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/* |
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======================================================================= |
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Routines for building out-of-core octree data structure |
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|
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Adapted from: Kontkanen J., Tabellion E. and Overbeck R.S., |
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"Coherent Out-of-Core Point-Based Global Illumination", |
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EGSR 2011. |
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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.c,v 1.23 2015/09/15 13:32:13 taschreg Exp taschreg $ |
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*/ |
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|
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|
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#include "oococt.h" |
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#include "oocsort.h" |
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#include <stdlib.h> |
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#include <string.h> |
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|
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|
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/* Test for empty/full input queue, return pointer to head/tail */ |
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#define QueueFull(q) ((q) -> len == (q) -> cap) |
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#define QueueEmpty(q) (!(q) -> len) |
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#define QueueHead(q) ((q) -> data + (q) -> head * (q) -> recSize) |
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#define QueueTail(q) ((q) -> data + \ |
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((q)->head + (q)->len-1) % (q)->cap * (q)->recSize) |
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|
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|
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|
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/* Input queue for bottom-up octree construction */ |
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typedef struct { |
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void *data; |
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unsigned head, len, cap, recSize; /* Queue head, length (from head), |
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capacity and record size */ |
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FILE *in; /* Input file for data records */ |
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} OOC_BuildQueue; |
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|
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|
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static OOC_BuildQueue *QueueInit (OOC_BuildQueue *q, unsigned recSize, |
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unsigned capacity) |
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/* Initialise queue of #capacity records of size recSize each; returns queue |
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* pointer or NULL if failed. */ |
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{ |
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if (!(q && (q -> data = calloc(capacity, recSize)))) |
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return NULL; |
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|
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q -> cap = capacity; |
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q -> recSize = recSize; |
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q -> head = q -> len = 0; |
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|
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return q; |
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} |
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|
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|
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static int QueuePush (OOC_BuildQueue *q, const void *rec) |
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/* Append record to queue tail; return new queue length or -1 on failure */ |
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{ |
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if (!q || !rec || QueueFull(q)) |
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return -1; |
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|
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++q->len; |
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memcpy(QueueTail(q), rec, q -> recSize); |
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|
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return q -> len; |
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} |
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|
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|
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static int QueuePop (OOC_BuildQueue *q, void *rec) |
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/* Remove record from queue head and return in rec if not NULL; return new |
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* queue length or -1 on failure */ |
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{ |
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if (!q || QueueEmpty(q)) |
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return -1; |
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|
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/* Return head if rec != NULL */ |
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if (rec) |
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memcpy(rec, QueueHead(q), q -> recSize); |
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|
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q -> head = (q -> head + 1) % q -> cap; |
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|
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return --q -> len; |
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} |
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|
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|
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static int QueueFill (OOC_BuildQueue *q) |
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/* Read records from q -> in until the queue is full; return queue |
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* length or -1 on failure */ |
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{ |
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static void *rec = NULL; |
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|
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if (!rec && !(rec = malloc(q -> recSize))) |
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return -1; |
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|
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while (!QueueFull(q) && !feof(q -> in) && |
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fread(rec, q -> recSize, 1, q -> in)) |
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QueuePush(q, rec); |
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|
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return q -> len; |
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} |
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|
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|
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|
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static OOC_DataIdx OOC_BuildRecurse (OOC_Octree *oct, OOC_Node* node, |
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FVECT org, RREAL size, unsigned depth, |
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OOC_BuildQueue *queue) |
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/* Recursive part of OOC_Build(); insert records from input queue into |
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* octree node and subdivide into kids if necessary. Returns number of |
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* records in subtree or OOC_DATAIDX_ERR if failed. */ |
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{ |
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int k; |
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const RREAL kidSize = size * 0.5; |
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|
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if (!oct || !node) |
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return OOC_DATAIDX_ERR; |
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|
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if (QueueEmpty(queue) || |
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!OOC_InBBox(oct, org, size, oct -> key(QueueHead(queue)))) |
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/* Input exhausted or queue head outside node */ |
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return 0; |
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|
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if (QueueFull(queue) && depth < oct -> maxDepth && |
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OOC_InBBox(oct, org, size, oct -> key(QueueTail(queue)))) { |
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/*************************** SUBDIVIDE NODE ************************* |
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* At least leafMax + 1 records (since the queue is full) lie inside |
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* the current node's bounding box, and maxDepth has not been reached |
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* ==> subdivide this node. |
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* (Note it suffices to only test the queue tail against the bounding |
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* box, as the records are in Z-order) |
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********************************************************************/ |
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OOC_Node kid [8]; |
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OOC_DataIdx dataCnt; |
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FVECT kidOrg; |
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|
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#ifdef DEBUG_OOC_BUILD |
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FVECT key; |
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unsigned k2 = 0; |
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#endif |
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|
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/* We recurse on the nonempty kids first, then finalise their nodes so |
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* they are ordered consecutively, since the parent only indexes the 1st kid */ |
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for (k = 0; k < 8; k++) { |
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/* Clear kid node and get its octant origin */ |
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OOC_CLEARNODE(kid + k); |
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|
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VCOPY(kidOrg, org); |
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OOC_OCTORIGIN(kidOrg, k, kidSize); |
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|
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/* Recurse on kid and check for early bailout */ |
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if (OOC_BuildRecurse(oct, kid + k, kidOrg, kidSize, |
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depth + 1, queue) == OOC_DATAIDX_ERR) |
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return OOC_DATAIDX_ERR; |
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|
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#ifdef DEBUG_OOC_BUILD |
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if (!QueueEmpty(queue)) { |
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VCOPY(key, oct -> key(QueueHead(queue))); |
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k2 = OOC_Branch(oct, org, kidSize, key, NULL); |
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if (OOC_InBBox(oct, org, size, key) && k2 < k) { |
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fprintf(stderr, |
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"OOC_BuildRecurse, node subdiv: unsorted key [%f, %f, %f] with " |
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"octant %d (last %d with bbox [%f-%f, %f-%f, %f-%f])\n", |
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key [0], key [1], key [2], k2, k, |
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kidOrg [0], kidOrg [0] + kidSize, kidOrg [1], kidOrg [1] + kidSize, |
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kidOrg [2], kidOrg [2] + kidSize); |
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}} |
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#endif |
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} |
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|
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/* Now finalise consecutive kid nodes, skipping empty ones */ |
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for (k = 0; k < 8; k++) |
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if ((dataCnt = OOC_DATACNT(kid + k))) { |
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/* Nonzero kid ==> allocate and set node */ |
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if (!NewNode(oct)) { |
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fputs("OOC_BuildRecurse: failed to allocate new node\n", |
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stderr); |
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return OOC_DATAIDX_ERR; |
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} |
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OOC_SETROOT(oct, kid + k); |
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|
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/* Sum kid's data count to parent's and check for overflow */ |
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if ((dataCnt += node -> node.num) <= OOC_DATAIDX_MAX) |
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node -> node.num = dataCnt; |
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else { |
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fputs("OOC_BuildRecurse: data count overflow in node\n", |
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stderr); |
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return OOC_DATAIDX_ERR; |
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} |
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|
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/* Set kid index in parent (if first kid) and corresponding |
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* branch bit. The kid is the most recent node and thus at the |
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* end of the node array, which coincides with the current |
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* subtree root */ |
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if (!node -> node.branch) |
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node -> node.kid = OOC_ROOTIDX(oct); |
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|
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OOC_SETBRANCH(node, k); |
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} |
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} |
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else { |
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/****************************** MAKE LEAF **************************** |
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* Queue contains no more than leafMax records, queue tail lies |
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* outside node's bounding box, or maxDepth reached |
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* ==> make this node a leaf. |
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*********************************************************************/ |
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RREAL *key; |
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|
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#ifdef DEBUG_OOC_BUILD |
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OOC_MortonIdx zIdx, lastzIdx = 0; |
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FVECT /* key, */ |
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lastKey, kidOrg; |
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unsigned lastk = 0; |
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#endif |
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|
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/* Mark as leaf (note it's been cleared by the parent call) */ |
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OOC_SETLEAF(node); |
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|
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while (!QueueEmpty(queue) && |
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OOC_InBBox(oct, org, size, (key = oct->key(QueueHead(queue))))) { |
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/* Record lies inside leaf; increment data counter for octant |
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* containing record. */ |
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|
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if ((k = OOC_Branch(oct, org, kidSize, key, NULL)) < 0) { |
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/* Shouldn't happen, as key tested within bbox above */ |
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fprintf(stderr, "OOC_BuildRecurse: buggered Morton code, " |
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"disruption in space-time continuum?\n"); |
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return OOC_DATAIDX_ERR; |
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} |
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|
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if (node -> leaf.num [k] == OOC_OCTCNT_MAX) { |
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/* Currently we're buggered here; merge records instead? */ |
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fprintf(stderr, "OOC_BuildRecurse: data count overflow in " |
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"leaf: depth = %d, count = %d\n", |
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depth, node -> leaf.num [k]); |
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return OOC_DATAIDX_ERR; |
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} |
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|
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++node -> leaf.num [k]; |
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|
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#ifdef DEBUG_OOC_BUILD |
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/* VCOPY(key, oct -> key(QueueHead(queue))); */ |
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if ((zIdx = OOC_KEY2MORTON(key, oct)) < lastzIdx) { |
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fprintf(stderr, "OOC_BuildRecurse, make leaf: unsorted zIdx %020ld for " |
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"key [%f, %f, %f] (previous zIdx %020ld for " |
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"key [%f, %f, %f]\n", zIdx, key [0], key [1], key [2], |
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lastzIdx, lastKey [0], lastKey [1], lastKey [2]); |
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} |
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|
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VCOPY(kidOrg, org); |
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OOC_OCTORIGIN(kidOrg, k, kidSize); |
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if (k < lastk || zIdx < lastzIdx) { |
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fprintf(stderr, |
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"OOC_BuildRecurse, make leaf: unsorted octant %d (last %d) with " |
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"bbox [%f-%f, %f-%f, %f-%f] for key [%f, %f, %f] with zIdx %020ld " |
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"(last [%f, %f, %f], zIdx %020ld)\n", |
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k, lastk, kidOrg [0], kidOrg [0] + kidSize, |
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kidOrg [1], kidOrg [1] + kidSize, kidOrg [2], kidOrg [2] + kidSize, |
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key [0], key [1], key [2], zIdx, |
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lastKey [0], lastKey [1], lastKey [2], lastzIdx); |
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} |
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lastk = k; |
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lastzIdx = zIdx; |
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VCOPY(lastKey, key); |
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#endif |
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|
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/* Remove record from queue */ |
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QueuePop(queue, NULL); |
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} |
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|
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/* Refill queue for next node(s) */ |
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if (QueueFill(queue) < 0) { |
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fputs("OOC_Build: failed input queue fill\n", stderr); |
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return OOC_DATAIDX_ERR; |
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} |
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} |
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|
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return OOC_DATACNT(node); |
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} |
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|
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|
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|
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OOC_Octree *OOC_Build (OOC_Octree *oct, unsigned leafMax, unsigned maxDepth) |
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/* Bottom-up construction of out-of-core octree in postorder traversal. The |
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* octree oct is assumed to be initialised with its origin (oct -> org), |
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* size (oct -> size), key callback (oct -> key), and its associated leaf |
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* file (oct -> leafFile). |
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|
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* Records are read from the leafFile and assumed to be sorted in Z-order, |
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* which defines an octree leaf ordering. Leaves (terminal nodes) are |
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* constructed such that they contain <= leafMax records and have a maximum |
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* 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 limited |
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* 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 read |
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* 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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{ |
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OOC_BuildQueue queue; |
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OOC_Node root; |
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|
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if (!oct || !oct -> size) { |
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fputs("OOC_Build: octree not initialised", stderr); |
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return NULL; |
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} |
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|
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if (!oct -> leafFile) { |
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fputs("OOC_Build: empty leaf file", stderr); |
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return NULL; |
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} |
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|
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oct -> leafMax = leafMax; |
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oct -> maxDepth = maxDepth; |
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queue.in = oct -> leafFile; |
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rewind(queue.in); |
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|
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/* Init queue and fill from leaf file */ |
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if (!QueueInit(&queue, oct -> recSize, leafMax + 1) || |
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QueueFill(&queue) < 0) { |
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fputs("OOC_Build: failed input queue init\n", stderr); |
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return NULL; |
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} |
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|
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/* Clear octree root and recurse */ |
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OOC_CLEARNODE(&root); |
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if (OOC_BuildRecurse(oct, &root, oct -> org, oct -> size, 0, &queue) == |
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OOC_DATAIDX_ERR) |
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return NULL; |
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|
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/* Finalise octree root */ |
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if (!NewNode(oct)) { |
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fputs("OOC_Build: failed to allocate octree root\n", stderr); |
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return NULL; |
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} |
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OOC_SETROOT(oct, &root); |
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/* Passing OOC_ROOT(oct) avoids annoying compiler warnings about (&root) |
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* always evaluating to true when calling OOC_DATAIDX() */ |
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oct -> numData = OOC_DATACNT(OOC_ROOT(oct)); |
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|
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return oct; |
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} |