update

[xogo.git] / variants / Coronation / class.js

diff --git a/variants/Coronation/class.js b/variants/Coronation/class.js
new file mode 100644 (file)
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+++ b/variants/Coronation/class.js
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+import ChessRules from "/base_rules.js";
+
+export default class CoronationRules extends ChessRules {
+
+  get hasSelfCaptures() {
+    return true;
+  }
+
+  canSelfTake([x1, y1], [x2, y2]) {
+    const c = this.getColor(x1, y1);
+    if (
+      this.board.some(row =>
+        row.some(square =>
+          square[0] == c && square[1] == 'q')
+      )
+    ) {
+      // Already a queen on the board: no coronation
+      return false;
+    }
+    const [p1, p2] = [this.getPiece(x1, y1), this.getPiece(x2, y2)];
+    return ((p1 == 'r' && p2 == 'b') || (p1 == 'b' && p2 == 'r'));
+  }
+
+  getPotentialMovesOf(piece, [x, y]) {
+    const res = super.getPotentialMovesOf(piece, [x, y]);
+    if (['r', 'b'].includes(piece)) {
+      res.forEach(m => {
+        if (
+          m.vanish.length == 2 &&
+          m.appear.length == 1 &&
+          m.vanish[1].c == m.vanish[0].c
+        ) {
+          m.appear[0].p = 'q';
+        }
+      });
+    }
+    return res;
+  }
+
+};