Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
Term::Animation(3)    User Contributed Perl Documentation   Term::Animation(3)

NAME
       Term::Animation - ASCII sprite animation	framework

SYNOPSIS
	 use Term::Animation;

	 # Constructors
	 $anim = Term::Animation->new();
	 $anim = Term::Animation->new($curses_window);

ABSTRACT
       A framework to produce sprite animations	using ASCII art.

DESCRIPTION
       This module provides a framework	to produce sprite animations using
       ASCII art. Each ASCII 'sprite' is given one or more frames, and placed
       into the	animation as an	'animation object'. An animation object	can
       have a callback routine that controls the position and frame of the
       object.

       If the constructor is passed no arguments, it assumes that it is
       running full screen, and	behaves	accordingly. Alternatively, it can
       accept a	curses window (created with the	Curses newwin call) as an
       argument, and will draw into that window.

EXAMPLES
       This example moves a small object across	the screen from	left to	right.

	   use Term::Animation;
	   use Curses;

	   $anim = Term::Animation->new();

	   # set the delay for getch
	   halfdelay( 2	);

	   # create a simple shape we can move around
	   $shape = "<=O=>";

	   # turn our shape into an animation object
	   $anim->new_entity(
			shape	      => $shape,	# object shape
			position      => [3, 7,	10],	# row /	column / depth
			callback_args => [1, 0,	0, 0],	# the default callback
							#  routine takes a list
							#  of x,y,z,frame deltas
			wrap	      => 1		# turn screen wrap on
	   );

	   # animation loop
	   while(1) {
	     # run and display a single	animation frame
	     $anim->animate();

	     # use getch to control the	frame rate, and	get input at the
	     # same time. (not a good idea if you are expecting	much input)
	     my	$input = getch();
	     if($input eq 'q') { last; }
	   }

	   # cleanly end the animation,	to avoid hosing	up the user's terminal
	   $anim->end();

       This illustrates	how to draw your animation into	an existing Curses
       window.

	   use Term::Animation;
	   use Curses;

	   # Term::Animation will not call initscr for you if
	   # you pass it a window
	   initscr();

	   $win	= newwin(5,10,8,7);

	   $anim = Term::Animation->new($win);

       Everything else would be	identical to the previous example.

METHODS
       new
	     $anim = Term::Animation->new();
	     $anim = Term::Animation->new($curses_window);

	   The constructor. Optionally takes an	existing curses	window to draw
	   in.

       new_entity
	     $anim->new_entity(
		   shape	 => $shape,
		   position	 => [ 1, 2, 3 ],
		   callback_args => [ 1, 0, 0 ]
	     );

	   Creates a new Term::Animation::Entity object	and adds it to the
	   animation. This is identical	to:

	     my	$entity	= Term::Animation::Entity->new(...);
	     $anim->add_entity($entity);

	   See Term::Animation::Entity/PARAMETERS and
	   Term::Animation::Entity/new in Term::Animation::Entity for details
	   on calling this method.

       color_name
	     $name = $anim->color_name(	$color );

	   Returns the full name of a color, given either a full name or a
	   single character abbreviation.

       color_id
	     $id = $anim->color_id( $color );

	   Returns the single character	abbreviation for a color, given	either
	   a full name or abbreviation.

       is_valid_color
	     my	$is_valid = $anim->is_valid_color($color_name);

	   Returns true	if the supplied	string is a valid color	name ('blue')
	   or a	valid color id ('b').

       color
	     my	$state = $anim->color();
	     $anim->color($new_state);

	   Enable or disable ANSI color. This MUST be called immediately after
	   creating the	animation object if you	want color, because the	Curses
	   start_color call must be made immediately. You can then turn	color
	   on and off whenever you want.

       background
	     $anim->background(	$color );

	   Change the background color.	The default background color is	black.
	   You can only	have one background color for the entire Curses	window
	   that	the animation is running in.

       animate
	     $anim->animate();

	   Perform a single animation cycle. Runs all of the callbacks,	does
	   collision detection,	and updates the	display.

       track_framerate
	     $anim->track_framerate(1);
	     $tracking_framerate = $anim->track_framerate();

	   Get or set the flag that indicates whether the module should	keep
	   track of the	animation framerate. This is enabled by	default.

       framerate
	     $frames_per_second	= $anim->framerate();

	   Returns the approximate number of frames being displayed per
	   second, as indicated	by calls to the	animate	method.

       screen_size
	     my	($width, $height, $assumed_size) = $anim->screen_size();

	   Returns the width and height	of the screen. The third value
	   returned is a boolean indicating whether or not the default screen
	   size	was used, because the size could not be	determined.

       update_term_size
	     $anim->update_term_size();

	   Call	this if	you suspect the	terminal size has changed (eg. if you
	   get a SIGWINCH signal). Call	remove_all_entities after this if you
	   want	to recreate your animation from	scratch.

       add_entity
	     $anim->add_entity(	$entity1, $entity2, $entity3 );

	   Add one or more animation entities to the animation.

       del_entity
	     $anim->del_entity(	$entity_name );
	     $anim->del_entity(	$entity_ref );

	   Removes an entity from the animation. Accepts either	an entity name
	   or a	reference to the entity	itself.

       remove_all_entities
	     $anim->remove_all_entities();

	   Removes every animation object. This	is useful if you need to start
	   the animation over (eg. after a screen resize)

       entity_count
	     $number_of_entities = $anim->entity_count();

	   Returns the number of entities in the animation.

       get_entities
	     $entity_list = $anim->get_entities();

	   Returns a reference to a list of all	entities in the	animation.

       get_entities_of_type
	     $entity_list = $anim->get_entities_of_type( $type );

	   Returns a reference to a list of all	entities in the	animation that
	   have	the given type.

       is_living
	     my	$is_living = $anim->is_living( $entity );

	   Return 1 if the entity name or reference is in the animation	and is
	   not scheduled for deletion. Returns 0 otherwise.

       entity
	     $entity_ref = $anim->entity( $entity_name );

	   If the animation contains an	entity with the	given name, the
	   Term::Animation::Entity object associated with the name is
	   returned. Otherwise,	undef is returned.

       width
	     $width = $anim->width();

	   Returns the width of	the screen

       height
	     $height = $anim->height();

	   Returns the height of the screen

       size()
	     $size = $anim->size();

	   Returns the number of characters in the curses window (width	*
	   height)

       redraw_screen
	     $anim->redraw_screen();

	   Clear everything from the screen, and redraw	what should be there.
	   This	should be called after update_term_size, or if the user
	   indicates that the screen should be redrawn to get rid of
	   artifacts.

       gen_path
	     # gen_path	(x,y,z,	x,y,z, [ frame_pattern ], [ steps ])

	     $anim->gen_path( $x1, $y1,	$z1, $x2, $y2, $z2, [ 1, 2, 0, 2 ], 'longest' );

	   Given beginning and end points, this	will return a path for the
	   entity to follow that can be	given to the default callback routine,
	   move_entity.	The first set of x,y,z coordinates are the point the
	   entity will begin at, the second set	is the point the entity	will
	   end at.

	   You can optionally supply a list of frames to cycle through.	The
	   list	will be	repeated as many times as needed to finish the path.
	   If no list of frames	is supplied, only the first frame will be
	   used.

	   You can also	request	the number of steps you	would like for the
	   entity to take to finish the	path. The default is 'shortest'.
	   Valid arguments are:
	     longest	  The longer of	the X and Y distances
	     shortest	  The shorter of the X and Y distances
	     X,Y or Z	  The x, y or z	distance
	     <number>	  Explicitly specify the number	of steps to take

       end
	     $anim->end();

	   Run the Curses endwin function to get your terminal back to its
	   normal mode.	This is	called automatically when the object is
	   destroyed if	the animation is running full screen (if you did not
	   pass	an existing Curses window to the constructor).

CALLBACK ROUTINES
       Callback	routines for all entities are called each time animate is
       called. A default callback routine is supplied, move_entity, which is
       sufficient for most basic movement. If you want to create an entity
       that exhibits more complex behavior, you	will have to write a custom
       callback	routine	for it.

       Callback	routines take two arguments, a reference to the
       Term::Animation::Entity object that it should act on, and a reference
       to the Term::Animation instance that called it. Any arguments required
       to tell the callback what to do with the	object,	or any state that
       needs to	be maintained, should be put in	the callback_args element of
       the object. callback_args is only referenced by the callback routine,
       and thus	can contain any	datastructure that you find useful.

       Here is an example custom callback that will make an entity move
       randomly	around the screen:

	 sub random_movement {
	     my	($entity, $anim) = @_;

	     # get the current position	of the entity
	     my	($x, $y, $z) = $entity->position();

	     # we'll use callback_args to store	the last axis we moved in
	     my	$last_move = $entity->callback_args();

	     # if we moved in x	last time, move	in y this time
	     if($last_move eq 'x') {
		 $entity->callback_args('y');
		 # move	by -1, 0 or 1
		 $y += int(rand(3)) - 1;
	     } else {
		 $entity->callback_args('x');
		 $x += int(rand(3)) - 1;
	     }

	     # return the absolute x,y,z coordinates to	move to
	     return ($x, $y, $z);
	 }

       The return value	of your	callback routine should	be of the form:

	   return ($x, $y, $z, $frame)

       $x, $y and $z represent the X, Y	and Z coordinates to which the object
       should move. $frame is the frame	number that the	object should display,
       if it has multiple frames of animation. Any values that are unspecified
       or undef	will remain unchanged.

       You can also call the default callback from within your callback, if
       you want	it to handle movement for you. For example, if your callback
       is simply used to decide	when an	entity should die:

	 sub wait_for_file {
	     my	($entity, $anim) = @_;

	     # kill this entity	if a certain file shows	up
	     if(-e "/path/to/file") {
		 $entity->kill();
		 return();
	     }

	     # use the default callback	to handle the actual movement
	     return $entity->move_entity($anim);
	 }

       If you use this,	be aware that move_entity relies on callback_args, so
       you cannot use it to store your own arbitrary data.

COLOR
       ANSI color is available for terminals that support it. Only a single
       background color	can be used for	the window (it would look terrible in
       most cases otherwise anyway). Colors for	entities are specified by
       using a 'mask' that indicates the color for each	character. For
       example,	say we had a single frame of a bird:

	 $bird = q#

	 ---. .-. .---
	   --\'v'/--
	      \	/
	      "	"
	 #;

       To indicate the colors you want to use for the bird, create a matching
       mask, with the first letter of each color in the	appropriate position
       (except black, which is 'k'). Pass this mask as the color parameter.

	 $mask = q#

	 BBBB BBB BBBB
	   BBBWYWBBB
	      B	B
	      Y	Y
	 #;

       When specifying a color,	using uppercase	indicates the color should be
       bold. So	'BLUE' or 'B' means bold blue, and 'blue' or 'b' means non-
       bold blue. 'Blue' means you get an error	message.

       You can also provide a default color with the default_color parameter.
       This color will be used for any character that does not have an entry
       in the mask. If you want	the entire entity to be	a single color,	you
       can just	provide	a default color	with no	mask.

       The available colors are: red, green, blue, cyan, magenta, yellow,
       black and white.

       Here's an example call to build_object for the bird above.

	   $anim->new_entity (
		     name	       => "Bird",
		     shape	       => $bird,
		     position	       => [ 5, 8, 7 ],
		     callback_args     => [ 1, 2, 0, 0 ],
		     color	       => $mask,
		     default_color     => "BLUE"
	   );

AUTHOR
       Kirk Baucom, <kbaucom@schizoid.com>

SEE ALSO
       Curses

POD ERRORS
       Hey! The	above document had some	coding errors, which are explained
       below:

       Around line 179:
	   alternative text 'Term::Animation::Entity/PARAMETERS' contains non-
	   escaped | or	/

	   alternative text 'Term::Animation::Entity/new' contains non-escaped
	   | or	/

perl v5.24.1			  2011-03-29		    Term::Animation(3)

NAME | SYNOPSIS | ABSTRACT | DESCRIPTION | EXAMPLES | METHODS | CALLBACK ROUTINES | COLOR | AUTHOR | SEE ALSO | POD ERRORS

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=Term::Animation&sektion=3&manpath=FreeBSD+12.1-RELEASE+and+Ports>

home | help