public bool Equals(GridLocation g)
{
if (this.X == g.X && this.Y == g.Y)
return true;
return false;
}
public bool Equals(GridLocation o)
{
if (o == null)
return false;
return this == o;
}
/// <summary>
///
/// </summary>
/// <param name="gridLocation"></param>
/// <returns>
/// A list of the <see cref="GridLocation"/>s surrounding
/// <paramref name="gridLocation"/> so long as they exist in the world.
/// </returns>
private List<GridLocation> GetSurrounding(GridLocation gridLocation)
{
GridLocation g = gridLocation;
List<GridLocation> surrounding = new List<GridLocation>(8);
surrounding.Add(new GridLocation((Int16)(g.X - 1), (Int16)(g.Y - 1), cellSize));
surrounding.Add(new GridLocation((Int16)(g.X - 1), (Int16)g.Y, cellSize));
surrounding.Add(new GridLocation((Int16)(g.X - 1), (Int16)(g.Y + 1), cellSize));
surrounding.Add(new GridLocation((Int16)g.X, (Int16)(g.Y - 1), cellSize));
//surrounding.Add(new GridLocation((Int16)g.X, (Int16)g.Y, cellSize)); - the cell itself
surrounding.Add(new GridLocation((Int16)g.X, (Int16)(g.Y + 1), cellSize));
surrounding.Add(new GridLocation((Int16)(g.X + 1), (Int16)(g.Y - 1), cellSize));
surrounding.Add(new GridLocation((Int16)(g.X + 1), (Int16)g.Y, cellSize));
surrounding.Add(new GridLocation((Int16)(g.X + 1), (Int16)(g.Y + 1), cellSize));
// check to make sure the surrounding cells are inside the world, remove any that don't
surrounding.RemoveAll(
s => s.X < minGrid.X || s.X > maxGrid.X || s.Y < minGrid.Y || s.Y > maxGrid.Y
);
return surrounding;
}
/// <summary>
///
/// </summary>
/// <param name="worldObject"></param>
/// <returns>A list of all <see cref="GridLocation"/>s containing the <see cref="IWorldObject"/></returns>
public List<GridLocation> Intersects(IWorldObject worldObject)
{
List<GridLocation> found = new List<GridLocation>(gridSize.X * gridSize.Y);
List<GridLocation> missed = new List<GridLocation>(gridSize.X * gridSize.Y);
UniqueList<GridLocation> toTest = new UniqueList<GridLocation>(gridSize.X * gridSize.Y);
UniqueList<GridLocation> newToBeTested = new UniqueList<GridLocation>(gridSize.X * gridSize.Y);
// the GridLocation that contains the center of the object
GridLocation hasCenter;
// STEP 1 - determine the GridLocation of the object's center
Point cellCoord;
// Use integer division to find cell coordinates.
// Since the grid cell coords are in the upperleft corner
// 1 must be subtracted from the division if we are in the negative (left or up)
// direction - effectively rounding up in absolute value.
if (worldObject.Position.X < 0)
cellCoord.X = (Int16)(((Int16)worldObject.Position.X / (Int16)cellSize.X) - 1);
else
cellCoord.X = (Int16)(((Int16)worldObject.Position.X / (Int16)cellSize.X));
if (worldObject.Position.Y < 0)
cellCoord.Y = (Int16)(((Int16)worldObject.Position.Y / (Int16)cellSize.Y) - 1);
else
cellCoord.Y = (Int16)(((Int16)worldObject.Position.Y / (Int16)cellSize.Y));
// check to makes sure these coordinates are in the world
if (minGrid.X <= cellCoord.X && cellCoord.X <= maxGrid.X &&
minGrid.Y <= cellCoord.Y && cellCoord.Y <= maxGrid.Y)
{
hasCenter = new GridLocation((Int16)cellCoord.X,
(Int16)cellCoord.Y,
cellSize);
}
// if they are not in the world, return the empty list
else
{
return found;
}
// add it to the found list
found.Add(hasCenter);
// STEP 2 - determine all surrounding GridLocations that contain the object
toTest.UnionWith(GetSurrounding(hasCenter));
while (toTest.Count != 0)
{
foreach (GridLocation gridLocation in toTest)
{
// if a surrounding GridLocation intersects the object do 4 things
if (worldObject.Bounds.Intersects(gridLocation.Bounds))
{
// 1. Add it to the found list
found.Add(gridLocation);
// 2. Get its surrounding GridLocations
newToBeTested.UnionWith(GetSurrounding(gridLocation));
// 3. Remove any that are already known to not contain the object
foreach (GridLocation g in missed)
{
newToBeTested.Remove(g);
}
// 4. Remove any that are already known to contain the object
foreach (GridLocation g in found)
{
newToBeTested.Remove(g);
}
}
// if a surrounding GridLocation DOES NOT intersect the object add it to missed
else
{
missed.Add(gridLocation);
}
}
// since we have checked everything in toTest flush it
toTest.Clear();
// add the newly found surrounding candidates to toTest
toTest.UnionWith(newToBeTested);
// flush the temp list
newToBeTested.Clear();
}
return found;
}
/// <summary>
///
/// </summary>
/// <param name="gridLocation"></param>
/// <returns><see cref="IWorldObject"/>s associated with a given <paramref name="gridLocation"/></returns>
public List<IWorldObject> getLocationObjectsOf(GridLocation gridLocation)
{
return grid[gridLocation];
}
/// <summary>
///
/// </summary>
/// <param name="gridLocation"></param>
/// <returns>
/// A list of the <see cref="GridLocation"/>s surrounding
/// <paramref name="gridLocation"/> so long as they exist in the world.
/// </returns>
private List<GridLocation> GetSurrounding(GridLocation gridLocation)
{
GridLocation g = gridLocation;
List<GridLocation> surrounding = new List<GridLocation>();
surrounding.Add(new GridLocation((UInt16)(g.X - g.Width), (UInt16)(g.Y - g.Height), g.Width, g.Height));
surrounding.Add(new GridLocation((UInt16)(g.X - g.Width), (UInt16)g.Y , g.Width, g.Height));
surrounding.Add(new GridLocation((UInt16)(g.X - g.Width), (UInt16)(g.Y + g.Height), g.Width, g.Height));
surrounding.Add(new GridLocation((UInt16)g.X , (UInt16)(g.Y - g.Height), g.Width, g.Height));
//surrounding.Add(new GridLocation((UInt16)g.X , (UInt16)g.Y , g.Width, g.Height)); - the cell itself
surrounding.Add(new GridLocation((UInt16)g.X , (UInt16)(g.Y + g.Height), g.Width, g.Height));
surrounding.Add(new GridLocation((UInt16)(g.X + g.Width), (UInt16)(g.Y - g.Height), g.Width, g.Height));
surrounding.Add(new GridLocation((UInt16)(g.X + g.Width), (UInt16)g.Y , g.Width, g.Height));
surrounding.Add(new GridLocation((UInt16)(g.X + g.Width), (UInt16)(g.Y + g.Height), g.Width, g.Height));
// check to make sure the surrounding cells are inside the world
foreach (GridLocation s in surrounding)
{
if (s.X < minWorld.X && s.X > maxWorld.X &&
s.Y < minWorld.Y && s.Y > maxWorld.Y)
{
surrounding.Remove(s);
}
}
return surrounding;
}
/// <summary>
///
/// </summary>
/// <param name="worldObject"></param>
/// <returns>A list of all <see cref="GridLocation"/>s containing the <see cref="IWorldObject"/></returns>
public List<GridLocation> Intersects(IWorldObject worldObject)
{
List<GridLocation> found = new List<GridLocation>();
//List<GridLocation> missed = new List<GridLocation>(); - i forgot why we need this
HashSet<GridLocation> toTest = new HashSet<GridLocation>();
// determine the GridLocation of the object's center
GridLocation hasCenter = new GridLocation((UInt16)((worldObject.Position.X / cellSize.X) * cellSize.X),
(UInt16)((worldObject.Position.Y / cellSize.Y) * cellSize.Y),
cellSize.X, cellSize.Y);
// add it to the found list
found.Add(hasCenter);
// determine all surrounding GridLocations that contain the object
toTest.UnionWith(GetSurrounding(hasCenter));
while (toTest.Count != 0)
{
foreach (GridLocation gridLocation in toTest)
{
if (worldObject.Bounds.Intersects(gridLocation.Bounds))
{
found.Add(gridLocation);
toTest.UnionWith(GetSurrounding(gridLocation));
toTest.Remove(gridLocation);
}
else
{
// missed.Add(g) Why do we need this?
}
}
}
return found;
}
