/// <summary>
/// Sets all the tiles in a specified line on this grid to the specified type.
/// Note that point1 and point2 MUST lie on the same line
/// (i.e. either their x coordinates are equal or their y coordinates are equal),
/// or I'm going to crash your program.
/// If prioritize is false,
/// this function will only mark tiles which are currently empty.
/// </summary>
/// <param name="point1">An endpoint</param>
/// <param name="point2">Another endpoint</param>
/// <param name="type">Tile type to set this line to</param>
/// <param name="prioritize">Whether this method should override existing non-empty tiles</param>
public void setTypeLine(Coord2DObject point1, Coord2DObject point2,
TileObject.TileType type, bool prioritize)
{
assertBounds(point1); assertBounds(point2);
Assert.raiseExceptions = true;
Assert.IsTrue(point1.x == point2.x || point1.y == point2.y,
"point1 " + point1.ToString() + " and point2 " + point2.ToString() + " must lie on a straight line");
if (point1.Equals(point2) &&
(prioritize || getTile(point1).type == TileObject.TileType.EMPTY))
{
getTile(point1).type = type;
return;
}
// If on the same row
if (point1.y == point2.y)
{
// Iterate from least x to greater x,
// whichever is which
int biggerX = (point1.x > point2.x ? point1.x : point2.x);
int smallerX = (point1.x < point2.x ? point1.x : point2.x);
for (int i = smallerX; i <= biggerX; i++)
{
TileObject thisTile = getTile(new Coord2DObject(i, point1.y));
if (thisTile == null)
{
Debug.Log("i is " + i + ", point1.y is " + point1.y);
}
if (prioritize || thisTile.type == TileObject.TileType.EMPTY)
{
thisTile.type = type;
}
}
}
// Else, they're on the same column
else
{
// Iterate from least y to greatest y,
// whichever is which
int biggerY = (point1.y > point2.y ? point1.y : point2.y);
int smallerY = (point1.y < point2.y ? point1.y : point2.y);
for (int i = smallerY; i <= biggerY; i++)
{
TileObject thisTile = getTile(new Coord2DObject(point1.x, i));
if (prioritize || thisTile.type == TileObject.TileType.EMPTY)
{
thisTile.type = type;
}
}
}
}
/// <summary>
/// Returns a list of random Coord2DObjects of specified size.
/// As long as p1UpRight and p2LowLeft are initialized,
/// you are guaranteed that this list will have no duplicate values,
/// and will also not contain the values p1UpRight or p2LowLeft.
/// Additionally, none of these points shall fall within the bases.
/// </summary>
/// <param name="amount">Number of random points to generate</param>
/// <returns>List of distinct Coord2DObject's</returns>
private List <Coord2DObject> getDistinctRandomPoints(int amount)
{
HashSet <Coord2DObject> pointsSet = new HashSet <Coord2DObject>();
// Use a while loop instead of a for loop
// because there's a small chance
// that we could accidentally generate duplicate Coord2D's
while (pointsSet.Count < amount)
{
Coord2DObject randCoord = getRandomNonBase();
// These two will populate pointsSet later,
// so check for duplicates now
if (!randCoord.Equals(p1UpRight) && !randCoord.Equals(p2LowLeft))
{
pointsSet.Add(randCoord);
}
}
// As far as this function is concerned,
// order does not matter,
// so we can clumsily return a list from our set
return(new List <Coord2DObject>(pointsSet));
}
/// <summary>
/// Populates this Path's "joints" list with the best path between point1 and point2.
/// This is accomplished by implementing Dijkstra's algorithm.
/// This path's grid and joints MUST be initialized before this method is called.
/// Algorithm adopted from the pseudocode found here:
/// https://en.wikipedia.org/wiki/Dijkstra%27s_algorithm#Pseudocode
/// </summary>
/// <param name="src">The coordinate that the path should start from</param>
/// <param name="dest">The coordinate that the path should start from</param>
private void populateBestPath(Coord2DObject src, Coord2DObject dest)
{
Grid2DObject tempGrid = new Grid2DObject(grid); // generate copy, maintaining tile types
TileObject srcTile = tempGrid.getTile(src);
TileObject destTile = tempGrid.getTile(dest);
srcTile.distance = 0;
// Do some error checking
Assert.raiseExceptions = true;
Assert.IsTrue(!src.Equals(dest), "Attempted autopath to the same tile " + src.ToString());
Assert.IsTrue(srcTile.type != TileObject.TileType.NON_TRAVERSABLE,
"Path attempted on srcTile non-traversable tile " + srcTile.ToString() + " to destTile " + destTile.ToString());
Assert.IsTrue(destTile.type != TileObject.TileType.NON_TRAVERSABLE,
"Path attempted on destTile non-traversable tile " + destTile.ToString() + " from srcTile " + srcTile.ToString());
// Populate set Q
HashSet <TileObject> setQ = new HashSet <TileObject>();
foreach (TileObject t in tempGrid)
{
if (t.type != TileObject.TileType.NON_TRAVERSABLE)
{
setQ.Add(t);
}
}
List <TileObject> listQ = new List <TileObject>(setQ);
shuffleList <TileObject>(listQ);
TileObject uTile = null;
while (listQ.Count > 0)
{
// Get tile with minimum distance from setQ
int runningMin = System.Int32.MaxValue;
foreach (TileObject t in listQ)
{
if (t.distance < runningMin)
{
runningMin = t.distance;
uTile = t;
}
}
// Make sure uTile is properly set,
// then remove it from setQ
Assert.IsTrue(uTile != null, "Minimum distance tile uTile not properly set");
Assert.IsTrue(listQ.Contains(uTile), "setQ doesn't contain uTile " + uTile.ToString());
listQ.Remove(uTile);
// Break out if we've reached the destination,
// we now need to construct the path via reverse iteration
if (uTile == destTile) // check for identity, not just equivalence
{
break;
}
// Update distances of all uTile's current neighbors
HashSet <TileObject> uNeighbors = tempGrid.getTraversableNeighbors(uTile.location);
foreach (TileObject thisNeighbor in uNeighbors)
{
int currentDist = uTile.distance + 1;
if (currentDist < thisNeighbor.distance)
{
thisNeighbor.distance = currentDist;
thisNeighbor.prev = uTile;
}
}
}
// Ensure that uTile is actually usable
Assert.IsTrue(uTile.prev != null || uTile == srcTile,
"Condition specified by Dijkstra's not met");
// Populate joints by backtracing
while (uTile != null)
{
joints.Add(uTile.location);
uTile = uTile.prev;
// Make sure if we're about to break out,
// that we have enough joints to do so
// (i.e. that we have at least 2 joints)
Assert.IsTrue(!(uTile == null && joints.Count < 2),
"Not enough prev's? For sure not enough joints\n"
+ "Perhaps src and dest are the same?\n"
+ "src: " + srcTile.ToString() + '\n'
+ "dest: " + destTile.ToString() + '\n'
+ "src.equals(dest)? " + src.Equals(dest));
}
}