3-axis iteration - less branchy, less nesting - easier to look at

gistfile1.cpp

struct BoxIterator
{
	BoxIterator(const math::boxi& range)
		: range(range)
	{
		// Clamp any negative deltas to zero before calculating volume
		// Also add 1 to make the max inclusive
		delta.x = max(range.max.x - range.min.x + 1, 0);
		delta.y = max(range.max.y - range.min.y + 1, 0);
		delta.z = max(range.max.z - range.min.z + 1, 0);

		slice_size = delta.x * delta.y;
		size = slice_size * delta.z;
	}
	
	void GetPos(int i, math::vec3i& pos) const
	{
		// Calculate position within the range delta
		pos.z = i / slice_size;
		i -= pos.z * slice_size;
		pos.y = i / delta.x;
		pos.x = i - pos.y * delta.x;

		// Offset that to get the actual position
		pos.x += range.min.x;
		pos.y += range.min.y;
		pos.z += range.min.z;
	}

	const math::boxi& range;
	math::vec3i delta;
	i32 slice_size;
	i32 size;
};


BoxIterator node_iterator(node_range);
for (i32 i = 0; i < node_iterator.size; i++)
{
	math::vec3i node_pos;
	node_iterator.GetPos(i, node_pos);
}