Some work on incremental update of attack map

diff --git a/hachu.c b/hachu.c
index c59149b..8f7eac7 100644 (file)
--- a/hachu.c
+++ b/hachu.c
@@ -857,8 +857,8 @@ MapFromScratch (int *map)
 \r
 void\r
 Connect (int sqr, int piece, int dir)\r
-{\r
-  int x, step = kStep[dir], r1 = p[piece].range[dir], r2 = p[piece].range[dir+1], piece1, piece2;\r
+{ // scan to both sides along ray to elongate attacks from there, and remove our own attacks on there, if needed\r
+  int x, step = kStep[dir], r1 = p[piece].range[dir], r2 = p[piece].range[dir+4], piece1, piece2;\r
   int d1, d2, r, y, c;\r
 \r
   if((attacks[2*sqr] + attacks[2*sqr+1]) & attackMask[dir]) {         // there are incoming attack(s) from 'behind'\r
@@ -877,15 +877,17 @@ Connect (int sqr, int piece, int dir)
        attacks[2*y + (piece1 & WHITE)] += one[dir];                  // count attack\r
        UPDATE_MOBILITY(piece1, d2);\r
       } else UPDATE_MOBILITY(piece1, r1 - d1);                        // does not connect, but could still gain mobility\r
-      if(d1 + d2 <= (r2 = p[piece2].range[dir])) {                    // 2 hits 1\r
+      if(d1 + d2 <= (r2 = p[piece2].range[dir+4])) {                  // 2 hits 1\r
        attacks[2*x + (piece2 & WHITE)] += one[dir+4];                // count attack\r
        UPDATE_MOBILITY(piece2, d1);\r
       } else UPDATE_MOBILITY(piece2, r2 - d2);                        // does not connect, but could still gain mobility\r
+      // if r1 or r2<0, moves typically jump, and thus cannot be unblocked. Exceptions are FF and BS distant moves.\r
+      // test for d1+d2 > 2 && rN == F && d== 3 or rN == S\r
 \r
     } else { // we were only attacked from behind\r
 \r
       r = (r2 = p[piece1].range[dir]) - d1;\r
-      if(r < 0 || c > one[dir+1]) { // Oops! This was not our attacker, or not the only one. There must be a jump attack from even further behind!\r
+      if(r < 0 || c > one[dir+4]) { // Oops! This was not our attacker, or not the only one. There must be a jump attack from even further behind!\r
        // for now, forget jumpers\r
       }\r
       y = sqr; \r
@@ -901,7 +903,7 @@ Connect (int sqr, int piece, int dir)
        }\r
       // we hit nothing with the extended move of the attacker behind us.\r
       UPDATE_MOBILITY(piece1, r2 - d1);\r
-      r = r1 - r2;                                            // extra squares covered by mover\r
+      r = r1 - r2 + d1;                                       // extra squares covered by mover\r
       while(r-- > 0)\r
        if(board[y+=step] != EMPTY) {\r
          d2 = dist[y-sqr]; piece2 = board[y];\r
@@ -911,6 +913,7 @@ Connect (int sqr, int piece, int dir)
          return;\r
        }\r
     }\r
+    // if r2<0 we should again test for F and S moves\r
 \r
   } else // no incoming attack from behind\r
   if(c = (attacks[2*sqr] + attacks[2*sqr+1]) & attackMask[dir+4]) { // but incoming attack(s) from 'ahead'\r
@@ -935,7 +938,7 @@ Connect (int sqr, int piece, int dir)
        }\r
       // we hit nothing with the extended move of the attacker behind us.\r
       UPDATE_MOBILITY(piece2, r2 - d1);\r
-      r = r2 - r1;                                                  // extra squares covered by mover\r
+      r = r2 - r1 + d2;                                             // extra squares covered by mover\r
       while(r-- > 0)\r
        if(board[x-=step] != EMPTY) {\r
          d1 = dist[x-sqr]; piece1 = board[x];\r
@@ -964,25 +967,64 @@ Connect (int sqr, int piece, int dir)
   }\r
 }\r
 \r
+inline int\r
+Hit (int r, int d)\r
+{ // test if move with range r reaches over (un-obstructed) distance d\r
+  if(r < 0) switch(r) {\r
+    case J: return (d == 2);\r
+    case D:\r
+    case L: return (d <= 2);\r
+    case T:\r
+    case F: return (d <= 3);\r
+    case S: return 1;\r
+    default: return 0;\r
+  } else return (d <= r);\r
+  return 0; // not reached\r
+}\r
+\r
 void\r
-Disconnect (int sqr, int dir)\r
+Disconnect (int sqr, int piece, int dir)\r
 {\r
-  int x = sqr, step = kStep[dir], piece1, piece2, y;\r
+  int x = sqr, step = kStep[dir], piece1, piece2, d1, d2, r1, r2, y;\r
   while( board[x+=step] == EMPTY );\r
-  if(board[x] != EDGE) { // x has hit a piece\r
-    piece1 = board[x];\r
+  piece1 = board[x];\r
+  if(piece1 != EDGE) { // x has hit a piece\r
+    d1 = dist[x-sqr];\r
+    r1 = p[piece1].range[dir+4];\r
     y = sqr; while( board[y-=step] == EMPTY );\r
-    if(board[y] != EDGE) { // both ends of the ray hit a piece\r
-      piece2 = board[y];\r
-      \r
+    piece2 = board[y];\r
+    if(piece2 != EDGE) { // both ends of the ray hit a piece\r
+      d2 = dist[y-sqr];\r
+      r2 = p[piece2].range[dir];\r
+      if(r1 >= d1) {      // piece1 hits us\r
+       attacks[2*sqr + (piece1 & WHITE)] += one[dir+4];\r
+       if(r1 >= d1 + d2) // was hitting piece2 before, now blocked\r
+         attacks[2*y + (piece1 & WHITE)] -= one[dir+4];\r
+      }\r
+      if(r2 >= d2) {      // piece2 hits us\r
+       attacks[2*sqr + (piece2 & WHITE)] += one[dir];\r
+       if(r2 >= d1 + d2) // was hitting piece1 before, now blocked\r
+         attacks[2*x + (piece2 & WHITE)] -= one[dir];\r
+      }\r
+      if( Hit(p[piece].range[dir], d1) )\r
+       attacks[2*sqr + stm] += one[dir];\r
+      if( Hit(p[piece].range[dir+4], d2) )\r
+       attacks[2*sqr + stm] += one[dir+4];\r
       return;\r
     }\r
   } else {\r
     x = sqr; while( board[x-=step] == EMPTY );\r
-    if(board[x] == EDGE) return; // ray empty on both sides\r
+    piece1 = board[x];\r
+    if(piece1 == EDGE) return; // ray empty on both sides\r
+    d1 = dist[x-sqr];\r
+    r1 = p[piece1].range[dir];\r
+    dir += 4;\r
   }\r
-  // we only get here if one side hits a \r
-  \r
+  // we only get here if one side looks to the board edge\r
+  if(r1 >= d1) // piece1 hits us\r
+    attacks[2*sqr + (piece1 & WHITE)] += one[dir^4];\r
+  if( Hit(p[piece].range[dir], d1) )\r
+    attacks[2*sqr + stm] += one[dir];\r
 }\r
 \r
 void\r
@@ -990,7 +1032,7 @@ Occupy (int sqr)
 { // determines attacks on square and blocking when a piece lands on an empty square\r
   int i;\r
   for(i=0; i<4; i++) {\r
-    Disconnect(sqr, i);\r
+    Disconnect(sqr, board[sqr], i);\r
   }\r
 }\r
 \r