Some fixes, and add 2 variants: Checkless and Parachute
[vchess.git] / client / src / variants / Atomic.js
1 import { ChessRules, PiPo } from "@/base_rules";
2
3 export class AtomicRules extends ChessRules {
4 getPotentialMovesFrom([x, y]) {
5 let moves = super.getPotentialMovesFrom([x, y]);
6
7 // Handle explosions
8 moves.forEach(m => {
9 // NOTE: if vanish.length==2 and appear.length==2, this is castle
10 if (m.vanish.length > 1 && m.appear.length <= 1) {
11 // Explosion! (TODO?: drop moves which explode our king here)
12 let steps = [
13 [-1, -1],
14 [-1, 0],
15 [-1, 1],
16 [0, -1],
17 [0, 1],
18 [1, -1],
19 [1, 0],
20 [1, 1]
21 ];
22 for (let step of steps) {
23 let x = m.end.x + step[0];
24 let y = m.end.y + step[1];
25 if (
26 V.OnBoard(x, y) &&
27 this.board[x][y] != V.EMPTY &&
28 this.getPiece(x, y) != V.PAWN
29 ) {
30 m.vanish.push(
31 new PiPo({
32 p: this.getPiece(x, y),
33 c: this.getColor(x, y),
34 x: x,
35 y: y
36 })
37 );
38 }
39 }
40 m.end = { x: m.appear[0].x, y: m.appear[0].y };
41 m.appear.pop(); //Nothin appears in this case
42 }
43 });
44
45 return moves;
46 }
47
48 getPotentialKingMoves([x, y]) {
49 // King cannot capture:
50 let moves = [];
51 const steps = V.steps[V.ROOK].concat(V.steps[V.BISHOP]);
52 for (let step of steps) {
53 const i = x + step[0];
54 const j = y + step[1];
55 if (V.OnBoard(i, j) && this.board[i][j] == V.EMPTY)
56 moves.push(this.getBasicMove([x, y], [i, j]));
57 }
58 return moves.concat(this.getCastleMoves([x, y]));
59 }
60
61 isAttacked(sq, color) {
62 if (
63 this.getPiece(sq[0], sq[1]) == V.KING &&
64 this.isAttackedByKing(sq, color)
65 ) {
66 // A king next to the enemy king is immune to attacks
67 return false;
68 }
69 return (
70 this.isAttackedByPawn(sq, color) ||
71 this.isAttackedByRook(sq, color) ||
72 this.isAttackedByKnight(sq, color) ||
73 this.isAttackedByBishop(sq, color) ||
74 this.isAttackedByQueen(sq, color)
75 // No "attackedByKing": it cannot take
76 );
77 }
78
79 postPlay(move) {
80 super.postPlay(move);
81 if (move.appear.length == 0) {
82 // Capture
83 const firstRank = { w: 7, b: 0 };
84 for (let c of ["w", "b"]) {
85 // Did we explode king of color c ? (TODO: remove move earlier)
86 if (
87 Math.abs(this.kingPos[c][0] - move.end.x) <= 1 &&
88 Math.abs(this.kingPos[c][1] - move.end.y) <= 1
89 ) {
90 this.kingPos[c] = [-1, -1];
91 this.castleFlags[c] = [8, 8];
92 } else {
93 // Now check if init rook(s) exploded
94 if (Math.abs(move.end.x - firstRank[c]) <= 1) {
95 if (Math.abs(move.end.y - this.castleFlags[c][0]) <= 1)
96 this.castleFlags[c][0] = 8;
97 if (Math.abs(move.end.y - this.castleFlags[c][1]) <= 1)
98 this.castleFlags[c][1] = 8;
99 }
100 }
101 }
102 }
103 }
104
105 postUndo(move) {
106 super.postUndo(move);
107 const c = this.turn;
108 const oppCol = V.GetOppCol(c);
109 if ([this.kingPos[c][0], this.kingPos[oppCol][0]].some(e => e < 0)) {
110 // There is a chance that last move blowed some king away..
111 for (let psq of move.vanish) {
112 if (psq.p == "k")
113 this.kingPos[psq.c == c ? c : oppCol] = [psq.x, psq.y];
114 }
115 }
116 }
117
118 underCheck(color) {
119 const oppCol = V.GetOppCol(color);
120 let res = undefined;
121 // If our king disappeared, move is not valid
122 if (this.kingPos[color][0] < 0) res = true;
123 // If opponent king disappeared, move is valid
124 else if (this.kingPos[oppCol][0] < 0) res = false;
125 // Otherwise, if we remain under check, move is not valid
126 else res = this.isAttacked(this.kingPos[color], oppCol);
127 return res;
128 }
129
130 getCheckSquares(color) {
131 let res = [];
132 if (
133 this.kingPos[color][0] >= 0 && //king might have exploded
134 this.isAttacked(this.kingPos[color], V.GetOppCol(color))
135 ) {
136 res = [JSON.parse(JSON.stringify(this.kingPos[color]))];
137 }
138 return res;
139 }
140
141 getCurrentScore() {
142 const color = this.turn;
143 const kp = this.kingPos[color];
144 if (kp[0] < 0)
145 // King disappeared
146 return color == "w" ? "0-1" : "1-0";
147 if (this.atLeastOneMove()) return "*";
148 if (!this.isAttacked(kp, V.GetOppCol(color))) return "1/2";
149 return color == "w" ? "0-1" : "1-0"; //checkmate
150 }
151 };