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|
#!/usr/bin/perl
use strict;
########################################
my $bits = 2;
my $dimension_mm = 40; # outer diameter (mm)
my $innerdimension_mm = 20; # inner diameter (mm)
my $strutsize_mm = 2; # strut thickness (mm)
my $axialdimension_mm = 6; # centre axis/axle size (mm)
my $span = 360; # degrees
my $stagger_mm = 0; # stagger distance between sensor centres (approx mm)
my $filebase = "test";
my $template = 1; # 0 or 1: generate sensor placement template (over mid item)
my $bitmapresolution = 300; # resolution for bitmaps (dpi)
my $portion = 1; # fraction of top left corner to include
my $reps = 2; # Number of times to repeat pattern around object
my $fillcentre = 1;
my $do_bitmap = 1;
my $do_stl = 0;
########################################
my $pi = 3.1415926535897932384626;
my ($dimension, $innerdimension, $strutsize, $axialdimension, $stagger);
my $maxval = 1 << $bits;
$axialdimension /= 2; # we want radius
sub scale
{
my $size = shift;
return $bitmapresolution * $size / 25.4;
}
sub gray
{
my $val = shift;
return $val ^ ($val >> 1);
}
sub bin
{
my($val, $width, $b, $i, $res);
($val, $width) = @_;
for($b = 1; $i < $width; $i++) {
if ($val & $b) {
$res = "1" . $res;
} else {
$res = "0" . $res;
}
$b <<= 1;
}
return $res;
}
sub near
{
my($v, $target);
($v, $target) = @_;
if ($v > $target - 0.01 && $v < $target + 0.01) {
return 1;
} else {
return 0;
}
}
sub atan2r
{
my($x, $y);
($x, $y) = @_;
my $res = atan2($x, $y);
# $res -= $pi / 2;
# $res -= 2 * $pi if ($res > $pi);
return $res;
}
sub generate_bitmap
{
my($x, $y);
my($xc, $yc, $theta, $grad, $r, $i);
my(@grays);
if ($template) {
open(TOUT, "| ppmtogif > $filebase-cut.gif") || die;
print TOUT "P1\n" . int($dimension*$portion) . " " .
int($dimension*$portion) . "\n";
}
open(OUT, "| ppmtogif > $filebase-out.gif") || die;
print OUT "P1\n" . int($dimension*$portion) . " " .
int($dimension*$portion) . "\n";
for($i = 0; $i < $maxval; $i++) {
$grays[$i] = bin(gray($i), $bits);
}
my($pixel, $tpixel);
my ($g0,$g1);
for($y = 0; $y < int($dimension * $portion); $y++) {
$yc = $y - ($dimension >> 1);
for($x = 0; $x < int($dimension * $portion); $x++) {
$xc = $x - ($dimension >> 1);
if ($xc == 0 && $yc < 0) {
$grad = 0;
} else {
$grad = (atan2r($xc, $yc) + $pi) / (2.0 * $pi); # in grads
}
$g0 = $grad;
$grad *= $reps * 360 / $span;
$grad -= int($grad);
$grad += 1 if ($grad < 0);
$g1 = $grad;
$r = sqrt($xc * $xc + $yc * $yc);
if ($r >= $innerdimension / 2 && $r <= $dimension / 2) {
my $b = $bits * 2 * ($r - $innerdimension/2) /
($dimension-$innerdimension);
$b-- if ($b == $bits);
$b = int($b);
my $edge_radius =
($b * $dimension - $b * $innerdimension
+ $bits * $innerdimension) / (2 * $bits);
#print "$r, $b, $edge_radius\n";
$grad += $stagger * $b * 360 /
($span * sqrt($edge_radius) * 120);
if ($grad > 360 / $span) {
$grad -= 360 / $span;
}
}
$theta = $maxval * $grad;
#print "$theta\n";
$theta = int($theta);
#$theta -= $maxval if ($theta >= $maxval);
#$theta &= ($maxval-1) if ($span == 360);
$pixel = "0";
$tpixel = "0";
if ($theta >= 0 && $theta < $maxval) {
if ($r >= $innerdimension / 2 && $r <= $dimension / 2) {
my $b = $bits * 2 * ($r - $innerdimension/2) /
($dimension-$innerdimension);
$b-- if ($b == $bits);
$b = int($b);
my $strut0 = ($b + 1) *
($dimension/2 - $innerdimension/2) / $bits +
$innerdimension / 2;
$pixel = 1 if ($r > $strut0 - $strutsize && $r <= $strut0);
#print "$theta $b " . $grays[$theta] . "\n";
if (substr($grays[$theta], $b, 1) == 1) {
$pixel = 1;
}
$tpixel = 1 if ($theta == 0);
#print "$y, $x, $yc, $xc, " . atan2($xc,$yc) .
#", g0=$g0, g1=$g1, grad=$grad, $theta\n";
}
}
if ($fillcentre && $r < $innerdimension / 2 && $r >= $axialdimension) {
$pixel = 1;
}
if ($r < $axialdimension && $r > 0.9 * $axialdimension) {
$pixel = 1;
$tpixel = 1;
}
if ($r < $axialdimension && (
near($grad*$span/360,0) ||
near($grad*$span/360,0.25) ||
near($grad*$span/360,0.5) ||
near($grad*$span/360,0.75) ||
near($grad*$span/360,1))) {
$pixel = 1;
$tpixel = 1;
}
print OUT $pixel;
print TOUT $tpixel if ($template);
}
}
close(OUT);
close(TOUT) if ($template);
}
sub stl_facet {
#my($norm_x, $norm_y, $norm_z,
# $v1_x, $v1_y, $v1_z,
# $v2_x, $v2_y, $v2_z,
# $v3_x, $v3_y, $v3_z);
my $colour = 0;
print OUT pack("f12S", @_, $colour);
}
# Create a 2D triangular pattern
# And convert to STL, adding depth
sub generate_stl
{
open(OUT, "> $filebase-out.stl");
my $title = 'Graycode Wheel';
my $facets = 8;
my($norm_x, $norm_y, $norm_z,
$v1_x, $v1_y, $v1_z,
$v2_x, $v2_y, $v2_z,
$v3_x, $v3_y, $v3_z);
print OUT pack("A80L", $title, $facets);
stl_facet(-1, 0, 0,
0, 1, 0,
0, 0, 0,
0, 1, 1);
stl_facet(-1, 0, 0,
0, 0, 0,
0, 0, 1,
0, 1, 1);
stl_facet( 0, 0,-1,
1, 0, 0,
0, 0, 0,
1, 1, 0);
stl_facet( 0, 0,-1,
0, 0, 0,
0, 1, 0,
1, 1, 0);
stl_facet( 0,-1, 0,
0, 0, 1,
0, 0, 0,
1, 0, 0);
stl_facet( 0.707107, 0, 0.707107,
1, 0, 0,
1, 1, 0,
0, 0, 1);
stl_facet( 0, 1, 0,
0, 1, 1,
1, 1, 0,
0, 1, 0);
stl_facet( 0.707107, 0, 0.707107,
1, 1, 0,
0, 1, 1,
0, 0, 1);
close(OUT);
}
# Calculate absolute pixel sizes for bitmaps
$dimension = scale($dimension_mm);
$innerdimension = scale($innerdimension_mm);
$strutsize = scale($strutsize_mm);
$axialdimension = scale($axialdimension_mm);
$stagger = scale($stagger_mm);
generate_bitmap if ($do_bitmap);
generate_stl if ($do_stl);
|
