Draft Hiddenqueen, Grasshopper and Knightmate chess (rules unwritten)
[vchess.git] / client / src / variants / Hiddenqueen.js
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BA
1import { ChessRules, PiPo, Move } from "@/base_rules";
2import { ArrayFun } from "@/utils/array";
3import { randInt } from "@/utils/alea";
4
5export const VariantRules = class HiddenqueenRules extends ChessRules {
6 // Analyse in Hiddenqueen mode makes no sense
7 static get CanAnalyze() {
8 return false;
9 }
10
11 static get HIDDEN_QUEEN() {
12 return 't';
13 }
14
15 static get PIECES() {
16 return ChessRules.PIECES.concat(Object.values(V.HIDDEN_CODE));
17 }
18
19 getPiece(i, j) {
20 const piece = this.board[i][j].charAt(1);
21 if (
22 piece != V.HIDDEN_QUEEN ||
23 // 'side' is used to determine what I see: a pawn or a (hidden)queen?
24 this.getColor(i, j) == this.side
25 ) {
26 return piece;
27 }
28 return V.PAWN;
29 }
30
31 getPpath(b, color, score) {
32 if (b[1] == V.HIDDEN_QUEEN) {
33 // Supposed to be hidden.
34 if (score == "*" && (!color || color != b[0]))
35 return b[0] + "p";
36 return "Hiddenqueen/" + b[0] + "t";
37 }
38 return b;
39 }
40
41 isValidPawnMove(move) {
42 const color = move.vanish[0].c;
43 const pawnShift = color == "w" ? -1 : 1;
44 const startRank = color == "w" ? V.size.x - 2 : 1;
45 const lastRank = color == "w" ? 0 : V.size.x - 1;
46 return (
47 // The queen is discovered if she reaches the 8th rank,
48 // even if this would be a technically valid pawn move.
49 move.end.x != lastRank &&
50 (
51 (
52 move.end.x - move.start.x == pawnShift &&
53 (
54 (
55 // Normal move
56 move.end.y == move.start.y &&
57 this.board[move.end.x][move.end.y] == V.EMPTY
58 )
59 ||
60 (
61 // Capture
62 Math.abs(move.end.y - move.start.y) == 1 &&
63 this.board[move.end.x][move.end.y] != V.EMPTY
64 )
65 )
66 )
67 ||
68 (
69 // Two-spaces initial jump
70 move.start.x == startRank &&
71 move.end.y == move.start.y &&
72 move.end.x - move.start.x == 2 * pawnShift &&
73 this.board[move.end.x][move.end.y] == V.EMPTY
74 )
75 )
76 );
77 }
78
79 getPotentialMovesFrom([x, y]) {
80 if (this.getPiece(x, y) == V.HIDDEN_QUEEN) {
81 const pawnMoves = super.getPotentialPawnMoves([x, y]);
82 let queenMoves = super.getPotentialQueenMoves([x, y]);
83 // Remove from queen moves those corresponding to a pawn move:
84 queenMoves = queenMoves
85 .filter(m => !this.isValidPawnMove(m))
86 // Hidden queen is revealed if moving like a queen:
87 .map(m => {
88 m.appear[0].p = V.QUEEN;
89 return m;
90 });
91 return pawnMoves.concat(queenMoves);
92 }
93 return super.getPotentialMovesFrom([x, y]);
94 }
95
96 getPossibleMovesFrom(sq) {
97 this.side = this.turn;
98 return this.filterValid(this.getPotentialMovesFrom(sq));
99 }
100
101 static GenRandInitFen() {
102 let fen = ChessRules.GenRandInitFen();
103 // Place hidden queens at random:
104 let hiddenQueenPos = randInt(8);
105 let pawnRank = "PPPPPPPP".split("");
106 pawnRank[hiddenQueenPos] = "T";
107 fen = fen.replace("PPPPPPPP", pawnRank.join(""));
108 hiddenQueenPos = randInt(8);
109 pawnRank = "pppppppp".split("");
110 pawnRank[hiddenQueenPos] = "t";
111 fen = fen.replace("pppppppp", pawnRank.join(""));
112 return fen;
113 }
114
115 updateVariables(move) {
116 super.updateVariables(move);
117 if (move.vanish.length == 2 && move.vanish[1].p == V.KING)
118 // We took opponent king
119 this.kingPos[this.turn] = [-1, -1];
120 }
121
122 unupdateVariables(move) {
123 super.unupdateVariables(move);
124 const c = move.vanish[0].c;
125 const oppCol = V.GetOppCol(c);
126 if (this.kingPos[oppCol][0] < 0)
127 // Last move took opponent's king:
128 this.kingPos[oppCol] = [move.vanish[1].x, move.vanish[1].y];
129 }
130
131 getCurrentScore() {
132 const color = this.turn;
133 if (this.kingPos[color][0] < 0)
134 // King disappeared
135 return color == "w" ? "0-1" : "1-0";
136 return super.getCurrentScore();
137 }
138
139 // Search is biased, so not really needed to explore deeply
140 static get SEARCH_DEPTH() {
141 return 2;
142 }
143
144 static get VALUES() {
145 return Object.assign(
146 { t: 9 },
147 ChessRules.VALUES
148 );
149 }
150
151 getComputerMove() {
152 this.side = this.turn;
153 return super.getComputerMove();
154 }
155};