/// <summary>
/// Initializes <see cref="EndiannessSwapper{T}"/> by generating the appropriate swapping method.
/// </summary>
unsafe static EndiannessSwapper()
{
var valueParam = Expression.Parameter(typeof(WrappedPointer <T>), "value");
var resultParam = Expression.Parameter(typeof(WrappedPointer <T>), "result");
var indexer = typeof(WrappedPointer <T>).GetProperty("Item");
IEnumerable <Expression> GetBody(int byteCount)
{
for (var offset = 0; offset < byteCount; offset++)
{
var valueOffset = Expression.Constant(offset);
var accessValue = Expression.MakeIndex(instance: valueParam,
indexer: indexer,
arguments: System.Linq.Enumerable.Repeat(valueOffset, 1));
var resultOffset = Expression.Constant(byteCount - offset - 1);
var accessResult = Expression.MakeIndex(instance: resultParam,
indexer: indexer,
arguments: System.Linq.Enumerable.Repeat(resultOffset, 1));
yield return(Expression.Assign(accessResult, accessValue));
}
}
var body = Expression.Block(GetBody(sizeof(T)));
Swapper = Expression.Lambda <SwapMethod>(body, valueParam, resultParam)
.Compile();
}
/// <summary> Swap object A and B using the chosen SwapMethod. </summary>
/// <param name="swapWhich"></param>
public void Swap(SwapMethod swapWhich)
{
if (this.CanSwap())
{
if (swapWhich == SwapMethod.Objects)
{
this.Log("Swapping " + this.objectA.name + " and " + this.objectB.name + ".");
this.SwapObjects();
}
else if (swapWhich == SwapMethod.Children)
{
this.Log("Swapping children of " + this.objectA.name + " and " + this.objectB.name + ".");
this.SwapChildren();
}
}
}
