C++ VoxelArea::index方法代码示例

void VoxelManipulator::copyTo(MapNode *dst, VoxelArea dst_area,
		v3s16 dst_pos, v3s16 from_pos, v3s16 size)
{
	for(s16 z=0; z<size.Z; z++)
	for(s16 y=0; y<size.Y; y++)
	{
		s32 i_dst = dst_area.index(dst_pos.X, dst_pos.Y+y, dst_pos.Z+z);
		s32 i_local = m_area.index(from_pos.X, from_pos.Y+y, from_pos.Z+z);
		memcpy(&dst[i_dst], &m_data[i_local], size.X*sizeof(MapNode));
	}
}

void VoxelManipulator::copyFrom(MapNode *src, VoxelArea src_area,
		v3s16 from_pos, v3s16 to_pos, v3s16 size)
{
	for(s16 z=0; z<size.Z; z++)
	for(s16 y=0; y<size.Y; y++)
	{
		s32 i_src = src_area.index(from_pos.X, from_pos.Y+y, from_pos.Z+z);
		s32 i_local = m_area.index(to_pos.X, to_pos.Y+y, to_pos.Z+z);
		memcpy(&m_data[i_local], &src[i_src], size.X*sizeof(MapNode));
		memset(&m_flags[i_local], 0, size.X);
	}
}

void VoxelManipulator::copyTo(MapNode *dst, const VoxelArea& dst_area,
		v3s16 dst_pos, v3s16 from_pos, v3s16 size)
{
	for(s16 z=0; z<size.Z; z++)
	for(s16 y=0; y<size.Y; y++)
	{
		s32 i_dst = dst_area.index(dst_pos.X, dst_pos.Y+y, dst_pos.Z+z);
		s32 i_local = m_area.index(from_pos.X, from_pos.Y+y, from_pos.Z+z);
		for (s16 x = 0; x < size.X; x++) {
			if (m_data[i_local].getContent() != CONTENT_IGNORE)
				dst[i_dst] = m_data[i_local];
			i_dst++;
			i_local++;
		}
	}
}

void VoxelManipulator::copyFrom(MapNode *src, const VoxelArea& src_area,
		v3s16 from_pos, v3s16 to_pos, v3s16 size)
{
	/* The reason for this optimised code is that we're a member function
	 * and the data type/layout of m_data is know to us: it's stored as
	 * [z*h*w + y*h + x]. Therefore we can take the calls to m_area index
	 * (which performs the preceding mapping/indexing of m_data) out of the
	 * inner loop and calculate the next index as we're iterating to gain
	 * performance.
	 *
	 * src_step and dest_step is the amount required to be added to our index
	 * every time y increments. Because the destination area may be larger
	 * than the source area we need one additional variable (otherwise we could
	 * just continue adding dest_step as is done for the source data): dest_mod.
	 * dest_mod is the difference in size between a "row" in the source data
	 * and a "row" in the destination data (I am using the term row loosely
	 * and for illustrative purposes). E.g.
	 *
	 * src       <-------------------->|'''''' dest mod ''''''''
	 * dest      <--------------------------------------------->
	 *
	 * dest_mod (it's essentially a modulus) is added to the destination index
	 * after every full iteration of the y span.
	 *
	 * This method falls under the category "linear array and incrementing
	 * index".
	 */

	s32 src_step = src_area.getExtent().X;
	s32 dest_step = m_area.getExtent().X;
	s32 dest_mod = m_area.index(to_pos.X, to_pos.Y, to_pos.Z + 1)
			- m_area.index(to_pos.X, to_pos.Y, to_pos.Z)
			- dest_step * size.Y;

	s32 i_src = src_area.index(from_pos.X, from_pos.Y, from_pos.Z);
	s32 i_local = m_area.index(to_pos.X, to_pos.Y, to_pos.Z);

	for (s16 z = 0; z < size.Z; z++) {
		for (s16 y = 0; y < size.Y; y++) {
			memcpy(&m_data[i_local], &src[i_src], size.X * sizeof(*m_data));
			memset(&m_flags[i_local], 0, size.X);
			i_src += src_step;
			i_local += dest_step;
		}
		i_local += dest_mod;
	}
}