my @slope = (($ne[1]-$nw[1])/($ne[0]-$nw[0]),
             ($se[1]-$sw[1])/($se[0]-$sw[0]),
             ($se[0]-$ne[0])/($se[1]-$ne[1]),
             ($sw[0]-$nw[0])/($sw[1]-$nw[1]));
my @start = ($ne[1]-$ne[0]*$slope[0],
             $se[1]-$se[0]*$slope[1],
             $nw[0]-$nw[1]*$slope[2],
             $ne[0]-$ne[1]*$slope[3]);
my $in_quad = $find[0]*$slope[0]+$start[0]>=$find[1]
          and $find[0]*$slope[1]+$start[1]<=$find[1]
          and $find[1]*$slope[2]+$start[2]>=$find[0]
          and $find[1]*$slope[3]+$start[3]<=$find[0];

##</code><code>##

$find[0]*$slopetop[0]+$start[0]>=$find[1]*$slopebot[0]

##</code><code>##

$ne[1]*$slopebot[0]-$ne[0]*$slopetop[0]