Early draft of Wildebeest + Grand
[vchess.git] / public / javascripts / variants / Zen.js
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1class ZenRules extends ChessRules
2{
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3 // NOTE: enPassant, if enabled, would need to redefine carefully getEpSquare
4 getEpSquare(move)
5 {
6 return undefined;
7 }
8
1d184b4c 9 // TODO: some duplicated code in 2 next functions
46302e64 10 getSlideNJumpMoves([x,y], steps, oneStep)
1d184b4c 11 {
46302e64 12 const color = this.getColor(x,y);
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13 var moves = [];
14 let [sizeX,sizeY] = VariantRules.size;
15 outerLoop:
16 for (var loop=0; loop<steps.length; loop++)
17 {
18 var step = steps[loop];
19 var i = x + step[0];
20 var j = y + step[1];
21 while (i>=0 && i<sizeX && j>=0 && j<sizeY
22 && this.board[i][j] == VariantRules.EMPTY)
23 {
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24 moves.push(this.getBasicMove([x,y], [i,j]));
25 if (!!oneStep)
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26 continue outerLoop;
27 i += step[0];
28 j += step[1];
29 }
30 // No capture check: handled elsewhere (next method)
31 }
32 return moves;
33 }
34
35 // follow steps from x,y until something is met.
36 // if met piece is opponent and same movement (asA): eat it!
46302e64 37 findCaptures_aux([x,y], asA)
1d184b4c 38 {
46302e64 39 const color = this.getColor(x,y);
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40 var moves = [];
41 var V = VariantRules;
42 var steps = asA != V.PAWN
43 ? V.steps[asA]
44 : color=='w' ? [[-1,-1],[-1,1]] : [[1,-1],[1,1]];
45 var oneStep = (asA==V.KNIGHT || asA==V.PAWN); //we don't capture king
46 let [sizeX,sizeY] = V.size;
47 let lastRank = (color == 'w' ? 0 : sizeY-1);
48 let promotionPieces = [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN];
49 outerLoop:
50 for (var loop=0; loop<steps.length; loop++)
51 {
52 var step = steps[loop];
53 var i = x + step[0];
54 var j = y + step[1];
55 while (i>=0 && i<sizeX && j>=0 && j<sizeY
56 && this.board[i][j] == V.EMPTY)
57 {
58 if (oneStep)
59 continue outerLoop;
60 i += step[0];
61 j += step[1];
62 }
63 if (i>=0 && i<sizeX && j>=0 && j<sizeY &&
64 this.getColor(i,j) == this.getOppCol(color) && this.getPiece(i,j) == asA)
65 {
66 // eat!
67 if (this.getPiece(x,y) == V.PAWN && i == lastRank)
68 {
69 // Special case of promotion:
70 promotionPieces.forEach(p => {
46302e64 71 moves.push(this.getBasicMove([x,y], [i,j], {c:color,p:p}));
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72 });
73 }
74 else
75 {
76 // All other cases
46302e64 77 moves.push(this.getBasicMove([x,y], [i,j]));
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78 }
79 }
80 }
81 return moves;
82 }
83
84 // Find possible captures from a square: look in every direction!
46302e64 85 findCaptures(sq)
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86 {
87 var moves = [];
88
89 // PAWN
46302e64 90 Array.prototype.push.apply(moves, this.findCaptures_aux(sq, VariantRules.PAWN));
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91
92 // ROOK
46302e64 93 Array.prototype.push.apply(moves, this.findCaptures_aux(sq, VariantRules.ROOK));
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94
95 // KNIGHT
46302e64 96 Array.prototype.push.apply(moves, this.findCaptures_aux(sq, VariantRules.KNIGHT));
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97
98 // BISHOP
46302e64 99 Array.prototype.push.apply(moves, this.findCaptures_aux(sq, VariantRules.BISHOP));
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100
101 // QUEEN
46302e64 102 Array.prototype.push.apply(moves, this.findCaptures_aux(sq, VariantRules.QUEEN));
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103
104 return moves;
105 }
106
46302e64 107 getPotentialPawnMoves([x,y])
1d184b4c 108 {
46302e64 109 const color = this.getColor(x,y);
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110 var moves = [];
111 var V = VariantRules;
112 let [sizeX,sizeY] = VariantRules.size;
113 let shift = (color == 'w' ? -1 : 1);
114 let startRank = (color == 'w' ? sizeY-2 : 1);
01ca2adc 115 let firstRank = (color == 'w' ? sizeY-1 : 0);
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116 let lastRank = (color == "w" ? 0 : sizeY-1);
117
118 if (x+shift >= 0 && x+shift < sizeX && x+shift != lastRank)
119 {
120 // Normal moves
121 if (this.board[x+shift][y] == V.EMPTY)
122 {
46302e64 123 moves.push(this.getBasicMove([x,y], [x+shift,y]));
01ca2adc 124 if ([startRank,firstRank].includes(x) && this.board[x+2*shift][y] == V.EMPTY)
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125 {
126 //two squares jump
46302e64 127 moves.push(this.getBasicMove([x,y], [x+2*shift,y]));
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128 }
129 }
130 }
131
132 if (x+shift == lastRank)
133 {
134 // Promotion
135 let promotionPieces = [V.ROOK,V.KNIGHT,V.BISHOP,V.QUEEN];
136 promotionPieces.forEach(p => {
137 // Normal move
138 if (this.board[x+shift][y] == V.EMPTY)
46302e64 139 moves.push(this.getBasicMove([x,y], [x+shift,y], {c:color,p:p}));
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140 });
141 }
142
33ee1916 143 // No en passant here
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144
145 // Add "zen" captures
46302e64 146 Array.prototype.push.apply(moves, this.findCaptures([x,y]));
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147
148 return moves;
149 }
150
46302e64 151 getPotentialRookMoves(sq)
1d184b4c 152 {
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153 let noCaptures = this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.ROOK]);
154 let captures = this.findCaptures(sq);
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155 return noCaptures.concat(captures);
156 }
157
46302e64 158 getPotentialKnightMoves(sq)
1d184b4c 159 {
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160 let noCaptures = this.getSlideNJumpMoves(sq,
161 VariantRules.steps[VariantRules.KNIGHT], "oneStep");
46302e64 162 let captures = this.findCaptures(sq);
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163 return noCaptures.concat(captures);
164 }
165
46302e64 166 getPotentialBishopMoves(sq)
1d184b4c 167 {
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168 let noCaptures = this.getSlideNJumpMoves(sq, VariantRules.steps[VariantRules.BISHOP]);
169 let captures = this.findCaptures(sq);
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170 return noCaptures.concat(captures);
171 }
172
46302e64 173 getPotentialQueenMoves(sq)
1d184b4c 174 {
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175 const V = VariantRules;
176 let noCaptures = this.getSlideNJumpMoves(sq, V.steps[V.ROOK.concat(V.steps[V.BISHOP])]);
46302e64 177 let captures = this.findCaptures(sq);
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178 return noCaptures.concat(captures);
179 }
180
46302e64 181 getPotentialKingMoves(sq)
1d184b4c 182 {
a37076f1 183 const V = VariantRules;
1d184b4c 184 // Initialize with normal moves
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185 let noCaptures = this.getSlideNJumpMoves(sq,
186 V.steps[V.ROOK].concat(V.steps[V.BISHOP]), "oneStep");
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187 let captures = this.findCaptures(sq);
188 return noCaptures.concat(captures).concat(this.getCastleMoves(sq));
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189 }
190
191 getNotation(move)
192 {
193 // Recognize special moves first
194 if (move.appear.length == 2)
195 {
196 // castle
197 if (move.end.y < move.start.y)
198 return "0-0-0";
199 else
200 return "0-0";
201 }
202
203 // Translate initial square (because pieces may fly unusually in this variant!)
204 let initialSquare =
205 String.fromCharCode(97 + move.start.y) + (VariantRules.size[0]-move.start.x);
206
207 // Translate final square
208 let finalSquare =
209 String.fromCharCode(97 + move.end.y) + (VariantRules.size[0]-move.end.x);
210
211 let notation = "";
52b1e238 212 let piece = this.getPiece(move.start.x, move.start.y);
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213 if (piece == VariantRules.PAWN)
214 {
215 // pawn move (TODO: enPassant indication)
216 if (move.vanish.length > 1)
217 {
218 // capture
219 notation = initialSquare + "x" + finalSquare;
220 }
221 else //no capture
222 notation = finalSquare;
223 if (piece != move.appear[0].p) //promotion
224 notation += "=" + move.appear[0].p.toUpperCase();
225 }
226
227 else
228 {
229 // Piece movement
230 notation = piece.toUpperCase();
231 if (move.vanish.length > 1)
232 notation += initialSquare + "x";
233 notation += finalSquare;
234 }
235 return notation;
236 }
237
238 static get VALUES() { //TODO: experimental
239 return {
240 'p': 1,
241 'r': 3,
242 'n': 2,
243 'b': 2,
244 'q': 5,
245 'k': 1000
246 }
247 }
248}