Draft Checkless. Add 'trackKingWrap' method, untested. Use 'canSelfTake'

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

diff --git a/variants/Checkless/class.js b/variants/Checkless/class.js
new file mode 100644 (file)
index 0000000..bc85184
--- /dev/null
+++ b/variants/Checkless/class.js
@@ -0,0 +1,46 @@
+import ChessRules from "/base_rules.js";
+
+export default class ChecklessRules extends ChessRules {
+
+  // Cannot use super.atLeastOneMove: lead to infinite recursion
+  atLeastOneMove_aux(kingPos, oppKingPos, color, oppCol) {
+    for (let i = 0; i < this.size.x; i++) {
+      for (let j = 0; j < this.size.y; j++) {
+        if (this.getColor(i, j) == color) {
+          const moves = this.getPotentialMovesFrom([i, j]);
+          for (let m of moves) {
+            this.playOnBoard(m);
+            const res = this.trackKingWrap(m, kingPos, (kp) => {
+              return !this.underCheck(kp, [oppCol]);
+            });
+            this.undoOnBoard(m);
+            if (res)
+              return true;
+          }
+        }
+      }
+    }
+    return false;
+  }
+
+  filterValid(moves) {
+    fmoves = super.filterValid(moves);
+    // Filter out moves giving check but not checkmate
+    const color = this.turn;
+    const oppCol = C.GetOppTurn(color);
+    let kingPos = this.searchKingPos(color),
+        oppKingPos = this.searchKingPos(oppCol);
+    return fmoves.filter(m => {
+      this.playOnBoard(m);
+      const res = this.trackKingWrap(m, oppKingPos, (oppKp) => {
+        return (
+          !this.underCheck(oppKp, [color]) ||
+          this.atLeastOneMove_aux(oppKp, kingPos, oppCol, color)
+        );
+      });
+      this.undoOnBoard(m);
+      return res;
+    });
+  }
+
+};