rect_tree_from_ptarray()

RECT_NODE* rect_tree_from_ptarray	(	const POINTARRAY *	pa,
		int	geom_type
	)

Definition at line 632 of file lwtree.c.

{
        int num_edges = 0, i = 0, j = 0;
        RECT_NODE_SEG_TYPE seg_type = lwgeomTypeArc[geom_type];
        RECT_NODE **nodes = NULL;
        RECT_NODE *tree = NULL;
 
        /* No-op on empty ring/line/pt */
        if ( pa->npoints < 1 )
                return NULL;
 
        /* For arcs, 3 points per edge, for lines, 2 per edge */
        switch(seg_type)
        {
                case RECT_NODE_SEG_POINT:
                        return rect_node_leaf_new(pa, 0, geom_type);
                        break;
                case RECT_NODE_SEG_LINEAR:
                        num_edges = pa->npoints - 1;
                        break;
                case RECT_NODE_SEG_CIRCULAR:
                        num_edges = (pa->npoints - 1)/2;
                        break;
                default:
                        lwerror("%s: unsupported seg_type - %d", __func__, seg_type);
        }
 
        /* First create a flat list of nodes, one per edge. */
        nodes = lwalloc(sizeof(RECT_NODE*) * num_edges);
        for (i = 0; i < num_edges; i++)
        {
                RECT_NODE *node = rect_node_leaf_new(pa, i, geom_type);
                if (node) /* Not zero length? */
                        nodes[j++] = node;
        }
 
        /* Merge the list into a tree */
        tree = rect_nodes_merge(nodes, j);
 
        /* Free the old list structure, leaving the tree in place */
        lwfree(nodes);
 
        /* Return top of tree */
        return tree;
}

References lwalloc(), lwerror(), lwfree(), lwgeomTypeArc, POINTARRAY::npoints, rect_node_leaf_new(), RECT_NODE_SEG_CIRCULAR, RECT_NODE_SEG_LINEAR, RECT_NODE_SEG_POINT, and rect_nodes_merge().

Referenced by rect_tree_from_lwline(), rect_tree_from_lwpoint(), and rect_tree_from_lwpoly().

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