RadiancePmap/oocmorton.c
dc807d38cb08precompContrib

oocmorton.c
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			#ifndef lint
			static const char RCSid[] = "$Id: oocmorton.c,v 2.2 2017/08/14 21:12:10 rschregle Exp $";
			#endif


			/*
			=========================================================================
			Routines to generate and compare Morton Codes, i.e. indices on space
			filling Z-curves.

			Roland Schregle (roland.schregle@{hslu.ch, gmail.com})
			(c) Lucerne University of Applied Sciences and Arts,
			supported by the Swiss National Science Foundation (SNSF, #147053)
			=========================================================================

			$Id: oocmorton.c,v 2.2 2017/08/14 21:12:10 rschregle Exp $
			*/


			#if !defined(_WIN32) && !defined(_WIN64) \|\| defined(PMAP_OOC)
			/* No Windoze support for now */

			#include "oocmorton.h"



			OOC_MortonIdx OOC_Key2Morton (const FVECT key, const FVECT org, RREAL scale)
			/* Compute Morton code (Z-curve index) of length 3 * OOC_MORTON_BITS bits
			* for 3D key within bounding box defined by org and scaled to maximum index
			* with scale */
			{
			unsigned i;
			OOC_MortonIdx k [3];

			/* Normalise key and map each dim to int of OOC_MORTON_BITS */
			for (i = 0; i < 3; i++)
			k [i] = scale * (key [i] - org [i]);

			/* Interleave each dim with zeros and merge */
			return OOC_BitInterleave(k [0]) \| OOC_BitInterleave(k [1]) << 1 \|
			OOC_BitInterleave(k [2]) << 2;
			}

			#endif /* NIX / PMAP_OOC */