101pong

#!/usr/bin/perl

use strict;
use warnings;
use Term::ANSIColor;
use Math::BigFloat;
use Math::Trig;

sub affichage {
print "USAGE\n	./101pong x0 y0 z0 x1 y1 z1 n\n\nDESCRIPTION\n";
print "       x0   ball abscissa at time t - 1\n";
print "       y0   ball ordinate at time t - 1\n";
print "       z0   ball altitude at time t - 1\n";
print "       x1   ball abscissa at time t\n";
print "       y1   ball ordinate at time t\n";
print "       z1   ball altitude at time t\n";
print "       n    time shift (greater than or equal to zero, integer)\n";
}
sub calcul_position {
    my ($t,$xB,$yB,$zB,$xAB,$yAB,$zAB) = @_;
    my ($xball,$yball,$zball) = (0,0,0);
    $xball = $t*$xAB + $xB;
    $yball = $t*$yAB + $yB;
    $zball = $t*$zAB + $zB;
    return ($xball,$yball,$zball);
}

sub error_management {
    my (@arg) = @ARGV;
    my $i = 1;
    my $useless = 0;
    for (; $i != 7; $i += 1)
    {
        if ($ARGV[$i] =~ m/[^0-9.-]/)
        {
            exit (84);
        } else { $useless += 1;
        }
    }
}
sub check_div_by_zero {
    my ($norm1,$norm2) = @_;

    if ($norm1 == 0 || $norm2 == 0)
    {
        exit (84);
    }
}

if ($ARGV[0] eq "-h")
{
	&affichage;
	exit (0);
}

if (@ARGV != 7) 
{
    exit (84);
}

sub main {
    &error_management;
if ($ARGV[6] < 0)
{
	exit (84);
}

my ($xA,$yA,$zA,$xB,$yB,$zB,$t) = @ARGV;
my ($xC,$yC,$zC) = ($xB,$yB,$zA);
my $xAB = $xB-$xA;
my $yAB = $yB-$yA;
my $zAB = $zB-$zA;
my $xAC = $xC-$xA;
my $yAC = $yC-$yA;
my $zAC = $zC-$zA;

my ($xball,$yball,$zball) = &calcul_position($t,$xB,$yB,$zB,$xAB,$yAB,$zAB);

print "The velocity vector of the ball is:\n(";
print(sprintf("%.2f",$xAB));
print ", ";
print(sprintf("%.2f",$yAB));
print ", ";
print(sprintf("%.2f",$zAB));
print ")\n";


print "At time t + $t, ball coordinates will be:\n(";
print(sprintf("%.2f",$xball));
print ", ";
print(sprintf("%.2f",$yball));
print ", ";
print(sprintf("%.2f",$zball));
print ")\n";

my $normAB = sqrt(($xB-$xA)**2 + ($yB-$yA)**2 + ($zB-$zA)**2);
my $normAC = sqrt(($xC-$xA)**2 + ($yC-$yA)**2 + ($zC-$zA)**2);
my $vectormul = ($xAB*$xAC) + ($yAB*$yAC) + ($zAB*$zAC);

&check_div_by_zero($normAB,$normAC);

my $costeta = $vectormul/($normAB*$normAC);
my $angle = rad2deg(acos($costeta));

if (($zB < 0 && $zball > 0) || ($zB > 0 && $zball < 0))
{
$angle =~ s/(.\d{2})\d*/$1/;
    printf "The incidence angle is:\n$angle degrees\n";
} else { print "The ball won't reach the bat.\n";
        }
}