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