//TODO: @herman, check at the examples.
/// <summary>
/// Returns a list containing lines connected to the given points. A line is a list of points.
/// Only returns correct results for square or hex grids.
/// </summary>
/// <example>
/// <code>
/// private bool IsSameColour(point1, point2)
/// {
/// return grid[point1].Color == grid[point2].Color;
/// }
///
/// private SomeMethod()
/// {
/// ...
/// var rays = GetConnectedRays<ColourCell, PointyHexPoint, PointyHexNeighborIndex>(
/// grid, point, IsSameColour);
/// ...
/// }
/// </code>
/// You can of course also use a lambda expression, like this:
/// <code>
/// //The following code returns all lines that radiate from the given point
/// GetConnectedRays<ColourCell, PointyHexPoint, PointyHexNeighborIndex>(
/// grid, point, (x, y) => grid[x].Color == grid[y].Color);
/// </code>
/// </example>
/// <typeparam name="TPoint">The type of point of the grid that this algorithm takes.</typeparam>
/// <param name="grid">Grid in which the calculations are made.</param>
/// <param name="point">Point where the calculations start.</param>
/// <param name="rayGenerators"></param> //TODO: Remove this argument? Make that as part of the rayGenerator?
/// <param name="isNeighborsConnected">
/// A functions that returns true or false, depending on whether
/// two points can be considered connected when they are neighbors.For example, if you want
/// rays of points that refer to cells of the same color, you can pass in a functions that
/// compares the DefaultColors of cells.
/// </param>
public static IEnumerable <IEnumerable <TPoint> > GetConnectedRays <TPoint>(
IImplicitShape <TPoint> grid,
TPoint point,
IEnumerable <IForwardMap <TPoint, TPoint> > rayGenerators,
Func <TPoint, TPoint, bool> isNeighborsConnected)
{
var lines = new List <IEnumerable <TPoint> >();
foreach (var rayGenertor in rayGenerators)
{
var line = new StructList <TPoint>();
var rayEnd = point;
while (grid.Contains(rayEnd) && isNeighborsConnected(point, rayEnd))
{
line.Add(rayEnd);
rayEnd = rayGenertor.Forward(rayEnd);
}
if (line.Count > 1)
{
lines.Add(line);
}
}
return(lines);
}
//TODO remove construction of list!
/// <summary>
/// It construct a list of Points that represent a path by using a Dictionary that hold the information from where the point came from.
/// </summary>
/// <typeparam name="TPoint">The type of the point.</typeparam>
/// <param name="cameFrom">Dictionary holding the information from where the point came from.</param>
/// <param name="currentNode">Node that start the path.</param>
private static IList <TPoint> ReconstructPath <TPoint>(
Dictionary <TPoint, TPoint> cameFrom,
TPoint currentNode)
{
IList <TPoint> path = new StructList <TPoint>();
ReconstructPath(cameFrom, currentNode, path);
return(path);
}
/// <summary>
/// Gets the longest line of connected points that contains this point.
/// <see cref="GetConnectedRays{TPoint}"/>
/// </summary>
/// <typeparam name="TPoint">The type of point of the grid that this algorithm takes.</typeparam>
/// <param name="grid">Grid in which the calculations are made.</param>
/// <param name="point">Point where the calculations start.</param>
/// <param name="lineGenerators">List of line generators.</param> //TODO is Generator the right word?
/// <param name="isNeighborsConnected">
/// A functions that returns true or false, depending on whether
/// two points can be considered connected when they are neighbors.For example, if you want
/// rays of points that refer to cells of the same color, you can pass in a functions that
/// compares the DefaultColors of cells.
/// </param>
public static IEnumerable <IEnumerable <TPoint> > GetConnectedLines <TPoint>(
IImplicitShape <TPoint> grid,
TPoint point,
IEnumerable <IMap <TPoint, TPoint> > lineGenerators,
Func <TPoint, TPoint, bool> isNeighborsConnected)
{
var lines = new List <IEnumerable <TPoint> >();
foreach (var lineGenerator in lineGenerators)
{
var line = new StructList <TPoint>();
var edge = point;
//go forwards
while (grid.Contains(edge) && isNeighborsConnected(point, edge))
{
edge = lineGenerator.Forward(edge);
}
//TPoint oppositeNeighbor = point.MoveBy(direction.Negate());
edge = lineGenerator.Reverse(edge);
//go backwards
while (grid.Contains(edge) && isNeighborsConnected(point, edge))
{
line.Add(edge);
edge = lineGenerator.Reverse(edge);
}
if (line.Count > 1)
{
lines.Add(line);
}
}
return(lines);
}
/// <summary>
/// Gets all the points (and their costs) from a given point in a given range. This result is stored and returned
/// in a dictionary.
/// </summary>
/// <typeparam name="TPoint">The type of the point used on the grid.</typeparam>
/// <param name="grid">The grid used to make the calculations.</param>
/// <param name="start">Point where the calculations will start.</param>
/// <param name="getConnectedPoints">This function is used to get the connected points to a given point.</param>
/// <param name="isAccessible">This function is used to know if a point is acessible within the grid.</param>
/// <param name="getCellMoveCost">This function is used to get the movement cost from moving to a cell.</param>
/// <param name="moveRange">Range of movement where make the calculations.</param>
/// <returns></returns>
public static Dictionary <TPoint, int> GetPointsInRangeCost <TPoint>(
IGrid <TPoint> grid,
TPoint start,
Func <TPoint, IEnumerable <TPoint> > getConnectedPoints,
Func <TPoint, bool> isAccessible,
Func <TPoint, TPoint, int> getCellMoveCost,
int moveRange)
{
// Nodes in range
var closedSet = new HashSet <TPoint>();
var costToReach = new Dictionary <TPoint, int>();
var openSet = new StructList <TPoint> {
start
};
// Cost from start along best known path up to current point
var costToReachContains = grid.CloneStructure(false);
costToReach[start] = 0;
var currentNeighbors = new List <TPoint>();
while (!openSet.IsEmpty())
{
// Process current node
var current = FindNodeWithLowestScore(openSet, costToReach);
openSet.Remove(current);
closedSet.Add(current);
CheckGridNeighbors(getConnectedPoints(current), grid, currentNeighbors);
for (int i = 0; i < currentNeighbors.Count; i++)
{
var neighbor = currentNeighbors[i];
if (!closedSet.Contains(neighbor) &&
!openSet.Contains(neighbor) &&
isAccessible(neighbor) &&
(costToReach[current] + getCellMoveCost(current, neighbor) <= moveRange)
)
{
// Cost of current node + neighbor's move cost
int newCost = costToReach[current] + getCellMoveCost(current, neighbor);
if (costToReachContains[neighbor])
{
if (costToReach[neighbor] > newCost)
{
costToReach[neighbor] = newCost;
}
}
else
{
costToReach[neighbor] = newCost;
costToReachContains[neighbor] = true;
}
openSet.Add(neighbor);
}
}
}
return(costToReach);
}
