[ViewVC] Diff of: cvs/rxvt-unicode/src/perl/background

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.39 by root, Fri Jun 8 22:19:03 2012 UTC vs.
Revision 1.69 by root, Mon Jul 2 01:32:26 2012 UTC

…		…
1	#! perl	1	#! perl
2		2
3	#:META:X_RESOURCE:%.expr:string:background expression	3	#:META:X_RESOURCE:%.expr:string:background expression
4	#:META:X_RESOURCE:%.border.:boolean:respect the terminal border	4	#:META:X_RESOURCE:%.border:boolean:respect the terminal border
		5	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
5		6
6	#TODO: once, rootalign	7	=head1 NAME
7		8
8	=head1 background - manage terminal background	9	background - manage terminal background
9		10
10	=head2 SYNOPSIS	11	=head1 SYNOPSIS
11		12
12	urxvt --background-expr 'background expression'	13	urxvt --background-expr 'background expression'
13	--background-border	14	--background-border
		15	--background-interval seconds
14		16
15	=head2 DESCRIPTION	17	=head1 DESCRIPTION
16		18
17	This extension manages the terminal background by creating a picture that	19	This extension manages the terminal background by creating a picture that
18	is behind the text, replacing the normal background colour.	20	is behind the text, replacing the normal background colour.
19		21
20	It does so by evaluating a Perl expression that I<calculates> the image on	22	It does so by evaluating a Perl expression that I<calculates> the image on
24	to be as simple as possible.	26	to be as simple as possible.
25		27
26	For example, to load an image and scale it to the window size, you would	28	For example, to load an image and scale it to the window size, you would
27	use:	29	use:
28		30
29	urxvt --background-expr 'scale load "/path/to/mybg.png"'	31	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
30		32
31	Or specified as a X resource:	33	Or specified as a X resource:
32		34
33	URxvt.background-expr: scale load "/path/to/mybg.png"	35	URxvt.background-expr: scale keep { load "/path/to/mybg.png" }
34		36
35	=head2 THEORY OF OPERATION	37	=head1 THEORY OF OPERATION
36		38
37	At startup, just before the window is mapped for the first time, the	39	At startup, just before the window is mapped for the first time, the
38	expression is evaluated and must yield an image. The image is then	40	expression is evaluated and must yield an image. The image is then
39	extended as necessary to cover the whole terminal window, and is set as a	41	extended as necessary to cover the whole terminal window, and is set as a
40	background pixmap.	42	background pixmap.
…		…
51	If any of the parameters that the expression relies on changes (when the	53	If any of the parameters that the expression relies on changes (when the
52	window is moved or resized, its position or size changes; when the root	54	window is moved or resized, its position or size changes; when the root
53	pixmap is replaced by another one the root background changes; or when the	55	pixmap is replaced by another one the root background changes; or when the
54	timer elapses), then the expression will be evaluated again.	56	timer elapses), then the expression will be evaluated again.
55		57
56	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	58	For example, an expression such as C<scale keep { load "$HOME/mybg.png"
57	image to the window size, so it relies on the window size and will	59	}> scales the image to the window size, so it relies on the window size
58	be reevaluated each time it is changed, but not when it moves for	60	and will be reevaluated each time it is changed, but not when it moves for
59	example. That ensures that the picture always fills the terminal, even	61	example. That ensures that the picture always fills the terminal, even
60	after it's size changes.	62	after its size changes.
61		63
62	=head3 EXPRESSIONS	64	=head2 EXPRESSIONS
63		65
64	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
65	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
66		68
		69	scale keep {
67	again 3600;	70	again 3600;
68	if (localtime now)[6]) {	71	if (localtime now)[6]) {
69	return scale load "$HOME/weekday.png";	72	return load "$HOME/weekday.png";
70	} else {	73	} else {
71	return scale load "$HOME/sunday.png";	74	return load "$HOME/sunday.png";
		75	}
72	}	76	}
73		77
74	This expression gets evaluated once per hour. It will set F<sunday.png> as	78	This inner expression is evaluated once per hour (and whenever the
		79	temrinal window is resized). It sets F<sunday.png> as background on
75	background on Sundays, and F<weekday.png> on all other days.	80	Sundays, and F<weekday.png> on all other days.
76		81
77	Fortunately, we expect that most expressions will be much simpler, with	82	Fortunately, we expect that most expressions will be much simpler, with
78	little Perl knowledge needed.	83	little Perl knowledge needed.
79		84
80	Basically, you always start with a function that "generates" an image	85	Basically, you always start with a function that "generates" an image
…		…
97	its result becomes the argument to the C<scale> function.	102	its result becomes the argument to the C<scale> function.
98		103
99	Many operators also allow some parameters preceding the input image	104	Many operators also allow some parameters preceding the input image
100	that modify its behaviour. For example, C<scale> without any additional	105	that modify its behaviour. For example, C<scale> without any additional
101	arguments scales the image to size of the terminal window. If you specify	106	arguments scales the image to size of the terminal window. If you specify
102	an additional argument, it uses it as a percentage:	107	an additional argument, it uses it as a scale factor (multiply by 100 to
		108	get a percentage):
103		109
104	scale 200, load "$HOME/mypic.png"	110	scale 2, load "$HOME/mypic.png"
105		111
106	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>	112	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
107	has now two arguments, the C<200> and the C<load> expression, while	113	has now two arguments, the C<200> and the C<load> expression, while
108	C<load> only has one argument. Arguments are separated from each other by	114	C<load> only has one argument. Arguments are separated from each other by
109	commas.	115	commas.
110		116
111	Scale also accepts two arguments, which are then separate factors for both	117	Scale also accepts two arguments, which are then separate factors for both
112	horizontal and vertical dimensions. For example, this halves the image	118	horizontal and vertical dimensions. For example, this halves the image
113	width and doubles the image height:	119	width and doubles the image height:
114		120
115	scale 50, 200, load "$HOME/mypic.png"	121	scale 0.5, 2, load "$HOME/mypic.png"
116		122
117	Other effects than scalign are also readily available, for exmaple, you can	123	IF you try out these expressions, you might suffer from some sluggishness,
118	tile the image to fill the whole window, instead of resizing it:	124	because each time the terminal is resized, it loads the PNG image agin
		125	and scales it. Scaling is usually fast (and unavoidable), but loading the
		126	image can be quite time consuming. This is where C<keep> comes in handy:
119		127
		128	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		129
		130	The C<keep> operator executes all the statements inside the braces only
		131	once, or when it thinks the outcome might change. In other cases it
		132	returns the last value computed by the brace block.
		133
		134	This means that the C<load> is only executed once, which makes it much
		135	faster, but also means that more memory is being used, because the loaded
		136	image must be kept in memory at all times. In this expression, the
		137	trade-off is likely worth it.
		138
		139	But back to effects: Other effects than scaling are also readily
		140	available, for example, you can tile the image to fill the whole window,
		141	instead of resizing it:
		142
120	tile load "$HOME/mypic.png"	143	tile keep { load "$HOME/mypic.png" }
121		144
122	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	145	In fact, images returned by C<load> are in C<tile> mode by default, so the
123	is kind of superfluous.	146	C<tile> operator is kind of superfluous.
124		147
125	Another common effect is to mirror the image, so that the same edges touch:	148	Another common effect is to mirror the image, so that the same edges
		149	touch:
126		150
127	mirror load "$HOME/mypic.png"	151	mirror keep { load "$HOME/mypic.png" }
128		152
129	This is also a typical background expression:	153	Another common background expression is:
130		154
131	rootalign root	155	rootalign root
132		156
133	It first takes a snapshot of the screen background image, and then	157	This one first takes a snapshot of the screen background image, and then
134	moves it to the upper left corner of the screen - the result is	158	moves it to the upper left corner of the screen (as opposed to the upper
135	pseudo-transparency, as the image seems to be static while the window is	159	left corner of the terminal window)- the result is pseudo-transparency:
136	moved around.	160	the image seems to be static while the window is moved around.
137		161
138	=head3 CYCLES AND CACHING	162	=head2 CACHING AND SENSITIVITY
139		163
140	As has been mentioned before, the expression might be evaluated multiple	164	Since some operations (such as C<load> and C<blur>) can take a long time,
141	times. Each time the expression is reevaluated, a new cycle is said to	165	caching results can be very important for a smooth operation. Caching can
142	have begun. Many operators cache their results till the next cycle.	166	also be useful to reduce memory usage, though, for example, when an image
		167	is cached by C<load>, it could be shared by multiple terminal windows
		168	running inside urxvtd.
143		169
144	For example, the C<load> operator keeps a copy of the image. If it is	170	=head3 C<keep { ... }> caching
145	asked to load the same image on the next cycle it will not load it again,
146	but return the cached copy.
147		171
148	This only works for one cycle though, so as long as you load the same	172	The most important way to cache expensive operations is to use C<keep {
149	image every time, it will always be cached, but when you load a different	173	... }>. The C<keep> operator takes a block of multiple statements enclosed
150	image, it will forget about the first one.	174	by C<{}> and keeps the return value in memory.
151		175
152	This allows you to either speed things up by keeping multiple images in	176	An expression can be "sensitive" to various external events, such as
153	memory, or comserve memory by loading images more often.	177	scaling or moving the window, root background changes and timers. Simply
		178	using an expression (such as C<scale> without parameters) that depends on
		179	certain changing values (called "variables"), or using those variables
		180	directly, will make an expression sensitive to these events - for example,
		181	using C<scale> or C<TW> will make the expression sensitive to the terminal
		182	size, and thus to resizing events.
154		183
155	For example, you can keep two images in memory and use a random one like	184	When such an event happens, C<keep> will automatically trigger a
156	this:	185	reevaluation of the whole expression with the new value of the expression.
157		186
158	my $img1 = load "img1.png";	187	C<keep> is most useful for expensive operations, such as C<blur>:
159	my $img2 = load "img2.png";
160	(0.5 > rand) ? $img1 : $img2
161		188
162	Since both images are "loaded" every time the expression is evaluated,	189	rootalign keep { blur 20, root }
163	they are always kept in memory. Contrast this version:
164		190
165	my $path1 = "img1.png";	191	This makes a blurred copy of the root background once, and on subsequent
166	my $path2 = "img2.png";	192	calls, just root-aligns it. Since C<blur> is usually quite slow and
167	load ((0.5 > rand) ? $path1 : $path2)	193	C<rootalign> is quite fast, this trades extra memory (for the cached
		194	blurred pixmap) with speed (blur only needs to be redone when root
		195	changes).
168		196
169	Here, a path is selected randomly, and load is only called for one image,	197	=head3 C<load> caching
170	so keeps only one image in memory. If, on the next evaluation, luck
171	decides to use the other path, then it will have to load that image again.
172		198
		199	The C<load> operator itself does not keep images in memory, but as long as
		200	the image is still in memory, C<load> will use the in-memory image instead
		201	of loading it freshly from disk.
		202
		203	That means that this expression:
		204
		205	keep { load "$HOME/path..." }
		206
		207	Not only caches the image in memory, other terminal instances that try to
		208	C<load> it can reuse that in-memory copy.
		209
173	=head2 REFERENCE	210	=head1 REFERENCE
174		211
175	=head3 COMMAND LINE SWITCHES	212	=head2 COMMAND LINE SWITCHES
176		213
177	=over 4	214	=over 4
178		215
179	=item --background-expr perl-expression	216	=item --background-expr perl-expression
180		217
…		…
186	overwriting borders and any other areas, such as the scrollbar.	223	overwriting borders and any other areas, such as the scrollbar.
187		224
188	Specifying this flag changes the behaviour, so that the image only	225	Specifying this flag changes the behaviour, so that the image only
189	replaces the background of the character area.	226	replaces the background of the character area.
190		227
		228	=item --background-interval seconds
		229
		230	Since some operations in the underlying XRender extension can effectively
		231	freeze your X-server for prolonged time, this extension enforces a minimum
		232	time between updates, which is normally about 0.1 seconds.
		233
		234	If you want to do updates more often, you can decrease this safety
		235	interval with this switch.
		236
191	=back	237	=back
192		238
193	=cut	239	=cut
194		240
		241	our %_IMG_CACHE;
195	our $HOME;	242	our $HOME;
196	our ($self, $old, $new);	243	our ($self, $frame);
197	our ($x, $y, $w, $h);	244	our ($x, $y, $w, $h);
198		245
199	# enforce at least this interval between updates	246	# enforce at least this interval between updates
200	our $MIN_INTERVAL = 1/100;	247	our $MIN_INTERVAL = 6/59.951;
201		248
202	{	249	{
203	package urxvt::bgdsl; # background language	250	package urxvt::bgdsl; # background language
		251
		252	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		253	sub FR_CACHE () { 1 } # cached values
		254	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		255	sub FR_STATE () { 3 } # watchers etc.
		256
		257	use List::Util qw(min max sum shuffle);
204		258
205	=head2 PROVIDERS/GENERATORS	259	=head2 PROVIDERS/GENERATORS
206		260
207	These functions provide an image, by loading it from disk, grabbing it	261	These functions provide an image, by loading it from disk, grabbing it
208	from the root screen or by simply generating it. They are used as starting	262	from the root screen or by simply generating it. They are used as starting
…		…
213	=item load $path	267	=item load $path
214		268
215	Loads the image at the given C<$path>. The image is set to plane tiling	269	Loads the image at the given C<$path>. The image is set to plane tiling
216	mode.	270	mode.
217		271
218	Loaded images will be cached for one cycle.	272	If the image is already in memory (e.g. because another terminal instance
		273	uses it), then the in-memory copy us returned instead.
		274
		275	=item load_uc $path
		276
		277	Load uncached - same as load, but does not cache the image, which means it
		278	is I<always> loaded from the filesystem again.
219		279
220	=cut	280	=cut
221		281
222	sub load($) {	282	sub load($) {
223	my ($path) = @_;	283	my ($path) = @_;
224		284
225	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	285	$_IMG_CACHE{$path} \|\| do {
		286	my $img = $self->new_img_from_file ($path);
		287	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		288	$img
		289	}
226	}	290	}
227		291
228	=item root	292	=item root
229		293
230	Returns the root window pixmap, that is, hopefully, the background image	294	Returns the root window pixmap, that is, hopefully, the background image
231	of your screen. The image is set to extend mode.	295	of your screen.
232		296
233	This function makes your expression root sensitive, that means it will be	297	This function makes your expression root sensitive, that means it will be
234	reevaluated when the bg image changes.	298	reevaluated when the bg image changes.
235		299
236	=cut	300	=cut
237		301
238	sub root() {	302	sub root() {
239	$new->{rootpmap_sensitive} = 1;	303	$frame->[FR_AGAIN]{rootpmap} = 1;
240	die "root op not supported, exg, we need you";	304	$self->new_img_from_root
241	}	305	}
242		306
243	=item solid $colour	307	=item solid $colour
244		308
245	=item solid $width, $height, $colour	309	=item solid $width, $height, $colour
246		310
247	Creates a new image and completely fills it with the given colour. The	311	Creates a new image and completely fills it with the given colour. The
248	image is set to tiling mode.	312	image is set to tiling mode.
249		313
250	If <$width> and C<$height> are omitted, it creates a 1x1 image, which is	314	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
251	useful for solid backgrounds or for use in filtering effects.	315	useful for solid backgrounds or for use in filtering effects.
252		316
253	=cut	317	=cut
254		318
255	sub solid($$;$) {	319	sub solid($;$$) {
256	my $colour = pop;	320	my $colour = pop;
257		321
258	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	322	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
259	$img->fill ($colour);	323	$img->fill ($colour);
260	$img	324	$img
261	}	325	}
262		326
263	=back	327	=item clone $img
264		328
265	=head2 VARIABLES	329	Returns an exact copy of the image. This is useful if you want to have
		330	multiple copies of the same image to apply different effects to.
266		331
267	The following functions provide variable data such as the terminal
268	window dimensions. Most of them make your expression sensitive to some
269	events, for example using C<TW> (terminal width) means your expression is
270	evaluated again when the terminal is resized.
271
272	=over 4
273
274	=item TX
275
276	=item TY
277
278	Return the X and Y coordinates of the terminal window (the terminal
279	window is the full window by default, and the character area only when in
280	border-respect mode).
281
282	Using these functions make your expression sensitive to window moves.
283
284	These functions are mainly useful to align images to the root window.
285
286	Example: load an image and align it so it looks as if anchored to the
287	background.
288
289	move -TX, -TY, load "mybg.png"
290
291	=item TW
292
293	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
294	terminal window is the full window by default, and the character area only
295	when in border-respect mode).
296
297	Using these functions make your expression sensitive to window resizes.
298
299	These functions are mainly useful to scale images, or to clip images to
300	the window size to conserve memory.
301
302	Example: take the screen background, clip it to the window size, blur it a
303	bit, align it to the window position and use it as background.
304
305	clip move -TX, -TY, blur 5, root
306
307	=cut	332	=cut
308		333
309	sub TX() { $new->{position_sensitive} = 1; $x }
310	sub TY() { $new->{position_sensitive} = 1; $y }
311	sub TW() { $new->{size_sensitive} = 1; $w }
312	sub TH() { $new->{size_sensitive} = 1; $h }
313
314	=item now
315
316	Returns the current time as (fractional) seconds since the epoch.
317
318	Using this expression does I<not> make your expression sensitive to time,
319	but the next two functions do.
320
321	=item again $seconds
322
323	When this function is used the expression will be reevaluated again in
324	C<$seconds> seconds.
325
326	Example: load some image and rotate it according to the time of day (as if it were
327	the hour pointer of a clock). Update this image every minute.
328
329	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
330
331	=item counter $seconds
332
333	Like C<again>, but also returns an increasing counter value, starting at
334	0, which might be useful for some simple animation effects.
335
336	=cut
337
338	sub now() { urxvt::NOW }
339
340	sub again($) {
341	$new->{again} = $_[0];
342	}
343
344	sub counter($) {	334	sub clone($) {
345	$new->{again} = $_[0];	335	$_[0]->clone
346	$self->{counter} + 0
347	}	336	}
348		337
349	=back	338	=item merge $img ...
		339
		340	Takes any number of images and merges them together, creating a single
		341	image containing them all. The tiling mode of the first image is used as
		342	the tiling mode of the resulting image.
		343
		344	This function is called automatically when an expression returns multiple
		345	images.
		346
		347	=cut
		348
		349	sub merge(@) {
		350	return $_[0] unless $#_;
		351
		352	# rather annoyingly clumsy, but optimisation is for another time
		353
		354	my $x0 = +1e9;
		355	my $y0 = +1e9;
		356	my $x1 = -1e9;
		357	my $y1 = -1e9;
		358
		359	for (@_) {
		360	my ($x, $y, $w, $h) = $_->geometry;
		361
		362	$x0 = $x if $x0 > $x;
		363	$y0 = $y if $y0 > $y;
		364
		365	$x += $w;
		366	$y += $h;
		367
		368	$x1 = $x if $x1 < $x;
		369	$y1 = $y if $y1 < $y;
		370	}
		371
		372	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		373	$base->repeat_mode ($_[0]->repeat_mode);
		374	$base->fill ([0, 0, 0, 0]);
		375
		376	$base->draw ($_)
		377	for @_;
		378
		379	$base
		380	}
350		381
351	=head2 TILING MODES	382	=head2 TILING MODES
352		383
353	The following operators modify the tiling mode of an image, that is, the	384	The following operators modify the tiling mode of an image, that is, the
354	way that pixels outside the image area are painted when the image is used.	385	way that pixels outside the image area are painted when the image is used.
…		…
384	become transparent. This mode is most useful when you want to place an	415	become transparent. This mode is most useful when you want to place an
385	image over another image or the background colour while leaving all	416	image over another image or the background colour while leaving all
386	background pixels outside the image unchanged.	417	background pixels outside the image unchanged.
387		418
388	Example: load an image and display it in the upper left corner. The rest	419	Example: load an image and display it in the upper left corner. The rest
389	of the space is left "empty" (transparent or wahtever your compisotr does	420	of the space is left "empty" (transparent or whatever your compositor does
390	in alpha mode, else background colour).	421	in alpha mode, else background colour).
391		422
392	pad load "mybg.png"	423	pad load "mybg.png"
393		424
394	=item extend $img	425	=item extend $img
395		426
396	Extends the image over the whole plane, using the closest pixel in the	427	Extends the image over the whole plane, using the closest pixel in the
397	area outside the image. This mode is mostly useful when you more complex	428	area outside the image. This mode is mostly useful when you use more complex
398	filtering operations and want the pixels outside the image to have the	429	filtering operations and want the pixels outside the image to have the
399	same values as the pixels near the edge.	430	same values as the pixels near the edge.
400		431
401	Example: just for curiosity, how does this pixel extension stuff work?	432	Example: just for curiosity, how does this pixel extension stuff work?
402		433
…		…
428	$img	459	$img
429	}	460	}
430		461
431	=back	462	=back
432		463
433	=head2 PIXEL OPERATORS	464	=head2 VARIABLE VALUES
434		465
435	The following operators modify the image pixels in various ways.	466	The following functions provide variable data such as the terminal window
		467	dimensions. They are not (Perl-) variables, they just return stuff that
		468	varies. Most of them make your expression sensitive to some events, for
		469	example using C<TW> (terminal width) means your expression is evaluated
		470	again when the terminal is resized.
436		471
437	=over 4	472	=over 4
438		473
439	=item clone $img	474	=item TX
440		475
441	Returns an exact copy of the image.	476	=item TY
442		477
443	=cut	478	Return the X and Y coordinates of the terminal window (the terminal
		479	window is the full window by default, and the character area only when in
		480	border-respect mode).
444		481
		482	Using these functions make your expression sensitive to window moves.
		483
		484	These functions are mainly useful to align images to the root window.
		485
		486	Example: load an image and align it so it looks as if anchored to the
		487	background (that's exactly what C<rootalign> does btw.):
		488
		489	move -TX, -TY, keep { load "mybg.png" }
		490
		491	=item TW
		492
		493	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		494	terminal window is the full window by default, and the character area only
		495	when in border-respect mode).
		496
		497	Using these functions make your expression sensitive to window resizes.
		498
		499	These functions are mainly useful to scale images, or to clip images to
		500	the window size to conserve memory.
		501
		502	Example: take the screen background, clip it to the window size, blur it a
		503	bit, align it to the window position and use it as background.
		504
		505	clip move -TX, -TY, keep { blur 5, root }
		506
		507	=cut
		508
		509	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
		510	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
		511	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
		512	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
		513
		514	=item now
		515
		516	Returns the current time as (fractional) seconds since the epoch.
		517
		518	Using this expression does I<not> make your expression sensitive to time,
		519	but the next two functions do.
		520
		521	=item again $seconds
		522
		523	When this function is used the expression will be reevaluated again in
		524	C<$seconds> seconds.
		525
		526	Example: load some image and rotate it according to the time of day (as if it were
		527	the hour pointer of a clock). Update this image every minute.
		528
		529	again 60;
		530	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
		531
		532	=item counter $seconds
		533
		534	Like C<again>, but also returns an increasing counter value, starting at
		535	0, which might be useful for some simple animation effects.
		536
		537	=cut
		538
		539	sub now() { urxvt::NOW }
		540
		541	sub again($) {
		542	$frame->[FR_AGAIN]{time} = $_[0];
		543	}
		544
445	sub clone($) {	545	sub counter($) {
446	$_[0]->clone	546	$frame->[FR_AGAIN]{time} = $_[0];
		547	$frame->[FR_STATE]{counter} + 0
447	}	548	}
		549
		550	=back
		551
		552	=head2 SHAPE CHANGING OPERATORS
		553
		554	The following operators modify the shape, size or position of the image.
		555
		556	=over 4
448		557
449	=item clip $img	558	=item clip $img
450		559
451	=item clip $width, $height, $img	560	=item clip $width, $height, $img
452		561
…		…
463	assumed.	572	assumed.
464		573
465	Example: load an image, blur it, and clip it to the window size to save	574	Example: load an image, blur it, and clip it to the window size to save
466	memory.	575	memory.
467		576
468	clip blur 10, load "mybg.png"	577	clip keep { blur 10, load "mybg.png" }
469		578
470	=cut	579	=cut
471		580
472	sub clip($;$$;$$) {	581	sub clip($;$$;$$) {
473	my $img = pop;	582	my $img = pop;
…		…
476	$img->sub_rect ($_[0], $_[1], $w, $h)	585	$img->sub_rect ($_[0], $_[1], $w, $h)
477	}	586	}
478		587
479	=item scale $img	588	=item scale $img
480		589
481	=item scale $size_percent, $img	590	=item scale $size_factor, $img
482		591
483	=item scale $width_percent, $height_percent, $img	592	=item scale $width_factor, $height_factor, $img
484		593
485	Scales the image by the given percentages in horizontal	594	Scales the image by the given factors in horizontal
486	(C<$width_percent>) and vertical (C<$height_percent>) direction.	595	(C<$width>) and vertical (C<$height>) direction.
487		596
488	If only one percentage is give, it is used for both directions.	597	If only one factor is give, it is used for both directions.
489		598
490	If no percentages are given, scales the image to the window size without	599	If no factors are given, scales the image to the window size without
491	keeping aspect.	600	keeping aspect.
492		601
493	=item resize $width, $height, $img	602	=item resize $width, $height, $img
494		603
495	Resizes the image to exactly C<$width> times C<$height> pixels.	604	Resizes the image to exactly C<$width> times C<$height> pixels.
496		605
497	=cut	606	=item fit $img
498		607
499	#TODO: maximise, maximise_fill?	608	=item fit $width, $height, $img
		609
		610	Fits the image into the given C<$width> and C<$height> without changing
		611	aspect, or the terminal size. That means it will be shrunk or grown until
		612	the whole image fits into the given area, possibly leaving borders.
		613
		614	=item cover $img
		615
		616	=item cover $width, $height, $img
		617
		618	Similar to C<fit>, but shrinks or grows until all of the area is covered
		619	by the image, so instead of potentially leaving borders, it will cut off
		620	image data that doesn't fit.
		621
		622	=cut
500		623
501	sub scale($;$;$) {	624	sub scale($;$;$) {
502	my $img = pop;	625	my $img = pop;
503		626
504	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	627	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
505	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	628	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
506	: $img->scale (TW, TH)	629	: $img->scale (TW, TH)
507	}	630	}
508		631
509	sub resize($$$) {	632	sub resize($$$) {
510	my $img = pop;	633	my $img = pop;
511	$img->scale ($_[0], $_[1])	634	$img->scale ($_[0], $_[1])
512	}	635	}
513		636
		637	sub fit($;$$) {
		638	my $img = pop;
		639	my $w = ($_[0] \|\| TW) / $img->w;
		640	my $h = ($_[1] \|\| TH) / $img->h;
		641	scale +(min $w, $h), $img
		642	}
		643
		644	sub cover($;$$) {
		645	my $img = pop;
		646	my $w = ($_[0] \|\| TW) / $img->w;
		647	my $h = ($_[1] \|\| TH) / $img->h;
		648	scale +(max $w, $h), $img
		649	}
		650
514	=item move $dx, $dy, $img	651	=item move $dx, $dy, $img
515		652
516	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	653	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
517	the vertical.	654	the vertical.
518		655
519	Example: move the image right by 20 pixels and down by 30.	656	Example: move the image right by 20 pixels and down by 30.
520		657
521	move 20, 30, ...	658	move 20, 30, ...
		659
		660	=item align $xalign, $yalign, $img
		661
		662	Aligns the image according to a factor - C<0> means the image is moved to
		663	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		664	exactly centered and C<1> means it touches the right or bottom edge.
		665
		666	Example: remove any visible border around an image, center it vertically but move
		667	it to the right hand side.
		668
		669	align 1, 0.5, pad $img
		670
		671	=item center $img
		672
		673	=item center $width, $height, $img
		674
		675	Centers the image, i.e. the center of the image is moved to the center of
		676	the terminal window (or the box specified by C<$width> and C<$height> if
		677	given).
		678
		679	Example: load an image and center it.
		680
		681	center keep { pad load "mybg.png" }
522		682
523	=item rootalign $img	683	=item rootalign $img
524		684
525	Moves the image so that it appears glued to the screen as opposed to the	685	Moves the image so that it appears glued to the screen as opposed to the
526	window. This gives the illusion of a larger area behind the window. It is	686	window. This gives the illusion of a larger area behind the window. It is
527	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	687	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
528	top left of the screen.	688	top left of the screen.
529		689
530	Example: load a background image, put it in mirror mode and root align it.	690	Example: load a background image, put it in mirror mode and root align it.
531		691
532	rootalign mirror load "mybg.png"	692	rootalign keep { mirror load "mybg.png" }
533		693
534	Example: take the screen background and align it, giving the illusion of	694	Example: take the screen background and align it, giving the illusion of
535	transparency as long as the window isn't in front of other windows.	695	transparency as long as the window isn't in front of other windows.
536		696
537	rootalign root	697	rootalign root
538		698
539	=cut	699	=cut
540		700
541	sub move($$;$) {	701	sub move($$;$) {
542	my $img = pop->clone;	702	my $img = pop->clone;
543	$img->move ($_[0], $_[1]);	703	$img->move ($_[0], $_[1]);
544	$img	704	$img
545	}	705	}
546		706
		707	sub align($;$$) {
		708	my $img = pop;
		709
		710	move $_[0] * (TW - $img->w),
		711	$_[1] * (TH - $img->h),
		712	$img
		713	}
		714
		715	sub center($;$$) {
		716	my $img = pop;
		717	my $w = $_[0] \|\| TW;
		718	my $h = $_[1] \|\| TH;
		719
		720	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		721	}
		722
547	sub rootalign($) {	723	sub rootalign($) {
548	move -TX, -TY, $_[0]	724	move -TX, -TY, $_[0]
549	}	725	}
550		726
		727	=item rotate $center_x, $center_y, $degrees, $img
		728
		729	Rotates the image clockwise by C<$degrees> degrees, around the point at
		730	C<$center_x> and C<$center_y> (specified as factor of image width/height).
		731
		732	Example: rotate the image by 90 degrees around it's center.
		733
		734	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
		735
		736	=cut
		737
		738	sub rotate($$$$) {
		739	my $img = pop;
		740	$img->rotate (
		741	$_[0] * ($img->w + $img->x),
		742	$_[1] * ($img->h + $img->y),
		743	$_[2] * (3.14159265 / 180),
		744	)
		745	}
		746
		747	=back
		748
		749	=head2 COLOUR MODIFICATIONS
		750
		751	The following operators change the pixels of the image.
		752
		753	=over 4
		754
551	=item contrast $factor, $img	755	=item contrast $factor, $img
552		756
553	=item contrast $r, $g, $b, $img	757	=item contrast $r, $g, $b, $img
554		758
555	=item contrast $r, $g, $b, $a, $img	759	=item contrast $r, $g, $b, $a, $img
556		760
557	Adjusts the I<contrast> of an image.	761	Adjusts the I<contrast> of an image.
558		762
559	#TODO#	763	The first form applies a single C<$factor> to red, green and blue, the
		764	second form applies separate factors to each colour channel, and the last
		765	form includes the alpha channel.
560		766
		767	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		768	contrast.
		769
		770	Due to limitations in the underlying XRender extension, lowering contrast
		771	also reduces brightness, while increasing contrast currently also
		772	increases brightness.
		773
561	=item brightness $factor, $img	774	=item brightness $bias, $img
562		775
563	=item brightness $r, $g, $b, $img	776	=item brightness $r, $g, $b, $img
564		777
565	=item brightness $r, $g, $b, $a, $img	778	=item brightness $r, $g, $b, $a, $img
566		779
567	Adjusts the brightness of an image.	780	Adjusts the brightness of an image.
		781
		782	The first form applies a single C<$bias> to red, green and blue, the
		783	second form applies separate biases to each colour channel, and the last
		784	form includes the alpha channel.
		785
		786	Values less than 0 reduce brightness, while values larger than 0 increase
		787	it. Useful range is from -1 to 1 - the former results in a black, the
		788	latter in a white picture.
		789
		790	Due to idiosyncrasies in the underlying XRender extension, biases less
		791	than zero can be I<very> slow.
568		792
569	=cut	793	=cut
570		794
571	sub contrast($$;$$;$) {	795	sub contrast($$;$$;$) {
572	my $img = pop;	796	my $img = pop;
573	my ($r, $g, $b, $a) = @_;	797	my ($r, $g, $b, $a) = @_;
574		798
575	($g, $b) = ($r, $r) if @_ < 4;	799	($g, $b) = ($r, $r) if @_ < 3;
576	$a = 1 if @_ < 5;	800	$a = 1 if @_ < 4;
577		801
578	$img = $img->clone;	802	$img = $img->clone;
579	$img->contrast ($r, $g, $b, $a);	803	$img->contrast ($r, $g, $b, $a);
580	$img	804	$img
581	}	805	}
582		806
583	sub brightness($$;$$;$) {	807	sub brightness($$;$$;$) {
584	my $img = pop;	808	my $img = pop;
585	my ($r, $g, $b, $a) = @_;	809	my ($r, $g, $b, $a) = @_;
586		810
587	($g, $b) = ($r, $r) if @_ < 4;	811	($g, $b) = ($r, $r) if @_ < 3;
588	$a = 1 if @_ < 5;	812	$a = 1 if @_ < 4;
589		813
590	$img = $img->clone;	814	$img = $img->clone;
591	$img->brightness ($r, $g, $b, $a);	815	$img->brightness ($r, $g, $b, $a);
592	$img	816	$img
593	}	817	}
…		…
609	sub blur($$;$) {	833	sub blur($$;$) {
610	my $img = pop;	834	my $img = pop;
611	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	835	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
612	}	836	}
613		837
614	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
615
616	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
617	pointer at C<$center_x> and C<$center_y> (specified as percentage of image
618	width/height), generating a new image with width C<$new_width> and height
619	C<$new_height>.
620
621	#TODO# new width, height, maybe more operators?
622
623	Example: rotate the image by 90 degrees
624
625	=cut
626
627	sub rotate($$$$$$) {
628	my $img = pop;
629	$img->rotate (
630	$_[0],
631	$_[1],
632	$_[2] * $img->w * .01,
633	$_[3] * $img->h * .01,
634	$_[4] * (3.14159265 / 180),
635	)
636	}
637
638	=back	838	=back
639		839
		840	=head2 OTHER STUFF
		841
		842	Anything that didn't fit any of the other categories, even after applying
		843	force and closing our eyes.
		844
		845	=over 4
		846
		847	=item keep { ... }
		848
		849	This operator takes a code block as argument, that is, one or more
		850	statements enclosed by braces.
		851
		852	The trick is that this code block is only evaluated when the outcome
		853	changes - on other calls the C<keep> simply returns the image it computed
		854	previously (yes, it should only be used with images). Or in other words,
		855	C<keep> I<caches> the result of the code block so it doesn't need to be
		856	computed again.
		857
		858	This can be extremely useful to avoid redoing slow operations - for
		859	example, if your background expression takes the root background, blurs it
		860	and then root-aligns it it would have to blur the root background on every
		861	window move or resize.
		862
		863	Another example is C<load>, which can be quite slow.
		864
		865	In fact, urxvt itself encloses the whole expression in some kind of
		866	C<keep> block so it only is reevaluated as required.
		867
		868	Putting the blur into a C<keep> block will make sure the blur is only done
		869	once, while the C<rootalign> is still done each time the window moves.
		870
		871	rootlign keep { blur 10, root }
		872
		873	This leaves the question of how to force reevaluation of the block,
		874	in case the root background changes: If expression inside the block
		875	is sensitive to some event (root background changes, window geometry
		876	changes), then it will be reevaluated automatically as needed.
		877
		878	=cut
		879
		880	sub keep(&) {
		881	my $id = $_[0]+0;
		882
		883	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		884
		885	unless ($frame->[FR_CACHE]) {
		886	$frame->[FR_CACHE] = [ $_[0]() ];
		887
		888	my $self = $self;
		889	my $frame = $frame;
		890	Scalar::Util::weaken $frame;
		891	$self->compile_frame ($frame, sub {
		892	# clear this frame cache, also for all parents
		893	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		894	undef $frame->[FR_CACHE];
		895	}
		896
		897	$self->recalculate;
		898	});
		899	};
		900
		901	# in scalar context we always return the first original result, which
		902	# is not quite how perl works.
		903	wantarray
		904	? @{ $frame->[FR_CACHE] }
		905	: $frame->[FR_CACHE][0]
		906	}
		907
		908	# sub keep_clear() {
		909	# delete $self->{frame_cache};
		910	# }
		911
		912	=back
		913
640	=cut	914	=cut
641		915
642	}	916	}
643		917
644	sub parse_expr {	918	sub parse_expr {
645	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	919	my $expr = eval
		920	"sub {\n"
		921	. "package urxvt::bgdsl;\n"
		922	. "#line 0 'background expression'\n"
		923	. "$_[0]\n"
		924	. "}";
646	die if $@;	925	die if $@;
647	$expr	926	$expr
648	}	927	}
649		928
650	# compiles a parsed expression	929	# compiles a parsed expression
651	sub set_expr {	930	sub set_expr {
652	my ($self, $expr) = @_;	931	my ($self, $expr) = @_;
653		932
		933	$self->{root} = [];
654	$self->{expr} = $expr;	934	$self->{expr} = $expr;
655	$self->recalculate;	935	$self->recalculate;
		936	}
		937
		938	# takes a hash of sensitivity indicators and installs watchers
		939	sub compile_frame {
		940	my ($self, $frame, $cb) = @_;
		941
		942	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		943	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		944
		945	# don't keep stuff alive
		946	Scalar::Util::weaken $state;
		947
		948	if ($again->{nested}) {
		949	$state->{nested} = 1;
		950	} else {
		951	delete $state->{nested};
		952	}
		953
		954	if (my $interval = $again->{time}) {
		955	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		956	if $state->{time}[0] != $interval;
		957
		958	# callback might have changed, although we could just rule that out
		959	$state->{time}[1]->cb (sub {
		960	++$state->{counter};
		961	$cb->();
		962	});
		963	} else {
		964	delete $state->{time};
		965	}
		966
		967	if ($again->{position}) {
		968	$state->{position} = $self->on (position_change => $cb);
		969	} else {
		970	delete $state->{position};
		971	}
		972
		973	if ($again->{size}) {
		974	$state->{size} = $self->on (size_change => $cb);
		975	} else {
		976	delete $state->{size};
		977	}
		978
		979	if ($again->{rootpmap}) {
		980	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		981	} else {
		982	delete $state->{rootpmap};
		983	}
656	}	984	}
657		985
658	# evaluate the current bg expression	986	# evaluate the current bg expression
659	sub recalculate {	987	sub recalculate {
660	my ($arg_self) = @_;	988	my ($arg_self) = @_;
…		…
670		998
671	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	999	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
672		1000
673	# set environment to evaluate user expression	1001	# set environment to evaluate user expression
674		1002
675	local $self = $arg_self;	1003	local $self = $arg_self;
676
677	local $HOME = $ENV{HOME};	1004	local $HOME = $ENV{HOME};
678	local $old = $self->{state};	1005	local $frame = [];
679	local $new = my $state = $self->{state} = {};
680		1006
681	($x, $y, $w, $h) =
682	$self->background_geometry ($self->{border});	1007	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
683		1008
684	# evaluate user expression	1009	# evaluate user expression
685		1010
686	my $img = eval { $self->{expr}->() };	1011	my @img = eval { $self->{expr}->() };
687	warn $@ if $@;#d#	1012	die $@ if $@;
		1013	die "background-expr did not return anything.\n" unless @img;
		1014	die "background-expr: expected image(s), got something else.\n"
688	die if !UNIVERSAL::isa $img, "urxvt::img";	1015	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
689		1016
690	$state->{size_sensitive} = 1	1017	my $img = urxvt::bgdsl::merge @img;
		1018
		1019	$frame->[FR_AGAIN]{size} = 1
691	if $img->repeat_mode != urxvt::RepeatNormal;	1020	if $img->repeat_mode != urxvt::RepeatNormal;
692		1021
693	# if the expression is sensitive to external events, prepare reevaluation then	1022	# if the expression is sensitive to external events, prepare reevaluation then
694		1023	$self->compile_frame ($frame, sub { $arg_self->recalculate });
695	my $repeat;
696
697	if (my $again = $state->{again}) {
698	$repeat = 1;
699	my $self = $self;
700	$state->{timer} = $again == $old->{again}
701	? $old->{timer}
702	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
703	++$self->{counter};
704	$self->recalculate
705	});
706	}
707
708	if (delete $state->{position_sensitive}) {
709	$repeat = 1;
710	$self->enable (position_change => sub { $_[0]->recalculate });
711	} else {
712	$self->disable ("position_change");
713	}
714
715	if (delete $state->{size_sensitive}) {
716	$repeat = 1;
717	$self->enable (size_change => sub { $_[0]->recalculate });
718	} else {
719	$self->disable ("size_change");
720	}
721
722	if (delete $state->{rootpmap_sensitive}) {
723	$repeat = 1;
724	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
725	} else {
726	$self->disable ("rootpmap_change");
727	}
728		1024
729	# clear stuff we no longer need	1025	# clear stuff we no longer need
730		1026
731	%$old = ();	1027	# unless (%{ $frame->[FR_STATE] }) {
732
733	unless ($repeat) {
734	delete $self->{state};	1028	# delete $self->{state};
735	delete $self->{expr};	1029	# delete $self->{expr};
736	}	1030	# }
737		1031
738	# set background pixmap	1032	# set background pixmap
739		1033
740	$self->set_background ($img, $self->{border});	1034	$self->set_background ($img, $self->{border});
741	$self->scr_recolour (0);	1035	$self->scr_recolour (0);
…		…
743	}	1037	}
744		1038
745	sub on_start {	1039	sub on_start {
746	my ($self) = @_;	1040	my ($self) = @_;
747		1041
748	my $expr = $self->x_resource ("background.expr")	1042	my $expr = $self->x_resource ("%.expr")
749	or return;	1043	or return;
750		1044
		1045	$self->has_render
		1046	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		1047
751	$self->set_expr (parse_expr $expr);	1048	$self->set_expr (parse_expr $expr);
752	$self->{border} = $self->x_resource_boolean ("background.border");	1049	$self->{border} = $self->x_resource_boolean ("%.border");
		1050
		1051	$MIN_INTERVAL = $self->x_resource ("%.interval");
753		1052
754	()	1053	()
755	}	1054	}
756		1055

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.39 by root, Fri Jun 8 22:19:03 2012 UTC vs. Revision 1.69 by root, Mon Jul 2 01:32:26 2012 UTC

Diff Legend

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.39 by root, Fri Jun 8 22:19:03 2012 UTC vs.
Revision 1.69 by root, Mon Jul 2 01:32:26 2012 UTC