#!usr/bin/perl
#use strict;

sub bmp {
my ($width, $height, $zoom, $function, $min, $max, $r) = @_;
my $Graph;

$err = &error(@_);return (0,$err) if $err;
my $instructions = &translate($function, $zoom); return (0,"Error in Function") unless $instructions;
my ($color1, $color2,$Graph);
my ($off_1, $off_2) = (int($height/2+.5), int($width/2+.5));


for (my $x=0; $x<=$max-$min; $x=$x+$r) {
	for (my $y=0; $y<=$max-$min; $y=$y+$r) {
		my ($R, $C) = &map($x+$min,$y+$min, $instructions);
		($C, $R) = (int($C+$off_1+.5), int($R+$off_2+.5));		#Offset.

		next if ($C < 0 || $R < 0);
		$color1 = (($x>=-1*$min) ? 1 : 3);
		$color2 = (($y>=-1*$min) ? 0 : 1);

		push ( @{$Graph->[$C]->[$R]} , ($x==-1*$min || $y==-1*$min) ? 5 : $color1 + $color2 );
		#print scalar(@{$Graph->[$C]->[$R]})."\t";
			#Now an Array!?
	}
}
return $Graph;

}

#Technical Subroutines
sub error {
	my ($w, $h, $z, $f, $min, $max, $step) = @_;
	my @Array = ("Improper Width or Height","Invalid Function Specified", "Improper Min/Max", "Step is too extreme");

	return $Array[0] if ($w > 2000 || $h > 1600 || $h < 0 || $w< 0);
	return $Array[1] if ($f !~ /z/i && $f !~ /^[\d\.]+$/);
	return $Array[2] if ($max<$min);
	return $Array[3] if ($step > 100 || $step < .01);
	return 0;	
}

sub disp {
	
	my @Total;
	my $n = scalar(@_);

	for (my $x=0; $x<$n; $x++) {
		my @Colors=(0,0,0);
		$Colors[($_[$x]+1)%3] = 255 if ($_[$x] && $_[$x] <= 3);		#Big endian or little endian?
		@Colors=(255,255,255) if $_[$x]==5;			#White
		@Colors=(0,255,255) if $_[$x]==4;			#Yellow
		for (my $y=0; $y<3; $y++) {
			$Total[$y]+=$Colors[$y];
			$Total[$y]=$Total[$y]%256 if ($x==$n-1);		# %256 Method
			#$Total[$y]=int($Total[$y]/$n +.5) if ($x==$n-1)		# 1/$n Method
		}
	}
	print $n." : ".join ('-', @Total)."\n" if $n != 1;
	return pack ("c3", @Total);
}

sub translate {
	$_[0]=~s/ //g;
	my @PlusMinus = $_[0] =~ /(\+|-)/g;
	my @Terms = split (/(?:\+|-)/, $_[0]);
	my $first_minus;
	if ($_[0] =~ /^-/) {
		shift (@Terms);$first_minus=shift(@PlusMinus);
	}
	my $n = scalar(@Terms);
	my $sub= ($n>1) ?  '&VA([' : '';

	for (my $x=0; $x<$n; $x++) {
		print "$x : $Terms[$x]\t";
		my ($m,$p) = $Terms[$x] =~ /(.*?|)(?:\*|)z(?:\^|)(.*)/i;
		$p = 1 if (!$p && $Terms[$x] =~ /z/);

		print " m = $m : p = $p\n";
		my $sub_temp;
		my $c =  (($x==0 && $first_minus) || ($x>0 && $PlusMinus[$x-1] eq '-')) ? -1 : 1;
		foreach ($m, $p) {
		 if ($_ =~ /(?:\/|\*)/) {
			my ($o) = $_ =~ /(\/|\*)/;
			my ($a, $b) = $_ =~ /(.*)$o(.*)/;
			if ($b) {
				$_ = ($o eq '/') ? $a/$b:$a*$b;
				#$_ = sprintf("%.5g", $_);		#Not sure if this iwll help.
			} else {
				#"Dividing by 0 will take considerable time to compute. Please wait.";
				return 0; 	
			}
		 }
		}
		if ($p) {
			$p=~ s/[^\d\.]//g and $p=int($p+.5) if $p !~ /^\d+$/;
			$m=1 if !$m;
			$sub_temp = ($p!=1) ? '&power('.$p.', $_[0] , $_[1])' : '$_[0], $_[1]';
			
			if ($m) {
				$sub_temp = '&SM('.$c*$m.', '.$sub_temp.')' unless ($c*$m==1);
			}
		} else {
			$sub_temp.=$c*$Terms[$x].', 0';
		}
		$sub.= ($n > 1) ? $sub_temp.'],[' : $sub_temp.',';
	}
	$sub =~ s/,(?:\[|)$//;
	$sub = '&SM('.$_[1].','.$sub.')' unless $_[1] == 1;
	$sub = "(".$sub.")" if ($sub !~ /(?:\(|\))/);
	$sub = ($n>1) ? $sub.');' : $sub.';';

	print STDOUT "$sub\n";
	#chomp($_ = <STDIN>);exit if $_ eq "q";

	return ($internet) ? &dummy($internet, $sub) : $sub;
}

		#Internet Version
sub dummy {
	open FILE, ">$_[0]" or return "There is an error.";		
	print FILE "#!/usr/bin/perl\n";
	print FILE  "sub dummy{\nreturn ".$_[1]."\n}";
	print FILE "1;";
	close FILE;
	require "$_[0]";
	return $_[0];
}

# ** Warning **
#Mathematics Below
# ** ** ** ** **

sub map {
	return ($internet) ? &dummy($_[0], $_[1]) : eval $_[2];
}

# Vector/Scalar Addition/Multiplication respectively
sub VM {
return ($_[0][0]*$_[1][0] - $_[1][1]*$_[0][1], $_[0][1]*$_[1][0] + $_[1][1]*$_[0][0]);
}

sub SM {
return ($_[0]*$_[1], $_[0]*$_[2]);
}

sub SA {
return ($_[1]+$_[0], $_[2]);
}

sub VA {
my ($a, $b) = ($_[0][0] , $_[0][1]);
for (my $x=0; $x<scalar(@_)-1; $x++) {
	($a, $b) = ($a + $_[$x+1][0] , $b + $_[$x+1][1]);
}
return ($a, $b);
}

sub power {
	my ($a, $b)= ($_[1],$_[2]);
for (my $x=1; $x<$_[0]; $x++) {
	($a, $b) = &VM([$a,$b], [$_[1], $_[2]]);
}

return ($a, $b);
}
1;