1Term::Animation(3) User Contributed Perl Documentation Term::Animation(3)
2
6 Term::Animation - ASCII sprite animation framework
7
9 use Term::Animation;
10 # Constructors
12 $anim = Term::Animation->new();
13 $anim = Term::Animation->new($curses_window);
14
16 A framework to produce sprite animations using ASCII art.
17
19 This module provides a framework to produce sprite animations using
20 ASCII art. Each ASCII 'sprite' is given one or more frames, and placed
21 into the animation as an 'animation object'. An animation object can
22 have a callback routine that controls the position and frame of the
23 object.
24 If the constructor is passed no arguments, it assumes that it is
26 running full screen, and behaves accordingly. Alternatively, it can
27 accept a curses window (created with the Curses newwin call) as an
28 argument, and will draw into that window.
29
31 This example moves a small object across the screen from left to right.
32 use Term::Animation;
34 use Curses;
35 $anim = Term::Animation->new();
37 # set the delay for getch
39 halfdelay( 2 );
40 # create a simple shape we can move around
42 $shape = "<=O=>";
43 # turn our shape into an animation object
45 $anim->new_entity(
46 shape => $shape, # object shape
47 position => [3, 7, 10], # row / column / depth
48 callback_args => [1, 0, 0, 0], # the default callback
49 # routine takes a list
50 # of x,y,z,frame deltas
51 wrap => 1 # turn screen wrap on
52 );
53 # animation loop
55 while(1) {
56 # run and display a single animation frame
57 $anim->animate();
58 # use getch to control the frame rate, and get input at the
60 # same time. (not a good idea if you are expecting much input)
61 my $input = getch();
62 if($input eq 'q') { last; }
63 }
64 # cleanly end the animation, to avoid hosing up the user's terminal
66 $anim->end();
67 This illustrates how to draw your animation into an existing Curses
69 window.
70 use Term::Animation;
72 use Curses;
73 # Term::Animation will not call initscr for you if
75 # you pass it a window
76 initscr();
77 $win = newwin(5,10,8,7);
79 $anim = Term::Animation->new($win);
81 Everything else would be identical to the previous example.
83
85 new
86 $anim = Term::Animation->new();
87 $anim = Term::Animation->new($curses_window);
88 The constructor. Optionally takes an existing curses window to draw
90 in.
91 new_entity
93 $anim->new_entity(
94 shape => $shape,
95 position => [ 1, 2, 3 ],
96 callback_args => [ 1, 0, 0 ]
97 );
98 Creates a new Term::Animation::Entity object and adds it to the
100 animation. This is identical to:
101 my $entity = Term::Animation::Entity->new(...);
103 $anim->add_entity($entity);
104 See PARAMETERS and new in Term::Animation::Entity for details on
106 calling this method.
107 color_name
109 $name = $anim->color_name( $color );
110 Returns the full name of a color, given either a full name or a
112 single character abbreviation.
113 color_id
115 $id = $anim->color_id( $color );
116 Returns the single character abbreviation for a color, given either
118 a full name or abbreviation.
119 is_valid_color
121 my $is_valid = $anim->is_valid_color($color_name);
122 Returns true if the supplied string is a valid color name ('blue')
124 or a valid color id ('b').
125 color
127 my $state = $anim->color();
128 $anim->color($new_state);
129 Enable or disable ANSI color. This MUST be called immediately after
131 creating the animation object if you want color, because the Curses
132 start_color call must be made immediately. You can then turn color
133 on and off whenever you want.
134 background
136 $anim->background( $color );
137 Change the background color. The default background color is black.
139 You can only have one background color for the entire Curses window
140 that the animation is running in.
141 animate
143 $anim->animate();
144 Perform a single animation cycle. Runs all of the callbacks, does
146 collision detection, and updates the display.
147 track_framerate
149 $anim->track_framerate(1);
150 $tracking_framerate = $anim->track_framerate();
151 Get or set the flag that indicates whether the module should keep
153 track of the animation framerate. This is enabled by default.
154 framerate
156 $frames_per_second = $anim->framerate();
157 Returns the approximate number of frames being displayed per
159 second, as indicated by calls to the animate method.
160 screen_size
162 my ($width, $height, $assumed_size) = $anim->screen_size();
163 Returns the width and height of the screen. The third value
165 returned is a boolean indicating whether or not the default screen
166 size was used, because the size could not be determined.
167 update_term_size
169 $anim->update_term_size();
170 Call this if you suspect the terminal size has changed (eg. if you
172 get a SIGWINCH signal). Call remove_all_entities after this if you
173 want to recreate your animation from scratch.
174 add_entity
176 $anim->add_entity( $entity1, $entity2, $entity3 );
177 Add one or more animation entities to the animation.
179 del_entity
181 $anim->del_entity( $entity_name );
182 $anim->del_entity( $entity_ref );
183 Removes an entity from the animation. Accepts either an entity name
185 or a reference to the entity itself.
186 remove_all_entities
188 $anim->remove_all_entities();
189 Removes every animation object. This is useful if you need to start
191 the animation over (eg. after a screen resize)
192 entity_count
194 $number_of_entities = $anim->entity_count();
195 Returns the number of entities in the animation.
197 get_entities
199 $entity_list = $anim->get_entities();
200 Returns a reference to a list of all entities in the animation.
202 get_entities_of_type
204 $entity_list = $anim->get_entities_of_type( $type );
205 Returns a reference to a list of all entities in the animation that
207 have the given type.
208 is_living
210 my $is_living = $anim->is_living( $entity );
211 Return 1 if the entity name or reference is in the animation and is
213 not scheduled for deletion. Returns 0 otherwise.
214 entity
216 $entity_ref = $anim->entity( $entity_name );
217 If the animation contains an entity with the given name, the
219 Term::Animation::Entity object associated with the name is
220 returned. Otherwise, undef is returned.
221 width
223 $width = $anim->width();
224 Returns the width of the screen
226 height
228 $height = $anim->height();
229 Returns the height of the screen
231 size()
233 $size = $anim->size();
234 Returns the number of characters in the curses window (width *
236 height)
237 redraw_screen
239 $anim->redraw_screen();
240 Clear everything from the screen, and redraw what should be there.
242 This should be called after update_term_size, or if the user
243 indicates that the screen should be redrawn to get rid of
244 artifacts.
245 gen_path
247 # gen_path (x,y,z, x,y,z, [ frame_pattern ], [ steps ])
248 $anim->gen_path( $x1, $y1, $z1, $x2, $y2, $z2, [ 1, 2, 0, 2 ], 'longest' );
250 Given beginning and end points, this will return a path for the
252 entity to follow that can be given to the default callback routine,
253 move_entity. The first set of x,y,z coordinates are the point the
254 entity will begin at, the second set is the point the entity will
255 end at.
256 You can optionally supply a list of frames to cycle through. The
258 list will be repeated as many times as needed to finish the path.
259 If no list of frames is supplied, only the first frame will be
260 used.
261 You can also request the number of steps you would like for the
263 entity to take to finish the path. The default is 'shortest'.
264 Valid arguments are:
265 longest The longer of the X and Y distances
266 shortest The shorter of the X and Y distances
267 X,Y or Z The x, y or z distance
268 <number> Explicitly specify the number of steps to take
269 end
271 $anim->end();
272 Run the Curses endwin function to get your terminal back to its
274 normal mode. This is called automatically when the object is
275 destroyed if the animation is running full screen (if you did not
276 pass an existing Curses window to the constructor).
277
279 Callback routines for all entities are called each time animate is
280 called. A default callback routine is supplied, move_entity, which is
281 sufficient for most basic movement. If you want to create an entity
282 that exhibits more complex behavior, you will have to write a custom
283 callback routine for it.
284 Callback routines take two arguments, a reference to the
286 Term::Animation::Entity object that it should act on, and a reference
287 to the Term::Animation instance that called it. Any arguments required
288 to tell the callback what to do with the object, or any state that
289 needs to be maintained, should be put in the callback_args element of
290 the object. callback_args is only referenced by the callback routine,
291 and thus can contain any datastructure that you find useful.
292 Here is an example custom callback that will make an entity move
294 randomly around the screen:
295 sub random_movement {
297 my ($entity, $anim) = @_;
298 # get the current position of the entity
300 my ($x, $y, $z) = $entity->position();
301 # we'll use callback_args to store the last axis we moved in
303 my $last_move = $entity->callback_args();
304 # if we moved in x last time, move in y this time
306 if($last_move eq 'x') {
307 $entity->callback_args('y');
308 # move by -1, 0 or 1
309 $y += int(rand(3)) - 1;
310 } else {
311 $entity->callback_args('x');
312 $x += int(rand(3)) - 1;
313 }
314 # return the absolute x,y,z coordinates to move to
316 return ($x, $y, $z);
317 }
318 The return value of your callback routine should be of the form:
320 return ($x, $y, $z, $frame)
322 $x, $y and $z represent the X, Y and Z coordinates to which the object
324 should move. $frame is the frame number that the object should display,
325 if it has multiple frames of animation. Any values that are unspecified
326 or undef will remain unchanged.
327 You can also call the default callback from within your callback, if
329 you want it to handle movement for you. For example, if your callback
330 is simply used to decide when an entity should die:
331 sub wait_for_file {
333 my ($entity, $anim) = @_;
334 # kill this entity if a certain file shows up
336 if(-e "/path/to/file") {
337 $entity->kill();
338 return();
339 }
340 # use the default callback to handle the actual movement
342 return $entity->move_entity($anim);
343 }
344 If you use this, be aware that move_entity relies on callback_args, so
346 you cannot use it to store your own arbitrary data.
347
349 ANSI color is available for terminals that support it. Only a single
350 background color can be used for the window (it would look terrible in
351 most cases otherwise anyway). Colors for entities are specified by
352 using a 'mask' that indicates the color for each character. For
353 example, say we had a single frame of a bird:
354 $bird = q#
356 ---. .-. .---
358 --\'v'/--
359 \ /
360 " "
361 #;
362 To indicate the colors you want to use for the bird, create a matching
364 mask, with the first letter of each color in the appropriate position
365 (except black, which is 'k'). Pass this mask as the color parameter.
366 $mask = q#
368 BBBB BBB BBBB
370 BBBWYWBBB
371 B B
372 Y Y
373 #;
374 When specifying a color, using uppercase indicates the color should be
376 bold. So 'BLUE' or 'B' means bold blue, and 'blue' or 'b' means non-
377 bold blue. 'Blue' means you get an error message.
378 You can also provide a default color with the default_color parameter.
380 This color will be used for any character that does not have an entry
381 in the mask. If you want the entire entity to be a single color, you
382 can just provide a default color with no mask.
383 The available colors are: red, green, blue, cyan, magenta, yellow,
385 black and white.
386 Here's an example call to build_object for the bird above.
388 $anim->new_entity (
390 name => "Bird",
391 shape => $bird,
392 position => [ 5, 8, 7 ],
393 callback_args => [ 1, 2, 0, 0 ],
394 color => $mask,
395 default_color => "BLUE"
396 );
397
399 Kirk Baucom, <kbaucom@schizoid.com>
400
402 Curses
403perl v5.30.0 2019-07-26 Term::Animation(3)