From 55decbbf2f418fa05b41657ba485f34851ea98c3 Mon Sep 17 00:00:00 2001
From: H.G.Muller <hgm@hgm-xboard.(none)>
Date: Mon, 6 Feb 2017 19:15:18 +0100
Subject: [PATCH] Indicate last rank in zone table

The least-sigificant bit in the zone table is nowused to indicate first
and second rank. This is used to forbid Pawn drops as check evasions.
Which is OK for crazyhouse, but is overruled on 1st rank for Shogi.
The last-2-ranks bits are suppressed in mini-Shogi (which has no Knight).
---
 dropper.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/dropper.c b/dropper.c
index d229f91..f2bf201 100644
--- a/dropper.c
+++ b/dropper.c
@@ -546,8 +546,9 @@ printf("# variant %d: %s\n", v, variants[v].name);
     }
     for(r=0; r<zone; r++) { // board-size table to indicate promotion zones and force-promotion zones
 	for(f=0; f<nrFiles; f++) {
-	    zoneTab[22*r + f]           = Z_BLACK & (Z_MUST | COLOR | (r<2)*Z_2ND);
-	    zoneTab[22*(nrRanks-1-r)+f] = Z_WHITE & (Z_MUST | COLOR | (r<2)*Z_2ND);
+	    int xr = nrRanks - 1 - r, c = Z_MUST | COLOR | (r==0)*Z_LAST | (r<2 && v!=1)*Z_2ND; // in mini-Shogi forelast not in zone
+	    zoneTab[22*r  + f] = Z_BLACK & c;
+	    zoneTab[22*xr + f] = Z_WHITE & c;
 	}
     }
 
-- 
1.7.0.4