Might it work to use the generated code for most of it and manually define the pieces that wouldn't work?
I suppose this would be an option; the 'Custom Pieces' section of the 'Wizard for GAME-code generation' article described how to add pieces that would need explicit programming. I think the Terror would not be problematic for the automatic conversion; it is the flying pieces that would need separate coding, in particular their jump-capturing moves. I suppose you could define thir moves in the I.D. as QK, RW and BF, and then replace the K, W or F moves by a routine for generating jump-captures in the described way.
But it might be simpler to clone the betza.txt file, and modify the move generator there with some dedicated code for this variant. And then use this modified version instead of the standard betza.txt in the preset. All that would have to be done is to insert some code at the point where it now is decided that an encountered piece can be hopped over by a test whether both pieces belong to the set {bat, eagle, raven, archer, spearman}, and abort the generation of that hopping move when they do.
Since this code would only be invoked when a hopper move hits a potential mount, it would not slow down the move generation very much, and I could even insert that in the standard include file. Then all what would have to be done is defining the pieces that cannot hop over each other in the Pre-Game code, like
set flying (...);
where the ... would be the list of labels of all the pieces (of either color) to which this applies.
I suppose this would be an option; the 'Custom Pieces' section of the 'Wizard for GAME-code generation' article described how to add pieces that would need explicit programming. I think the Terror would not be problematic for the automatic conversion; it is the flying pieces that would need separate coding, in particular their jump-capturing moves. I suppose you could define thir moves in the I.D. as QK, RW and BF, and then replace the K, W or F moves by a routine for generating jump-captures in the described way.
But it might be simpler to clone the betza.txt file, and modify the move generator there with some dedicated code for this variant. And then use this modified version instead of the standard betza.txt in the preset. All that would have to be done is to insert some code at the point where it now is decided that an encountered piece can be hopped over by a test whether both pieces belong to the set {bat, eagle, raven, archer, spearman}, and abort the generation of that hopping move when they do.
Since this code would only be invoked when a hopper move hits a potential mount, it would not slow down the move generation very much, and I could even insert that in the standard include file. Then all what would have to be done is defining the pieces that cannot hop over each other in the Pre-Game code, like
set flying (...);
where the ... would be the list of labels of all the pieces (of either color) to which this applies.