f030b080317fd8655ff6230352a1c47cf5063382
[vchess.git] / client / src / variants / Suicide.js
1 import { ChessRules } from "@/base_rules";
2 import { ArrayFun } from "@/utils/array";
3 import { randInt } from "@/utils/alea";
4
5 export const VariantRules = class SuicideRules extends ChessRules {
6 static get HasFlags() {
7 return false;
8 }
9
10 getPotentialPawnMoves([x, y]) {
11 let moves = super.getPotentialPawnMoves([x, y]);
12
13 // Complete with promotion(s) into king, if possible
14 const color = this.turn;
15 const shift = color == "w" ? -1 : 1;
16 const lastRank = color == "w" ? 0 : V.size.x - 1;
17 if (x + shift == lastRank) {
18 // Normal move
19 if (this.board[x + shift][y] == V.EMPTY)
20 moves.push(
21 this.getBasicMove([x, y], [x + shift, y], { c: color, p: V.KING })
22 );
23 // Captures
24 if (
25 y > 0 &&
26 this.canTake([x, y], [x + shift, y - 1]) &&
27 this.board[x + shift][y - 1] != V.EMPTY
28 ) {
29 moves.push(
30 this.getBasicMove([x, y], [x + shift, y - 1], { c: color, p: V.KING })
31 );
32 }
33 if (
34 y < V.size.y - 1 &&
35 this.canTake([x, y], [x + shift, y + 1]) &&
36 this.board[x + shift][y + 1] != V.EMPTY
37 ) {
38 moves.push(
39 this.getBasicMove([x, y], [x + shift, y + 1], { c: color, p: V.KING })
40 );
41 }
42 }
43
44 return moves;
45 }
46
47 getPotentialKingMoves(sq) {
48 // No castle:
49 return this.getSlideNJumpMoves(
50 sq,
51 V.steps[V.ROOK].concat(V.steps[V.BISHOP]),
52 "oneStep"
53 );
54 }
55
56 // Trim all non-capturing moves (not the most efficient, but easy)
57 static KeepCaptures(moves) {
58 return moves.filter(m => m.vanish.length == 2);
59 }
60
61 // Stop at the first capture found (if any)
62 atLeastOneCapture() {
63 const color = this.turn;
64 const oppCol = V.GetOppCol(color);
65 for (let i = 0; i < V.size.x; i++) {
66 for (let j = 0; j < V.size.y; j++) {
67 if (
68 this.board[i][j] != V.EMPTY &&
69 this.getColor(i, j) != oppCol &&
70 this.getPotentialMovesFrom([i, j]).some(m => m.vanish.length == 2)
71 ) {
72 return true;
73 }
74 }
75 }
76 return false;
77 }
78
79 getPossibleMovesFrom(sq) {
80 let moves = this.getPotentialMovesFrom(sq);
81 const captureMoves = V.KeepCaptures(moves);
82 if (captureMoves.length > 0) return captureMoves;
83 if (this.atLeastOneCapture()) return [];
84 return moves;
85 }
86
87 filterValid(moves) {
88 return moves;
89 }
90
91 getAllValidMoves() {
92 const moves = super.getAllValidMoves();
93 if (moves.some(m => m.vanish.length == 2)) return V.KeepCaptures(moves);
94 return moves;
95 }
96
97 atLeastOneMove() {
98 const color = this.turn;
99 for (let i = 0; i < V.size.x; i++) {
100 for (let j = 0; j < V.size.y; j++) {
101 if (
102 this.getColor(i, j) == color &&
103 this.getPotentialMovesFrom([i, j]).length > 0
104 ) {
105 return true;
106 }
107 }
108 }
109 return false;
110 }
111
112 getCheckSquares() {
113 return [];
114 }
115
116 // No variables update because no royal king + no castling
117 updateVariables() {}
118 unupdateVariables() {}
119
120 getCurrentScore() {
121 if (this.atLeastOneMove()) return "*";
122 // No valid move: the side who cannot move wins
123 return this.turn == "w" ? "1-0" : "0-1";
124 }
125
126 static get VALUES() {
127 return {
128 p: 1,
129 r: 7,
130 n: 3,
131 b: 3,
132 q: 5,
133 k: 5
134 };
135 }
136
137 static get SEARCH_DEPTH() {
138 return 4;
139 }
140
141 evalPosition() {
142 // Less material is better:
143 return -super.evalPosition();
144 }
145
146 static GenRandInitFen(randomness) {
147 if (randomness == 0)
148 return "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w 0 -";
149
150 let pieces = { w: new Array(8), b: new Array(8) };
151 // Shuffle pieces on first and last rank
152 for (let c of ["w", "b"]) {
153 if (c == 'b' && randomness == 1) {
154 pieces['b'] = pieces['w'];
155 break;
156 }
157
158 let positions = ArrayFun.range(8);
159
160 // Get random squares for bishops
161 let randIndex = 2 * randInt(4);
162 let bishop1Pos = positions[randIndex];
163 // The second bishop must be on a square of different color
164 let randIndex_tmp = 2 * randInt(4) + 1;
165 let bishop2Pos = positions[randIndex_tmp];
166 // Remove chosen squares
167 positions.splice(Math.max(randIndex, randIndex_tmp), 1);
168 positions.splice(Math.min(randIndex, randIndex_tmp), 1);
169
170 // Get random squares for knights
171 randIndex = randInt(6);
172 let knight1Pos = positions[randIndex];
173 positions.splice(randIndex, 1);
174 randIndex = randInt(5);
175 let knight2Pos = positions[randIndex];
176 positions.splice(randIndex, 1);
177
178 // Get random square for queen
179 randIndex = randInt(4);
180 let queenPos = positions[randIndex];
181 positions.splice(randIndex, 1);
182
183 // Random square for king (no castle)
184 randIndex = randInt(3);
185 let kingPos = positions[randIndex];
186 positions.splice(randIndex, 1);
187
188 // Rooks positions are now fixed
189 let rook1Pos = positions[0];
190 let rook2Pos = positions[1];
191
192 // Finally put the shuffled pieces in the board array
193 pieces[c][rook1Pos] = "r";
194 pieces[c][knight1Pos] = "n";
195 pieces[c][bishop1Pos] = "b";
196 pieces[c][queenPos] = "q";
197 pieces[c][kingPos] = "k";
198 pieces[c][bishop2Pos] = "b";
199 pieces[c][knight2Pos] = "n";
200 pieces[c][rook2Pos] = "r";
201 }
202 return (
203 pieces["b"].join("") +
204 "/pppppppp/8/8/8/8/PPPPPPPP/" +
205 pieces["w"].join("").toUpperCase() +
206 // En-passant allowed, but no flags
207 " w 0 -"
208 );
209 }
210 };