From 5b460b241c334dc0d5e1f5768c12c0b3e65bdc36 Mon Sep 17 00:00:00 2001
From: Benjamin Auder <benjamin.auder@somewhere>
Date: Thu, 30 Apr 2026 16:48:10 +0200
Subject: [PATCH] Some more code in 8-pieces

---
 base_rules.js                 |  8 +++---
 variants/Eightpieces/class.js | 47 ++++++++++++++++++++++++++++++-----
 2 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/base_rules.js b/base_rules.js
index b73776b..3866aa3 100644
--- a/base_rules.js
+++ b/base_rules.js
@@ -1375,7 +1375,8 @@ export default class ChessRules {
     return !this.isKing(x2, y2);
   }
 
-  canStepOver(i, j, p) {
+    // Can piece p (of color c) step over square i, j ?
+  canStepOver(i, j, p, c) {
     // In some variants, objects on boards don't stop movement (Chakart)
     return this.board[i][j] == "";
   }
@@ -1778,6 +1779,7 @@ export default class ChessRules {
     if (!allowed)
       allowed = (sq1, sq2) => this.canTake(sq1, sq2);
     const apparentPiece = this.getPiece(x, y); //how it looks
+    const c = this.getColor(x, y);
     let res = [];
     // Next 3 for Cylinder mode or circular (useless otherwise)
     let explored = {};
@@ -1798,7 +1800,7 @@ export default class ChessRules {
           let stepCounter = 0;
           while (
             this.onBoard(i, j) &&
-            ((i == x && j == y) || this.canStepOver(i, j, apparentPiece))
+            ((i == x && j == y) || this.canStepOver(i, j, apparentPiece, c))
           ) {
             if (!explored[i + "." + j] && (i != x || j != y)) {
               explored[i + "." + j] = true;
@@ -1878,7 +1880,7 @@ export default class ChessRules {
         ) {
           const apparentPiece = this.getPiece(i, j);
           // Quick check: does this potential attacker target x,y ?
-          if (this.canStepOver(x, y, apparentPiece))
+          if (this.canStepOver(x, y, apparentPiece, colIJ))
             continue;
           const stepSpec = this.getStepSpec(colIJ, i, j);
           if (stepSpec.indirectAttack) //e.g. 8-pieces (only?)
diff --git a/variants/Eightpieces/class.js b/variants/Eightpieces/class.js
index 70f3296..f836570 100644
--- a/variants/Eightpieces/class.js
+++ b/variants/Eightpieces/class.js
@@ -9,8 +9,7 @@ export default class EightpiecesRules extends ChessRules {
     return {
       select: C.Options.select,
       input: C.Options.input,
-      styles: ["crazyhouse", "cylinder", "doublemove", "progressive",
-        "recycle", "rifle", "teleport", "zen"]
+      styles: ["crazyhouse", "cylinder", "recycle", "teleport"]
     };
   }
 
@@ -143,6 +142,11 @@ export default class EightpiecesRules extends ChessRules {
     }, super.pieces(color, x, y));
   }
 
+  canStepOver(i, j, p, c) {
+    const colIJ = this.getColor(i, j);
+    return this.board[i][j] == "" || (V.LANCERS.includes(p) && c == colIJ);
+  }
+
   isImmobilized([x, y]) {
     const color = this.getColor(x, y);
     const oppCol = C.GetOppTurn(color);
@@ -160,9 +164,40 @@ export default class EightpiecesRules extends ChessRules {
     return false;
   }
 
+  getPassMoves(x, y) {
+    const col = this.getColor(x, y);
+    let res = [];
+    if (this.getPiece(x, y) == 'k') {
+      for (let i of [-1, 1]) {
+        for (let j of [-1, 1]) {
+          if (
+            this.onBoard(x + i, y + j) &&
+            this.getPiece(x + i, y + j) == 'j' &&
+            this.getColor(x + i, y + j) != col
+          ) {
+            res.push( new Move({
+              appear: [],
+              vanish: [],
+              start: {x: x, y: y},
+              end: {x: x + i, y: y + j}
+            }) );
+          }
+        }
+      }
+    }
+    return res;
+  }
+
+
+// TODO: finish lancers
+  // http://ftp.chessvariants.com/rules/8-piece-chess
+
+
   getPotentialMovesFrom([x, y], color) {
-    if (!this.pushFrom)
-      return super.getPotentialMovesFrom([x, y], color);
+    if (!this.pushFrom) {
+      return this.getPassMoves(x, y).concat(
+        super.getPotentialMovesFrom([x, y], color) );
+    }
     if (x != this.pushFrom.x || y != this.pushFrom.y)
       return [];
     // After sentry "attack": move enemy as if it was ours
@@ -180,8 +215,8 @@ export default class EightpiecesRules extends ChessRules {
     let finalMoves = [];
     for (const m of moves) {
       //if (m.vanish.length == 0 && ... TODO: drop
-      if (V.LANCERS.includes(m.vanish[0].p)) {
-        // TODO: how to know it's regular?
+      if (m.vanish.length > 0 && V.LANCERS.includes(m.vanish[0].p)) {
+        // TODO: how to know it's regular? (not sentry push)
         this.getLancerOptions(m.end.x, m.end.y).forEach(o => {
           finalMoves.push( new Move({
             appear: [new PiPo({x:m.end.x,y:m.end.y,c:m.appear[0].c,p:o})],
-- 
2.53.0