/// <summary>
/// Attempts to swap the <see cref="CarriedBlock"/>s currently carried in the
/// entity's <paramref name="first"/> and <paramref name="second"/> slots.
/// </summary>
/// <example cref="ArgumentNullException"> Thrown if entity is null. </exception>
public static bool Swap(this Entity entity, CarrySlot first, CarrySlot second)
{
if (first == second)
{
throw new ArgumentException("Slots can't be the same");
}
var carriedFirst = CarriedBlock.Get(entity, first);
var carriedSecond = CarriedBlock.Get(entity, second);
if ((carriedFirst == null) && (carriedSecond == null))
{
return(false);
}
CarriedBlock.Remove(entity, first);
CarriedBlock.Remove(entity, second);
if (carriedFirst != null)
{
carriedFirst.Set(entity, second);
}
if (carriedSecond != null)
{
carriedSecond.Set(entity, first);
}
return(true);
}
/// <summary> Attempts to make this entity drop its carried blocks from the
/// specified slots around its current position in the specified area. </summary>
/// <example cref="ArgumentNullException"> Thrown if entity or slots is null. </exception>
/// <example cref="ArgumentOutOfRangeException"> Thrown if hSize or vSize is negative. </exception>
public static void DropCarried(this Entity entity, IEnumerable <CarrySlot> slots,
int hSize = 2, int vSize = 4)
{
if (entity == null)
{
throw new ArgumentNullException(nameof(entity));
}
if (slots == null)
{
throw new ArgumentNullException(nameof(slots));
}
if (hSize < 0)
{
throw new ArgumentOutOfRangeException(nameof(hSize));
}
if (vSize < 0)
{
throw new ArgumentOutOfRangeException(nameof(vSize));
}
var remaining = new HashSet <CarriedBlock>(
slots.Select(s => entity.GetCarried(s))
.Where(c => (c != null)));
if (remaining.Count == 0)
{
return;
}
bool Drop(BlockPos pos, CarriedBlock block)
{
if (!block.PlaceDown(entity.World, new BlockSelection {
Position = pos
}, null))
{
return(false);
}
CarriedBlock.Remove(entity, block.Slot);
return(true);
}
var centerBlock = entity.Pos.AsBlockPos;
var nearbyBlocks = new List <BlockPos>((hSize * 2 + 1) * (hSize * 2 + 1));
for (int x = -hSize; x <= hSize; x++)
{
for (int z = -hSize; z <= hSize; z++)
{
nearbyBlocks.Add(centerBlock.AddCopy(x, 0, z));
}
}
nearbyBlocks = nearbyBlocks.OrderBy(b => b.DistanceTo(centerBlock)).ToList();
var accessor = entity.World.BlockAccessor;
var blockIndex = 0;
var distance = 0;
while (remaining.Count > 0)
{
var pos = nearbyBlocks[blockIndex];
if (Math.Abs(pos.Y - centerBlock.Y) <= vSize)
{
var sign = Math.Sign(pos.Y - centerBlock.Y);
var testBlock = accessor.GetBlock(pos);
var placeable = remaining.FirstOrDefault(c => testBlock.IsReplacableBy(c.Block));
if (sign == 0)
{
sign = ((placeable != null) ? -1 : 1);
}
else if (sign > 0)
{
if ((placeable != null) && Drop(pos, placeable))
{
remaining.Remove(placeable);
}
}
else if ((placeable == null))
{
var above = pos.UpCopy();
testBlock = accessor.GetBlock(above);
placeable = remaining.FirstOrDefault(c => testBlock.IsReplacableBy(c.Block));
if ((placeable != null) && Drop(above, placeable))
{
remaining.Remove(placeable);
}
}
pos.Add(0, sign, 0);
}
else if (blockIndex >= nearbyBlocks.Count)
{
break;
}
if (++distance > 2)
{
distance = 0;
blockIndex++;
if (blockIndex % 4 == 4)
{
if (++blockIndex >= nearbyBlocks.Count)
{
blockIndex = 0;
}
}
}
}
// FIXME: Drop container contents if blocks could not be placed.
// Right now, the player just gets to keep them equipped.
}