Update TODO, improve style for Crazyhouse variant, fix an introduced bug in example...
[vchess.git] / client / src / variants / Magnetic.js
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1import { ChessRules, PiPo } from "@/base_rules";
2
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3export const VariantRules = class MagneticRules extends ChessRules {
4 static get HasEnpassant() {
5 return false;
6 }
2d7194bd 7
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8 getPotentialMovesFrom([x, y]) {
9 let standardMoves = super.getPotentialMovesFrom([x, y]);
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10 let moves = [];
11 standardMoves.forEach(m => {
12 let newMove_s = this.applyMagneticLaws(m);
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13 if (newMove_s.length == 1) moves.push(newMove_s[0]);
14 //promotion
15 else moves = moves.concat(newMove_s);
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16 });
17 return moves;
18 }
2526c041 19
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20 // Complete a move with magnetic actions
21 // TODO: job is done multiple times for (normal) promotions.
6808d7a1 22 applyMagneticLaws(move) {
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23 // Exception: kings are not charged
24 if (move.appear[0].p == V.KING && move.appear.length == 1) return [move];
25 // If castling, rook is charged:
26 const aIdx = move.appear[0].p != V.KING ? 0 : 1;
6808d7a1 27 const [x, y] = [move.appear[aIdx].x, move.appear[aIdx].y];
dac39588 28 const color = this.turn;
6808d7a1 29 const lastRank = color == "w" ? 0 : 7;
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30 const standardMove = JSON.parse(JSON.stringify(move));
31 this.play(standardMove);
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32 for (let step of [
33 [-1, 0],
34 [1, 0],
35 [0, -1],
36 [0, 1]
37 ]) {
38 let [i, j] = [x + step[0], y + step[1]];
39 while (V.OnBoard(i, j)) {
40 if (this.board[i][j] != V.EMPTY) {
dac39588 41 // Found something. Same color or not?
6808d7a1 42 if (this.getColor(i, j) != color) {
dac39588 43 // Attraction
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44 if (
45 (Math.abs(i - x) >= 2 || Math.abs(j - y) >= 2) &&
46 this.getPiece(i, j) != V.KING
47 ) {
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48 move.vanish.push(
49 new PiPo({
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50 p: this.getPiece(i, j),
51 c: this.getColor(i, j),
52 x: i,
53 y: j
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54 })
55 );
56 move.appear.push(
57 new PiPo({
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58 p: this.getPiece(i, j),
59 c: this.getColor(i, j),
60 x: x + step[0],
61 y: y + step[1]
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62 })
63 );
64 }
6808d7a1 65 } else {
dac39588 66 // Repulsion
6808d7a1 67 if (this.getPiece(i, j) != V.KING) {
dac39588 68 // Push it until we meet an obstacle or edge of the board
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69 let [ii, jj] = [i + step[0], j + step[1]];
70 while (V.OnBoard(ii, jj)) {
71 if (this.board[ii][jj] != V.EMPTY) break;
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72 ii += step[0];
73 jj += step[1];
74 }
75 ii -= step[0];
76 jj -= step[1];
6808d7a1 77 if (Math.abs(ii - i) >= 1 || Math.abs(jj - j) >= 1) {
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78 move.vanish.push(
79 new PiPo({
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80 p: this.getPiece(i, j),
81 c: this.getColor(i, j),
82 x: i,
83 y: j
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84 })
85 );
86 move.appear.push(
87 new PiPo({
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88 p: this.getPiece(i, j),
89 c: this.getColor(i, j),
90 x: ii,
91 y: jj
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92 })
93 );
94 }
95 }
96 }
97 break;
98 }
99 i += step[0];
100 j += step[1];
101 }
102 }
103 this.undo(standardMove);
104 let moves = [];
105 // Scan move for pawn (max 1) on 8th rank
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106 for (let i = 1; i < move.appear.length; i++) {
107 if (
108 move.appear[i].p == V.PAWN &&
109 move.appear[i].c == color &&
110 move.appear[i].x == lastRank
111 ) {
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112 move.appear[i].p = V.ROOK;
113 moves.push(move);
6808d7a1 114 for (let piece of [V.KNIGHT, V.BISHOP, V.QUEEN]) {
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115 let cmove = JSON.parse(JSON.stringify(move));
116 cmove.appear[i].p = piece;
117 moves.push(cmove);
118 }
119 // Swap appear[i] and appear[0] for moves presentation (TODO: this is awkward)
120 moves.forEach(m => {
121 let tmp = m.appear[0];
122 m.appear[0] = m.appear[i];
123 m.appear[i] = tmp;
124 });
125 break;
126 }
127 }
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128 if (moves.length == 0)
129 //no pawn on 8th rank
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130 moves.push(move);
131 return moves;
132 }
1af36beb 133
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134 atLeastOneMove() {
135 if (this.kingPos[this.turn][0] < 0) return false;
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136 return true; //TODO: is it right?
137 }
1af36beb 138
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139 filterValid(moves) {
140 // There are no checks
141 return moves;
dac39588 142 }
1af36beb 143
6808d7a1 144 getCheckSquares() {
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145 return [];
146 }
1af36beb 147
6808d7a1 148 updateVariables(move) {
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149 super.updateVariables(move);
150 const c = move.vanish[0].c;
6808d7a1 151 if (move.vanish.length >= 2 && move.vanish[1].p == V.KING) {
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152 // We took opponent king !
153 const oppCol = V.GetOppCol(c);
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154 this.kingPos[oppCol] = [-1, -1];
155 this.castleFlags[oppCol] = [false, false];
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156 }
157 // Did we magnetically move our (init) rooks or opponents' ones ?
6808d7a1 158 const firstRank = c == "w" ? 7 : 0;
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159 const oppFirstRank = 7 - firstRank;
160 const oppCol = V.GetOppCol(c);
161 move.vanish.forEach(psq => {
162 if (psq.x == firstRank && this.INIT_COL_ROOK[c].includes(psq.y))
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163 this.castleFlags[c][psq.y == this.INIT_COL_ROOK[c][0] ? 0 : 1] = false;
164 else if (
165 psq.x == oppFirstRank &&
166 this.INIT_COL_ROOK[oppCol].includes(psq.y)
167 )
168 this.castleFlags[oppCol][
169 psq.y == this.INIT_COL_ROOK[oppCol][0] ? 0 : 1
170 ] = false;
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171 });
172 }
1af36beb 173
6808d7a1 174 unupdateVariables(move) {
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175 super.unupdateVariables(move);
176 const c = move.vanish[0].c;
177 const oppCol = V.GetOppCol(c);
6808d7a1 178 if (this.kingPos[oppCol][0] < 0) {
dac39588 179 // Last move took opponent's king
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180 for (let psq of move.vanish) {
181 if (psq.p == "k") {
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182 this.kingPos[oppCol] = [psq.x, psq.y];
183 break;
184 }
185 }
186 }
187 }
1af36beb 188
6808d7a1 189 getCurrentScore() {
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190 const color = this.turn;
191 const kp = this.kingPos[color];
6808d7a1 192 if (kp[0] < 0)
31e9e40a 193 // King disappeared
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194 return color == "w" ? "0-1" : "1-0";
195 if (this.atLeastOneMove())
196 // game not over
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197 return "*";
198 return "1/2"; //no moves but kings still there
dac39588 199 }
9e42b4dd 200
6808d7a1 201 static get THRESHOLD_MATE() {
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202 return 500; //checkmates evals may be slightly below 1000
203 }
6808d7a1 204};