peano.c File Reference

#include <mpi.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <gsl/gsl_heapsort.h>
#include "peano.h"

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Functions
peano_t	peano_hilbert_key (int x, int y, int z, int bits)

Variables
const unsigned char	rottable3 [48][8]
const unsigned char	subpix3 [48][8]

Function Documentation

peano_hilbert_key()

peano_t peano_hilbert_key	(	int	x,
		int	y,
		int	z,
		int	bits
	)

This function computes a Peano-Hilbert key for an integer triplet (x,y,z), with x,y,z in the range between 0 and 2^bits-1.

Definition at line 119 of file peano.c.

{
    int mask;
    unsigned char rotation = 0;
    peano_t key = 0;
 
    for(mask = 1 << (bits - 1); mask > 0; mask >>= 1)
    {
        unsigned char pix = ((x & mask) ? 4 : 0) | ((y & mask) ? 2 : 0) | ((z & mask) ? 1 : 0);
 
        key <<= 3;
        key |= subpix3[rotation][pix];
        rotation = rottable3[rotation][pix];
    }
 
    return key;
}

References rottable3, and subpix3.

Referenced by force_create_node_for_topnode(), and PEANO().

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Variable Documentation

rottable3

const unsigned char rottable3[48][8]

Definition at line 14 of file peano.c.

Referenced by peano_hilbert_key().

subpix3

const unsigned char subpix3[48][8]

Definition at line 65 of file peano.c.

Referenced by peano_hilbert_key().