/// <summary>
/// A BoardQualityEvaluator that calculates how "open" the board is.
/// </summary>
public static float Openness(FastBoard board)
{
int total = 0;
for (int x = 0; x < FastBoard.Width; x++)
{
for (int y = 0; y < FastBoard.Height; y++)
{
ulong cardIndex = board.GetCardIndex(x, y);
if (cardIndex == 0)
{
// 2 points for an empty cell.
total += 2;
}
else
{
ulong leftCardIndex = x > 0 ? board.GetCardIndex(x - 1, y) : 0;
ulong rightCardIndex = x < FastBoard.Width - 1 ? board.GetCardIndex(x + 1, y) : 0;
ulong upCardIndex = y > 0 ? board.GetCardIndex(x, y - 1) : 0;
ulong downCardIndex = y < FastBoard.Height - 1 ? board.GetCardIndex(x, y + 1) : 0;
// 1 point for each adjacent card we can merge with.
if (leftCardIndex != 0 && FastBoard.CanCardsMerge(cardIndex, leftCardIndex))
{
total += 1;
}
if (rightCardIndex != 0 && FastBoard.CanCardsMerge(cardIndex, rightCardIndex))
{
total += 1;
}
if (upCardIndex != 0 && FastBoard.CanCardsMerge(cardIndex, upCardIndex))
{
total += 1;
}
if (downCardIndex != 0 && FastBoard.CanCardsMerge(cardIndex, downCardIndex))
{
total += 1;
}
// -1 point if we're trapped between higher-valued cards, either horizontally or vertically.
if ((x == 0 || (leftCardIndex >= 3 && cardIndex < leftCardIndex)) &&
(x == FastBoard.Width - 1 || (rightCardIndex >= 3 && cardIndex < rightCardIndex)))
{
total -= 1;
}
if ((y == 0 || (upCardIndex >= 3 && cardIndex < upCardIndex)) &&
(y == FastBoard.Height - 1 || (downCardIndex >= 3 && cardIndex < downCardIndex)))
{
total -= 1;
}
// 1 point if next to at least one card twice our value.
if (cardIndex >= 3)
{
if ((leftCardIndex != 0 && leftCardIndex == cardIndex + 1) ||
(rightCardIndex != 0 && rightCardIndex == cardIndex + 1) ||
(upCardIndex != 0 && upCardIndex == cardIndex + 1) ||
(downCardIndex != 0 && downCardIndex == cardIndex + 1))
{
total += 1;
}
}
}
}
}
return(total);
}
/// <summary>
/// A BoardQualityEvaluator that calculates how "open" the board is.
/// </summary>
public static float OpennessMatthew(FastBoard board)
{
var maxIndex = board.GetMaxCardIndex();
int total = 0;
for (int x = 0; x < FastBoard.Width; x++)
{
for (int y = 0; y < FastBoard.Height; y++)
{
ulong cardIndex = board.GetCardIndex(x, y);
if (cardIndex == 0)
{
// 2 points for an empty cell.
total += 3;
}
else
{
ulong leftCardIndex = x > 0 ? board.GetCardIndex(x - 1, y) : 0;
ulong rightCardIndex = x < FastBoard.Width - 1 ? board.GetCardIndex(x + 1, y) : 0;
ulong upCardIndex = y > 0 ? board.GetCardIndex(x, y - 1) : 0;
ulong downCardIndex = y < FastBoard.Height - 1 ? board.GetCardIndex(x, y + 1) : 0;
// for each adjacent card we can merge with.
if (leftCardIndex != 0 && FastBoard.CanCardsMerge(cardIndex, leftCardIndex))
{
total += 2;
}
if (rightCardIndex != 0 && FastBoard.CanCardsMerge(cardIndex, rightCardIndex))
{
total += 2;
}
if (upCardIndex != 0 && FastBoard.CanCardsMerge(cardIndex, upCardIndex))
{
total += 2;
}
if (downCardIndex != 0 && FastBoard.CanCardsMerge(cardIndex, downCardIndex))
{
total += 2;
}
// negative if we're trapped between higher-valued cards, either horizontally or vertically.
if ((x == 0 || (leftCardIndex >= 3 && cardIndex < leftCardIndex)) &&
(x == FastBoard.Width - 1 || (rightCardIndex >= 3 && cardIndex < rightCardIndex)))
{
total -= 5;
}
if ((y == 0 || (upCardIndex >= 3 && cardIndex < upCardIndex)) &&
(y == FastBoard.Height - 1 || (downCardIndex >= 3 && cardIndex < downCardIndex)))
{
total -= 5;
}
// point if next to at least one card twice our value.
if (cardIndex >= 3)
{
if ((leftCardIndex != 0 && leftCardIndex == cardIndex + 1) ||
(rightCardIndex != 0 && rightCardIndex == cardIndex + 1) ||
(upCardIndex != 0 && upCardIndex == cardIndex + 1) ||
(downCardIndex != 0 && downCardIndex == cardIndex + 1))
{
total += 2;
}
}
if (maxIndex > 4)
{
// for each wall we're touching if we're the biggest card
if (cardIndex == maxIndex)
{
if (x == 0 || x == 3)
{
total += 3;
}
if (y == 0 || y == 3)
{
total += 3;
}
}
// for sticking next to the biggest piece
if (cardIndex == maxIndex - 1)
{
int testX, testY;
if (NeighborsWith(board, x, y, maxIndex, out testX, out testY))
{
total += 1;
// and a bonus if we're also along a wall
if (x == 0 || x == 3)
{
total += 1;
}
if (y == 0 || y == 3)
{
total += 1;
}
}
}
// if we're two below
if (cardIndex == maxIndex - 2)
{
// and we're neighbors with a 1-below
int testX, testY;
if (NeighborsWith(board, x, y, maxIndex - 1, out testX, out testY))
{
// who is also neighbors with the max
if (NeighborsWith(board, testX, testY, maxIndex, out testX, out testY))
{
total += 1;
}
}
}
}
}
}
}
return(total);
}