Draft Hiddenqueen, Grasshopper and Knightmate chess (rules unwritten)

[vchess.git] / client / src / variants / Hiddenqueen.js

diff --git a/client/src/variants/Hiddenqueen.js b/client/src/variants/Hiddenqueen.js
new file mode 100644 (file)
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+++ b/client/src/variants/Hiddenqueen.js
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+import { ChessRules, PiPo, Move } from "@/base_rules";
+import { ArrayFun } from "@/utils/array";
+import { randInt } from "@/utils/alea";
+
+export const VariantRules = class HiddenqueenRules extends ChessRules {
+  // Analyse in Hiddenqueen mode makes no sense
+  static get CanAnalyze() {
+    return false;
+  }
+
+  static get HIDDEN_QUEEN() {
+    return 't';
+  }
+
+  static get PIECES() {
+    return ChessRules.PIECES.concat(Object.values(V.HIDDEN_CODE));
+  }
+
+  getPiece(i, j) {
+    const piece = this.board[i][j].charAt(1);
+    if (
+      piece != V.HIDDEN_QUEEN ||
+      // 'side' is used to determine what I see: a pawn or a (hidden)queen?
+      this.getColor(i, j) == this.side
+    ) {
+      return piece;
+    }
+    return V.PAWN;
+  }
+
+  getPpath(b, color, score) {
+    if (b[1] == V.HIDDEN_QUEEN) {
+      // Supposed to be hidden.
+      if (score == "*" && (!color || color != b[0]))
+        return b[0] + "p";
+      return "Hiddenqueen/" + b[0] + "t";
+    }
+    return b;
+  }
+
+  isValidPawnMove(move) {
+    const color = move.vanish[0].c;
+    const pawnShift = color == "w" ? -1 : 1;
+    const startRank = color == "w" ? V.size.x - 2 : 1;
+    const lastRank = color == "w" ? 0 : V.size.x - 1;
+    return (
+      // The queen is discovered if she reaches the 8th rank,
+      // even if this would be a technically valid pawn move.
+      move.end.x != lastRank &&
+      (
+        (
+          move.end.x - move.start.x == pawnShift &&
+          (
+            (
+              // Normal move
+              move.end.y == move.start.y &&
+              this.board[move.end.x][move.end.y] == V.EMPTY
+            )
+            ||
+            (
+              // Capture
+              Math.abs(move.end.y - move.start.y) == 1 &&
+              this.board[move.end.x][move.end.y] != V.EMPTY
+            )
+          )
+        )
+        ||
+        (
+          // Two-spaces initial jump
+          move.start.x == startRank &&
+          move.end.y == move.start.y &&
+          move.end.x - move.start.x == 2 * pawnShift &&
+          this.board[move.end.x][move.end.y] == V.EMPTY
+        )
+      )
+    );
+  }
+
+  getPotentialMovesFrom([x, y]) {
+    if (this.getPiece(x, y) == V.HIDDEN_QUEEN) {
+      const pawnMoves = super.getPotentialPawnMoves([x, y]);
+      let queenMoves = super.getPotentialQueenMoves([x, y]);
+      // Remove from queen moves those corresponding to a pawn move:
+      queenMoves = queenMoves
+        .filter(m => !this.isValidPawnMove(m))
+        // Hidden queen is revealed if moving like a queen:
+        .map(m => {
+          m.appear[0].p = V.QUEEN;
+          return m;
+        });
+      return pawnMoves.concat(queenMoves);
+    }
+    return super.getPotentialMovesFrom([x, y]);
+  }
+
+  getPossibleMovesFrom(sq) {
+    this.side = this.turn;
+    return this.filterValid(this.getPotentialMovesFrom(sq));
+  }
+
+  static GenRandInitFen() {
+    let fen = ChessRules.GenRandInitFen();
+    // Place hidden queens at random:
+    let hiddenQueenPos = randInt(8);
+    let pawnRank = "PPPPPPPP".split("");
+    pawnRank[hiddenQueenPos] = "T";
+    fen = fen.replace("PPPPPPPP", pawnRank.join(""));
+    hiddenQueenPos = randInt(8);
+    pawnRank = "pppppppp".split("");
+    pawnRank[hiddenQueenPos] = "t";
+    fen = fen.replace("pppppppp", pawnRank.join(""));
+    return fen;
+  }
+
+  updateVariables(move) {
+    super.updateVariables(move);
+    if (move.vanish.length == 2 && move.vanish[1].p == V.KING)
+      // We took opponent king
+      this.kingPos[this.turn] = [-1, -1];
+  }
+
+  unupdateVariables(move) {
+    super.unupdateVariables(move);
+    const c = move.vanish[0].c;
+    const oppCol = V.GetOppCol(c);
+    if (this.kingPos[oppCol][0] < 0)
+      // Last move took opponent's king:
+      this.kingPos[oppCol] = [move.vanish[1].x, move.vanish[1].y];
+  }
+
+  getCurrentScore() {
+    const color = this.turn;
+    if (this.kingPos[color][0] < 0)
+      // King disappeared
+      return color == "w" ? "0-1" : "1-0";
+    return super.getCurrentScore();
+  }
+
+  // Search is biased, so not really needed to explore deeply
+  static get SEARCH_DEPTH() {
+    return 2;
+  }
+
+  static get VALUES() {
+    return Object.assign(
+      { t: 9 },
+      ChessRules.VALUES
+    );
+  }
+
+  getComputerMove() {
+    this.side = this.turn;
+    return super.getComputerMove();
+  }
+};