aparler/RosettaCodeData
1
0
Fork 0
Code Issues 12 Pull requests 3 Projects Releases Packages Wiki Activity Actions

Data commit

Browse source
This commit is contained in:
Ingy döt Net 2023-07-01 11:58:00 -04:00
parent 7387c8f97b
commit cb5bb5e222
199093 changed files with 3378972 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

66
Task/Animate-a-pendulum/Perl/animate-a-pendulum.pl Normal file
View file

@ -0,0 +1,66 @@
use strict;
use warnings;
use Tk;
use Math::Trig qw/:pi/;
my $root = new MainWindow( -title => 'Pendulum Animation' );
my $canvas = $root->Canvas(-width => 320, -height => 200);
my $after_id;
for ($canvas) {
$_->createLine( 0, 25, 320, 25, -tags => [qw/plate/], -width => 2, -fill => 'grey50' );
$_->createOval( 155, 20, 165, 30, -tags => [qw/pivot outline/], -fill => 'grey50' );
$_->createLine( 1, 1, 1, 1, -tags => [qw/rod width/], -width => 3, -fill => 'black' );
$_->createOval( 1, 1, 2, 2, -tags => [qw/bob outline/], -fill => 'yellow' );
}
$canvas->raise('pivot');
$canvas->pack(-fill => 'both', -expand => 1);
my ($Theta, $dTheta, $length, $homeX, $homeY) =
(45, 0, 150, 160, 25);
sub show_pendulum {
my $angle = $Theta * pi() / 180;
my $x = $homeX + $length * sin($angle);
my $y = $homeY + $length * cos($angle);
$canvas->coords('rod', $homeX, $homeY, $x, $y);
$canvas->coords('bob', $x-15, $y-15, $x+15, $y+15);
}
sub recompute_angle {
my $scaling = 3000.0 / ($length ** 2);
# first estimate
my $firstDDTheta = -sin($Theta * pi / 180) * $scaling;
my $midDTheta = $dTheta + $firstDDTheta;
my $midTheta = $Theta + ($dTheta + $midDTheta)/2;
# second estimate
my $midDDTheta = -sin($midTheta * pi/ 180) * $scaling;
$midDTheta = $dTheta + ($firstDDTheta + $midDDTheta)/2;
$midTheta = $Theta + ($dTheta + $midDTheta)/2;
# again, first
$midDDTheta = -sin($midTheta * pi/ 180) * $scaling;
my $lastDTheta = $midDTheta + $midDDTheta;
my $lastTheta = $midTheta + ($midDTheta + $lastDTheta)/2;
# again, second
my $lastDDTheta = -sin($lastTheta * pi/180) * $scaling;
$lastDTheta = $midDTheta + ($midDDTheta + $lastDDTheta)/2;
$lastTheta = $midTheta + ($midDTheta + $lastDTheta)/2;
# Now put the values back in our globals
$dTheta = $lastDTheta;
$Theta = $lastTheta;
}
sub animate {
recompute_angle;
show_pendulum;
$after_id = $root->after(15 => sub {animate() });
}
show_pendulum;
$after_id = $root->after(500 => sub {animate});
$canvas->bind('<Destroy>' => sub {$after_id->cancel});
MainLoop;