From 860d8145f1394d5fa92371cd166359ca4284eb75 Mon Sep 17 00:00:00 2001
From: David Jardim <david@thejardim.com>
Date: Sat, 15 Apr 2017 21:40:43 -0400
Subject: [PATCH] Added hueristics.cpp with 8 Heuristic functions

---
 src/heuristics.cpp | 107 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 src/heuristics.cpp

diff --git a/src/heuristics.cpp b/src/heuristics.cpp
new file mode 100644
index 0000000..14ea28a
--- /dev/null
+++ b/src/heuristics.cpp
@@ -0,0 +1,107 @@
+#include <cstdint>
+#include <limits.h>
+#include <string>
+#include "BitBoard.h"
+
+/* Heuristic Functions */
+
+// counts number of setbits
+int const count(uint32_t i){
+  unt cnt;
+  while(i){
+    cnt += i & 1;
+    i >>= 1;
+  }  
+  return cnt;
+  
+}
+
+// current players pieces
+uint32_t const BitBoard::playerPieces(){
+  return misBLacksTurn ? m_blackPieces : m_whitePieces;
+}
+
+// Number of  pawns
+int const BitBoard::h1()
+{
+  return count(playerPieces() & ~m_kings);
+}
+
+// Number of kings
+int const BitBoard::h2()
+{
+  return count(playerPieces() & m_kings);
+}
+
+// Number of safe pawns
+int const BitBoard::h3()
+{
+  return count(playerPieces() & ~m_kings & edgeLoc);
+}
+
+// Number of safe kings
+int const BitBoard::h4()
+{
+  return count(playerPieces() & m_kings & edgeLoc);
+}
+
+// Aggregated distance of pawns to promotion line
+int const BitBoard::h5()
+{
+  int aggrDistance = 0;
+  if(m_isBlacksTurn)
+    for(int i=0, i<7; i++)
+      aggrDistance += (7-i)*count(m_blackPieces & m_kings & rowMask[i]);
+  else
+    for(int i=1, i<8; i++)
+      aggrDistance += i*count(m_whitePieces & m_kings & rowMask[i]);
+
+  return aggrDistance;
+}
+
+// Number of defender pieces, closest two rows on players side
+int const BitBoard::h6()
+{
+  if(m_isBlacksTurn)
+    return count(m_blackPieces & (rowMask[0] | rowMask[1]));
+  else
+    return count(m_whitePieces & (rowMask[6] | rowMask[7]));
+}
+
+// Number of attacking pawns, position in upper three most rows, opponents side
+int const BitBoard::h7()
+{
+  if(m_isBlacksTurn)
+    return count(m_blackPieces & ~m_kings & ( rowMask[7] | rowMask[6] | rowMask[5]));
+  else
+    return count(m_whitePieces & ~m_kings & ( rowMask[2] | rowMask[1] | rowMask[0]));
+}
+
+// Number of unoccupied fields on  promotion line
+int const BitBoard::h8()
+{
+  if(m_isBlacksTurn)
+    return count( (m_blackPieces | m_whitePieces) & rowMask[7]);
+  else
+    return count( (m_blackPieces | m_whitePieces) & rowMask[0]);
+}
+
+
+
+uint32_t const BitBoard::rotl32 (uint32_t n, unsigned int c)
+{
+  const unsigned int mask = (CHAR_BIT*sizeof(n)-1);
+
+   c &= mask;  // avoid undef behaviour with NDEBUG.  0 overhead for most types / compilers
+    return (n<<c) | (n>>( (-c)&mask ));
+}
+
+uint32_t const BitBoard::rotr32 (uint32_t n, unsigned int c)
+{
+  const unsigned int mask = (CHAR_BIT*sizeof(n)-1);
+
+   c &= mask;  // avoid undef behaviour with NDEBUG.  0 overhead for most types / compilers
+    return (n>>c) | (n<<( (-c)&mask ));
+}
+
+