Draft of Ultima chess rules; almost OK HalfChess
[vchess.git] / public / javascripts / variants / Wildebeest.js
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8a196305 1class WildebeestRules extends ChessRules
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2{
3 static getPpath(b)
4 {
5 const V = VariantRules;
6 return ([V.CAMEL,V.WILDEBEEST].includes(b[1]) ? "Wildebeest/" : "") + b;
7 }
8
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9 static get size() { return [10,11]; }
10
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11 static get CAMEL() { return 'c'; }
12 static get WILDEBEEST() { return 'w'; }
13
14 static get steps() {
15 return Object.assign(
16 ChessRules.steps, //add camel moves:
17 {'c': [ [-3,-1],[-3,1],[-1,-3],[-1,3],[1,-3],[1,3],[3,-1],[3,1] ]}
18 );
19 }
20
8a196305 21 // En-passant after 2-sq or 3-sq jumps
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22 getEpSquare(move)
23 {
24 const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x];
8a196305 25 if (this.getPiece(sx,sy) == VariantRules.PAWN && Math.abs(sx - ex) >= 2)
a37076f1 26 {
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27 const step = (ex-sx) / Math.abs(ex-sx);
28 let res = [{
29 x: sx + step,
a37076f1 30 y: sy
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31 }];
32 if (sx + 2*step != ex) //3-squares move
33 {
34 res.push({
35 x: sx + 2*step,
36 y: sy
37 });
38 }
39 return res;
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40 }
41 return undefined; //default
42 }
43
44 getPotentialMovesFrom([x,y])
45 {
46 switch (this.getPiece(x,y))
47 {
48 case VariantRules.CAMEL:
49 return this.getPotentialCamelMoves([x,y]);
50 case VariantRules.WILDEBEEST:
51 return this.getPotentialWildebeestMoves([x,y]);
52 default:
53 return super.getPotentialMovesFrom([x,y])
54 }
55 }
56
8a196305 57 // Pawns jump 2 or 3 squares, and promote to queen or wildebeest
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58 getPotentialPawnMoves([x,y])
59 {
60 const color = this.turn;
61 let moves = [];
62 const V = VariantRules;
63 const [sizeX,sizeY] = VariantRules.size;
64 const shift = (color == "w" ? -1 : 1);
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65 const startRanks = (color == "w" ? [sizeX-2,sizeX-3] : [1,2]);
66 const lastRank = (color == "w" ? 0 : sizeX-1);
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67
68 if (x+shift >= 0 && x+shift < sizeX && x+shift != lastRank)
69 {
70 // Normal moves
71 if (this.board[x+shift][y] == V.EMPTY)
72 {
73 moves.push(this.getBasicMove([x,y], [x+shift,y]));
8a196305 74 if (startRanks.includes(x) && this.board[x+2*shift][y] == V.EMPTY)
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75 {
76 // Two squares jump
77 moves.push(this.getBasicMove([x,y], [x+2*shift,y]));
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78 if (x == startRanks[0] && this.board[x+3*shift][y] == V.EMPTY)
79 {
80 // 3-squares jump
81 moves.push(this.getBasicMove([x,y], [x+3*shift,y]));
82 }
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83 }
84 }
85 // Captures
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86 if (y>0 && this.canTake([x,y], [x+shift,y-1])
87 && this.board[x+shift][y-1] != V.EMPTY)
88 {
a37076f1 89 moves.push(this.getBasicMove([x,y], [x+shift,y-1]));
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90 }
91 if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1])
92 && this.board[x+shift][y+1] != V.EMPTY)
93 {
a37076f1 94 moves.push(this.getBasicMove([x,y], [x+shift,y+1]));
92342261 95 }
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96 }
97
98 if (x+shift == lastRank)
99 {
100 // Promotion
8a196305 101 let promotionPieces = [V.QUEEN,V.WILDEBEEST];
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102 promotionPieces.forEach(p => {
103 // Normal move
104 if (this.board[x+shift][y] == V.EMPTY)
105 moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p}));
106 // Captures
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107 if (y>0 && this.canTake([x,y], [x+shift,y-1])
108 && this.board[x+shift][y-1] != V.EMPTY)
109 {
a37076f1 110 moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:p}));
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111 }
112 if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1])
113 && this.board[x+shift][y+1] != V.EMPTY)
114 {
a37076f1 115 moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:p}));
92342261 116 }
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117 });
118 }
119
120 // En passant
121 const Lep = this.epSquares.length;
122 const epSquare = Lep>0 ? this.epSquares[Lep-1] : undefined;
8a196305 123 if (!!epSquare)
a37076f1 124 {
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125 for (let epsq of epSquare)
126 {
127 // TODO: some redundant checks
128 if (epsq.x == x+shift && Math.abs(epsq.y - y) == 1)
129 {
130 let epStep = epsq.y - y;
131 var enpassantMove = this.getBasicMove([x,y], [x+shift,y+epStep]);
132 enpassantMove.vanish.push({
133 x: x,
134 y: y+epStep,
135 p: 'p',
136 c: this.getColor(x,y+epStep)
137 });
138 moves.push(enpassantMove);
139 }
140 }
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141 }
142
143 return moves;
144 }
145
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146 // TODO: wildebeest castle
147
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148 getPotentialCamelMoves(sq)
149 {
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150 return this.getSlideNJumpMoves(
151 sq, VariantRules.steps[VariantRules.CAMEL], "oneStep");
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152 }
153
154 getPotentialWildebeestMoves(sq)
155 {
156 const V = VariantRules;
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157 return this.getSlideNJumpMoves(
158 sq, V.steps[V.KNIGHT].concat(V.steps[V.CAMEL]), "oneStep");
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159 }
160
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161 isAttacked(sq, colors)
162 {
8a196305 163 return super.isAttacked(sq, colors)
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164 || this.isAttackedByCamel(sq, colors)
165 || this.isAttackedByWildebeest(sq, colors);
166 }
167
168 isAttackedByCamel(sq, colors)
169 {
170 return this.isAttackedBySlideNJump(sq, colors,
cf130369 171 VariantRules.CAMEL, VariantRules.steps[VariantRules.CAMEL], "oneStep");
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172 }
173
174 isAttackedByWildebeest(sq, colors)
175 {
176 const V = VariantRules;
177 return this.isAttackedBySlideNJump(sq, colors, V.WILDEBEEST,
cf130369 178 V.steps[V.KNIGHT].concat(V.steps[V.CAMEL]), "oneStep");
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179 }
180
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181 checkGameEnd()
182 {
183 // No valid move: game is lost (stalemate is a win)
184 return this.turn == "w" ? "0-1" : "1-0";
185 }
efb20746 186
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187 static get VALUES() {
188 return Object.assign(
189 ChessRules.VALUES,
190 {'c': 3, 'w': 7} //experimental
191 );
192 }
193
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194 static get SEARCH_DEPTH() { return 2; }
195
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196 static GenRandInitFen()
197 {
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198 let pieces = { "w": new Array(10), "b": new Array(10) };
199 for (let c of ["w","b"])
a37076f1 200 {
8a196305 201 let positions = _.range(11);
a37076f1 202
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203 // Get random squares for bishops + camels (different colors)
204 let randIndexes = _.sample(_.range(6), 2).map(i => { return 2*i; });
205 let bishop1Pos = positions[randIndexes[0]];
206 let camel1Pos = positions[randIndexes[1]];
207 // The second bishop (camel) must be on a square of different color
208 let randIndexes_tmp = _.sample(_.range(5), 2).map(i => { return 2*i+1; });
209 let bishop2Pos = positions[randIndexes_tmp[0]];
210 let camel2Pos = positions[randIndexes_tmp[1]];
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211 for (let idx of randIndexes.concat(randIndexes_tmp)
212 .sort((a,b) => { return b-a; })) //largest indices first
213 {
dca02599 214 positions.splice(idx, 1);
92342261 215 }
a37076f1 216
dca02599 217 let randIndex = _.random(6);
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218 let knight1Pos = positions[randIndex];
219 positions.splice(randIndex, 1);
dca02599 220 randIndex = _.random(5);
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221 let knight2Pos = positions[randIndex];
222 positions.splice(randIndex, 1);
223
8a196305 224 randIndex = _.random(4);
dca02599 225 let queenPos = positions[randIndex];
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226 positions.splice(randIndex, 1);
227
92342261 228 // Random square for wildebeest
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229 randIndex = _.random(3);
230 let wildebeestPos = positions[randIndex];
231 positions.splice(randIndex, 1);
232
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233 let rook1Pos = positions[0];
234 let kingPos = positions[1];
235 let rook2Pos = positions[2];
236
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237 pieces[c][rook1Pos] = 'r';
238 pieces[c][knight1Pos] = 'n';
239 pieces[c][bishop1Pos] = 'b';
240 pieces[c][queenPos] = 'q';
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241 pieces[c][camel1Pos] = 'c';
242 pieces[c][camel2Pos] = 'c';
243 pieces[c][wildebeestPos] = 'w';
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244 pieces[c][kingPos] = 'k';
245 pieces[c][bishop2Pos] = 'b';
246 pieces[c][knight2Pos] = 'n';
247 pieces[c][rook2Pos] = 'r';
248 }
92342261 249 let fen = pieces["b"].join("") +
8a196305 250 "/ppppppppppp/11/11/11/11/11/11/PPPPPPPPPPP/" +
92342261 251 pieces["w"].join("").toUpperCase() +
8a196305 252 " 1111";
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253 return fen;
254 }
255}