[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 1.89 by root, Sat Dec 13 12:24:33 2014 UTC

…		…
1	#! perl	1	#! perl
2		2
3	#:META:X_RESOURCE:%.expr:string:background expression	3	#:META:RESOURCE:%.expr:string:background expression
4	#:META:X_RESOURCE:%.border.:boolean:respect the terminal border	4	#:META:RESOURCE:%.border:boolean:respect the terminal border
		5	#:META: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
		17	=head1 QUICK AND DIRTY CHEAT SHEET
		18
		19	Just load a random jpeg image and tile the background with it without
		20	scaling or anything else:
		21
		22	load "/path/to/img.jpg"
		23
		24	The same, but use mirroring/reflection instead of tiling:
		25
		26	mirror load "/path/to/img.jpg"
		27
		28	Load an image and scale it to exactly fill the terminal window:
		29
		30	scale keep { load "/path/to/img.jpg" }
		31
		32	Implement pseudo-transparency by using a suitably-aligned root pixmap
		33	as window background:
		34
		35	rootalign root
		36
		37	Likewise, but keep a blurred copy:
		38
		39	rootalign keep { blur 10, root }
		40
15	=head2 DESCRIPTION	41	=head1 DESCRIPTION
16		42
17	This extension manages the terminal background by creating a picture that	43	This extension manages the terminal background by creating a picture that
18	is behind the text, replacing the normal background colour.	44	is behind the text, replacing the normal background colour.
19		45
20	It does so by evaluating a Perl expression that I<calculates> the image on	46	It does so by evaluating a Perl expression that I<calculates> the image on
24	to be as simple as possible.	50	to be as simple as possible.
25		51
26	For example, to load an image and scale it to the window size, you would	52	For example, to load an image and scale it to the window size, you would
27	use:	53	use:
28		54
29	urxvt --background-expr 'scale load "/path/to/mybg.png"'	55	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
30		56
31	Or specified as a X resource:	57	Or specified as a X resource:
32		58
33	URxvt.background-expr: scale load "/path/to/mybg.png"	59	URxvt.background-expr: scale keep { load "/path/to/mybg.png" }
34		60
35	=head2 THEORY OF OPERATION	61	=head1 THEORY OF OPERATION
36		62
37	At startup, just before the window is mapped for the first time, the	63	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	64	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	65	extended as necessary to cover the whole terminal window, and is set as a
40	background pixmap.	66	background pixmap.
…		…
51	If any of the parameters that the expression relies on changes (when the	77	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	78	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	79	pixmap is replaced by another one the root background changes; or when the
54	timer elapses), then the expression will be evaluated again.	80	timer elapses), then the expression will be evaluated again.
55		81
56	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	82	For example, an expression such as C<scale keep { load "$HOME/mybg.png"
57	image to the window size, so it relies on the window size and will	83	}> 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	84	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	85	example. That ensures that the picture always fills the terminal, even
60	after it's size changes.	86	after its size changes.
61		87
62	=head3 EXPRESSIONS	88	=head2 EXPRESSIONS
63		89
64	Expressions are normal Perl expressions, in fact, they are Perl blocks -	90	Expressions are normal Perl expressions, in fact, they are Perl blocks -
65	which means you could use multiple lines and statements:	91	which means you could use multiple lines and statements:
66		92
		93	scale keep {
67	again 3600;	94	again 3600;
68	if (localtime now)[6]) {	95	if (localtime now)[6]) {
69	return scale load "$HOME/weekday.png";	96	return load "$HOME/weekday.png";
70	} else {	97	} else {
71	return scale load "$HOME/sunday.png";	98	return load "$HOME/sunday.png";
		99	}
72	}	100	}
73		101
74	This expression gets evaluated once per hour. It will set F<sunday.png> as	102	This inner expression is evaluated once per hour (and whenever the
		103	terminal window is resized). It sets F<sunday.png> as background on
75	background on Sundays, and F<weekday.png> on all other days.	104	Sundays, and F<weekday.png> on all other days.
76		105
77	Fortunately, we expect that most expressions will be much simpler, with	106	Fortunately, we expect that most expressions will be much simpler, with
78	little Perl knowledge needed.	107	little Perl knowledge needed.
79		108
80	Basically, you always start with a function that "generates" an image	109	Basically, you always start with a function that "generates" an image
…		…
97	its result becomes the argument to the C<scale> function.	126	its result becomes the argument to the C<scale> function.
98		127
99	Many operators also allow some parameters preceding the input image	128	Many operators also allow some parameters preceding the input image
100	that modify its behaviour. For example, C<scale> without any additional	129	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	130	arguments scales the image to size of the terminal window. If you specify
102	an additional argument, it uses it as a percentage:	131	an additional argument, it uses it as a scale factor (multiply by 100 to
		132	get a percentage):
103		133
104	scale 200, load "$HOME/mypic.png"	134	scale 2, load "$HOME/mypic.png"
105		135
106	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>	136	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	137	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	138	C<load> only has one argument. Arguments are separated from each other by
109	commas.	139	commas.
110		140
111	Scale also accepts two arguments, which are then separate factors for both	141	Scale also accepts two arguments, which are then separate factors for both
112	horizontal and vertical dimensions. For example, this halves the image	142	horizontal and vertical dimensions. For example, this halves the image
113	width and doubles the image height:	143	width and doubles the image height:
114		144
115	scale 50, 200, load "$HOME/mypic.png"	145	scale 0.5, 2, load "$HOME/mypic.png"
116		146
117	Other effects than scalign are also readily available, for exmaple, you can	147	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:	148	because each time the terminal is resized, it loads the PNG image again
		149	and scales it. Scaling is usually fast (and unavoidable), but loading the
		150	image can be quite time consuming. This is where C<keep> comes in handy:
119		151
		152	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		153
		154	The C<keep> operator executes all the statements inside the braces only
		155	once, or when it thinks the outcome might change. In other cases it
		156	returns the last value computed by the brace block.
		157
		158	This means that the C<load> is only executed once, which makes it much
		159	faster, but also means that more memory is being used, because the loaded
		160	image must be kept in memory at all times. In this expression, the
		161	trade-off is likely worth it.
		162
		163	But back to effects: Other effects than scaling are also readily
		164	available, for example, you can tile the image to fill the whole window,
		165	instead of resizing it:
		166
120	tile load "$HOME/mypic.png"	167	tile keep { load "$HOME/mypic.png" }
121		168
122	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	169	In fact, images returned by C<load> are in C<tile> mode by default, so the
123	is kind of superfluous.	170	C<tile> operator is kind of superfluous.
124		171
125	Another common effect is to mirror the image, so that the same edges touch:	172	Another common effect is to mirror the image, so that the same edges
		173	touch:
126		174
127	mirror load "$HOME/mypic.png"	175	mirror keep { load "$HOME/mypic.png" }
128		176
129	This is also a typical background expression:	177	Another common background expression is:
130		178
131	rootalign root	179	rootalign root
132		180
133	It first takes a snapshot of the screen background image, and then	181	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	182	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	183	left corner of the terminal window)- the result is pseudo-transparency:
136	moved around.	184	the image seems to be static while the window is moved around.
137		185
138	=head3 CYCLES AND CACHING	186	=head2 COLOUR SPECIFICATIONS
139		187
140	As has been mentioned before, the expression might be evaluated multiple	188	Whenever an operator expects a "colour", then this can be specified in one
141	times. Each time the expression is reevaluated, a new cycle is said to	189	of two ways: Either as string with an X11 colour specification, such as:
142	have begun. Many operators cache their results till the next cycle.
143		190
144	For example, the C<load> operator keeps a copy of the image. If it is	191	"red" # named colour
145	asked to load the same image on the next cycle it will not load it again,	192	"#f00" # simple rgb
146	but return the cached copy.	193	"[50]red" # red with 50% alpha
		194	"TekHVC:300/50/50" # anything goes
147		195
148	This only works for one cycle though, so as long as you load the same	196	OR as an array reference with one, three or four components:
149	image every time, it will always be cached, but when you load a different
150	image, it will forget about the first one.
151		197
152	This allows you to either speed things up by keeping multiple images in	198	[0.5] # 50% gray, 100% alpha
153	memory, or comserve memory by loading images more often.	199	[0.5, 0, 0] # dark red, no green or blur, 100% alpha
		200	[0.5, 0, 0, 0.7] # same with explicit 70% alpha
154		201
155	For example, you can keep two images in memory and use a random one like	202	=head2 CACHING AND SENSITIVITY
156	this:
157		203
158	my $img1 = load "img1.png";	204	Since some operations (such as C<load> and C<blur>) can take a long time,
159	my $img2 = load "img2.png";	205	caching results can be very important for a smooth operation. Caching can
160	(0.5 > rand) ? $img1 : $img2	206	also be useful to reduce memory usage, though, for example, when an image
		207	is cached by C<load>, it could be shared by multiple terminal windows
		208	running inside urxvtd.
161		209
162	Since both images are "loaded" every time the expression is evaluated,	210	=head3 C<keep { ... }> caching
163	they are always kept in memory. Contrast this version:
164		211
165	my $path1 = "img1.png";	212	The most important way to cache expensive operations is to use C<keep {
166	my $path2 = "img2.png";	213	... }>. The C<keep> operator takes a block of multiple statements enclosed
167	load ((0.5 > rand) ? $path1 : $path2)	214	by C<{}> and keeps the return value in memory.
168		215
169	Here, a path is selected randomly, and load is only called for one image,	216	An expression can be "sensitive" to various external events, such as
170	so keeps only one image in memory. If, on the next evaluation, luck	217	scaling or moving the window, root background changes and timers. Simply
171	decides to use the other path, then it will have to load that image again.	218	using an expression (such as C<scale> without parameters) that depends on
		219	certain changing values (called "variables"), or using those variables
		220	directly, will make an expression sensitive to these events - for example,
		221	using C<scale> or C<TW> will make the expression sensitive to the terminal
		222	size, and thus to resizing events.
172		223
		224	When such an event happens, C<keep> will automatically trigger a
		225	reevaluation of the whole expression with the new value of the expression.
		226
		227	C<keep> is most useful for expensive operations, such as C<blur>:
		228
		229	rootalign keep { blur 20, root }
		230
		231	This makes a blurred copy of the root background once, and on subsequent
		232	calls, just root-aligns it. Since C<blur> is usually quite slow and
		233	C<rootalign> is quite fast, this trades extra memory (for the cached
		234	blurred pixmap) with speed (blur only needs to be redone when root
		235	changes).
		236
		237	=head3 C<load> caching
		238
		239	The C<load> operator itself does not keep images in memory, but as long as
		240	the image is still in memory, C<load> will use the in-memory image instead
		241	of loading it freshly from disk.
		242
		243	That means that this expression:
		244
		245	keep { load "$HOME/path..." }
		246
		247	Not only caches the image in memory, other terminal instances that try to
		248	C<load> it can reuse that in-memory copy.
		249
173	=head2 REFERENCE	250	=head1 REFERENCE
174		251
175	=head3 COMMAND LINE SWITCHES	252	=head2 COMMAND LINE SWITCHES
176		253
177	=over 4	254	=over 4
178		255
179	=item --background-expr perl-expression	256	=item --background-expr perl-expression
180		257
…		…
186	overwriting borders and any other areas, such as the scrollbar.	263	overwriting borders and any other areas, such as the scrollbar.
187		264
188	Specifying this flag changes the behaviour, so that the image only	265	Specifying this flag changes the behaviour, so that the image only
189	replaces the background of the character area.	266	replaces the background of the character area.
190		267
		268	=item --background-interval seconds
		269
		270	Since some operations in the underlying XRender extension can effectively
		271	freeze your X-server for prolonged time, this extension enforces a minimum
		272	time between updates, which is normally about 0.1 seconds.
		273
		274	If you want to do updates more often, you can decrease this safety
		275	interval with this switch.
		276
191	=back	277	=back
192		278
193	=cut	279	=cut
194		280
		281	our %_IMG_CACHE;
195	our $HOME;	282	our $HOME;
196	our ($self, $old, $new);	283	our ($self, $frame);
197	our ($x, $y, $w, $h);	284	our ($x, $y, $w, $h, $focus);
198		285
199	# enforce at least this interval between updates	286	# enforce at least this interval between updates
200	our $MIN_INTERVAL = 1/100;	287	our $MIN_INTERVAL = 6/59.951;
201		288
202	{	289	{
203	package urxvt::bgdsl; # background language	290	package urxvt::bgdsl; # background language
		291
		292	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		293	sub FR_CACHE () { 1 } # cached values
		294	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		295	sub FR_STATE () { 3 } # watchers etc.
		296
		297	use List::Util qw(min max sum shuffle);
204		298
205	=head2 PROVIDERS/GENERATORS	299	=head2 PROVIDERS/GENERATORS
206		300
207	These functions provide an image, by loading it from disk, grabbing it	301	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	302	from the root screen or by simply generating it. They are used as starting
…		…
213	=item load $path	307	=item load $path
214		308
215	Loads the image at the given C<$path>. The image is set to plane tiling	309	Loads the image at the given C<$path>. The image is set to plane tiling
216	mode.	310	mode.
217		311
218	Loaded images will be cached for one cycle.	312	If the image is already in memory (e.g. because another terminal instance
		313	uses it), then the in-memory copy is returned instead.
219		314
		315	=item load_uc $path
		316
		317	Load uncached - same as load, but does not cache the image, which means it
		318	is I<always> loaded from the filesystem again, even if another copy of it
		319	is in memory at the time.
		320
220	=cut	321	=cut
		322
		323	sub load_uc($) {
		324	$self->new_img_from_file ($_[0])
		325	}
221		326
222	sub load($) {	327	sub load($) {
223	my ($path) = @_;	328	my ($path) = @_;
224		329
225	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	330	$_IMG_CACHE{$path} \|\| do {
		331	my $img = load_uc $path;
		332	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		333	$img
		334	}
226	}	335	}
227		336
228	=item root	337	=item root
229		338
230	Returns the root window pixmap, that is, hopefully, the background image	339	Returns the root window pixmap, that is, hopefully, the background image
231	of your screen. The image is set to extend mode.	340	of your screen.
232		341
233	This function makes your expression root sensitive, that means it will be	342	This function makes your expression root sensitive, that means it will be
234	reevaluated when the bg image changes.	343	reevaluated when the bg image changes.
235		344
236	=cut	345	=cut
237		346
238	sub root() {	347	sub root() {
239	$new->{rootpmap_sensitive} = 1;	348	$frame->[FR_AGAIN]{rootpmap} = 1;
240	die "root op not supported, exg, we need you";	349	$self->new_img_from_root
241	}	350	}
242		351
243	=item solid $colour	352	=item solid $colour
244		353
245	=item solid $width, $height, $colour	354	=item solid $width, $height, $colour
246		355
247	Creates a new image and completely fills it with the given colour. The	356	Creates a new image and completely fills it with the given colour. The
248	image is set to tiling mode.	357	image is set to tiling mode.
249		358
250	If <$width> and C<$height> are omitted, it creates a 1x1 image, which is	359	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
251	useful for solid backgrounds or for use in filtering effects.	360	useful for solid backgrounds or for use in filtering effects.
252		361
253	=cut	362	=cut
254		363
255	sub solid($$;$) {	364	sub solid($;$$) {
256	my $colour = pop;	365	my $colour = pop;
257		366
258	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	367	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
259	$img->fill ($colour);	368	$img->fill ($colour);
260	$img	369	$img
261	}	370	}
262		371
263	=back	372	=item clone $img
264		373
265	=head2 VARIABLES	374	Returns an exact copy of the image. This is useful if you want to have
		375	multiple copies of the same image to apply different effects to.
266		376
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	377	=cut
308		378
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} = $_[0];
342	}
343
344	sub counter($) {	379	sub clone($) {
345	$new->{again} = $_[0];	380	$_[0]->clone
346	$self->{counter} + 0	381	}
		382
		383	=item merge $img ...
		384
		385	Takes any number of images and merges them together, creating a single
		386	image containing them all. The tiling mode of the first image is used as
		387	the tiling mode of the resulting image.
		388
		389	This function is called automatically when an expression returns multiple
		390	images.
		391
		392	=cut
		393
		394	sub merge(@) {
		395	return $_[0] unless $#_;
		396
		397	# rather annoyingly clumsy, but optimisation is for another time
		398
		399	my $x0 = +1e9;
		400	my $y0 = +1e9;
		401	my $x1 = -1e9;
		402	my $y1 = -1e9;
		403
		404	for (@_) {
		405	my ($x, $y, $w, $h) = $_->geometry;
		406
		407	$x0 = $x if $x0 > $x;
		408	$y0 = $y if $y0 > $y;
		409
		410	$x += $w;
		411	$y += $h;
		412
		413	$x1 = $x if $x1 < $x;
		414	$y1 = $y if $y1 < $y;
		415	}
		416
		417	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		418	$base->repeat_mode ($_[0]->repeat_mode);
		419	$base->fill ([0, 0, 0, 0]);
		420
		421	$base->draw ($_)
		422	for @_;
		423
		424	$base
347	}	425	}
348		426
349	=back	427	=back
350		428
351	=head2 TILING MODES	429	=head2 TILING MODES
…		…
384	become transparent. This mode is most useful when you want to place an	462	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	463	image over another image or the background colour while leaving all
386	background pixels outside the image unchanged.	464	background pixels outside the image unchanged.
387		465
388	Example: load an image and display it in the upper left corner. The rest	466	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	467	of the space is left "empty" (transparent or whatever your compositor does
390	in alpha mode, else background colour).	468	in alpha mode, else background colour).
391		469
392	pad load "mybg.png"	470	pad load "mybg.png"
393		471
394	=item extend $img	472	=item extend $img
395		473
396	Extends the image over the whole plane, using the closest pixel in the	474	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	475	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	476	filtering operations and want the pixels outside the image to have the
399	same values as the pixels near the edge.	477	same values as the pixels near the edge.
400		478
401	Example: just for curiosity, how does this pixel extension stuff work?	479	Example: just for curiosity, how does this pixel extension stuff work?
402		480
…		…
428	$img	506	$img
429	}	507	}
430		508
431	=back	509	=back
432		510
433	=head2 PIXEL OPERATORS	511	=head2 VARIABLE VALUES
434		512
435	The following operators modify the image pixels in various ways.	513	The following functions provide variable data such as the terminal window
		514	dimensions. They are not (Perl-) variables, they just return stuff that
		515	varies. Most of them make your expression sensitive to some events, for
		516	example using C<TW> (terminal width) means your expression is evaluated
		517	again when the terminal is resized.
436		518
437	=over 4	519	=over 4
438		520
439	=item clone $img	521	=item TX
440		522
441	Returns an exact copy of the image.	523	=item TY
442		524
443	=cut	525	Return the X and Y coordinates of the terminal window (the terminal
		526	window is the full window by default, and the character area only when in
		527	border-respect mode).
444		528
		529	Using these functions makes your expression sensitive to window moves.
		530
		531	These functions are mainly useful to align images to the root window.
		532
		533	Example: load an image and align it so it looks as if anchored to the
		534	background (that's exactly what C<rootalign> does btw.):
		535
		536	move -TX, -TY, keep { load "mybg.png" }
		537
		538	=item TW
		539
		540	=item TH
		541
		542	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		543	terminal window is the full window by default, and the character area only
		544	when in border-respect mode).
		545
		546	Using these functions makes your expression sensitive to window resizes.
		547
		548	These functions are mainly useful to scale images, or to clip images to
		549	the window size to conserve memory.
		550
		551	Example: take the screen background, clip it to the window size, blur it a
		552	bit, align it to the window position and use it as background.
		553
		554	clip move -TX, -TY, keep { blur 5, root }
		555
		556	=item FOCUS
		557
		558	Returns a boolean indicating whether the terminal window has keyboard
		559	focus, in which case it returns true.
		560
		561	Using this function makes your expression sensitive to focus changes.
		562
		563	A common use case is to fade the background image when the terminal loses
		564	focus, often together with the C<-fade> command line option. In fact,
		565	there is a special function for just that use case: C<focus_fade>.
		566
		567	Example: use two entirely different background images, depending on
		568	whether the window has focus.
		569
		570	FOCUS ? keep { load "has_focus.jpg" } : keep { load "no_focus.jpg" }
		571
		572	=cut
		573
		574	sub TX () { $frame->[FR_AGAIN]{position} = 1; $x }
		575	sub TY () { $frame->[FR_AGAIN]{position} = 1; $y }
		576	sub TW () { $frame->[FR_AGAIN]{size} = 1; $w }
		577	sub TH () { $frame->[FR_AGAIN]{size} = 1; $h }
		578	sub FOCUS() { $frame->[FR_AGAIN]{focus} = 1; $focus }
		579
		580	=item now
		581
		582	Returns the current time as (fractional) seconds since the epoch.
		583
		584	Using this expression does I<not> make your expression sensitive to time,
		585	but the next two functions do.
		586
		587	=item again $seconds
		588
		589	When this function is used the expression will be reevaluated again in
		590	C<$seconds> seconds.
		591
		592	Example: load some image and rotate it according to the time of day (as if it were
		593	the hour pointer of a clock). Update this image every minute.
		594
		595	again 60;
		596	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
		597
		598	=item counter $seconds
		599
		600	Like C<again>, but also returns an increasing counter value, starting at
		601	0, which might be useful for some simple animation effects.
		602
		603	=cut
		604
		605	sub now() { urxvt::NOW }
		606
		607	sub again($) {
		608	$frame->[FR_AGAIN]{time} = $_[0];
		609	}
		610
445	sub clone($) {	611	sub counter($) {
446	$_[0]->clone	612	$frame->[FR_AGAIN]{time} = $_[0];
		613	$frame->[FR_STATE]{counter} + 0
447	}	614	}
		615
		616	=back
		617
		618	=head2 SHAPE CHANGING OPERATORS
		619
		620	The following operators modify the shape, size or position of the image.
		621
		622	=over 4
448		623
449	=item clip $img	624	=item clip $img
450		625
451	=item clip $width, $height, $img	626	=item clip $width, $height, $img
452		627
…		…
455	Clips an image to the given rectangle. If the rectangle is outside the	630	Clips an image to the given rectangle. If the rectangle is outside the
456	image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is	631	image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is
457	larger than the image, then the tiling mode defines how the extra pixels	632	larger than the image, then the tiling mode defines how the extra pixels
458	will be filled.	633	will be filled.
459		634
460	If C<$x> an C<$y> are missing, then C<0> is assumed for both.	635	If C<$x> and C<$y> are missing, then C<0> is assumed for both.
461		636
462	If C<$width> and C<$height> are missing, then the window size will be	637	If C<$width> and C<$height> are missing, then the window size will be
463	assumed.	638	assumed.
464		639
465	Example: load an image, blur it, and clip it to the window size to save	640	Example: load an image, blur it, and clip it to the window size to save
466	memory.	641	memory.
467		642
468	clip blur 10, load "mybg.png"	643	clip keep { blur 10, load "mybg.png" }
469		644
470	=cut	645	=cut
471		646
472	sub clip($;$$;$$) {	647	sub clip($;$$;$$) {
473	my $img = pop;	648	my $img = pop;
…		…
476	$img->sub_rect ($_[0], $_[1], $w, $h)	651	$img->sub_rect ($_[0], $_[1], $w, $h)
477	}	652	}
478		653
479	=item scale $img	654	=item scale $img
480		655
481	=item scale $size_percent, $img	656	=item scale $size_factor, $img
482		657
483	=item scale $width_percent, $height_percent, $img	658	=item scale $width_factor, $height_factor, $img
484		659
485	Scales the image by the given percentages in horizontal	660	Scales the image by the given factors in horizontal
486	(C<$width_percent>) and vertical (C<$height_percent>) direction.	661	(C<$width>) and vertical (C<$height>) direction.
487		662
488	If only one percentage is give, it is used for both directions.	663	If only one factor is given, it is used for both directions.
489		664
490	If no percentages are given, scales the image to the window size without	665	If no factors are given, scales the image to the window size without
491	keeping aspect.	666	keeping aspect.
492		667
493	=item resize $width, $height, $img	668	=item resize $width, $height, $img
494		669
495	Resizes the image to exactly C<$width> times C<$height> pixels.	670	Resizes the image to exactly C<$width> times C<$height> pixels.
496		671
497	=cut	672	=item fit $img
498		673
499	#TODO: maximise, maximise_fill?	674	=item fit $width, $height, $img
		675
		676	Fits the image into the given C<$width> and C<$height> without changing
		677	aspect, or the terminal size. That means it will be shrunk or grown until
		678	the whole image fits into the given area, possibly leaving borders.
		679
		680	=item cover $img
		681
		682	=item cover $width, $height, $img
		683
		684	Similar to C<fit>, but shrinks or grows until all of the area is covered
		685	by the image, so instead of potentially leaving borders, it will cut off
		686	image data that doesn't fit.
		687
		688	=cut
500		689
501	sub scale($;$;$) {	690	sub scale($;$;$) {
502	my $img = pop;	691	my $img = pop;
503		692
504	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	693	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
505	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	694	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
506	: $img->scale (TW, TH)	695	: $img->scale (TW, TH)
507	}	696	}
508		697
509	sub resize($$$) {	698	sub resize($$$) {
510	my $img = pop;	699	my $img = pop;
511	$img->scale ($_[0], $_[1])	700	$img->scale ($_[0], $_[1])
512	}	701	}
513		702
		703	sub fit($;$$) {
		704	my $img = pop;
		705	my $w = ($_[0] \|\| TW) / $img->w;
		706	my $h = ($_[1] \|\| TH) / $img->h;
		707	scale +(min $w, $h), $img
		708	}
		709
		710	sub cover($;$$) {
		711	my $img = pop;
		712	my $w = ($_[0] \|\| TW) / $img->w;
		713	my $h = ($_[1] \|\| TH) / $img->h;
		714	scale +(max $w, $h), $img
		715	}
		716
514	=item move $dx, $dy, $img	717	=item move $dx, $dy, $img
515		718
516	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	719	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
517	the vertical.	720	the vertical.
518		721
519	Example: move the image right by 20 pixels and down by 30.	722	Example: move the image right by 20 pixels and down by 30.
520		723
521	move 20, 30, ...	724	move 20, 30, ...
		725
		726	=item align $xalign, $yalign, $img
		727
		728	Aligns the image according to a factor - C<0> means the image is moved to
		729	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		730	exactly centered and C<1> means it touches the right or bottom edge.
		731
		732	Example: remove any visible border around an image, center it vertically but move
		733	it to the right hand side.
		734
		735	align 1, 0.5, pad $img
		736
		737	=item center $img
		738
		739	=item center $width, $height, $img
		740
		741	Centers the image, i.e. the center of the image is moved to the center of
		742	the terminal window (or the box specified by C<$width> and C<$height> if
		743	given).
		744
		745	Example: load an image and center it.
		746
		747	center keep { pad load "mybg.png" }
522		748
523	=item rootalign $img	749	=item rootalign $img
524		750
525	Moves the image so that it appears glued to the screen as opposed to the	751	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	752	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	753	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
528	top left of the screen.	754	top left of the screen.
529		755
530	Example: load a background image, put it in mirror mode and root align it.	756	Example: load a background image, put it in mirror mode and root align it.
531		757
532	rootalign mirror load "mybg.png"	758	rootalign keep { mirror load "mybg.png" }
533		759
534	Example: take the screen background and align it, giving the illusion of	760	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.	761	transparency as long as the window isn't in front of other windows.
536		762
537	rootalign root	763	rootalign root
538		764
539	=cut	765	=cut
540		766
541	sub move($$;$) {	767	sub move($$;$) {
542	my $img = pop->clone;	768	my $img = pop->clone;
543	$img->move ($_[0], $_[1]);	769	$img->move ($_[0], $_[1]);
544	$img	770	$img
545	}	771	}
546		772
		773	sub align($;$$) {
		774	my $img = pop;
		775
		776	move $_[0] * (TW - $img->w),
		777	$_[1] * (TH - $img->h),
		778	$img
		779	}
		780
		781	sub center($;$$) {
		782	my $img = pop;
		783	my $w = $_[0] \|\| TW;
		784	my $h = $_[1] \|\| TH;
		785
		786	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		787	}
		788
547	sub rootalign($) {	789	sub rootalign($) {
548	move -TX, -TY, $_[0]	790	move -TX, -TY, $_[0]
549	}	791	}
550		792
		793	=item rotate $center_x, $center_y, $degrees, $img
		794
		795	Rotates the image clockwise by C<$degrees> degrees, around the point at
		796	C<$center_x> and C<$center_y> (specified as factor of image width/height).
		797
		798	Example: rotate the image by 90 degrees around its center.
		799
		800	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
		801
		802	=cut
		803
		804	sub rotate($$$$) {
		805	my $img = pop;
		806	$img->rotate (
		807	$_[0] * ($img->w + $img->x),
		808	$_[1] * ($img->h + $img->y),
		809	$_[2] * (3.14159265 / 180),
		810	)
		811	}
		812
		813	=back
		814
		815	=head2 COLOUR MODIFICATIONS
		816
		817	The following operators change the pixels of the image.
		818
		819	=over 4
		820
		821	=item tint $color, $img
		822
		823	Tints the image in the given colour.
		824
		825	Example: tint the image red.
		826
		827	tint "red", load "rgb.png"
		828
		829	Example: the same, but specify the colour by component.
		830
		831	tint [1, 0, 0], load "rgb.png"
		832
		833	=cut
		834
		835	sub tint($$) {
		836	$_[1]->tint ($_[0])
		837	}
		838
		839	=item shade $factor, $img
		840
		841	Shade the image by the given factor.
		842
		843	=cut
		844
		845	sub shade($$) {
		846	$_[1]->shade ($_[0])
		847	}
		848
551	=item contrast $factor, $img	849	=item contrast $factor, $img
552		850
553	=item contrast $r, $g, $b, $img	851	=item contrast $r, $g, $b, $img
554		852
555	=item contrast $r, $g, $b, $a, $img	853	=item contrast $r, $g, $b, $a, $img
556		854
557	Adjusts the I<contrast> of an image.	855	Adjusts the I<contrast> of an image.
558		856
559	#TODO#	857	The first form applies a single C<$factor> to red, green and blue, the
		858	second form applies separate factors to each colour channel, and the last
		859	form includes the alpha channel.
560		860
		861	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		862	contrast.
		863
		864	Due to limitations in the underlying XRender extension, lowering contrast
		865	also reduces brightness, while increasing contrast currently also
		866	increases brightness.
		867
561	=item brightness $factor, $img	868	=item brightness $bias, $img
562		869
563	=item brightness $r, $g, $b, $img	870	=item brightness $r, $g, $b, $img
564		871
565	=item brightness $r, $g, $b, $a, $img	872	=item brightness $r, $g, $b, $a, $img
566		873
567	Adjusts the brightness of an image.	874	Adjusts the brightness of an image.
		875
		876	The first form applies a single C<$bias> to red, green and blue, the
		877	second form applies separate biases to each colour channel, and the last
		878	form includes the alpha channel.
		879
		880	Values less than 0 reduce brightness, while values larger than 0 increase
		881	it. Useful range is from -1 to 1 - the former results in a black, the
		882	latter in a white picture.
		883
		884	Due to idiosyncrasies in the underlying XRender extension, biases less
		885	than zero can be I<very> slow.
		886
		887	You can also try the experimental(!) C<muladd> operator.
568		888
569	=cut	889	=cut
570		890
571	sub contrast($$;$$;$) {	891	sub contrast($$;$$;$) {
572	my $img = pop;	892	my $img = pop;
573	my ($r, $g, $b, $a) = @_;	893	my ($r, $g, $b, $a) = @_;
574		894
575	($g, $b) = ($r, $r) if @_ < 4;	895	($g, $b) = ($r, $r) if @_ < 3;
576	$a = 1 if @_ < 5;	896	$a = 1 if @_ < 4;
577		897
578	$img = $img->clone;	898	$img = $img->clone;
579	$img->contrast ($r, $g, $b, $a);	899	$img->contrast ($r, $g, $b, $a);
580	$img	900	$img
581	}	901	}
582		902
583	sub brightness($$;$$;$) {	903	sub brightness($$;$$;$) {
584	my $img = pop;	904	my $img = pop;
585	my ($r, $g, $b, $a) = @_;	905	my ($r, $g, $b, $a) = @_;
586		906
587	($g, $b) = ($r, $r) if @_ < 4;	907	($g, $b) = ($r, $r) if @_ < 3;
588	$a = 1 if @_ < 5;	908	$a = 1 if @_ < 4;
589		909
590	$img = $img->clone;	910	$img = $img->clone;
591	$img->brightness ($r, $g, $b, $a);	911	$img->brightness ($r, $g, $b, $a);
592	$img	912	$img
		913	}
		914
		915	=item muladd $mul, $add, $img # EXPERIMENTAL
		916
		917	First multiplies the pixels by C<$mul>, then adds C<$add>. This can be used
		918	to implement brightness and contrast at the same time, with a wider value
		919	range than contrast and brightness operators.
		920
		921	Due to numerous bugs in XRender implementations, it can also introduce a
		922	number of visual artifacts.
		923
		924	Example: increase contrast by a factor of C<$c> without changing image
		925	brightness too much.
		926
		927	muladd $c, (1 - $c) * 0.5, $img
		928
		929	=cut
		930
		931	sub muladd($$$) {
		932	$_[2]->muladd ($_[0], $_[1])
593	}	933	}
594		934
595	=item blur $radius, $img	935	=item blur $radius, $img
596		936
597	=item blur $radius_horz, $radius_vert, $img	937	=item blur $radius_horz, $radius_vert, $img
…		…
609	sub blur($$;$) {	949	sub blur($$;$) {
610	my $img = pop;	950	my $img = pop;
611	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	951	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
612	}	952	}
613		953
614	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees	954	=item focus_fade $img
615		955
616	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	956	=item focus_fade $factor, $img
617	pointer at C<$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		957
621	#TODO# new width, height, maybe more operators?	958	=item focus_fade $factor, $color, $img
622		959
623	Example: rotate the image by 90 degrees	960	Fades the image by the given factor (and colour) when focus is lost (the
		961	same as the C<-fade>/C<-fadecolor> command line options, which also supply
		962	the default values for C<factor> and C<$color>. Unlike with C<-fade>, the
		963	C<$factor> is a real value, not a percentage value (that is, 0..1, not
		964	0..100).
624		965
625	=cut	966	Example: do the right thing when focus fading is requested.
626		967
627	sub rotate($$$$$$) {	968	focus_fade load "mybg.jpg";
		969
		970	=cut
		971
		972	sub focus_fade($;$$) {
628	my $img = pop;	973	my $img = pop;
629	$img->rotate (	974
630	$_[0],	975	return $img
631	$_[1],	976	if FOCUS;
632	$_[2] * $img->w * .01,	977
633	$_[3] * $img->h * .01,	978	my $fade = @_ >= 1 ? $_[0] : defined $self->resource ("fade") ? $self->resource ("fade") * 0.01 : 0;
634	$_[4] * (3.14159265 / 180),	979	my $color = @_ >= 2 ? $_[1] : $self->resource ("color+" . urxvt::Color_fade);
635	)	980
		981	$img = $img->tint ($color) if $color ne "rgb:00/00/00";
		982	$img = $img->muladd (1 - $fade, 0) if $fade;
		983
		984	$img
636	}	985	}
637		986
638	=back	987	=back
639		988
		989	=head2 OTHER STUFF
		990
		991	Anything that didn't fit any of the other categories, even after applying
		992	force and closing our eyes.
		993
		994	=over 4
		995
		996	=item keep { ... }
		997
		998	This operator takes a code block as argument, that is, one or more
		999	statements enclosed by braces.
		1000
		1001	The trick is that this code block is only evaluated when the outcome
		1002	changes - on other calls the C<keep> simply returns the image it computed
		1003	previously (yes, it should only be used with images). Or in other words,
		1004	C<keep> I<caches> the result of the code block so it doesn't need to be
		1005	computed again.
		1006
		1007	This can be extremely useful to avoid redoing slow operations - for
		1008	example, if your background expression takes the root background, blurs it
		1009	and then root-aligns it it would have to blur the root background on every
		1010	window move or resize.
		1011
		1012	Another example is C<load>, which can be quite slow.
		1013
		1014	In fact, urxvt itself encloses the whole expression in some kind of
		1015	C<keep> block so it only is reevaluated as required.
		1016
		1017	Putting the blur into a C<keep> block will make sure the blur is only done
		1018	once, while the C<rootalign> is still done each time the window moves.
		1019
		1020	rootalign keep { blur 10, root }
		1021
		1022	This leaves the question of how to force reevaluation of the block,
		1023	in case the root background changes: If expression inside the block
		1024	is sensitive to some event (root background changes, window geometry
		1025	changes), then it will be reevaluated automatically as needed.
		1026
		1027	=cut
		1028
		1029	sub keep(&) {
		1030	my $id = $_[0]+0;
		1031
		1032	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		1033
		1034	unless ($frame->[FR_CACHE]) {
		1035	$frame->[FR_CACHE] = [ $_[0]() ];
		1036
		1037	my $self = $self;
		1038	my $frame = $frame;
		1039	Scalar::Util::weaken $frame;
		1040	$self->compile_frame ($frame, sub {
		1041	# clear this frame cache, also for all parents
		1042	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		1043	undef $frame->[FR_CACHE];
		1044	}
		1045
		1046	$self->recalculate;
		1047	});
		1048	};
		1049
		1050	# in scalar context we always return the first original result, which
		1051	# is not quite how perl works.
		1052	wantarray
		1053	? @{ $frame->[FR_CACHE] }
		1054	: $frame->[FR_CACHE][0]
		1055	}
		1056
		1057	# sub keep_clear() {
		1058	# delete $self->{frame_cache};
		1059	# }
		1060
		1061	=back
		1062
640	=cut	1063	=cut
641		1064
642	}	1065	}
643		1066
644	sub parse_expr {	1067	sub parse_expr {
645	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	1068	my $expr = eval
		1069	"sub {\n"
		1070	. "package urxvt::bgdsl;\n"
		1071	. "#line 0 'background expression'\n"
		1072	. "$_[0]\n"
		1073	. "}";
646	die if $@;	1074	die if $@;
647	$expr	1075	$expr
648	}	1076	}
649		1077
650	# compiles a parsed expression	1078	# compiles a parsed expression
651	sub set_expr {	1079	sub set_expr {
652	my ($self, $expr) = @_;	1080	my ($self, $expr) = @_;
653		1081
		1082	$self->{root} = []; # the outermost frame
654	$self->{expr} = $expr;	1083	$self->{expr} = $expr;
655	$self->recalculate;	1084	$self->recalculate;
		1085	}
		1086
		1087	# takes a hash of sensitivity indicators and installs watchers
		1088	sub compile_frame {
		1089	my ($self, $frame, $cb) = @_;
		1090
		1091	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		1092	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		1093
		1094	# don't keep stuff alive
		1095	Scalar::Util::weaken $state;
		1096
		1097	if ($again->{nested}) {
		1098	$state->{nested} = 1;
		1099	} else {
		1100	delete $state->{nested};
		1101	}
		1102
		1103	if (my $interval = $again->{time}) {
		1104	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		1105	if $state->{time}[0] != $interval;
		1106
		1107	# callback might have changed, although we could just rule that out
		1108	$state->{time}[1]->cb (sub {
		1109	++$state->{counter};
		1110	$cb->();
		1111	});
		1112	} else {
		1113	delete $state->{time};
		1114	}
		1115
		1116	if ($again->{position}) {
		1117	$state->{position} = $self->on (position_change => $cb);
		1118	} else {
		1119	delete $state->{position};
		1120	}
		1121
		1122	if ($again->{size}) {
		1123	$state->{size} = $self->on (size_change => $cb);
		1124	} else {
		1125	delete $state->{size};
		1126	}
		1127
		1128	if ($again->{rootpmap}) {
		1129	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		1130	} else {
		1131	delete $state->{rootpmap};
		1132	}
		1133
		1134	if ($again->{focus}) {
		1135	$state->{focus} = $self->on (focus_in => $cb, focus_out => $cb);
		1136	} else {
		1137	delete $state->{focus};
		1138	}
656	}	1139	}
657		1140
658	# evaluate the current bg expression	1141	# evaluate the current bg expression
659	sub recalculate {	1142	sub recalculate {
660	my ($arg_self) = @_;	1143	my ($arg_self) = @_;
…		…
670		1153
671	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1154	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
672		1155
673	# set environment to evaluate user expression	1156	# set environment to evaluate user expression
674		1157
675	local $self = $arg_self;	1158	local $self = $arg_self;
676
677	local $HOME = $ENV{HOME};	1159	local $HOME = $ENV{HOME};
678	local $old = $self->{state};	1160	local $frame = $self->{root};
679	local $new = my $state = $self->{state} = {};
680		1161
681	($x, $y, $w, $h) =
682	$self->background_geometry ($self->{border});	1162	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
		1163	$focus = $self->focus;
683		1164
684	# evaluate user expression	1165	# evaluate user expression
685		1166
686	my $img = eval { $self->{expr}->() };	1167	my @img = eval { $self->{expr}->() };
687	warn $@ if $@;#d#	1168	die $@ if $@;
		1169	die "background-expr did not return anything.\n" unless @img;
		1170	die "background-expr: expected image(s), got something else.\n"
688	die if !UNIVERSAL::isa $img, "urxvt::img";	1171	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
689		1172
690	$state->{size_sensitive} = 1	1173	my $img = urxvt::bgdsl::merge @img;
		1174
		1175	$frame->[FR_AGAIN]{size} = 1
691	if $img->repeat_mode != urxvt::RepeatNormal;	1176	if $img->repeat_mode != urxvt::RepeatNormal;
692		1177
693	# if the expression is sensitive to external events, prepare reevaluation then	1178	# if the expression is sensitive to external events, prepare reevaluation then
694		1179	$self->compile_frame ($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	$self->disable ("rootpmap_change");
727	}
728		1180
729	# clear stuff we no longer need	1181	# clear stuff we no longer need
730		1182
731	%$old = ();	1183	# unless (%{ $frame->[FR_STATE] }) {
732
733	unless ($repeat) {
734	delete $self->{state};	1184	# delete $self->{state};
735	delete $self->{expr};	1185	# delete $self->{expr};
736	}	1186	# }
737		1187
738	# set background pixmap	1188	# set background pixmap
739		1189
740	$self->set_background ($img, $self->{border});	1190	$self->set_background ($img, $self->{border});
741	$self->scr_recolour (0);	1191	$self->scr_recolor (0);
742	$self->want_refresh;	1192	$self->want_refresh;
743	}	1193	}
744		1194
745	sub on_start {	1195	sub on_start {
746	my ($self) = @_;	1196	my ($self) = @_;
747		1197
748	my $expr = $self->x_resource ("background.expr")	1198	my $expr = $self->x_resource ("%.expr")
749	or return;	1199	or return;
750		1200
		1201	$self->has_render
		1202	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		1203
751	$self->set_expr (parse_expr $expr);	1204	$self->set_expr (parse_expr $expr);
752	$self->{border} = $self->x_resource_boolean ("background.border");	1205	$self->{border} = $self->x_resource_boolean ("%.border");
		1206
		1207	$MIN_INTERVAL = $self->x_resource ("%.interval");
753		1208
754	()	1209	()
755	}	1210	}
756		1211

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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 1.89 by root, Sat Dec 13 12:24:33 2014 UTC

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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 1.89 by root, Sat Dec 13 12:24:33 2014 UTC