#!/usr/local/bin/perl

# perl script for Equal 8 Sided Octagon Rafter Calculations

use CGI::Carp qw(fatalsToBrowser); #comment out this line when your done debugging this script

$|++;	#dont't buffer output

#use strict;

# file name:: full-octagon.cgi
#	Created on Sunday, July 15, 2007 by	Sim Ayers of SBE Builders
#   get latest version of this script at http://www.sbebuilders.com 
###################################################
#   You are free to customize this script as you wish.
#	DISCLAIMER
#	The information and code provided is provided 'as is' without 
#	warranty of any kind, either express or implied. In no event 
#	shall the Company SBE Builders be liable for any damages whatsoever 
#	including direct, indirect, incidental, consequential, loss of 
#	business profits or special damages, even if the author has been 
#	advised  of the possibility of such damages.
#	DO NOT USE THIS SCRIPT UNLESS YOU CAN FULLY AGREE WITH THIS 
#	DISCLAIMER.
#   copyright(C) 2007
###################################################
=head
In a circle of radius r, the length of the chord that 
subtends a central angle x is r * sin( x/2). 

This script uses the theory of an octagon inscribed inside of a circle.
So the radius is the run of the octagon hips and
the chord is the length of the sides of the octagon.

=cut


my ($content_type_printed,%data,$back_wall,$projection,$face_wall,$pitch,$show_feet_inches);
# print out perl headers to browser
print "Content-type: text/plain\n\n" unless $content_type_printed++;

&read_input();		#read user input variables


if ($data{'face_wall'} eq ""){
# hand edit octagon variables below for default values
$face_wall = 67.88;
$pitch = 8;
$show_feet_inches = 'no';
$jack_spacing = 12;
$overhang = 24;
}
else{
$face_wall = $data{'face_wall'};
$pitch = $data{'pitch'};
$show_feet_inches = $data{'show_feet_inches'};
$jack_spacing = $data{'jack_spacing'};
$overhang = $data{'overhang'};
}


#Global symbols
# http://perldoc.perl.org/Math/Complex.html
use Math::Complex qw(:trig);
use POSIX qw(ceil floor);

$PIE  = 3.14159265358979323846;
$RAD_TO_DEGREE  = (180/pi);
$DEGREE_TO_RAD  = ($PIE/180);
$RAD_TO_DEGREE45  = (0.785398163397448309616);
$dxf_line_count = 100;
$DXF_STYLE=0;      	#dxf Line style
$DXF_LAYER=0;     	#dxf file LAYER number
$DXF_COLOR=0;    	# dxf line color
$DXF_TSIZE=4.0;  	#dxf default dxf text size
$half_the_thickness_of_the_hips = 0.75;

$nsides=8;
# walls at 45 degree angles to face wall
$projection = $face_wall * cos(45 * $DEGREE_TO_RAD);
$projection_offset = $projection;


# get geometry angles for baywindow
$run = (($projection * 2) + $face_wall) / 2;
$face_wall_half = $face_wall /2;

$projection_wall_angle_deg = 45;
$projection_offset_wall_angle_deg = 90 - $projection_wall_angle_deg;
$interior_wall_angle_deg = 135;

$projection_wall_length = $projection_offset / cos($projection_wall_angle_deg * $DEGREE_TO_RAD);

$half_projection_wall_length  = $projection_wall_length  / 2;

$bay_hip_rafter_run_bisect_angle_deg = $RAD_TO_DEGREE * atan($run / $face_wall_half);
$bay_hip_rafter_top_angle_deg = 90 - $bay_hip_rafter_run_bisect_angle_deg;

$pitch_angle = $RAD_TO_DEGREE * atan($pitch / 12);
$Major_Pitch = atan($pitch / 12);


$common_rafter_rise = $run * ($pitch / 12);
$common_rafter_length = $run / cos(atan($pitch / 12));
$common_jackrafter_run = $jack_spacing * tan($bay_hip_rafter_run_bisect_angle_deg * $DEGREE_TO_RAD);
$common_jackrafter_length = $common_jackrafter_run / cos(atan($pitch / 12));
$overhang_face_wall_length = $overhang / cos(atan($pitch / 12));

$bay_hip_rafter_run = $face_wall_half / cos($bay_hip_rafter_run_bisect_angle_deg * $DEGREE_TO_RAD);
$radius = $bay_hip_rafter_run;

$bay_hip_rafter_angle = atan($common_rafter_rise / $bay_hip_rafter_run);
$bay_hip_rafter_length = $bay_hip_rafter_run / cos($bay_hip_rafter_angle);
$bay_hip_rafter_bevel_angle = 90 - $bay_hip_rafter_run_bisect_angle_deg;

$bay_hip_rafter_unit_run = (12 / sin($DEGREE_TO_RAD * $bay_hip_rafter_run_bisect_angle_deg)); 

$overhang_bay_hip_run = $overhang / cos($bay_hip_rafter_top_angle_deg * $DEGREE_TO_RAD);
$overhang_bay_hip_length = $overhang_bay_hip_run / cos($bay_hip_rafter_angle);

print "Equal 8 Sided Octagon Rafter Calculations";
print "\nCalculations are rounded to the nearest 1/16 inch";

print "\n\n Face Wall length = " .convertTOfeet($face_wall);
print "\n\n Total Width of Octagon = " .convertTOfeet($run*2);
print "\n\n Diameter of Octagon = " .convertTOfeet($bay_hip_rafter_run*2);
print "\n\n Radius of Octagon = " .convertTOfeet($bay_hip_rafter_run);

print "\n\n Projection of Bay Window = " .convertTOfeet($projection);
print "\n\n Projection Offset = " .convertTOfeet($projection_offset);
print "\n\n Projection Wall Length = " .convertTOfeet($projection_wall_length);
print "\n\n Projection Wall Angle = " .roundAngle($projection_wall_angle_deg);
print "\n\n Projection Offset Wall Angle = " .roundAngle($projection_offset_wall_angle_deg);
print "\n\n Interior Wall Angle = " .roundAngle($interior_wall_angle_deg);
print "\n\n Bay Hip Rafter Run Bisect Angle = " .roundAngle($bay_hip_rafter_run_bisect_angle_deg);
print "\n\n Common Rafter Run = " .convertTOfeet($run);
print "\n\n Common Rafter Pitch = " .roundAngle($pitch);
print "\n\n Common Rafter Pitch Angle = " .roundAngle($pitch_angle);
print "\n\n Common Rafter Rise = " .convertTOfeet($common_rafter_rise);
print "\n\n Common Rafter Length = " .convertTOfeet($common_rafter_length);
print "\n\n Common Rafter Overhang Run = " .convertTOfeet($overhang);
print "\n\n Common Overhang Rafter Length = " .convertTOfeet($overhang_face_wall_length);
print "\n\n Common Jack Rafter Difference in Length = " .convertTOfeet($common_jackrafter_length);
print "\n\n Bay Hip Rafter Angle = " .roundAngle($bay_hip_rafter_angle * $RAD_TO_DEGREE);
print "\n\n Bay Hip Rafter Bevel Angle = " .roundAngle($bay_hip_rafter_bevel_angle);
print "\n\n Bay Hip Rafter Run = " .convertTOfeet($bay_hip_rafter_run);
print "\n\n Bay Hip Rafter Length = " .convertTOfeet($bay_hip_rafter_length);
print "\n\n Bay Hip Rafter Overhang Run = " .convertTOfeet($overhang_bay_hip_run);
print "\n\n Bay Hip Rafter Overhang Rafter Length = " .convertTOfeet($overhang_bay_hip_length);

$Major_Side_Plan_Angle = $bay_hip_rafter_run_bisect_angle_deg * $DEGREE_TO_RAD;

$Frieze_Block_Angle = atan (sin ($Major_Pitch) / tan($Major_Side_Plan_Angle));

$Frieze_Block_Bevel_Angle = atan (sin ($Frieze_Block_Angle) / tan ($Major_Pitch));

print "\n\n Bay Hip Plan Angle = " .roundAngle($Major_Side_Plan_Angle * $RAD_TO_DEGREE);
print "\n\n Frieze Block Angle = " .roundAngle($Frieze_Block_Angle * $RAD_TO_DEGREE);
print "\n\n Frieze Block Bevel Angle = " .roundAngle($Frieze_Block_Bevel_Angle * $RAD_TO_DEGREE);
$Backing_Angle = acos (cos($pitch_angle * $DEGREE_TO_RAD) / cos ($bay_hip_rafter_angle));

print "\n\n Bay Hip Rafter Backing Angle = " .roundAngle($Backing_Angle * $RAD_TO_DEGREE);

$bay_hip_rafter_drop = ($pitch * ($half_the_thickness_of_the_hips / tan($bay_hip_rafter_run_bisect_angle_deg * $DEGREE_TO_RAD))/$bay_hip_rafter_unit_run);
print "\n\n Bay Hip Rafter Drop = " .convertTOfeet($bay_hip_rafter_drop);


# text file with dxf header information
$DXF_HEADER_FILE = "dxf_header.txt";
# text file to save dxf drawing to
$DXF_File="full-octagon.dxf";

#load dxf header file
$dxf_header = get_dxf_header_file($DXF_HEADER_FILE);

open(FILE, ">$DXF_File") ||  die("$DXF_File:  Can't  open because ($!).");

# add dxf header information to dxf output file
print FILE  "$dxf_header\n0\n";

# origin center in dxf document
$originX = 100;
$originY = 100;


$poly_start_angle = (2 * $PIE) / $nsides;

$theta = $poly_start_angle;
$start_angle = $theta / 2;
$x1 = $originX; 
$y1 = $originY; 

$radius2 = $overhang_bay_hip_run + $radius;
$radius3 = $overhang + $run;

$sfx2 = $originX + $radius * cos(($theta ) + $start_angle);
$sfy2 = $originY + $radius * sin(($theta ) + $start_angle);
$sfx22 = $originX + $radius2 * cos(($theta ) + $start_angle);
$sfy22 = $originY + $radius2 * sin(($theta ) + $start_angle);
	 


# draw wall line
for($i=1; $i<$nsides+2; $i++){          
	 
	 $x2 = $radius * cos(($theta * $i) + $start_angle);
	 $y2 = $radius * sin(($theta * $i) + $start_angle);
	 $x2 += $originX;
	 $y2 += $originY;	 
     dxf_line($x2,$y2,$sfx2,$sfy2);
     $sfx2 = $x2; $sfy2 = $y2;
     
     $x22 = $radius2 * cos(($theta * $i) + $start_angle);
	 $y22 = $radius2 * sin(($theta * $i) + $start_angle);
	 $x22 += $originX;
	 $y22 += $originY;	 
     dxf_line($x22,$y22,$sfx22,$sfy22);
     $sfx22 = $x22; $sfy22 = $y22;
     
}

# draw hips & king common rafters
 for($i=1; $i<=$nsides; $i++){          
	 
	 $x2 = $radius2 * cos(($theta * $i) + $start_angle);
	 $y2 = $radius2 * sin(($theta * $i) + $start_angle);
	 $x2 += $originX;
	 $y2 += $originY;	 
     dxf_line($x1,$y1,$x2,$y2);    
     $x2 = $radius3 * cos(($theta * $i));
	 $y2 = $radius3 * sin(($theta * $i));
	 $x2 += $originX;
	 $y2 += $originY;	 
     dxf_line($x1,$y1,$x2,$y2);     
}
 

 # draw jack rafters
$max = abs($face_wall_half / $jack_spacing);
$common_jackrafter_run = $jack_spacing * tan($bay_hip_rafter_run_bisect_angle_deg * $DEGREE_TO_RAD);
$common_jackrafter_run = $jack_spacing * tan($bay_hip_rafter_run_bisect_angle_deg * $DEGREE_TO_RAD);
$offset = $jack_spacing / cos ($bay_hip_rafter_run_bisect_angle_deg * $DEGREE_TO_RAD);
$offset_run = $jack_spacing * tan ($bay_hip_rafter_run_bisect_angle_deg * $DEGREE_TO_RAD);

for($j=1; $j<$max; $j++){  
        $jack_offset = $run - ($offset_run * $j);
        $common_jackrafter_length = $jack_offset / cos($Major_Pitch);
        print "\n\nJack Rafter # $j = " .convertTOfeet($common_jackrafter_length);
 
    for($i=1; $i<=$nsides; $i++){ 
      
        $radius = ($overhang + $run) - ($offset_run * $j);
        $x1 = $originX + ($offset * ($j ))* sin(($theta * $i)+ $start_angle); 
        $y1 = $originY + ($offset * ($j ))* cos(($theta * $i)+ $start_angle);
        $x2 = $radius * sin(($theta * $i) + $start_angle*2);
        $y2 = $radius * cos(($theta * $i) + $start_angle*2);
        $x2 += $x1;
        $y2 += $y1;	 
        dxf_line($x1,$y1,$x2,$y2);  
        
        $x1 = $originX + ($offset * ($j ))* sin(($theta * $i)+ $start_angle); 
        $y1 = $originY + ($offset * ($j ))* cos(($theta * $i)+ $start_angle);
        $x2 = $radius * sin(($theta * $i));
        $y2 = $radius * cos(($theta * $i));
        $x2 += $x1;
        $y2 += $y1;	 
        dxf_line($x1,$y1,$x2,$y2);  
    }  

}



$str= "ENDSEC\n0\nEOF";

print FILE  $str;
close FILE;


exit;


###################################
# library sub routines follow
###################################
# [Ctrl]+E for zoom extents 

sub dxf_line
{
my ($x1,$y1,$x2,$y2) = @_;

    $color=0;
	$dxf_line_count++;
	
	
	$str = sprintf("LINE\n5\n%dD\n8\n%d\n6\nCONTINOUS\n62\n%d\n10\n%lf\n20\n%lf\n30\n0.0\n11\n%lf\n21\n%lf\n31\n0.0\n0\n",
	$dxf_line_count,$DXF_LAYER,$DFX_COLOR,$x1,$y1,$x2,$y2);

    #print $str;
	print FILE  $str;
}

#=============================================================================#
sub escape_string {
    my($esc) = @_;
    $esc =~ s/([^a-zA-Z0-9_\-.])/uc sprintf("%%%02x",ord($1))/eg;
	$esc =~ s/ /+/g;
    return $esc;
}

#=============================================================================#
sub get_dxf_header_file{
    my($file)=shift;
    my $header;
    open(FH, "<$file") ||  die("$file:  Can't  open because ($!).");
	while(<FH>){
	   $header .= $_;
	}
	close(FH);
	return $header;
}	
#=============================================================================#
sub hypot{
my ($x,$y) = @_;
my $s = sqrt( $x* $x + $y * $y);
return $s;
}
#=============================================================================#
sub convertTOfeet{
my ($decimal) = @_;
    return $decimal unless $show_feet_inches eq 'yes';
    
    #print "\n inches decimal = " .$decimal;
    
   my $wholefeet = floor($decimal/12);
   my $wholeinch = floor($decimal - ($wholefeet*12));
   my $decimalfrac = ($decimal*1) - floor($decimal);
   my ($frac1,$frac2,$frac_str);
   $frac2 = 16;
   if ($decimalfrac >= 0.9774) # 15/16 = 0.9375
   {
      $wholeinch++;
      $decimalfrac = 0.00;
      if($wholeinch == 12)
      {
         $wholefeet++;
         $wholeinch = 0;
      }
   }
   
   if ($decimalfrac > 0.0001)
   {      
        $frac1 = $decimalfrac * $frac2;
        my $wholefrac = floor($decimalfrac * $frac2);
        $frac1 = ceil($decimalfrac * $frac2);
        $frac1 = 15 if($frac1 == 16);
        ($frac1,$frac2) = check_frac($frac1,$frac2);
        $frac_str =	sprintf(" %d/%d",$frac1,$frac2);
	}
	
   my $str =	sprintf("%d'-%d%s''",
	$wholefeet,$wholeinch,$frac_str);
	

   return $str;
}

#=============================================================================#
sub check_frac{
my ($numerator ,$denominator) = @_;
          
    return (7,8) if $numerator  eq 14;
    return (3,4) if $numerator  eq 12;
    return (5,8) if $numerator  eq 10;
    return (1,2) if $numerator  eq 8;
    return (3,8) if $numerator  eq 6;
    return (1,4) if $numerator  eq 4;
    return (1,8) if $numerator  eq 2;	
    return ("","") if $numerator  eq 0;	
    return ("","") if $denominator  eq 0;	

   return ($numerator ,$denominator);
}

#=============================================================================#
sub roundAngle{
my ($angle) = @_;
 my $str =	sprintf("%.2f",$angle);
 return $str;
 
}
#===================================================================#
sub read_input {

	my($buffer) = undef;
	my ($item);
	if ($ENV{'REQUEST_METHOD'} eq 'POST') {	
		read(STDIN,$buffer,$ENV{'CONTENT_LENGTH'});
	}
	else {
		$buffer=$ENV{'QUERY_STRING'};
	}

	$buffer = $ARGV[0]  if (not $buffer);

	my @pairs=split(/&/,$buffer);
	foreach $item(@pairs) {
		my ($key,$content)=split (/=/,$item,2);    # Split into key and value.
		$content =~ tr/+/ /; # Convert plus's to spaces
		$content =~ s/%(..)/pack("c",hex($1))/ge;	# Convert %XX from hex numbers to alphanumeric
		$content =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
		# prevent hackers from exploiting the input name
		$key =~ tr/+/ /; # Convert plus's to spaces
		$key =~ s/%(..)/pack("c",hex($1))/ge;	# Convert %XX from hex numbers to alphanumeric
		$key =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;	
        $key =~ s/ /_/g;
   
		# get rid of attempts to insert HTML tags
		$content =~ s/<!--(.|\n)*-->//g;  # server-side-includes
		$content =~ s/<([^>]|\n)*>//gs;
		$content =~ s/</&lt;/g; 
		$content =~ s/>/&gt;/g;

	
		# get rid of attempts to insert illegal characters
		$content =~ s/\\//g; # remove black slashes
		$content =~ s/\0//g; # remove nulls
		$content =~ s/[\\\&\;\`\'\"\|\*\?\~\^\[\]\{\}\$]//gs;
		$content =~ s/\cM/\n/g;	#convert CR to LF
		$content =~ s/^\s+|\s+$//gs;
		$content = substr($content,0,4096);
		$data{$key} = $content;
		
	}
	return 1;
}