NAME¶
Tk::Animation - Display sequence of Tk::Photo images
SYNOPSIS¶
use Tk::Animation
my $img = $widget->Animation('-format' => 'gif', -file => 'somefile.gif');
$img->add_frame(@images);
$img->start_animation;
$img->start_animation( $period );
$img->next_image;
$img->prev_image;
$img->set_image( 0 .. $#frames );
$img->pause_animation;
$img->resume_animation( $period );
$img->fast_forward( $multiplier );
$img->fast_reverse( $multiplier );
$img->stop_animation;
$img->set_disposal_method( $boolean );
DESCRIPTION¶
In the simple case when "Animation" is passed a GIF89 style GIF with
multiple 'frames', it will build an internal array of "Photo"
images.
The "add_frame" method adds images to the sequence. It is provided to
allow animations to be constructed from separate images. All images must be
"Photo"s and should all be the same size.
"start_animation($period)" then initiates a "repeat" with
specified
$period to sequence through these images. As
for raw "repeat"
$period is in milliseconds,
for a 50Hz monitor it should be at least 20ms. If
$period
is omitted it is determined from the GIF metadata (see below), or if this is
not possible it defaults to 100 milliseconds.
"stop_animation" cancels the "repeat" and resets the image
to the first image in the sequence.
For fine-grained control "next_image" and "prev_image" move
one frame forward or backward. "set_image" randomly positions the
animation to a particular frame.
"pause_animation" pauses the movie and "resume_animation"
continues from the pause point.
"fast_forward" and "fast_reverse" speed through the movie
either forwards or backwards. $multiplier specifies how much faster the
animation moves.
If Image::Info is installed, then the repeat period time and disposal method of
GIF animations are determined from the GIF metadata directly. Otherwise the
disposal method must be set manually by using "set_disposal_method"
(1 for blanking the previous images, 0 for leaving the previous images as is).
The repeat period time may be given in the "start_animation" method.
NOTES¶
"set_disposal_method" was formerly known as "blank" method,
but the naming of this method was a mistake.
If the disposal method is not set correctly, either by
"set_disposal_method" or by determining from the GIF metadata, then
the following may happen: By default Animation leaves the previous movie frame
in the animation photo. Many times overlaying subsequent frames produces a
composite that looks blurred.
BUGS¶
This module should not depend on a module which is not declared as a dependency
(Image::Info).
The delays between images may vary in a GIF animation. This cannot be handled by
this module yet.
The handling of the various disposal methods is not correct.