public (GameState state, bool combatEnds) PlayRound()
{
bool combatEnds = false;
var coordinates = new List <(int x, int y)>();
int height = Grid.GetLength(0);
int width = Grid.GetLength(1);
for (int y = 0; y < height; ++y)
{
for (int x = 0; x < width; ++x)
{
GridCell cell = Grid[y, x];
if (cell.IsElf || cell.IsGoblin)
{
coordinates.Add((x, y));
}
}
}
var elfHitPoints = ElfHitPoints;
var goblinHitPoints = GoblinHitPoints;
GridCell[,] grid = Grid;
for (int i = 0; i < coordinates.Count; ++i)
{
var xy = coordinates[i];
GridCell unitCell = grid[xy.y, xy.x];
if (!(unitCell.IsElf || unitCell.IsGoblin))
{
// Already taken out in an earlier turn this round.
continue;
}
if ((unitCell.IsElf && !goblinHitPoints.Any(kv => kv.Value > 0)) ||
(unitCell.IsGoblin && !elfHitPoints.Any(kv => kv.Value > 0)))
{
combatEnds = true;
break;
}
int hitPower = unitCell.IsElf
? elfHitPoints[unitCell.ElfId.Value]
: goblinHitPoints[unitCell.GoblinId.Value];
// Move if appropriate.
var move = GridOperations.CalculateMove(grid, xy.x, xy.y);
if (move.HasValue)
{
bool isElf = unitCell.IsElf;
int unitId = isElf ? unitCell.ElfId.Value : unitCell.GoblinId.Value;
RemoveItem(height, width, grid, xy);
var newCoordinates = (x : xy.x + move.Value.dx, y : xy.y + move.Value.dy);
grid[newCoordinates.y, newCoordinates.x] = isElf
? GridCell.Elf(unitId)
: GridCell.Goblin(unitId);
GridOperations.CalculateCloseness(_gridPair);
coordinates[i] = newCoordinates;
}
// Attack if appropriate.
xy = coordinates[i];
var match = GridOperations.FindBest(
grid,
xy.x,
xy.y,
c =>
{
bool isTarget = unitCell.IsElf ? c.IsGoblin : c.IsElf;
return(isTarget
? NullIfDead(unitCell.IsElf ? goblinHitPoints[c.GoblinId.Value] : elfHitPoints[c.ElfId.Value])
: default);
int?NullIfDead(int v) => v > 0 ? v : default;
},
private static bool ProcessOneClosenessStep(
GridCell[,] lastGrid,
GridCell[,] newGrid)
{
bool changed = false;
int height = lastGrid.GetLength(0);
int width = lastGrid.GetLength(1);
for (int y = 0; y < height; ++y)
{
for (int x = 0; x < width; ++x)
{
GridCell lastCell = lastGrid[y, x];
GridCell newCell = lastCell;
if (!lastCell.IsWall &&
((!lastCell.IsElf && !lastCell.DistanceToElfInRange.HasValue) ||
(!lastCell.IsGoblin && !lastCell.DistanceToGoblinInRange.HasValue)))
{
if (!lastCell.IsElf && !newCell.DistanceToElfInRange.HasValue)
{
var match = FindNearest(
c => c.IsElf ? 0 : c.DistanceToElfInRange,
(c, _) => c.IsElf ? (x, y) : c.ElfInRangePosition.Value);
if (match.HasValue)
{
(GridCell elfNearest, int hitX, int hitY) = match.Value;
int inRangeX, inRangeY;
bool hitWasOnUnitItself = !elfNearest.DistanceToElfInRange.HasValue;
if (hitWasOnUnitItself)
{
inRangeX = x;
inRangeY = y;
}
else
{
(inRangeX, inRangeY) = lastGrid[hitY, hitX].ElfInRangePosition.Value;
}
newCell = newCell.WithDistanceToElfInRange(
(elfNearest.DistanceToElfInRange ?? 0) + 1,
elfNearest.ElfId.Value,
inRangeX,
inRangeY);
changed = true;
}
}
if (!newCell.IsGoblin && !newCell.DistanceToGoblinInRange.HasValue)
{
var match = FindNearest(
c => c.IsGoblin ? 0 : c.DistanceToGoblinInRange,
(c, _) => c.IsGoblin ? (x, y) : c.GoblinInRangePosition.Value);
if (match.HasValue)
{
(GridCell goblinNearest, int hitX, int hitY) = match.Value;
int inRangeX, inRangeY;
bool hitWasOnUnitItself = !goblinNearest.DistanceToGoblinInRange.HasValue;
if (hitWasOnUnitItself)
{
inRangeX = x;
inRangeY = y;
}
else
{
(inRangeX, inRangeY) = lastGrid[hitY, hitX].GoblinInRangePosition.Value;
}
newCell = newCell.WithDistanceToGoblinInRange(
(goblinNearest.DistanceToGoblinInRange ?? 0) + 1,
goblinNearest.GoblinId.Value,
inRangeX,
inRangeY);
changed = true;
}
}
(GridCell cell, int x, int y)? FindNearest(
Func <GridCell, int?> distanceSelector,
Func <GridCell, (int x, int y), (int x, int y)> orderingSelector)
{
return(FindBest(
lastGrid,
x,
y,
c =>
{
var distance = distanceSelector(c);
return distance == 0 ? distance :
(c.IsGoblin || c.IsElf) ? default : distance;
},
orderingSelector));
}
}
newGrid[y, x] = newCell;
}
}
return(changed);
}