namespace dk {
	namespace implem {
		///----------------------------------------------------------------------
		///----------------------------------------------------------------------
		template <size_t D>
		typename LayerBase<D>::coords::value_type area (const typename LayerBase<D>::coords& parVec) {
			typename LayerBase<D>::coords::value_type retval(1);
			for (size_t d = 0; d < D; ++d) {
				retval *= parVec[d];
			}
			return retval;
		}
	}

	///--------------------------------------------------------------------------
	///--------------------------------------------------------------------------
	template <size_t D>
	LayerBase<D>::LayerBase (const coords& parCount, const coords& parTileSize, const coords& parMasterTileSize) :
		m_count(parCount),
		m_tilesize(parTileSize),
		m_mastersize(parMasterTileSize)
	{
		DK_ASSERT((parMasterTileSize / parTileSize) * parTileSize == parMasterTileSize);
	}

	///--------------------------------------------------------------------------
	///--------------------------------------------------------------------------
	template <typename T, size_t D>
	Layer<T, D>::Layer (const coords& parCount, const coords& parTileSize, const coords& parMasterTileSize, streamer_type&& parStreamer) :
		LayerBase<D>(parCount, parTileSize, parMasterTileSize),
		m_streamer(std::move(parStreamer)),
		m_activeViewport(*this)
	{
		DK_ASSERT(m_streamer.tilesCount() == this->m_count);
		setActiveViewport(coords(0), parCount);
	}

	///--------------------------------------------------------------------------
	///--------------------------------------------------------------------------
	template <typename T, size_t D>
	typename Layer<T, D>::iterator Layer<T, D>::begin() {
		return iterator(&m_tiles, coords(0), this->m_count);
	}

	///--------------------------------------------------------------------------
	///--------------------------------------------------------------------------
	template <typename T, size_t D>
	void Layer<T, D>::setActiveViewport (const coords& parFrom, const coords& parCount) {
		m_tiles.clear();
		const auto area = implem::area<D>(parCount);
		m_tiles.reserve(area);
		m_streamer.copy(m_tiles, parFrom, parFrom + parCount);
		m_activeViewport.setFrom(parFrom);
		m_activeViewport.setSize(parCount);
	}
}