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/****************************************************************************** |
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* $Id$ |
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* |
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* Project: Shapelib |
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* Purpose: Implementation of quadtree building and searching functions. |
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* Author: Frank Warmerdam, [email protected] |
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* |
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****************************************************************************** |
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* Copyright (c) 1999, Frank Warmerdam |
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* |
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* This software is available under the following "MIT Style" license, |
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* or at the option of the licensee under the LGPL (see LICENSE.LGPL). This |
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* option is discussed in more detail in shapelib.html. |
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* |
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* -- |
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* |
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* Permission is hereby granted, free of charge, to any person obtaining a |
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* copy of this software and associated documentation files (the "Software"), |
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* to deal in the Software without restriction, including without limitation |
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* the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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* and/or sell copies of the Software, and to permit persons to whom the |
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* Software is furnished to do so, subject to the following conditions: |
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* |
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* The above copyright notice and this permission notice shall be included |
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* in all copies or substantial portions of the Software. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
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* DEALINGS IN THE SOFTWARE. |
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****************************************************************************** |
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* |
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* $Log$ |
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* Revision 1.1 2003/08/19 21:29:25 jan |
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* These files have been moved here from thuban/extensions/shapelib/ |
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* See there in the Attic for the older history. |
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* |
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* Revision 1.2 2002/05/08 13:48:43 bh |
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* * extensions/shapelib/shptree.c (compare_ints): Make arguments |
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* const void * as in the qsort prototype |
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* (SHPTreeFindLikelyShapes): Remove some unused variables. |
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* |
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* Revision 1.1 2002/05/07 14:09:34 bh |
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* * extensions/shapelib/shptree.c: Modified version of shptree.c of |
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* shapelib 1.2.9. The only real difference is the use of qsort |
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* instead of a bubble sort implementation |
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* |
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* Revision 1.6 2001/05/23 13:36:52 warmerda |
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* added use of SHPAPI_CALL |
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* |
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* Revision 1.5 1999/11/05 14:12:05 warmerda |
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* updated license terms |
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* |
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* Revision 1.4 1999/06/02 18:24:21 warmerda |
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* added trimming code |
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* |
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* Revision 1.3 1999/06/02 17:56:12 warmerda |
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* added quad'' subnode support for trees |
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* |
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* Revision 1.2 1999/05/18 19:11:11 warmerda |
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* Added example searching capability |
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* |
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* Revision 1.1 1999/05/18 17:49:20 warmerda |
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* New |
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* |
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*/ |
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|
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static char rcsid[] = |
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"$Id$"; |
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|
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#include "shapefil.h" |
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|
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#include <math.h> |
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#include <assert.h> |
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|
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#include <stdlib.h> |
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|
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#ifndef TRUE |
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# define TRUE 1 |
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# define FALSE 0 |
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#endif |
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|
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|
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/* -------------------------------------------------------------------- */ |
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/* If the following is 0.5, nodes will be split in half. If it */ |
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/* is 0.6 then each subnode will contain 60% of the parent */ |
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/* node, with 20% representing overlap. This can be help to */ |
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/* prevent small objects on a boundary from shifting too high */ |
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/* up the tree. */ |
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/* -------------------------------------------------------------------- */ |
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|
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#define SHP_SPLIT_RATIO 0.55 |
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|
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/************************************************************************/ |
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/* SfRealloc() */ |
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/* */ |
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/* A realloc cover function that will access a NULL pointer as */ |
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/* a valid input. */ |
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/************************************************************************/ |
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|
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static void * SfRealloc( void * pMem, int nNewSize ) |
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|
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{ |
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if( pMem == NULL ) |
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return( (void *) malloc(nNewSize) ); |
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else |
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return( (void *) realloc(pMem,nNewSize) ); |
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} |
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|
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/************************************************************************/ |
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/* SHPTreeNodeInit() */ |
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/* */ |
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/* Initialize a tree node. */ |
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/************************************************************************/ |
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|
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static SHPTreeNode *SHPTreeNodeCreate( double * padfBoundsMin, |
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double * padfBoundsMax ) |
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|
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{ |
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SHPTreeNode *psTreeNode; |
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|
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psTreeNode = (SHPTreeNode *) malloc(sizeof(SHPTreeNode)); |
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|
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psTreeNode->nShapeCount = 0; |
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psTreeNode->panShapeIds = NULL; |
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psTreeNode->papsShapeObj = NULL; |
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|
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psTreeNode->nSubNodes = 0; |
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|
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if( padfBoundsMin != NULL ) |
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memcpy( psTreeNode->adfBoundsMin, padfBoundsMin, sizeof(double) * 4 ); |
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|
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if( padfBoundsMax != NULL ) |
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memcpy( psTreeNode->adfBoundsMax, padfBoundsMax, sizeof(double) * 4 ); |
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|
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return psTreeNode; |
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} |
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|
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|
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/************************************************************************/ |
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/* SHPCreateTree() */ |
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/************************************************************************/ |
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|
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SHPTree SHPAPI_CALL1(*) |
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SHPCreateTree( SHPHandle hSHP, int nDimension, int nMaxDepth, |
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double *padfBoundsMin, double *padfBoundsMax ) |
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|
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{ |
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SHPTree *psTree; |
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|
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if( padfBoundsMin == NULL && hSHP == NULL ) |
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return NULL; |
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|
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/* -------------------------------------------------------------------- */ |
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/* Allocate the tree object */ |
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/* -------------------------------------------------------------------- */ |
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psTree = (SHPTree *) malloc(sizeof(SHPTree)); |
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|
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psTree->hSHP = hSHP; |
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psTree->nMaxDepth = nMaxDepth; |
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psTree->nDimension = nDimension; |
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|
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/* -------------------------------------------------------------------- */ |
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/* If no max depth was defined, try to select a reasonable one */ |
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/* that implies approximately 8 shapes per node. */ |
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/* -------------------------------------------------------------------- */ |
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if( psTree->nMaxDepth == 0 && hSHP != NULL ) |
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{ |
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int nMaxNodeCount = 1; |
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int nShapeCount; |
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|
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SHPGetInfo( hSHP, &nShapeCount, NULL, NULL, NULL ); |
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while( nMaxNodeCount*4 < nShapeCount ) |
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{ |
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psTree->nMaxDepth += 1; |
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nMaxNodeCount = nMaxNodeCount * 2; |
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} |
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} |
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|
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/* -------------------------------------------------------------------- */ |
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/* Allocate the root node. */ |
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/* -------------------------------------------------------------------- */ |
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psTree->psRoot = SHPTreeNodeCreate( padfBoundsMin, padfBoundsMax ); |
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|
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/* -------------------------------------------------------------------- */ |
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/* Assign the bounds to the root node. If none are passed in, */ |
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/* use the bounds of the provided file otherwise the create */ |
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/* function will have already set the bounds. */ |
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/* -------------------------------------------------------------------- */ |
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if( padfBoundsMin == NULL ) |
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{ |
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SHPGetInfo( hSHP, NULL, NULL, |
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psTree->psRoot->adfBoundsMin, |
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psTree->psRoot->adfBoundsMax ); |
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} |
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|
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/* -------------------------------------------------------------------- */ |
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/* If we have a file, insert all it's shapes into the tree. */ |
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/* -------------------------------------------------------------------- */ |
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if( hSHP != NULL ) |
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{ |
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int iShape, nShapeCount; |
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|
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SHPGetInfo( hSHP, &nShapeCount, NULL, NULL, NULL ); |
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|
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for( iShape = 0; iShape < nShapeCount; iShape++ ) |
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{ |
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SHPObject *psShape; |
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|
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psShape = SHPReadObject( hSHP, iShape ); |
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SHPTreeAddShapeId( psTree, psShape ); |
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SHPDestroyObject( psShape ); |
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} |
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} |
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|
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return psTree; |
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} |
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|
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/************************************************************************/ |
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/* SHPDestroyTreeNode() */ |
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/************************************************************************/ |
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|
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static void SHPDestroyTreeNode( SHPTreeNode * psTreeNode ) |
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|
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{ |
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int i; |
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|
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for( i = 0; i < psTreeNode->nSubNodes; i++ ) |
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{ |
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if( psTreeNode->apsSubNode[i] != NULL ) |
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SHPDestroyTreeNode( psTreeNode->apsSubNode[i] ); |
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} |
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|
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if( psTreeNode->panShapeIds != NULL ) |
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free( psTreeNode->panShapeIds ); |
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|
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if( psTreeNode->papsShapeObj != NULL ) |
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{ |
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for( i = 0; i < psTreeNode->nShapeCount; i++ ) |
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{ |
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if( psTreeNode->papsShapeObj[i] != NULL ) |
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SHPDestroyObject( psTreeNode->papsShapeObj[i] ); |
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} |
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|
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free( psTreeNode->papsShapeObj ); |
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} |
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|
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free( psTreeNode ); |
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} |
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|
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/************************************************************************/ |
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/* SHPDestroyTree() */ |
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/************************************************************************/ |
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|
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void SHPAPI_CALL |
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SHPDestroyTree( SHPTree * psTree ) |
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|
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{ |
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SHPDestroyTreeNode( psTree->psRoot ); |
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free( psTree ); |
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} |
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|
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/************************************************************************/ |
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/* SHPCheckBoundsOverlap() */ |
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/* */ |
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/* Do the given boxes overlap at all? */ |
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/************************************************************************/ |
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|
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int SHPAPI_CALL |
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SHPCheckBoundsOverlap( double * padfBox1Min, double * padfBox1Max, |
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double * padfBox2Min, double * padfBox2Max, |
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int nDimension ) |
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|
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{ |
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int iDim; |
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|
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for( iDim = 0; iDim < nDimension; iDim++ ) |
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{ |
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if( padfBox2Max[iDim] < padfBox1Min[iDim] ) |
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return FALSE; |
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|
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if( padfBox1Max[iDim] < padfBox2Min[iDim] ) |
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return FALSE; |
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} |
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|
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return TRUE; |
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} |
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|
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/************************************************************************/ |
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/* SHPCheckObjectContained() */ |
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/* */ |
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/* Does the given shape fit within the indicated extents? */ |
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/************************************************************************/ |
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|
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static int SHPCheckObjectContained( SHPObject * psObject, int nDimension, |
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double * padfBoundsMin, double * padfBoundsMax ) |
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|
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{ |
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if( psObject->dfXMin < padfBoundsMin[0] |
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|| psObject->dfXMax > padfBoundsMax[0] ) |
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return FALSE; |
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|
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if( psObject->dfYMin < padfBoundsMin[1] |
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|| psObject->dfYMax > padfBoundsMax[1] ) |
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return FALSE; |
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|
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if( nDimension == 2 ) |
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return TRUE; |
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|
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if( psObject->dfZMin < padfBoundsMin[2] |
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|| psObject->dfZMax < padfBoundsMax[2] ) |
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return FALSE; |
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|
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if( nDimension == 3 ) |
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return TRUE; |
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|
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if( psObject->dfMMin < padfBoundsMin[3] |
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|| psObject->dfMMax < padfBoundsMax[3] ) |
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return FALSE; |
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|
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return TRUE; |
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} |
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|
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/************************************************************************/ |
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/* SHPTreeSplitBounds() */ |
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/* */ |
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/* Split a region into two subregion evenly, cutting along the */ |
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/* longest dimension. */ |
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/************************************************************************/ |
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|
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void SHPAPI_CALL |
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SHPTreeSplitBounds( double *padfBoundsMinIn, double *padfBoundsMaxIn, |
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double *padfBoundsMin1, double * padfBoundsMax1, |
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double *padfBoundsMin2, double * padfBoundsMax2 ) |
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|
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{ |
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/* -------------------------------------------------------------------- */ |
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/* The output bounds will be very similar to the input bounds, */ |
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/* so just copy over to start. */ |
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/* -------------------------------------------------------------------- */ |
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memcpy( padfBoundsMin1, padfBoundsMinIn, sizeof(double) * 4 ); |
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memcpy( padfBoundsMax1, padfBoundsMaxIn, sizeof(double) * 4 ); |
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memcpy( padfBoundsMin2, padfBoundsMinIn, sizeof(double) * 4 ); |
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memcpy( padfBoundsMax2, padfBoundsMaxIn, sizeof(double) * 4 ); |
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|
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/* -------------------------------------------------------------------- */ |
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/* Split in X direction. */ |
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/* -------------------------------------------------------------------- */ |
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if( (padfBoundsMaxIn[0] - padfBoundsMinIn[0]) |
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> (padfBoundsMaxIn[1] - padfBoundsMinIn[1]) ) |
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{ |
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double dfRange = padfBoundsMaxIn[0] - padfBoundsMinIn[0]; |
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|
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padfBoundsMax1[0] = padfBoundsMinIn[0] + dfRange * SHP_SPLIT_RATIO; |
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padfBoundsMin2[0] = padfBoundsMaxIn[0] - dfRange * SHP_SPLIT_RATIO; |
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} |
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|
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/* -------------------------------------------------------------------- */ |
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/* Otherwise split in Y direction. */ |
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/* -------------------------------------------------------------------- */ |
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else |
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{ |
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double dfRange = padfBoundsMaxIn[1] - padfBoundsMinIn[1]; |
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|
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padfBoundsMax1[1] = padfBoundsMinIn[1] + dfRange * SHP_SPLIT_RATIO; |
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padfBoundsMin2[1] = padfBoundsMaxIn[1] - dfRange * SHP_SPLIT_RATIO; |
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} |
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} |
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|
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/************************************************************************/ |
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/* SHPTreeNodeAddShapeId() */ |
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/************************************************************************/ |
| 376 |
|
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static int |
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SHPTreeNodeAddShapeId( SHPTreeNode * psTreeNode, SHPObject * psObject, |
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int nMaxDepth, int nDimension ) |
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|
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{ |
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int i; |
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|
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/* -------------------------------------------------------------------- */ |
| 385 |
/* If there are subnodes, then consider wiether this object */ |
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/* will fit in them. */ |
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/* -------------------------------------------------------------------- */ |
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if( nMaxDepth > 1 && psTreeNode->nSubNodes > 0 ) |
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{ |
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for( i = 0; i < psTreeNode->nSubNodes; i++ ) |
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{ |
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if( SHPCheckObjectContained(psObject, nDimension, |
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psTreeNode->apsSubNode[i]->adfBoundsMin, |
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psTreeNode->apsSubNode[i]->adfBoundsMax)) |
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{ |
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return SHPTreeNodeAddShapeId( psTreeNode->apsSubNode[i], |
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psObject, nMaxDepth-1, |
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nDimension ); |
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} |
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} |
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} |
| 402 |
|
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/* -------------------------------------------------------------------- */ |
| 404 |
/* Otherwise, consider creating four subnodes if could fit into */ |
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/* them, and adding to the appropriate subnode. */ |
| 406 |
/* -------------------------------------------------------------------- */ |
| 407 |
#if MAX_SUBNODE == 4 |
| 408 |
else if( nMaxDepth > 1 && psTreeNode->nSubNodes == 0 ) |
| 409 |
{ |
| 410 |
double adfBoundsMinH1[4], adfBoundsMaxH1[4]; |
| 411 |
double adfBoundsMinH2[4], adfBoundsMaxH2[4]; |
| 412 |
double adfBoundsMin1[4], adfBoundsMax1[4]; |
| 413 |
double adfBoundsMin2[4], adfBoundsMax2[4]; |
| 414 |
double adfBoundsMin3[4], adfBoundsMax3[4]; |
| 415 |
double adfBoundsMin4[4], adfBoundsMax4[4]; |
| 416 |
|
| 417 |
SHPTreeSplitBounds( psTreeNode->adfBoundsMin, |
| 418 |
psTreeNode->adfBoundsMax, |
| 419 |
adfBoundsMinH1, adfBoundsMaxH1, |
| 420 |
adfBoundsMinH2, adfBoundsMaxH2 ); |
| 421 |
|
| 422 |
SHPTreeSplitBounds( adfBoundsMinH1, adfBoundsMaxH1, |
| 423 |
adfBoundsMin1, adfBoundsMax1, |
| 424 |
adfBoundsMin2, adfBoundsMax2 ); |
| 425 |
|
| 426 |
SHPTreeSplitBounds( adfBoundsMinH2, adfBoundsMaxH2, |
| 427 |
adfBoundsMin3, adfBoundsMax3, |
| 428 |
adfBoundsMin4, adfBoundsMax4 ); |
| 429 |
|
| 430 |
if( SHPCheckObjectContained(psObject, nDimension, |
| 431 |
adfBoundsMin1, adfBoundsMax1) |
| 432 |
|| SHPCheckObjectContained(psObject, nDimension, |
| 433 |
adfBoundsMin2, adfBoundsMax2) |
| 434 |
|| SHPCheckObjectContained(psObject, nDimension, |
| 435 |
adfBoundsMin3, adfBoundsMax3) |
| 436 |
|| SHPCheckObjectContained(psObject, nDimension, |
| 437 |
adfBoundsMin4, adfBoundsMax4) ) |
| 438 |
{ |
| 439 |
psTreeNode->nSubNodes = 4; |
| 440 |
psTreeNode->apsSubNode[0] = SHPTreeNodeCreate( adfBoundsMin1, |
| 441 |
adfBoundsMax1 ); |
| 442 |
psTreeNode->apsSubNode[1] = SHPTreeNodeCreate( adfBoundsMin2, |
| 443 |
adfBoundsMax2 ); |
| 444 |
psTreeNode->apsSubNode[2] = SHPTreeNodeCreate( adfBoundsMin3, |
| 445 |
adfBoundsMax3 ); |
| 446 |
psTreeNode->apsSubNode[3] = SHPTreeNodeCreate( adfBoundsMin4, |
| 447 |
adfBoundsMax4 ); |
| 448 |
|
| 449 |
/* recurse back on this node now that it has subnodes */ |
| 450 |
return( SHPTreeNodeAddShapeId( psTreeNode, psObject, |
| 451 |
nMaxDepth, nDimension ) ); |
| 452 |
} |
| 453 |
} |
| 454 |
#endif /* MAX_SUBNODE == 4 */ |
| 455 |
|
| 456 |
/* -------------------------------------------------------------------- */ |
| 457 |
/* Otherwise, consider creating two subnodes if could fit into */ |
| 458 |
/* them, and adding to the appropriate subnode. */ |
| 459 |
/* -------------------------------------------------------------------- */ |
| 460 |
#if MAX_SUBNODE == 2 |
| 461 |
else if( nMaxDepth > 1 && psTreeNode->nSubNodes == 0 ) |
| 462 |
{ |
| 463 |
double adfBoundsMin1[4], adfBoundsMax1[4]; |
| 464 |
double adfBoundsMin2[4], adfBoundsMax2[4]; |
| 465 |
|
| 466 |
SHPTreeSplitBounds( psTreeNode->adfBoundsMin, psTreeNode->adfBoundsMax, |
| 467 |
adfBoundsMin1, adfBoundsMax1, |
| 468 |
adfBoundsMin2, adfBoundsMax2 ); |
| 469 |
|
| 470 |
if( SHPCheckObjectContained(psObject, nDimension, |
| 471 |
adfBoundsMin1, adfBoundsMax1)) |
| 472 |
{ |
| 473 |
psTreeNode->nSubNodes = 2; |
| 474 |
psTreeNode->apsSubNode[0] = SHPTreeNodeCreate( adfBoundsMin1, |
| 475 |
adfBoundsMax1 ); |
| 476 |
psTreeNode->apsSubNode[1] = SHPTreeNodeCreate( adfBoundsMin2, |
| 477 |
adfBoundsMax2 ); |
| 478 |
|
| 479 |
return( SHPTreeNodeAddShapeId( psTreeNode->apsSubNode[0], psObject, |
| 480 |
nMaxDepth - 1, nDimension ) ); |
| 481 |
} |
| 482 |
else if( SHPCheckObjectContained(psObject, nDimension, |
| 483 |
adfBoundsMin2, adfBoundsMax2) ) |
| 484 |
{ |
| 485 |
psTreeNode->nSubNodes = 2; |
| 486 |
psTreeNode->apsSubNode[0] = SHPTreeNodeCreate( adfBoundsMin1, |
| 487 |
adfBoundsMax1 ); |
| 488 |
psTreeNode->apsSubNode[1] = SHPTreeNodeCreate( adfBoundsMin2, |
| 489 |
adfBoundsMax2 ); |
| 490 |
|
| 491 |
return( SHPTreeNodeAddShapeId( psTreeNode->apsSubNode[1], psObject, |
| 492 |
nMaxDepth - 1, nDimension ) ); |
| 493 |
} |
| 494 |
} |
| 495 |
#endif /* MAX_SUBNODE == 2 */ |
| 496 |
|
| 497 |
/* -------------------------------------------------------------------- */ |
| 498 |
/* If none of that worked, just add it to this nodes list. */ |
| 499 |
/* -------------------------------------------------------------------- */ |
| 500 |
psTreeNode->nShapeCount++; |
| 501 |
|
| 502 |
psTreeNode->panShapeIds = |
| 503 |
SfRealloc( psTreeNode->panShapeIds, |
| 504 |
sizeof(int) * psTreeNode->nShapeCount ); |
| 505 |
psTreeNode->panShapeIds[psTreeNode->nShapeCount-1] = psObject->nShapeId; |
| 506 |
|
| 507 |
if( psTreeNode->papsShapeObj != NULL ) |
| 508 |
{ |
| 509 |
psTreeNode->papsShapeObj = |
| 510 |
SfRealloc( psTreeNode->papsShapeObj, |
| 511 |
sizeof(void *) * psTreeNode->nShapeCount ); |
| 512 |
psTreeNode->papsShapeObj[psTreeNode->nShapeCount-1] = NULL; |
| 513 |
} |
| 514 |
|
| 515 |
return TRUE; |
| 516 |
} |
| 517 |
|
| 518 |
/************************************************************************/ |
| 519 |
/* SHPTreeAddShapeId() */ |
| 520 |
/* */ |
| 521 |
/* Add a shape to the tree, but don't keep a pointer to the */ |
| 522 |
/* object data, just keep the shapeid. */ |
| 523 |
/************************************************************************/ |
| 524 |
|
| 525 |
int SHPAPI_CALL |
| 526 |
SHPTreeAddShapeId( SHPTree * psTree, SHPObject * psObject ) |
| 527 |
|
| 528 |
{ |
| 529 |
return( SHPTreeNodeAddShapeId( psTree->psRoot, psObject, |
| 530 |
psTree->nMaxDepth, psTree->nDimension ) ); |
| 531 |
} |
| 532 |
|
| 533 |
/************************************************************************/ |
| 534 |
/* SHPTreeCollectShapesIds() */ |
| 535 |
/* */ |
| 536 |
/* Work function implementing SHPTreeFindLikelyShapes() on a */ |
| 537 |
/* tree node by tree node basis. */ |
| 538 |
/************************************************************************/ |
| 539 |
|
| 540 |
void SHPAPI_CALL |
| 541 |
SHPTreeCollectShapeIds( SHPTree *hTree, SHPTreeNode * psTreeNode, |
| 542 |
double * padfBoundsMin, double * padfBoundsMax, |
| 543 |
int * pnShapeCount, int * pnMaxShapes, |
| 544 |
int ** ppanShapeList ) |
| 545 |
|
| 546 |
{ |
| 547 |
int i; |
| 548 |
|
| 549 |
/* -------------------------------------------------------------------- */ |
| 550 |
/* Does this node overlap the area of interest at all? If not, */ |
| 551 |
/* return without adding to the list at all. */ |
| 552 |
/* -------------------------------------------------------------------- */ |
| 553 |
if( !SHPCheckBoundsOverlap( psTreeNode->adfBoundsMin, |
| 554 |
psTreeNode->adfBoundsMax, |
| 555 |
padfBoundsMin, |
| 556 |
padfBoundsMax, |
| 557 |
hTree->nDimension ) ) |
| 558 |
return; |
| 559 |
|
| 560 |
/* -------------------------------------------------------------------- */ |
| 561 |
/* Grow the list to hold the shapes on this node. */ |
| 562 |
/* -------------------------------------------------------------------- */ |
| 563 |
if( *pnShapeCount + psTreeNode->nShapeCount > *pnMaxShapes ) |
| 564 |
{ |
| 565 |
*pnMaxShapes = (*pnShapeCount + psTreeNode->nShapeCount) * 2 + 20; |
| 566 |
*ppanShapeList = (int *) |
| 567 |
SfRealloc(*ppanShapeList,sizeof(int) * *pnMaxShapes); |
| 568 |
} |
| 569 |
|
| 570 |
/* -------------------------------------------------------------------- */ |
| 571 |
/* Add the local nodes shapeids to the list. */ |
| 572 |
/* -------------------------------------------------------------------- */ |
| 573 |
for( i = 0; i < psTreeNode->nShapeCount; i++ ) |
| 574 |
{ |
| 575 |
(*ppanShapeList)[(*pnShapeCount)++] = psTreeNode->panShapeIds[i]; |
| 576 |
} |
| 577 |
|
| 578 |
/* -------------------------------------------------------------------- */ |
| 579 |
/* Recurse to subnodes if they exist. */ |
| 580 |
/* -------------------------------------------------------------------- */ |
| 581 |
for( i = 0; i < psTreeNode->nSubNodes; i++ ) |
| 582 |
{ |
| 583 |
if( psTreeNode->apsSubNode[i] != NULL ) |
| 584 |
SHPTreeCollectShapeIds( hTree, psTreeNode->apsSubNode[i], |
| 585 |
padfBoundsMin, padfBoundsMax, |
| 586 |
pnShapeCount, pnMaxShapes, |
| 587 |
ppanShapeList ); |
| 588 |
} |
| 589 |
} |
| 590 |
|
| 591 |
/************************************************************************/ |
| 592 |
/* SHPTreeFindLikelyShapes() */ |
| 593 |
/* */ |
| 594 |
/* Find all shapes within tree nodes for which the tree node */ |
| 595 |
/* bounding box overlaps the search box. The return value is */ |
| 596 |
/* an array of shapeids terminated by a -1. The shapeids will */ |
| 597 |
/* be in order, as hopefully this will result in faster (more */ |
| 598 |
/* sequential) reading from the file. */ |
| 599 |
/************************************************************************/ |
| 600 |
|
| 601 |
/* helper for qsort */ |
| 602 |
static int |
| 603 |
compare_ints(const void * a, const void * b) |
| 604 |
{ |
| 605 |
return (*(int*)a) - (*(int*)b); |
| 606 |
} |
| 607 |
|
| 608 |
int SHPAPI_CALL1(*) |
| 609 |
SHPTreeFindLikelyShapes( SHPTree * hTree, |
| 610 |
double * padfBoundsMin, double * padfBoundsMax, |
| 611 |
int * pnShapeCount ) |
| 612 |
|
| 613 |
{ |
| 614 |
int *panShapeList=NULL, nMaxShapes = 0; |
| 615 |
|
| 616 |
/* -------------------------------------------------------------------- */ |
| 617 |
/* Perform the search by recursive descent. */ |
| 618 |
/* -------------------------------------------------------------------- */ |
| 619 |
*pnShapeCount = 0; |
| 620 |
|
| 621 |
SHPTreeCollectShapeIds( hTree, hTree->psRoot, |
| 622 |
padfBoundsMin, padfBoundsMax, |
| 623 |
pnShapeCount, &nMaxShapes, |
| 624 |
&panShapeList ); |
| 625 |
|
| 626 |
/* -------------------------------------------------------------------- */ |
| 627 |
/* Sort the id array */ |
| 628 |
/* -------------------------------------------------------------------- */ |
| 629 |
|
| 630 |
qsort(panShapeList, *pnShapeCount, sizeof(int), compare_ints); |
| 631 |
|
| 632 |
return panShapeList; |
| 633 |
} |
| 634 |
|
| 635 |
/************************************************************************/ |
| 636 |
/* SHPTreeNodeTrim() */ |
| 637 |
/* */ |
| 638 |
/* This is the recurve version of SHPTreeTrimExtraNodes() that */ |
| 639 |
/* walks the tree cleaning it up. */ |
| 640 |
/************************************************************************/ |
| 641 |
|
| 642 |
static int SHPTreeNodeTrim( SHPTreeNode * psTreeNode ) |
| 643 |
|
| 644 |
{ |
| 645 |
int i; |
| 646 |
|
| 647 |
/* -------------------------------------------------------------------- */ |
| 648 |
/* Trim subtrees, and free subnodes that come back empty. */ |
| 649 |
/* -------------------------------------------------------------------- */ |
| 650 |
for( i = 0; i < psTreeNode->nSubNodes; i++ ) |
| 651 |
{ |
| 652 |
if( SHPTreeNodeTrim( psTreeNode->apsSubNode[i] ) ) |
| 653 |
{ |
| 654 |
SHPDestroyTreeNode( psTreeNode->apsSubNode[i] ); |
| 655 |
|
| 656 |
psTreeNode->apsSubNode[i] = |
| 657 |
psTreeNode->apsSubNode[psTreeNode->nSubNodes-1]; |
| 658 |
|
| 659 |
psTreeNode->nSubNodes--; |
| 660 |
|
| 661 |
i--; /* process the new occupant of this subnode entry */ |
| 662 |
} |
| 663 |
} |
| 664 |
|
| 665 |
/* -------------------------------------------------------------------- */ |
| 666 |
/* We should be trimmed if we have no subnodes, and no shapes. */ |
| 667 |
/* -------------------------------------------------------------------- */ |
| 668 |
return( psTreeNode->nSubNodes == 0 && psTreeNode->nShapeCount == 0 ); |
| 669 |
} |
| 670 |
|
| 671 |
/************************************************************************/ |
| 672 |
/* SHPTreeTrimExtraNodes() */ |
| 673 |
/* */ |
| 674 |
/* Trim empty nodes from the tree. Note that we never trim an */ |
| 675 |
/* empty root node. */ |
| 676 |
/************************************************************************/ |
| 677 |
|
| 678 |
void SHPAPI_CALL |
| 679 |
SHPTreeTrimExtraNodes( SHPTree * hTree ) |
| 680 |
|
| 681 |
{ |
| 682 |
SHPTreeNodeTrim( hTree->psRoot ); |
| 683 |
} |
| 684 |
|
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