static Optional <int> GetSurfaceId(SurfaceCacheItem item)
{
if (item == null)
{
return(Optional.None());
}
return(item.Surface.GetSurfaceId());
}
void Swap(SurfaceCacheItem newFrontSurface)
{
if (GetSurfaceId(newFrontSurface) != GetSurfaceId(_backSurface))
{
// If new surface hasn't been cached, then pin the old one for deletion
if (_backSurface != null)
{
PinSurfaceItemForWipe(_backSurface);
}
}
_backSurface = _frontSurface;
_frontSurface = newFrontSurface;
_surfaceSwapped.OnNext(Unit.Default);
}
void PinSurfaceItemForWipe(SurfaceCacheItem item)
{
item.ThrowIfNull("item");
_surfacesToBeWiped.Enqueue(item);
}