SHPCreateTree( SHPHandle hSHP, int nDimension, int nMaxDepth,
double *padfBoundsMin, double *padfBoundsMax )
{
SHPTree *psTree;
if( padfBoundsMin == NULL && hSHP == NULL )
return NULL;
/* -------------------------------------------------------------------- */
/* Allocate the tree object */
/* -------------------------------------------------------------------- */
psTree = (SHPTree *) malloc(sizeof(SHPTree));
psTree->hSHP = hSHP;
psTree->nMaxDepth = nMaxDepth;
psTree->nDimension = nDimension;
/* -------------------------------------------------------------------- */
/* If no max depth was defined, try to select a reasonable one */
/* that implies approximately 8 shapes per node. */
/* -------------------------------------------------------------------- */
if( psTree->nMaxDepth == 0 && hSHP != NULL )
{
int nMaxNodeCount = 1;
int nShapeCount;
SHPGetInfo( hSHP, &nShapeCount, NULL, NULL, NULL );
while( nMaxNodeCount*4 < nShapeCount )
{
psTree->nMaxDepth += 1;
nMaxNodeCount = nMaxNodeCount * 2;
}
}
/* -------------------------------------------------------------------- */
/* Allocate the root node. */
/* -------------------------------------------------------------------- */
psTree->psRoot = SHPTreeNodeCreate( padfBoundsMin, padfBoundsMax );
/* -------------------------------------------------------------------- */
/* Assign the bounds to the root node. If none are passed in, */
/* use the bounds of the provided file otherwise the create */
/* function will have already set the bounds. */
/* -------------------------------------------------------------------- */
if( padfBoundsMin == NULL )
{
SHPGetInfo( hSHP, NULL, NULL,
psTree->psRoot->adfBoundsMin,
psTree->psRoot->adfBoundsMax );
}
/* -------------------------------------------------------------------- */
/* If we have a file, insert all it's shapes into the tree. */
/* -------------------------------------------------------------------- */
if( hSHP != NULL )
{
int iShape, nShapeCount;
SHPGetInfo( hSHP, &nShapeCount, NULL, NULL, NULL );
for( iShape = 0; iShape < nShapeCount; iShape++ )
{
SHPObject *psShape;
psShape = SHPReadObject( hSHP, iShape );
SHPTreeAddShapeId( psTree, psShape );
SHPDestroyObject( psShape );
}
}
return psTree;
}
static int
SHPTreeNodeAddShapeId( SHPTreeNode * psTreeNode, SHPObject * psObject,
int nMaxDepth, int nDimension )
{
int i;
/* -------------------------------------------------------------------- */
/* If there are subnodes, then consider wiether this object */
/* will fit in them. */
/* -------------------------------------------------------------------- */
if( nMaxDepth > 1 && psTreeNode->nSubNodes > 0 )
{
for( i = 0; i < psTreeNode->nSubNodes; i++ )
{
if( SHPCheckObjectContained(psObject, nDimension,
psTreeNode->apsSubNode[i]->adfBoundsMin,
psTreeNode->apsSubNode[i]->adfBoundsMax))
{
return SHPTreeNodeAddShapeId( psTreeNode->apsSubNode[i],
psObject, nMaxDepth-1,
nDimension );
}
}
}
/* -------------------------------------------------------------------- */
/* Otherwise, consider creating four subnodes if could fit into */
/* them, and adding to the appropriate subnode. */
/* -------------------------------------------------------------------- */
#if MAX_SUBNODE == 4
else if( nMaxDepth > 1 && psTreeNode->nSubNodes == 0 )
{
double adfBoundsMinH1[4], adfBoundsMaxH1[4];
double adfBoundsMinH2[4], adfBoundsMaxH2[4];
double adfBoundsMin1[4], adfBoundsMax1[4];
double adfBoundsMin2[4], adfBoundsMax2[4];
double adfBoundsMin3[4], adfBoundsMax3[4];
double adfBoundsMin4[4], adfBoundsMax4[4];
SHPTreeSplitBounds( psTreeNode->adfBoundsMin,
psTreeNode->adfBoundsMax,
adfBoundsMinH1, adfBoundsMaxH1,
adfBoundsMinH2, adfBoundsMaxH2 );
SHPTreeSplitBounds( adfBoundsMinH1, adfBoundsMaxH1,
adfBoundsMin1, adfBoundsMax1,
adfBoundsMin2, adfBoundsMax2 );
SHPTreeSplitBounds( adfBoundsMinH2, adfBoundsMaxH2,
adfBoundsMin3, adfBoundsMax3,
adfBoundsMin4, adfBoundsMax4 );
if( SHPCheckObjectContained(psObject, nDimension,
adfBoundsMin1, adfBoundsMax1)
|| SHPCheckObjectContained(psObject, nDimension,
adfBoundsMin2, adfBoundsMax2)
|| SHPCheckObjectContained(psObject, nDimension,
adfBoundsMin3, adfBoundsMax3)
|| SHPCheckObjectContained(psObject, nDimension,
adfBoundsMin4, adfBoundsMax4) )
{
psTreeNode->nSubNodes = 4;
psTreeNode->apsSubNode[0] = SHPTreeNodeCreate( adfBoundsMin1,
adfBoundsMax1 );
psTreeNode->apsSubNode[1] = SHPTreeNodeCreate( adfBoundsMin2,
adfBoundsMax2 );
psTreeNode->apsSubNode[2] = SHPTreeNodeCreate( adfBoundsMin3,
adfBoundsMax3 );
psTreeNode->apsSubNode[3] = SHPTreeNodeCreate( adfBoundsMin4,
adfBoundsMax4 );
/* recurse back on this node now that it has subnodes */
return( SHPTreeNodeAddShapeId( psTreeNode, psObject,
nMaxDepth, nDimension ) );
}
}
#endif /* MAX_SUBNODE == 4 */
/* -------------------------------------------------------------------- */
/* Otherwise, consider creating two subnodes if could fit into */
/* them, and adding to the appropriate subnode. */
/* -------------------------------------------------------------------- */
#if MAX_SUBNODE == 2
else if( nMaxDepth > 1 && psTreeNode->nSubNodes == 0 )
{
double adfBoundsMin1[4], adfBoundsMax1[4];
double adfBoundsMin2[4], adfBoundsMax2[4];
SHPTreeSplitBounds( psTreeNode->adfBoundsMin, psTreeNode->adfBoundsMax,
adfBoundsMin1, adfBoundsMax1,
adfBoundsMin2, adfBoundsMax2 );
if( SHPCheckObjectContained(psObject, nDimension,
adfBoundsMin1, adfBoundsMax1))
{
psTreeNode->nSubNodes = 2;
psTreeNode->apsSubNode[0] = SHPTreeNodeCreate( adfBoundsMin1,
adfBoundsMax1 );
psTreeNode->apsSubNode[1] = SHPTreeNodeCreate( adfBoundsMin2,
adfBoundsMax2 );
return( SHPTreeNodeAddShapeId( psTreeNode->apsSubNode[0], psObject,
nMaxDepth - 1, nDimension ) );
}
else if( SHPCheckObjectContained(psObject, nDimension,
adfBoundsMin2, adfBoundsMax2) )
{
psTreeNode->nSubNodes = 2;
psTreeNode->apsSubNode[0] = SHPTreeNodeCreate( adfBoundsMin1,
adfBoundsMax1 );
psTreeNode->apsSubNode[1] = SHPTreeNodeCreate( adfBoundsMin2,
adfBoundsMax2 );
return( SHPTreeNodeAddShapeId( psTreeNode->apsSubNode[1], psObject,
nMaxDepth - 1, nDimension ) );
}
}
#endif /* MAX_SUBNODE == 2 */
/* -------------------------------------------------------------------- */
/* If none of that worked, just add it to this nodes list. */
/* -------------------------------------------------------------------- */
psTreeNode->nShapeCount++;
psTreeNode->panShapeIds =
SfRealloc( psTreeNode->panShapeIds,
sizeof(int) * psTreeNode->nShapeCount );
psTreeNode->panShapeIds[psTreeNode->nShapeCount-1] = psObject->nShapeId;
if( psTreeNode->papsShapeObj != NULL )
{
psTreeNode->papsShapeObj =
SfRealloc( psTreeNode->papsShapeObj,
sizeof(void *) * psTreeNode->nShapeCount );
psTreeNode->papsShapeObj[psTreeNode->nShapeCount-1] = NULL;
}
return TRUE;
}
SHPCreateTree( SHPHandle hSHP, int nDimension, int nMaxDepth,
double *padfBoundsMin, double *padfBoundsMax )
{
SHPTree *psTree;
if( padfBoundsMin == NULL && hSHP == NULL )
return NULL;
/* -------------------------------------------------------------------- */
/* Allocate the tree object */
/* -------------------------------------------------------------------- */
psTree = (SHPTree *) malloc(sizeof(SHPTree));
if( NULL == psTree )
{
return NULL;
}
psTree->hSHP = hSHP;
psTree->nMaxDepth = nMaxDepth;
psTree->nDimension = nDimension;
psTree->nTotalCount = 0;
/* -------------------------------------------------------------------- */
/* If no max depth was defined, try to select a reasonable one */
/* that implies approximately 8 shapes per node. */
/* -------------------------------------------------------------------- */
if( psTree->nMaxDepth == 0 && hSHP != NULL )
{
int nMaxNodeCount = 1;
int nShapeCount;
SHPGetInfo( hSHP, &nShapeCount, NULL, NULL, NULL );
while( nMaxNodeCount*4 < nShapeCount )
{
psTree->nMaxDepth += 1;
nMaxNodeCount = nMaxNodeCount * 2;
}
#ifdef USE_CPL
CPLDebug( "Shape",
"Estimated spatial index tree depth: %d",
psTree->nMaxDepth );
#endif
/* NOTE: Due to problems with memory allocation for deep trees,
* automatically estimated depth is limited up to 12 levels.
* See Ticket #1594 for detailed discussion.
*/
if( psTree->nMaxDepth > MAX_DEFAULT_TREE_DEPTH )
{
psTree->nMaxDepth = MAX_DEFAULT_TREE_DEPTH;
#ifdef USE_CPL
CPLDebug( "Shape",
"Falling back to max number of allowed index tree levels (%d).",
MAX_DEFAULT_TREE_DEPTH );
#endif
}
}
/* -------------------------------------------------------------------- */
/* Allocate the root node. */
/* -------------------------------------------------------------------- */
psTree->psRoot = SHPTreeNodeCreate( padfBoundsMin, padfBoundsMax );
if( NULL == psTree->psRoot )
{
return NULL;
}
/* -------------------------------------------------------------------- */
/* Assign the bounds to the root node. If none are passed in, */
/* use the bounds of the provided file otherwise the create */
/* function will have already set the bounds. */
/* -------------------------------------------------------------------- */
assert( NULL != psTree );
assert( NULL != psTree->psRoot );
if( padfBoundsMin == NULL )
{
SHPGetInfo( hSHP, NULL, NULL,
psTree->psRoot->adfBoundsMin,
psTree->psRoot->adfBoundsMax );
}
/* -------------------------------------------------------------------- */
/* If we have a file, insert all it's shapes into the tree. */
/* -------------------------------------------------------------------- */
if( hSHP != NULL )
{
int iShape, nShapeCount;
SHPGetInfo( hSHP, &nShapeCount, NULL, NULL, NULL );
for( iShape = 0; iShape < nShapeCount; iShape++ )
{
SHPObject *psShape;
psShape = SHPReadObject( hSHP, iShape );
if( psShape != NULL )
{
SHPTreeAddShapeId( psTree, psShape );
SHPDestroyObject( psShape );
}
}
}
return psTree;
}
