#       ====
package Grid;
#       ====

use Carp;
use strict;
use integer;
use Exporter;
our @ISA = qw(Exporter);
our @EXPORT = qw(
   fitToColsVSort
   fitToColsHSort
   fitToRowsVSort
   fitToRowsHSort);

#   --------------
sub fitToColsVSort
#   --------------
{
    my($numItems, $numCols) = @_;
    my $rlOrder = [];
    my $leftOver = $numItems % $numCols;
    my $maxRowNo = $numItems / $numCols + ($leftOver ? 1 : 0);
    my $rowNo = 0;
    my $colNo = 0;
    for (1 .. $numItems)
    {
        push @$rlOrder, [$rowNo, $colNo];
	$rowNo ++;
	if($rowNo == $maxRowNo)
	{
	   if($leftOver)
	   {
	       $leftOver --;
	       $maxRowNo -- unless $leftOver;
	   }
	    $rowNo = 0;
	    $colNo ++;
	}
    }
    return $rlOrder;
}

#   --------------
sub fitToColsHSort
#   --------------
{
    my($numItems, $numCols) = @_;
    my $rlOrder = [];
    foreach my $item (0 .. ($numItems - 1))
    {
        push @$rlOrder, [($item) / $numCols,
	   ($item) % $numCols];
    }
    return $rlOrder;
}

#   --------------
sub fitToRowsVSort
#   --------------
{
    my($numItems, $numRows) = @_;
    my $rlOrder = [];
    foreach my $item (0 .. ($numItems - 1))
    {
        push @$rlOrder, [($item) % $numRows,
	   ($item) / $numRows];
    }
    return $rlOrder;
}

#   --------------
sub fitToRowsHSort
#   --------------
{
    my($numItems, $numRows) = @_;
    my $rlOrder = [];
    my $leftOver = $numItems % $numRows;
    my $maxColNo = $numItems / $numRows + ($leftOver ? 1 : 0);
    my $rowNo = 0;
    my $colNo = 0;
    for (1 .. $numItems)
    {
        push @$rlOrder, [$rowNo, $colNo];
	$colNo ++;
	if($colNo == $maxColNo)
	{
	   if($leftOver)
	   {
	       $leftOver --;
	       $maxColNo -- unless $leftOver;
	   }
	    $colNo = 0;
	    $rowNo ++;
	}
    }
    return $rlOrder;
}

1;