means the CGI argument p=... has become somewhat redundant; to get a bishop (which before required p=wbishop) now can simply be done by f=B. That means that the piece-combining also works, f=N-Q would give you an Amazon, and f=_Q an inverted Queen. I think I will keep the p=filename argument, but implement it to do the same as f=(filename), i.e. slam parentheses (or braces) around it, and then treat it as FEN.
It might also be worthwile to have a way to add board markers. Perhaps as a second 'color FEN' through the argument m=, where each letter then indicates a color (and perhaps a shape) to be drawn over the corresponding square.