357a5eb8eadaaf178b4f88d140d504c2f29fdf98
[vchess.git] / public / javascripts / variants / Wildebeest.js
1 class WildebeestRules extends ChessRules
2 {
3 static getPpath(b)
4 {
5 return ([V.CAMEL,V.WILDEBEEST].includes(b[1]) ? "Wildebeest/" : "") + b;
6 }
7
8 static get size() { return {x:10,y:11}; }
9
10 static get CAMEL() { return 'c'; }
11 static get WILDEBEEST() { return 'w'; }
12
13 static get PIECES()
14 {
15 return ChessRules.PIECES.concat([V.CAMEL,V.WILDEBEEST]);
16 }
17
18 static get steps()
19 {
20 return Object.assign(
21 ChessRules.steps, //add camel moves:
22 {'c': [ [-3,-1],[-3,1],[-1,-3],[-1,3],[1,-3],[1,3],[3,-1],[3,1] ]}
23 );
24 }
25
26 static IsGoodEnpassant(enpassant)
27 {
28 if (enpassant != "-")
29 {
30 const squares = enpassant.split(",");
31 if (squares.length > 2)
32 return false;
33 for (let sq of squares)
34 {
35 const ep = V.SquareToCoords(sq);
36 if (isNaN(ep.x) || !V.OnBoard(ep))
37 return false;
38 }
39 }
40 return true;
41 }
42
43 // There may be 2 enPassant squares (if pawn jump 3 squares)
44 getEnpassantFen()
45 {
46 const L = this.epSquares.length;
47 if (!this.epSquares[L-1])
48 return "-"; //no en-passant
49 let res = "";
50 this.epSquares[L-1].forEach(sq => {
51 res += V.CoordsToSquare(sq) + ",";
52 });
53 return res.slice(0,-1); //remove last comma
54 }
55
56 // En-passant after 2-sq or 3-sq jumps
57 getEpSquare(moveOrSquare)
58 {
59 if (!moveOrSquare)
60 return undefined;
61 if (typeof moveOrSquare === "string")
62 {
63 const square = moveOrSquare;
64 if (square == "-")
65 return undefined;
66 let res = [];
67 square.split(",").forEach(sq => {
68 res.push(V.SquareToCoords(sq));
69 });
70 return res;
71 }
72 // Argument is a move:
73 const move = moveOrSquare;
74 const [sx,sy,ex] = [move.start.x,move.start.y,move.end.x];
75 if (this.getPiece(sx,sy) == V.PAWN && Math.abs(sx - ex) >= 2)
76 {
77 const step = (ex-sx) / Math.abs(ex-sx);
78 let res = [{
79 x: sx + step,
80 y: sy
81 }];
82 if (sx + 2*step != ex) //3-squares move
83 {
84 res.push({
85 x: sx + 2*step,
86 y: sy
87 });
88 }
89 return res;
90 }
91 return undefined; //default
92 }
93
94 getPotentialMovesFrom([x,y])
95 {
96 switch (this.getPiece(x,y))
97 {
98 case V.CAMEL:
99 return this.getPotentialCamelMoves([x,y]);
100 case V.WILDEBEEST:
101 return this.getPotentialWildebeestMoves([x,y]);
102 default:
103 return super.getPotentialMovesFrom([x,y])
104 }
105 }
106
107 // Pawns jump 2 or 3 squares, and promote to queen or wildebeest
108 getPotentialPawnMoves([x,y])
109 {
110 const color = this.turn;
111 let moves = [];
112 const [sizeX,sizeY] = [V.size.x,V.size.y];
113 const shift = (color == "w" ? -1 : 1);
114 const startRanks = (color == "w" ? [sizeX-2,sizeX-3] : [1,2]);
115 const lastRank = (color == "w" ? 0 : sizeX-1);
116
117 if (x+shift >= 0 && x+shift < sizeX && x+shift != lastRank)
118 {
119 // Normal moves
120 if (this.board[x+shift][y] == V.EMPTY)
121 {
122 moves.push(this.getBasicMove([x,y], [x+shift,y]));
123 if (startRanks.includes(x) && this.board[x+2*shift][y] == V.EMPTY)
124 {
125 // Two squares jump
126 moves.push(this.getBasicMove([x,y], [x+2*shift,y]));
127 if (x == startRanks[0] && this.board[x+3*shift][y] == V.EMPTY)
128 {
129 // 3-squares jump
130 moves.push(this.getBasicMove([x,y], [x+3*shift,y]));
131 }
132 }
133 }
134 // Captures
135 if (y>0 && this.canTake([x,y], [x+shift,y-1])
136 && this.board[x+shift][y-1] != V.EMPTY)
137 {
138 moves.push(this.getBasicMove([x,y], [x+shift,y-1]));
139 }
140 if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1])
141 && this.board[x+shift][y+1] != V.EMPTY)
142 {
143 moves.push(this.getBasicMove([x,y], [x+shift,y+1]));
144 }
145 }
146
147 if (x+shift == lastRank)
148 {
149 // Promotion
150 let promotionPieces = [V.QUEEN,V.WILDEBEEST];
151 promotionPieces.forEach(p => {
152 // Normal move
153 if (this.board[x+shift][y] == V.EMPTY)
154 moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p}));
155 // Captures
156 if (y>0 && this.canTake([x,y], [x+shift,y-1])
157 && this.board[x+shift][y-1] != V.EMPTY)
158 {
159 moves.push(this.getBasicMove([x,y], [x+shift,y-1], {c:color,p:p}));
160 }
161 if (y<sizeY-1 && this.canTake([x,y], [x+shift,y+1])
162 && this.board[x+shift][y+1] != V.EMPTY)
163 {
164 moves.push(this.getBasicMove([x,y], [x+shift,y+1], {c:color,p:p}));
165 }
166 });
167 }
168
169 // En passant
170 const Lep = this.epSquares.length;
171 const epSquare = Lep>0 ? this.epSquares[Lep-1] : undefined;
172 if (!!epSquare)
173 {
174 for (let epsq of epSquare)
175 {
176 // TODO: some redundant checks
177 if (epsq.x == x+shift && Math.abs(epsq.y - y) == 1)
178 {
179 var enpassantMove = this.getBasicMove([x,y], [x+shift,epsq.y]);
180 enpassantMove.vanish.push({
181 x: x,
182 y: epsq.y,
183 p: 'p',
184 c: this.getColor(x,epsq.y)
185 });
186 moves.push(enpassantMove);
187 }
188 }
189 }
190
191 return moves;
192 }
193
194 // TODO: wildebeest castle
195
196 getPotentialCamelMoves(sq)
197 {
198 return this.getSlideNJumpMoves(sq, V.steps[V.CAMEL], "oneStep");
199 }
200
201 getPotentialWildebeestMoves(sq)
202 {
203 return this.getSlideNJumpMoves(
204 sq, V.steps[V.KNIGHT].concat(V.steps[V.CAMEL]), "oneStep");
205 }
206
207 isAttacked(sq, colors)
208 {
209 return super.isAttacked(sq, colors)
210 || this.isAttackedByCamel(sq, colors)
211 || this.isAttackedByWildebeest(sq, colors);
212 }
213
214 isAttackedByCamel(sq, colors)
215 {
216 return this.isAttackedBySlideNJump(sq, colors,
217 V.CAMEL, V.steps[V.CAMEL], "oneStep");
218 }
219
220 isAttackedByWildebeest(sq, colors)
221 {
222 return this.isAttackedBySlideNJump(sq, colors, V.WILDEBEEST,
223 V.steps[V.KNIGHT].concat(V.steps[V.CAMEL]), "oneStep");
224 }
225
226 checkGameEnd()
227 {
228 // No valid move: game is lost (stalemate is a win)
229 return this.turn == "w" ? "0-1" : "1-0";
230 }
231
232 static get VALUES() {
233 return Object.assign(
234 ChessRules.VALUES,
235 {'c': 3, 'w': 7} //experimental
236 );
237 }
238
239 static get SEARCH_DEPTH() { return 2; }
240
241 static GenRandInitFen()
242 {
243 let pieces = { "w": new Array(10), "b": new Array(10) };
244 for (let c of ["w","b"])
245 {
246 let positions = _.range(11);
247
248 // Get random squares for bishops + camels (different colors)
249 let randIndexes = _.sample(_.range(6), 2).map(i => { return 2*i; });
250 let bishop1Pos = positions[randIndexes[0]];
251 let camel1Pos = positions[randIndexes[1]];
252 // The second bishop (camel) must be on a square of different color
253 let randIndexes_tmp = _.sample(_.range(5), 2).map(i => { return 2*i+1; });
254 let bishop2Pos = positions[randIndexes_tmp[0]];
255 let camel2Pos = positions[randIndexes_tmp[1]];
256 for (let idx of randIndexes.concat(randIndexes_tmp)
257 .sort((a,b) => { return b-a; })) //largest indices first
258 {
259 positions.splice(idx, 1);
260 }
261
262 let randIndex = _.random(6);
263 let knight1Pos = positions[randIndex];
264 positions.splice(randIndex, 1);
265 randIndex = _.random(5);
266 let knight2Pos = positions[randIndex];
267 positions.splice(randIndex, 1);
268
269 randIndex = _.random(4);
270 let queenPos = positions[randIndex];
271 positions.splice(randIndex, 1);
272
273 // Random square for wildebeest
274 randIndex = _.random(3);
275 let wildebeestPos = positions[randIndex];
276 positions.splice(randIndex, 1);
277
278 let rook1Pos = positions[0];
279 let kingPos = positions[1];
280 let rook2Pos = positions[2];
281
282 pieces[c][rook1Pos] = 'r';
283 pieces[c][knight1Pos] = 'n';
284 pieces[c][bishop1Pos] = 'b';
285 pieces[c][queenPos] = 'q';
286 pieces[c][camel1Pos] = 'c';
287 pieces[c][camel2Pos] = 'c';
288 pieces[c][wildebeestPos] = 'w';
289 pieces[c][kingPos] = 'k';
290 pieces[c][bishop2Pos] = 'b';
291 pieces[c][knight2Pos] = 'n';
292 pieces[c][rook2Pos] = 'r';
293 }
294 return pieces["b"].join("") +
295 "/ppppppppppp/11/11/11/11/11/11/PPPPPPPPPPP/" +
296 pieces["w"].join("").toUpperCase() +
297 " w 1111 -";
298 }
299 }
300
301 const VariantRules = WildebeestRules;