private Point exploreFrontier(PriorityQueue <Point> frontier, Point target, Dictionary <Point, Point> cameFrom, Dictionary <Point, double> costSoFar)
{
Point closestTile = new Point();
Point currentTile;
double closestDistance = double.PositiveInfinity;
while (frontier.Count > 0)
{
currentTile = frontier.Dequeue();
double currentDistance = Math.Sqrt(
Math.Abs(currentTile.X - target.X) +
Math.Abs(currentTile.Y - target.Y));
if (currentDistance < closestDistance)
{
closestDistance = currentDistance;
closestTile = currentTile;
}
if (closestTile == target)
{
break;
}
List <Point> neighbors = gameMap.GetValidNeighbors(currentTile);
foreach (Point neighborTile in neighbors)
{
GameTile tileObject = gameMap.game_tiles[(int)neighborTile.Y, (int)neighborTile.X];
if (tileObject.IsPathable())
{
double tileModifier = 1.0;
double distanceFromTarget = Math.Sqrt(
Math.Abs(tileObject.Coordinates.X - target.X) +
Math.Abs(tileObject.Coordinates.Y - target.Y));
double newCost = (costSoFar[currentTile] + tileModifier) + distanceFromTarget;
if (!cameFrom.ContainsKey(neighborTile) || newCost < costSoFar[currentTile])
{
cameFrom[neighborTile] = currentTile;
costSoFar[neighborTile] = newCost;
frontier.Enqueue(neighborTile, newCost);
}
}
}
}
return(closestTile);
}
public List <Point> GetPath(Point start, Point target)
{
List <Point> path = new List <Point>();
Dictionary <Point, Point> cameFrom = new Dictionary <Point, Point>();
Dictionary <Point, double> costSoFar = new Dictionary <Point, double>();
Point closestTile = new Point();
cameFrom[start] = start;
costSoFar[start] = 0;
PriorityQueue <Point> frontier = new PriorityQueue <Point>();
List <Point> neighbors = gameMap.GetValidNeighbors(start);
foreach (Point tile in neighbors)
{
GameTile tileObject = gameMap.game_tiles[(int)tile.Y, (int)tile.X];
if (tileObject.IsPathable())
{
frontier.Enqueue(start, 0);
}
}
closestTile = exploreFrontier(
frontier, target, cameFrom, costSoFar);
List <Point> newPathSteps = new List <Point>();
newPathSteps.Add(closestTile);
while (true)
{
Point nextTile = newPathSteps[0];
if (nextTile == start)
{
break;
}
newPathSteps.Insert(0, cameFrom[nextTile]);
}
return(newPathSteps);
}
/// <summary>
/// Allows the game to run logic such as updating the world,
/// checking for collisions, gathering input, and playing audio.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Update(GameTime gameTime)
{
// IO events start
Random random = new Random();
KeyboardState lastKeyboardState = KeyboardState;
KeyboardState = Keyboard.GetState();
MouseState lastMouseState = MouseState;
MouseState = Mouse.GetState();
MousePos.X = MouseState.X;
MousePos.Y = MouseState.Y;
CursorMapPos = coordinateConverter.ScreenToMap(MousePos, DisplayShift);
if (KeyboardState.IsKeyDown(Keys.Right))
{
DisplayShift.X -= 5;
}
if (KeyboardState.IsKeyDown(Keys.Left))
{
DisplayShift.X += 5;
}
if (KeyboardState.IsKeyDown(Keys.Up))
{
DisplayShift.Y += 5;
}
if (KeyboardState.IsKeyDown(Keys.Down))
{
DisplayShift.Y -= 5;
}
if (KeyboardState.IsKeyDown(Keys.Escape))
{
Exit();
}
if (KeyboardState.IsKeyUp(Keys.P) &&
lastKeyboardState.IsKeyDown(Keys.P))
{
DisplayPaths = !DisplayPaths;
}
if (KeyboardState.IsKeyUp(Keys.S) &&
lastKeyboardState.IsKeyDown(Keys.S))
{
DisplayScore = !DisplayScore;
}
if (MouseState.LeftButton == ButtonState.Released &&
lastMouseState.LeftButton == ButtonState.Pressed)
{
Point mapCoords = coordinateConverter.ScreenToMap(MousePos, DisplayShift);
if (gameMap.IsPointInside(mapCoords) &&
gameMap.game_tiles[(int)mapCoords.Y, (int)mapCoords.X].IsPathable())
{
LumberCamp newLumberCamp = new LumberCamp(mapCoords);
gameMap.game_tiles[(int)mapCoords.Y, (int)mapCoords.X].Building = newLumberCamp;
gameMap.GetBuildings().Add(newLumberCamp);
List <Point> validNeighbors = gameMap.GetValidNeighbors(mapCoords);
List <Point> spawnableNeighbors = new List <Point>();
foreach (Point validNeighbor in validNeighbors)
{
if (gameMap.game_tiles[(int)validNeighbor.Y, (int)validNeighbor.X].IsPathable())
{
spawnableNeighbors.Add(validNeighbor);
}
}
for (int x = 0; x < 3; x++)
{
Point spawnTile = spawnableNeighbors[random.Next(spawnableNeighbors.Count)];
Laborer newLaborer = new Laborer(spawnTile);
gameMap.GetUnits().Add(newLaborer);
GameTile theTile = gameMap.game_tiles[(int)spawnTile.Y, (int)spawnTile.X];
theTile.Unit = newLaborer;
}
}
}
// IO events end
// game logic start
List <Entity> expiredEntities = new List <Entity>();
foreach (Unit unitObject in gameMap.GetUnits())
{
unitObject.Tick(gameMap, Player1, pathfinder);
}
foreach (Terrain terrainObject in gameMap.GetTerrain())
{
terrainObject.Tick(gameMap, Player1, pathfinder);
if (terrainObject.IsExpired())
{
expiredEntities.Add(terrainObject);
}
}
foreach (Entity entityObject in expiredEntities)
{
entityObject.OnDeath(gameMap);
gameMap.GetTerrain().Remove(entityObject);
gameMap.GetBuildings().Remove(entityObject);
}
// game logic ends
base.Update(gameTime);
}