I do not understand why after I move the rook I can castle with the cannon on the field that was supposed to be used only for the rook.
So far, you have not made it clear that the King moves to a different space when castling with each piece. The rules you have underneath the game do not even mention castling. The castle subroutine was not written with such a rule in mind. You might be able to make it work by adjusting the values of bcastle and wcastle after a Rook moves.
I think I haven't explained that properly but only one castle is aloud.
Castling is allowed only once, which I understand, but what you say next doesn't fit with you trying to say that. Are you trying to say that the King has only once space it can go to when castling with a certain piece?
Regarding your preset, I don't understand why you are using four colors for checkering the board. Also, the dark blue squares do not contrast well with the color used for highlighting legal moves, which makes it hard to see legal moves highlighted on those squares. Additionally, your rules could use images of the pieces, so that someone looking at a piece on the board can more easily tell how it moves. Remember to use the shortcodes for displaying pieces, so that the piece images below match those on the board no matter what piece set is used.
So far, you have not made it clear that the King moves to a different space when castling with each piece. The rules you have underneath the game do not even mention castling. The castle subroutine was not written with such a rule in mind. You might be able to make it work by adjusting the values of bcastle and wcastle after a Rook moves.
Castling is allowed only once, which I understand, but what you say next doesn't fit with you trying to say that. Are you trying to say that the King has only once space it can go to when castling with a certain piece?
Regarding your preset, I don't understand why you are using four colors for checkering the board. Also, the dark blue squares do not contrast well with the color used for highlighting legal moves, which makes it hard to see legal moves highlighted on those squares. Additionally, your rules could use images of the pieces, so that someone looking at a piece on the board can more easily tell how it moves. Remember to use the shortcodes for displaying pieces, so that the piece images below match those on the board no matter what piece set is used.