Fix Dark variant when en-passant captures are possible. Credit variants authors

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

diff --git a/client/src/variants/Dark.js b/client/src/variants/Dark.js
index 3944ca1..81f8700 100644 (file)
--- a/client/src/variants/Dark.js
+++ b/client/src/variants/Dark.js
@@ -63,6 +63,19 @@ export const VariantRules = class DarkRules extends ChessRules {
       this.enlightened["w"][move.end.x][move.end.y] = true;
     for (let move of movesBlack)
       this.enlightened["b"][move.end.x][move.end.y] = true;
+    // Include en-passant capturing square if any:
+    let moves = currentTurn == "w" ? movesWhite : movesBlack;
+    for (let m of moves) {
+      if (
+        m.appear[0].p == V.PAWN &&
+        m.vanish.length == 2 &&
+        m.vanish[1].x != m.end.x
+      ) {
+        const psq = m.vanish[1];
+        this.enlightened[currentTurn][psq.x][psq.y] = true;
+        break;
+      }
+    }
   }
 
   // Has to be redefined to avoid an infinite loop
@@ -223,19 +236,18 @@ export const VariantRules = class DarkRules extends ChessRules {
 
       // Can I take something ? If yes, do it if it seems good...
       if (move.vanish.length == 2 && move.vanish[1].c != color) {
-        //avoid castle
+        // OK this isn't a castling move
         const myPieceVal = V.VALUES[move.appear[0].p];
         const hisPieceVal = V.VALUES[move.vanish[1].p];
-        if (myPieceVal <= hisPieceVal) move.eval = hisPieceVal - myPieceVal + 2;
-        //favor captures
+        // Favor captures
+        if (myPieceVal <= hisPieceVal) move.eval = hisPieceVal - myPieceVal + 1;
         else {
           // Taking a pawn with minor piece,
           // or minor piece or pawn with a rook,
           // or anything but a queen with a queen,
           // or anything with a king.
-          // ==> Do it at random, although
-          //     this is clearly inferior to what a human can deduce...
-          move.eval = Math.random() < 0.5 ? 1 : -1;
+          move.eval = hisPieceVal - myPieceVal;
+                      //Math.random() < 0.5 ? 1 : -1;
         }
       }
     }