#!/usr/bin/perl

use strict;

my $pi = 3.1415926;

my $r = 1/8; # 1/4" endmill

my $phi_start = 0;
my $phi_end = 2*$pi;

my $phi_step_degrees = 2; # 2 degrees
my $phi_step = $phi_step_degrees * (2*$pi/360);

my $xmark = 0.001;
my $x_circle = 200; # 0.1" 

my $ymark = 0.001;
my $y_circle = 200; # 0.1"


my $x0 = 0;
my $y0 = 0;
my $R  = 1;

my $x_start = $x0 + ($R-$r)*cos( $phi_start );
my $y_start = $y0 + ($R-$r)*sin( $phi_start );

my $x_start_dial = 0;
my $y_start_dial = 0;

my $old_x_dial = $x_start_dial;
my $old_y_dial = $y_start_dial;

my $old_x_move = 0;
my $old_y_move = 0;

my $old_x = $x_start;
my $old_y = $y_start;

sub direction {
  my $q = shift;
  return "<=" if $q < 0;
  return "=>" if $q > 0;
  return "==";
}

print "Set X dial to $x_start_dial\n";
print "Set Y dial to $y_start_dial\n";


my $i = 0;

for( my $phi = $phi_start + $phi_step; $phi <= $phi_end; $phi += $phi_step ) {

  $i++;
  
  # Compute x, y!
  my $x = $x0 + ($R-$r)*cos( $phi );
  my $y = $y0 + ($R-$r)*sin( $phi );

  # Regardless of how to compute x, y!
  
  my $new_x_dial = ( int( $x/$xmark - $x_start/$xmark ) + $x_start_dial ) % $x_circle;

  # Y axis is reversed -- CW rotation of Y handle decreases Y
  my $new_y_dial = ( int( $y_start/$ymark - $y/$ymark ) + $y_start_dial ) % $y_circle;

  my $x_move = 0;
  my $y_move = 0;
  if( defined $old_x ) {
    $x_move = $x-$old_x;
    $y_move = $y-$old_y;

    if( $old_x_move * $x_move < 0 ) {
      print "IMPORTANT!!! Reverse backlash for X right now (but keep dial at $old_x_dial)\n";
    }
    
    if( $old_y_move * $y_move < 0 ) {
      print "IMPORTANT!!! Reverse backlash for Y right now (but keep dial at $old_y_dial)\n";
    }

    $old_x_move = $x_move;
    $old_y_move = $y_move;
  }

  $old_x = $x;
  $old_y = $y;
  
  $old_x_dial = $new_x_dial;
  $old_y_dial = $new_y_dial;
  
  print "$i: Move X " . direction( $x_move ) . " $new_x_dial, Y " . direction( $y_move ) . " $new_y_dial\n";
}