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/* |
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======================================================================= |
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Header for building out-of-core octree data structure |
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|
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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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|
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$Id: oocbuild.h,v 1.5 2015/08/05 17:29:01 taschreg Exp $ |
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*/ |
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|
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|
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#ifndef OOC_BUILD_H |
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#define OOC_BUILD_H |
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|
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/* Bottom-up construction of out-of-core octree in postorder traversal. |
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* The octree oct is assumed to be initialised with its origin (oct -> |
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* org), size (oct -> size), key callback (oct -> key), and its |
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* associated leaf file (oct -> leafFile). |
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|
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* Records are read from the leafFile and assumed to be sorted in |
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* Z-order, which defines an octree leaf ordering. Leaves (terminal |
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* nodes) are constructed such that they contain <= leafMax records and |
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* have a maximum depth of maxDepth. |
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|
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* Note that the following limits apply: |
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* leafMax <= OOC_OCTCNT_MAX (see oococt.h) |
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* maxDepth <= OOC_MORTON_BITS (see oocsort.h) |
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|
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* The maxDepth limit arises from the fact that the Z-ordering has a |
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* limited resolution and will map node coordinates beyond a depth of |
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* OOC_MORTON_BITS to the same Z-index, causing nodes to be potentially |
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* read out of sequence and winding up in the wrong octree nodes. |
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|
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* On success, the octree pointer oct is returned, with the constructed |
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* nodes in oct -> nodes, and the node count in oct -> numNodes. On |
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* failure, NULL is returned. */ |
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OOC_Octree *OOC_Build (OOC_Octree *oct, unsigned leafMax, |
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unsigned maxDepth); |
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#endif |
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