[gray-matter] r1624 committed - some heuristic modifications....

[codesite...@google.com]

Revision: 1624
Author: protonspring
Date: Tue Aug 3 21:15:42 2010
Log: some heuristic modifications.
removed illegal position checking for get_position


http://code.google.com/p/gray-matter/source/detail?r=1624

Modified:
/trunk/src/board_base.cpp
/trunk/src/board_heuristic.cpp

=======================================
--- /trunk/src/board_base.cpp Tue Aug 3 19:45:07 2010
+++ /trunk/src/board_base.cpp Tue Aug 3 21:15:42 2010
@@ -499,8 +499,8 @@
///· illegal position

// Is a king missing?
- if (!state.piece[WHITE][KING] || !state.piece[BLACK][KING])
- return ILLEGAL;
+ //if (!state.piece[WHITE][KING] || !state.piece[BLACK][KING])
+ //return ILLEGAL;

// Are the kings attacking one other?
//int n = FST(state.piece[WHITE][KING]);
@@ -508,8 +508,8 @@
//return ILLEGAL;

//if the king on move is in check, then this position is illegal
- if (check(state.piece[OFF_MOVE][KING], ON_MOVE))
- return ILLEGAL;
+ //if (check(state.piece[OFF_MOVE][KING], ON_MOVE))
+ //return ILLEGAL;

if (mate_test)
switch (mate())
=======================================
--- /trunk/src/board_heuristic.cpp Mon Aug 2 20:50:11 2010
+++ /trunk/src/board_heuristic.cpp Tue Aug 3 21:15:42 2010
@@ -384,8 +384,10 @@

// Reward bishops (over knights) during endgames with pawns on
both
// sides of the board.
- int friendly_piece_count = count_64(ALL(state, color));
- bool endgame = friendly_piece_count < 7;
+ //int friendly_piece_count = count_64(ALL(state, color));
+ bool endgame; // = friendly_piece_count < 7;
+ if (state.pieceCount < 7)
+ endgame = true;
if (!endgame)
goto no_bishop_over_knight;
enemy_bishop_present =
(state.piece[!color][BISHOP]?true:false);
@@ -576,10 +578,15 @@
{
// There are pawns on both sides of the board. The king
should be
// in the middle.
- if (color == WHITE)
- sum += sign * value_position[KING][x][y];
- else
- sum += sign * value_position[KING][7-x][7-y];
+ //if (color == WHITE)
+ //sum += sign * value_position[KING][x][y];
+ //else
+ //sum += sign * value_position[KING][7-x][7-y];
+
+ //NOTE: protonspring
+ //this seems to cause the king to wander towards the
+ //middle of the board, even in the middle of a heated battle
+
}
else if (pawns)
{
@@ -594,10 +601,18 @@
sum += sign * value_king_position[7-x][!color?y:7-y];
}
}
- else //there are no pawns left. . endgame likely
+
+ if (state.pieceCount < 7)
{
//middle of the board is better for end game
sum += sign * value_king_middle[x][y];
+
+ //but it is more important to push the other king
+ //to the edge if we can
+ int n = FST(state.piece[!color][KING]);
+ int x2 = n & 0x7;
+ int y2 = n >> 3;
+ sum += -2 * sign * value_king_middle[x2][y2];
}
}
return sum;