H. G. Muller wrote on Sat, Feb 29, 2020 08:59 AM UTC:
For 'engine-defined variants', the definition in the fmax.ini file should also specify a 'pieceToCharTable' (to indicate which images should be used for what piece) and a 'parent variant' (normally 'fairy', unless there are some special rules that you want to borrow from another variant, such as a wider promotion zone, or the possibility to gate pieces). They go on the 'Game:' line, after the name of the variant, separated by #, like
Game: frog # PNBRQ.FKpnbrq.fk # fairy
if you want to depict the Frog as an elephant (because the F is in the 7th place of the pieceToCharTable, and WinBoard's 7th piece image is an elephant). The last piece mentioned for each color will always use the King symbol.
It will also be helpful to make Fairy-Max inform WinBoard on how the Frog moves, so that you will be able to play the games with legality testing on. To this end you should append the following two lines to the game definition:
#
# F& FH
This will make Fairy-Max emit a 'piece' command at the start of the game for F (the '&' indicating it applies to F of both colors), to indicate it moves as a (Betza) FH. (The other pieces move as WinBoard would expect a piece with that image to move, so there is no need to (re)define their moves.) Unfortunately Fairy-Max is not smart enough to construct the Betza notation that XBoard needs from the move definition as it was given on the 'f:' line. I still hope that I can make some future version of Fairy-Max work entirely from Betza move definitions in the fmax.ini file, rather than from the list of step vectors and primary/secondary move rights it uses now.
For 'engine-defined variants', the definition in the fmax.ini file should also specify a 'pieceToCharTable' (to indicate which images should be used for what piece) and a 'parent variant' (normally 'fairy', unless there are some special rules that you want to borrow from another variant, such as a wider promotion zone, or the possibility to gate pieces). They go on the 'Game:' line, after the name of the variant, separated by #, like
if you want to depict the Frog as an elephant (because the F is in the 7th place of the pieceToCharTable, and WinBoard's 7th piece image is an elephant). The last piece mentioned for each color will always use the King symbol.
It will also be helpful to make Fairy-Max inform WinBoard on how the Frog moves, so that you will be able to play the games with legality testing on. To this end you should append the following two lines to the game definition:
This will make Fairy-Max emit a 'piece' command at the start of the game for F (the '&' indicating it applies to F of both colors), to indicate it moves as a (Betza) FH. (The other pieces move as WinBoard would expect a piece with that image to move, so there is no need to (re)define their moves.) Unfortunately Fairy-Max is not smart enough to construct the Betza notation that XBoard needs from the move definition as it was given on the 'f:' line. I still hope that I can make some future version of Fairy-Max work entirely from Betza move definitions in the fmax.ini file, rather than from the list of step vectors and primary/secondary move rights it uses now.