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/*
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=========================================================================
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Routines to generate and compare Morton Codes, i.e. indices on space
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filling Z-curves.
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Roland Schregle (roland.schregle@{hslu.ch, gmail.com})
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(c) Lucerne University of Applied Sciences and Arts,
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supported by the Swiss National Science Foundation (SNSF, #147053)
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=========================================================================
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$Id: oocmorton.c,v 1.2 2015/11/02 17:30:05 taschreg Exp taschreg $
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*/
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#include "oocmorton.h"
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OOC_MortonIdx OOC_Key2Morton (const FVECT key, const FVECT org, RREAL scale)
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/* Compute Morton code (Z-curve index) of length 3 * OOC_MORTON_BITS bits
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* for 3D key within bounding box defined by org and scaled to maximum index
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* with scale */
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{
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unsigned i;
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OOC_MortonIdx k [3];
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/* Normalise key and map each dim to int of OOC_MORTON_BITS */
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for (i = 0; i < 3; i++)
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k [i] = scale * (key [i] - org [i]);
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/* Interleave each dim with zeros and merge */
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return OOC_BitInterleave(k [0]) | OOC_BitInterleave(k [1]) << 1 |
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OOC_BitInterleave(k [2]) << 2;
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}
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