Draft of Ultima chess rules; almost OK HalfChess

[vchess.git] / public / javascripts / variants / Half.js

diff --git a/public/javascripts/variants/Half.js b/public/javascripts/variants/Half.js
new file mode 100644 (file)
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+++ b/public/javascripts/variants/Half.js
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+class HalfRules extends ChessRules
+{
+       // Standard rules on a 4x8 board with no pawns
+
+       initVariables(fen) { } //nothing to do
+
+       setFlags(fen)
+       {
+               // No castling, hence no flags; but flags defined for compatibility
+               this.castleFlags = { "w":[false,false], "b":[false,false] };
+       }
+
+       static get size() { return [8,4]; }
+
+       getPotentialKingMoves(sq)
+       {
+               const V = VariantRules;
+               // No castling
+               return this.getSlideNJumpMoves(sq,
+                       V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
+       }
+
+       isAttacked(sq, colors)
+       {
+               return (this.isAttackedByRook(sq, colors)
+                       || this.isAttackedByKnight(sq, colors)
+                       || this.isAttackedByBishop(sq, colors)
+                       || this.isAttackedByQueen(sq, colors)
+                       || this.isAttackedByKing(sq, colors));
+       }
+
+       // Unused:
+       updateVariables(move) { }
+       unupdateVariables(move) { }
+
+       static get SEARCH_DEPTH() { return 4; }
+
+       static GenRandInitFen()
+       {
+               let minorPieces = { "w": new Array(4), "b": new Array(4) };
+               let majorPieces = { "w": new Array(4), "b": new Array(4) };
+               for (let c of ["w","b"])
+               {
+                       // Minor pieces first (on 2nd rank)
+                       let positions = _.range(4);
+
+                       // Get random squares for bishops
+                       let randIndex = 2 * _.random(1);
+                       let bishop1Pos = positions[randIndex];
+                       let randIndex_tmp = 2 * _.random(1) + 1;
+                       let bishop2Pos = positions[randIndex_tmp];
+                       positions.splice(Math.max(randIndex,randIndex_tmp), 1);
+                       positions.splice(Math.min(randIndex,randIndex_tmp), 1);
+
+                       // Get random squares for knights
+                       randIndex = _.random(1);
+                       let knight1Pos = positions[randIndex];
+                       positions.splice(randIndex, 1);
+                       let knight2Pos = positions[0];
+
+                       minorPieces[c][bishop1Pos] = 'b';
+                       minorPieces[c][bishop2Pos] = 'b';
+                       minorPieces[c][knight1Pos] = 'n';
+                       minorPieces[c][knight2Pos] = 'n';
+
+                       // Major pieces then (on 1st rank)
+                       positions = _.range(4);
+
+                       // Get random square for queen
+                       randIndex = _.random(3);
+                       let queenPos = positions[randIndex];
+                       positions.splice(randIndex, 1);
+
+                       // Rooks and king positions:
+                       let rook1Pos = positions[0];
+                       let kingPos = positions[1];
+                       let rook2Pos = positions[2];
+
+                       majorPieces[c][rook1Pos] = 'r';
+                       majorPieces[c][rook2Pos] = 'r';
+                       majorPieces[c][kingPos] = 'k';
+                       majorPieces[c][queenPos] = 'q';
+               }
+               return majorPieces["b"].join("") + "/" + minorPieces["b"].join("") + "/4/4/4/4/" +
+                       minorPieces["w"].join("").toUpperCase() + "/" +
+                       majorPieces["w"].join("").toUpperCase() + " 0000"; //TODO: flags?!
+       }
+}