Paco-Sako: allow castling with a rook in union + fix a bug in isAttacked()
[vchess.git] / client / src / variants / Dark.js
CommitLineData
0c3fe8a6 1import { ChessRules } from "@/base_rules";
6808d7a1 2import { ArrayFun } from "@/utils/array";
0c3fe8a6
BA
3import { randInt } from "@/utils/alea";
4
32f6285e 5export class DarkRules extends ChessRules {
7e8a7ea1 6
20620465 7 // Analyse in Dark mode makes no sense
8477e53d 8 static get CanAnalyze() {
20620465
BA
9 return false;
10 }
11
12 // Moves are revealed only when game ends
13 static get ShowMoves() {
14 return "none";
15 }
16
00eef1ca
BA
17 static get SomeHiddenMoves() {
18 return true;
19 }
20
6808d7a1 21 setOtherVariables(fen) {
dac39588 22 super.setOtherVariables(fen);
6808d7a1 23 const [sizeX, sizeY] = [V.size.x, V.size.y];
dac39588 24 this.enlightened = {
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25 w: ArrayFun.init(sizeX, sizeY),
26 b: ArrayFun.init(sizeX, sizeY)
dac39588
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27 };
28 // Setup enlightened: squares reachable by each side
29 // (TODO: one side would be enough ?)
30 this.updateEnlightened();
31 }
375ecdd1 32
6808d7a1
BA
33 updateEnlightened() {
34 for (let i = 0; i < V.size.x; i++) {
35 for (let j = 0; j < V.size.y; j++) {
dac39588
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36 this.enlightened["w"][i][j] = false;
37 this.enlightened["b"][i][j] = false;
38 }
39 }
6808d7a1 40 const pawnShift = { w: -1, b: 1 };
dac39588 41 // Initialize with pieces positions (which are seen)
6808d7a1
BA
42 for (let i = 0; i < V.size.x; i++) {
43 for (let j = 0; j < V.size.y; j++) {
44 if (this.board[i][j] != V.EMPTY) {
2c5d7b20
BA
45 const c = this.getColor(i, j);
46 this.enlightened[c][i][j] = true;
dac39588 47 // Add potential squares visible by "impossible pawn capture"
6808d7a1
BA
48 if (this.getPiece(i, j) == V.PAWN) {
49 for (let shiftY of [-1, 1]) {
50 if (
2c5d7b20
BA
51 V.OnBoard(i + pawnShift[c], j + shiftY) &&
52 this.board[i + pawnShift[c]][j + shiftY] == V.EMPTY
6808d7a1 53 ) {
2c5d7b20 54 this.enlightened[c][i + pawnShift[c]][j + shiftY] = true;
dac39588
BA
55 }
56 }
57 }
58 }
59 }
60 }
61 const currentTurn = this.turn;
62 this.turn = "w";
63 const movesWhite = this.getAllValidMoves();
64 this.turn = "b";
65 const movesBlack = this.getAllValidMoves();
66 this.turn = currentTurn;
67 for (let move of movesWhite)
68 this.enlightened["w"][move.end.x][move.end.y] = true;
69 for (let move of movesBlack)
70 this.enlightened["b"][move.end.x][move.end.y] = true;
d048c4c9
BA
71 // Include en-passant capturing square if any:
72 let moves = currentTurn == "w" ? movesWhite : movesBlack;
73 for (let m of moves) {
74 if (
75 m.appear[0].p == V.PAWN &&
76 m.vanish.length == 2 &&
77 m.vanish[1].x != m.end.x
78 ) {
79 const psq = m.vanish[1];
80 this.enlightened[currentTurn][psq.x][psq.y] = true;
81 break;
82 }
83 }
dac39588 84 }
375ecdd1 85
c3d16e78
BA
86 filterValid(moves) {
87 // Used in the interface
88 return moves;
89 }
90
dac39588 91 // Has to be redefined to avoid an infinite loop
6808d7a1 92 getAllValidMoves() {
dac39588 93 const color = this.turn;
dac39588 94 let potentialMoves = [];
6808d7a1
BA
95 for (let i = 0; i < V.size.x; i++) {
96 for (let j = 0; j < V.size.y; j++) {
97 if (this.board[i][j] != V.EMPTY && this.getColor(i, j) == color)
98 Array.prototype.push.apply(
99 potentialMoves,
100 this.getPotentialMovesFrom([i, j])
101 );
dac39588
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102 }
103 }
104 return potentialMoves; //because there are no checks
105 }
f6dbe8e3 106
6808d7a1 107 getCheckSquares() {
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108 return [];
109 }
375ecdd1 110
3a2a7b5f
BA
111 postPlay(move) {
112 super.postPlay(move);
737a5daf 113 if (move.vanish.length == 2 && move.vanish[1].p == V.KING)
241bf8f2 114 // We took opponent king (because if castle vanish[1] is a rook)
6808d7a1 115 this.kingPos[this.turn] = [-1, -1];
388e4c40 116
dac39588
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117 // Update lights for both colors:
118 this.updateEnlightened();
119 }
388e4c40 120
3a2a7b5f
BA
121 postUndo(move) {
122 super.postUndo(move);
737a5daf 123 if (move.vanish.length == 2 && move.vanish[1].p == V.KING)
241bf8f2 124 // Last move took opponent's king:
737a5daf 125 this.kingPos[move.vanish[1].c] = [move.vanish[1].x, move.vanish[1].y];
388e4c40 126
dac39588
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127 // Update lights for both colors:
128 this.updateEnlightened();
129 }
375ecdd1 130
6808d7a1 131 getCurrentScore() {
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132 const color = this.turn;
133 const kp = this.kingPos[color];
6808d7a1 134 if (kp[0] < 0)
241bf8f2 135 // King disappeared
6808d7a1 136 return color == "w" ? "0-1" : "1-0";
241bf8f2
BA
137 // Assume that stalemate is impossible (I think so. Would need proof...)
138 return "*";
dac39588 139 }
375ecdd1 140
6808d7a1 141 static get THRESHOLD_MATE() {
dac39588
BA
142 return 500; //checkmates evals may be slightly below 1000
143 }
5915f720 144
dac39588 145 // In this special situation, we just look 1 half move ahead
6808d7a1 146 getComputerMove() {
dac39588
BA
147 const maxeval = V.INFINITY;
148 const color = this.turn;
149 const oppCol = V.GetOppCol(color);
6808d7a1 150 const pawnShift = color == "w" ? -1 : 1;
5915f720 151
dac39588
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152 // Do not cheat: the current enlightment is all we can see
153 const myLight = JSON.parse(JSON.stringify(this.enlightened[color]));
5915f720 154
dac39588
BA
155 // Can a slider on (i,j) apparently take my king?
156 // NOTE: inaccurate because assume yes if some squares are shadowed
6808d7a1 157 const sliderTake = ([i, j], piece) => {
dac39588
BA
158 const kp = this.kingPos[color];
159 let step = undefined;
6808d7a1
BA
160 if (piece == V.BISHOP) {
161 if (Math.abs(kp[0] - i) == Math.abs(kp[1] - j)) {
162 step = [
163 (i - kp[0]) / Math.abs(i - kp[0]),
164 (j - kp[1]) / Math.abs(j - kp[1])
dac39588
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165 ];
166 }
6808d7a1
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167 } else if (piece == V.ROOK) {
168 if (kp[0] == i) step = [0, (j - kp[1]) / Math.abs(j - kp[1])];
169 else if (kp[1] == j) step = [(i - kp[0]) / Math.abs(i - kp[0]), 0];
dac39588 170 }
6808d7a1 171 if (!step) return false;
dac39588
BA
172 // Check for obstacles
173 let obstacle = false;
174 for (
6808d7a1 175 let x = kp[0] + step[0], y = kp[1] + step[1];
dac39588 176 x != i && y != j;
6808d7a1
BA
177 x += step[0], y += step[1]
178 ) {
179 if (myLight[x][y] && this.board[x][y] != V.EMPTY) {
dac39588
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180 obstacle = true;
181 break;
182 }
183 }
6808d7a1 184 if (!obstacle) return true;
dac39588
BA
185 return false;
186 };
5915f720 187
dac39588
BA
188 // Do I see something which can take my king ?
189 const kingThreats = () => {
190 const kp = this.kingPos[color];
6808d7a1
BA
191 for (let i = 0; i < V.size.x; i++) {
192 for (let j = 0; j < V.size.y; j++) {
193 if (
194 myLight[i][j] &&
195 this.board[i][j] != V.EMPTY &&
196 this.getColor(i, j) != color
197 ) {
198 switch (this.getPiece(i, j)) {
dac39588 199 case V.PAWN:
6808d7a1 200 if (kp[0] + pawnShift == i && Math.abs(kp[1] - j) == 1)
dac39588
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201 return true;
202 break;
203 case V.KNIGHT:
6808d7a1
BA
204 if (
205 (Math.abs(kp[0] - i) == 2 && Math.abs(kp[1] - j) == 1) ||
206 (Math.abs(kp[0] - i) == 1 && Math.abs(kp[1] - j) == 2)
207 ) {
dac39588
BA
208 return true;
209 }
210 break;
211 case V.KING:
212 if (Math.abs(kp[0] - i) == 1 && Math.abs(kp[1] - j) == 1)
213 return true;
214 break;
215 case V.BISHOP:
6808d7a1 216 if (sliderTake([i, j], V.BISHOP)) return true;
dac39588
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217 break;
218 case V.ROOK:
6808d7a1 219 if (sliderTake([i, j], V.ROOK)) return true;
dac39588
BA
220 break;
221 case V.QUEEN:
6808d7a1 222 if (sliderTake([i, j], V.BISHOP) || sliderTake([i, j], V.ROOK))
dac39588
BA
223 return true;
224 break;
225 }
226 }
227 }
228 }
229 return false;
230 };
5915f720 231
dac39588 232 let moves = this.getAllValidMoves();
6808d7a1 233 for (let move of moves) {
dac39588 234 this.play(move);
6808d7a1 235 if (this.kingPos[oppCol][0] >= 0 && kingThreats()) {
dac39588
BA
236 // We didn't take opponent king, and our king will be captured: bad
237 move.eval = -maxeval;
238 }
239 this.undo(move);
4f518610 240
6808d7a1 241 if (move.eval) continue;
5915f720 242
dac39588 243 move.eval = 0; //a priori...
5915f720 244
dac39588 245 // Can I take something ? If yes, do it if it seems good...
6808d7a1 246 if (move.vanish.length == 2 && move.vanish[1].c != color) {
71ef1664 247 // OK this isn't a castling move
dac39588
BA
248 const myPieceVal = V.VALUES[move.appear[0].p];
249 const hisPieceVal = V.VALUES[move.vanish[1].p];
71ef1664 250 // Favor captures
2c5d7b20
BA
251 if (myPieceVal <= hisPieceVal)
252 move.eval = hisPieceVal - myPieceVal + 1;
6808d7a1 253 else {
dac39588
BA
254 // Taking a pawn with minor piece,
255 // or minor piece or pawn with a rook,
256 // or anything but a queen with a queen,
257 // or anything with a king.
71ef1664
BA
258 move.eval = hisPieceVal - myPieceVal;
259 //Math.random() < 0.5 ? 1 : -1;
dac39588
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260 }
261 }
262 }
5915f720 263
dac39588
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264 // TODO: also need to implement the case when an opponent piece (in light)
265 // is threatening something - maybe not the king, but e.g. pawn takes rook.
5915f720 266
6808d7a1 267 moves.sort((a, b) => b.eval - a.eval);
dac39588 268 let candidates = [0];
6808d7a1 269 for (let j = 1; j < moves.length && moves[j].eval == moves[0].eval; j++)
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BA
270 candidates.push(j);
271 return moves[candidates[randInt(candidates.length)]];
272 }
7e8a7ea1 273
6808d7a1 274};