public static Rect Intersect(Rect rect1, Rect rect2)
{
rect1.Intersect(rect2);
return rect1;
}
/// <summary>
/// Checks this Map for LOS between two positions.
/// </summary>
/// <param name="pos1">The start position.</param>
/// <param name="pos2">The end position.</param>
/// <returns>True if there is a clear LOS between the points.</returns>
internal bool HasLOS(Vector3 pos1, Vector3 pos2)
{
// The max distance check has already been performed.
var tile1Id = TileIdentifier.ByPosition(MapId, pos1);
if (tile1Id == null)
{
log.Warn("Got an invalid Tile Coord for {0}. Assuming LOS for now.", pos1);
return true;
}
var tile2Id = TileIdentifier.ByPosition(MapId, pos2);
if (tile2Id == null)
{
log.Warn("Got an invalid Tile Coord for {0}. ", pos1);
return true;
}
Tile tile;
if (!TryGetTile(tile1Id, out tile))
{
log.Error("Unable to load the given tile: {0} to check for LOS. Assuming LOS for now.", tile1Id);
return true;
}
// if the positions are on the same tile, things get easier
if (tile1Id == tile2Id)
{
return tile.HasLOS(pos1, pos2);
}
// else the LOS line segment crosses tile boundaries (possibly more than one.)
var lineRect = new Rect(new Point(pos1.X, pos1.Y), new Point(pos2.X, pos2.Y));
var tile1Rect = tile.Bounds;
lineRect.Intersect(tile1Rect);
// we know that pos1 was internal to tile1, so lineRect contains pos1 and the new pos2.
var newPoint = lineRect.BottomRight;
var newPos2 = new Vector3(newPoint.X, newPoint.Y, pos2.Z);
if (!tile.HasLOS(pos1, newPos2)) return false;
// clip the LOS line segment against the intervening tiles until tile2 is reached
pos1 = newPos2;
var dir = (pos2 - pos1);
dir.Normalize();
while(true)
{
// advance the start position by a small amount to ensure that we're on the new tile
pos1 += 1e-3f*dir;
tile1Id = TileIdentifier.ByPosition(MapId, pos1);
if (tile1Id == null)
{
log.Warn("Got an invalid Tile Coord for {0}. Assuming LOS for now.", pos1);
return true;
}
if (!TryGetTile(tile1Id, out tile))
{
log.Error("Unable to load the given tile: {0} to check for LOS. Assuming LOS for now.", tile1Id);
return true;
}
if (tile1Id == tile2Id)
{
return tile.HasLOS(pos1, pos2);
}
lineRect = new Rect(new Point(pos1.X, pos1.Y), new Point(pos2.X, pos2.Y));
tile1Rect = tile.Bounds;
lineRect.Intersect(tile1Rect);
newPoint = lineRect.BottomRight;
newPos2 = new Vector3(newPoint.X, newPoint.Y, pos2.Z);
if (!tile.HasLOS(pos1, newPos2)) return false;
pos1 = newPos2;
}
}
public static Rect Intersect(Rect rect1, Rect rect2)
{
rect1.Intersect(rect2);
return(rect1);
}
