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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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} |
