Jocly on github won't include Chu Shogi; it is one of the games I added. I do have a Jocly repository on my own website hgm.nubati.net, which does contain some of the modifications I made. Not all, though, as I originally started by hacking the compiled code, and never finished backporting all that to source code. So I am not sure whether that source would do Chu Shogi.
In any case, Jocly does not contain a 2d piece set especially for Chu. What I remember is this: each game can specify an image file as 'resource', which then contains all the 2d piece images it uses, side by side on a transparent background. For each piece type the game definition contains the number of the piece in that file; apparently the Jocly generic code cuts the piece out of the image, and pasts it on the board it displays.
My Chu implementation uses the standard file with Jocly 2d pieces, ( http://hgm.nubati.net/jocly/jocly-master/dist/browser/games/chessbase/res/fairy/wikipedia-fairy-sprites.png in the Jocly library on my website) which I had extended with a few pieces for other games I implemented. The way to go seems to make an alternative to that file, perhaps by copying and modifying it, and then point the Chu game definition to that file instead of the standard one. If needed by directly editing the Jocly library.
I admit that the current assignment of 2d symbols to the Chu-Shogi pieces sucks. I really only payed attention to creating the 3d kanji tiles. To qualify for incorporating Chu Shogi in the official library I suppose it should use kanji tiles in the 2d representation as well. But I dislike kanji representations, like all westerners other than the miniscule community of non-Japanese Shogi players, so it seemed a good idea to use the 2d representation as an alternative. Personally I would prefer the mnemonic representation for that, but a poll under Chess players revealed they would prefer a pictogram representation, where the symbols are a reminder for the name rather than the move of the piece.
Jocly on github won't include Chu Shogi; it is one of the games I added. I do have a Jocly repository on my own website hgm.nubati.net, which does contain some of the modifications I made. Not all, though, as I originally started by hacking the compiled code, and never finished backporting all that to source code. So I am not sure whether that source would do Chu Shogi.
In any case, Jocly does not contain a 2d piece set especially for Chu. What I remember is this: each game can specify an image file as 'resource', which then contains all the 2d piece images it uses, side by side on a transparent background. For each piece type the game definition contains the number of the piece in that file; apparently the Jocly generic code cuts the piece out of the image, and pasts it on the board it displays.
My Chu implementation uses the standard file with Jocly 2d pieces, ( http://hgm.nubati.net/jocly/jocly-master/dist/browser/games/chessbase/res/fairy/wikipedia-fairy-sprites.png in the Jocly library on my website) which I had extended with a few pieces for other games I implemented. The way to go seems to make an alternative to that file, perhaps by copying and modifying it, and then point the Chu game definition to that file instead of the standard one. If needed by directly editing the Jocly library.
I admit that the current assignment of 2d symbols to the Chu-Shogi pieces sucks. I really only payed attention to creating the 3d kanji tiles. To qualify for incorporating Chu Shogi in the official library I suppose it should use kanji tiles in the 2d representation as well. But I dislike kanji representations, like all westerners other than the miniscule community of non-Japanese Shogi players, so it seemed a good idea to use the 2d representation as an alternative. Personally I would prefer the mnemonic representation for that, but a poll under Chess players revealed they would prefer a pictogram representation, where the symbols are a reminder for the name rather than the move of the piece.