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Revision 1.43 by root, Sun Jun 10 11:23:20 2012 UTC vs.
Revision 1.92 by sf-exg, Thu Jul 14 05:33:26 2016 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		5	#:META:RESOURCE:%.interval:seconds:minimum time between updates
6	#TODO: once, rootalign	6	#:META:RESOURCE:pixmap:file[;geom]:set image as background
		7	#:META:RESOURCE:backgroundPixmap:file[;geom]:set image as background
		8	#:META:RESOURCE:tr:boolean:set root pixmap as background
		9	#:META:RESOURCE:transparent:boolean:set root pixmap as background
		10	#:META:RESOURCE:tint:color:tint background with color
		11	#:META:RESOURCE:tintColor:color:tint background with color
		12	#:META:RESOURCE:sh:number:shade background by number %
		13	#:META:RESOURCE:shading:number:shade background by number %
		14	#:META:RESOURCE:blr:HxV:gaussian-blur background with radii
		15	#:META:RESOURCE:blurRadius:HxV:gaussian-blur background with radii
7		16
8	=head1 NAME	17	=head1 NAME
9		18
10	background - manage terminal background	19	background - manage terminal background
11		20
12	=head1 SYNOPSIS	21	=head1 SYNOPSIS
13		22
14	urxvt --background-expr 'background expression'	23	urxvt --background-expr 'background expression'
15	--background-border	24	--background-border
		25	--background-interval seconds
		26
		27	=head1 QUICK AND DIRTY CHEAT SHEET
		28
		29	Just load a random jpeg image and tile the background with it without
		30	scaling or anything else:
		31
		32	load "/path/to/img.jpg"
		33
		34	The same, but use mirroring/reflection instead of tiling:
		35
		36	mirror load "/path/to/img.jpg"
		37
		38	Load an image and scale it to exactly fill the terminal window:
		39
		40	scale keep { load "/path/to/img.jpg" }
		41
		42	Implement pseudo-transparency by using a suitably-aligned root pixmap
		43	as window background:
		44
		45	rootalign root
		46
		47	Likewise, but keep a blurred copy:
		48
		49	rootalign keep { blur 10, root }
16		50
17	=head1 DESCRIPTION	51	=head1 DESCRIPTION
18		52
19	This extension manages the terminal background by creating a picture that	53	This extension manages the terminal background by creating a picture that
20	is behind the text, replacing the normal background colour.	54	is behind the text, replacing the normal background colour.
…		…
26	to be as simple as possible.	60	to be as simple as possible.
27		61
28	For example, to load an image and scale it to the window size, you would	62	For example, to load an image and scale it to the window size, you would
29	use:	63	use:
30		64
31	urxvt --background-expr 'scale load "/path/to/mybg.png"'	65	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
32		66
33	Or specified as a X resource:	67	Or specified as a X resource:
34		68
35	URxvt.background-expr: scale load "/path/to/mybg.png"	69	URxvt.background.expr: scale keep { load "/path/to/mybg.png" }
36		70
37	=head1 THEORY OF OPERATION	71	=head1 THEORY OF OPERATION
38		72
39	At startup, just before the window is mapped for the first time, the	73	At startup, just before the window is mapped for the first time, the
40	expression is evaluated and must yield an image. The image is then	74	expression is evaluated and must yield an image. The image is then
…		…
53	If any of the parameters that the expression relies on changes (when the	87	If any of the parameters that the expression relies on changes (when the
54	window is moved or resized, its position or size changes; when the root	88	window is moved or resized, its position or size changes; when the root
55	pixmap is replaced by another one the root background changes; or when the	89	pixmap is replaced by another one the root background changes; or when the
56	timer elapses), then the expression will be evaluated again.	90	timer elapses), then the expression will be evaluated again.
57		91
58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	92	For example, an expression such as C<scale keep { load "$HOME/mybg.png"
59	image to the window size, so it relies on the window size and will	93	}> scales the image to the window size, so it relies on the window size
60	be reevaluated each time it is changed, but not when it moves for	94	and will be reevaluated each time it is changed, but not when it moves for
61	example. That ensures that the picture always fills the terminal, even	95	example. That ensures that the picture always fills the terminal, even
62	after it's size changes.	96	after its size changes.
63		97
64	=head2 EXPRESSIONS	98	=head2 EXPRESSIONS
65		99
66	Expressions are normal Perl expressions, in fact, they are Perl blocks -	100	Expressions are normal Perl expressions, in fact, they are Perl blocks -
67	which means you could use multiple lines and statements:	101	which means you could use multiple lines and statements:
68		102
		103	scale keep {
69	again 3600;	104	again 3600;
70	if (localtime now)[6]) {	105	if (localtime now)[6]) {
71	return scale load "$HOME/weekday.png";	106	return load "$HOME/weekday.png";
72	} else {	107	} else {
73	return scale load "$HOME/sunday.png";	108	return load "$HOME/sunday.png";
		109	}
74	}	110	}
75		111
76	This expression gets evaluated once per hour. It will set F<sunday.png> as	112	This inner expression is evaluated once per hour (and whenever the
		113	terminal window is resized). It sets F<sunday.png> as background on
77	background on Sundays, and F<weekday.png> on all other days.	114	Sundays, and F<weekday.png> on all other days.
78		115
79	Fortunately, we expect that most expressions will be much simpler, with	116	Fortunately, we expect that most expressions will be much simpler, with
80	little Perl knowledge needed.	117	little Perl knowledge needed.
81		118
82	Basically, you always start with a function that "generates" an image	119	Basically, you always start with a function that "generates" an image
…		…
105	get a percentage):	142	get a percentage):
106		143
107	scale 2, load "$HOME/mypic.png"	144	scale 2, load "$HOME/mypic.png"
108		145
109	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>	146	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
110	has now two arguments, the C<200> and the C<load> expression, while	147	has now two arguments, the C<2> and the C<load> expression, while
111	C<load> only has one argument. Arguments are separated from each other by	148	C<load> only has one argument. Arguments are separated from each other by
112	commas.	149	commas.
113		150
114	Scale also accepts two arguments, which are then separate factors for both	151	Scale also accepts two arguments, which are then separate factors for both
115	horizontal and vertical dimensions. For example, this halves the image	152	horizontal and vertical dimensions. For example, this halves the image
116	width and doubles the image height:	153	width and doubles the image height:
117		154
118	scale 0.5, 2, load "$HOME/mypic.png"	155	scale 0.5, 2, load "$HOME/mypic.png"
119		156
120	Other effects than scalign are also readily available, for exmaple, you can	157	IF you try out these expressions, you might suffer from some sluggishness,
121	tile the image to fill the whole window, instead of resizing it:	158	because each time the terminal is resized, it loads the PNG image again
		159	and scales it. Scaling is usually fast (and unavoidable), but loading the
		160	image can be quite time consuming. This is where C<keep> comes in handy:
122		161
		162	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		163
		164	The C<keep> operator executes all the statements inside the braces only
		165	once, or when it thinks the outcome might change. In other cases it
		166	returns the last value computed by the brace block.
		167
		168	This means that the C<load> is only executed once, which makes it much
		169	faster, but also means that more memory is being used, because the loaded
		170	image must be kept in memory at all times. In this expression, the
		171	trade-off is likely worth it.
		172
		173	But back to effects: Other effects than scaling are also readily
		174	available, for example, you can tile the image to fill the whole window,
		175	instead of resizing it:
		176
123	tile load "$HOME/mypic.png"	177	tile keep { load "$HOME/mypic.png" }
124		178
125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	179	In fact, images returned by C<load> are in C<tile> mode by default, so the
126	is kind of superfluous.	180	C<tile> operator is kind of superfluous.
127		181
128	Another common effect is to mirror the image, so that the same edges touch:	182	Another common effect is to mirror the image, so that the same edges
		183	touch:
129		184
130	mirror load "$HOME/mypic.png"	185	mirror keep { load "$HOME/mypic.png" }
131		186
132	This is also a typical background expression:	187	Another common background expression is:
133		188
134	rootalign root	189	rootalign root
135		190
136	It first takes a snapshot of the screen background image, and then	191	This one first takes a snapshot of the screen background image, and then
137	moves it to the upper left corner of the screen - the result is	192	moves it to the upper left corner of the screen (as opposed to the upper
138	pseudo-transparency, as the image seems to be static while the window is	193	left corner of the terminal window)- the result is pseudo-transparency:
139	moved around.	194	the image seems to be static while the window is moved around.
140		195
141	=head2 CYCLES AND CACHING	196	=head2 COLOUR SPECIFICATIONS
142		197
143	As has been mentioned before, the expression might be evaluated multiple	198	Whenever an operator expects a "colour", then this can be specified in one
144	times. Each time the expression is reevaluated, a new cycle is said to	199	of two ways: Either as string with an X11 colour specification, such as:
145	have begun. Many operators cache their results till the next cycle.
146		200
147	For example, the C<load> operator keeps a copy of the image. If it is	201	"red" # named colour
148	asked to load the same image on the next cycle it will not load it again,	202	"#f00" # simple rgb
149	but return the cached copy.	203	"[50]red" # red with 50% alpha
		204	"TekHVC:300/50/50" # anything goes
150		205
151	This only works for one cycle though, so as long as you load the same	206	OR as an array reference with one, three or four components:
152	image every time, it will always be cached, but when you load a different
153	image, it will forget about the first one.
154		207
155	This allows you to either speed things up by keeping multiple images in	208	[0.5] # 50% gray, 100% alpha
156	memory, or comserve memory by loading images more often.	209	[0.5, 0, 0] # dark red, no green or blur, 100% alpha
		210	[0.5, 0, 0, 0.7] # same with explicit 70% alpha
157		211
158	For example, you can keep two images in memory and use a random one like	212	=head2 CACHING AND SENSITIVITY
159	this:
160		213
161	my $img1 = load "img1.png";	214	Since some operations (such as C<load> and C<blur>) can take a long time,
162	my $img2 = load "img2.png";	215	caching results can be very important for a smooth operation. Caching can
163	(0.5 > rand) ? $img1 : $img2	216	also be useful to reduce memory usage, though, for example, when an image
		217	is cached by C<load>, it could be shared by multiple terminal windows
		218	running inside urxvtd.
164		219
165	Since both images are "loaded" every time the expression is evaluated,	220	=head3 C<keep { ... }> caching
166	they are always kept in memory. Contrast this version:
167		221
168	my $path1 = "img1.png";	222	The most important way to cache expensive operations is to use C<keep {
169	my $path2 = "img2.png";	223	... }>. The C<keep> operator takes a block of multiple statements enclosed
170	load ((0.5 > rand) ? $path1 : $path2)	224	by C<{}> and keeps the return value in memory.
171		225
172	Here, a path is selected randomly, and load is only called for one image,	226	An expression can be "sensitive" to various external events, such as
173	so keeps only one image in memory. If, on the next evaluation, luck	227	scaling or moving the window, root background changes and timers. Simply
174	decides to use the other path, then it will have to load that image again.	228	using an expression (such as C<scale> without parameters) that depends on
		229	certain changing values (called "variables"), or using those variables
		230	directly, will make an expression sensitive to these events - for example,
		231	using C<scale> or C<TW> will make the expression sensitive to the terminal
		232	size, and thus to resizing events.
		233
		234	When such an event happens, C<keep> will automatically trigger a
		235	reevaluation of the whole expression with the new value of the expression.
		236
		237	C<keep> is most useful for expensive operations, such as C<blur>:
		238
		239	rootalign keep { blur 20, root }
		240
		241	This makes a blurred copy of the root background once, and on subsequent
		242	calls, just root-aligns it. Since C<blur> is usually quite slow and
		243	C<rootalign> is quite fast, this trades extra memory (for the cached
		244	blurred pixmap) with speed (blur only needs to be redone when root
		245	changes).
		246
		247	=head3 C<load> caching
		248
		249	The C<load> operator itself does not keep images in memory, but as long as
		250	the image is still in memory, C<load> will use the in-memory image instead
		251	of loading it freshly from disk.
		252
		253	That means that this expression:
		254
		255	keep { load "$HOME/path..." }
		256
		257	Not only caches the image in memory, other terminal instances that try to
		258	C<load> it can reuse that in-memory copy.
175		259
176	=head1 REFERENCE	260	=head1 REFERENCE
177		261
178	=head2 COMMAND LINE SWITCHES	262	=head2 COMMAND LINE SWITCHES
179		263
…		…
189	overwriting borders and any other areas, such as the scrollbar.	273	overwriting borders and any other areas, such as the scrollbar.
190		274
191	Specifying this flag changes the behaviour, so that the image only	275	Specifying this flag changes the behaviour, so that the image only
192	replaces the background of the character area.	276	replaces the background of the character area.
193		277
		278	=item --background-interval seconds
		279
		280	Since some operations in the underlying XRender extension can effectively
		281	freeze your X-server for prolonged time, this extension enforces a minimum
		282	time between updates, which is normally about 0.1 seconds.
		283
		284	If you want to do updates more often, you can decrease this safety
		285	interval with this switch.
		286
194	=back	287	=back
195		288
196	=cut	289	=cut
197		290
		291	our %_IMG_CACHE;
198	our $HOME;	292	our $HOME;
199	our ($self, $old, $new);	293	our ($self, $frame);
200	our ($x, $y, $w, $h);	294	our ($x, $y, $w, $h, $focus);
201		295
202	# enforce at least this interval between updates	296	# enforce at least this interval between updates
203	our $MIN_INTERVAL = 1/100;	297	our $MIN_INTERVAL = 6/59.951;
204		298
205	{	299	{
206	package urxvt::bgdsl; # background language	300	package urxvt::bgdsl; # background language
		301
		302	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		303	sub FR_CACHE () { 1 } # cached values
		304	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		305	sub FR_STATE () { 3 } # watchers etc.
207		306
208	use List::Util qw(min max sum shuffle);	307	use List::Util qw(min max sum shuffle);
209		308
210	=head2 PROVIDERS/GENERATORS	309	=head2 PROVIDERS/GENERATORS
211		310
…		…
218	=item load $path	317	=item load $path
219		318
220	Loads the image at the given C<$path>. The image is set to plane tiling	319	Loads the image at the given C<$path>. The image is set to plane tiling
221	mode.	320	mode.
222		321
223	Loaded images will be cached for one cycle.	322	If the image is already in memory (e.g. because another terminal instance
		323	uses it), then the in-memory copy is returned instead.
224		324
		325	=item load_uc $path
		326
		327	Load uncached - same as load, but does not cache the image, which means it
		328	is I<always> loaded from the filesystem again, even if another copy of it
		329	is in memory at the time.
		330
225	=cut	331	=cut
		332
		333	sub load_uc($) {
		334	$self->new_img_from_file ($_[0])
		335	}
226		336
227	sub load($) {	337	sub load($) {
228	my ($path) = @_;	338	my ($path) = @_;
229		339
230	$new->{load}{$path} = $old->{load}{$path} || $self->new_img_from_file ($path);	340	$_IMG_CACHE{$path} || do {
		341	my $img = load_uc $path;
		342	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		343	$img
		344	}
231	}	345	}
232		346
233	=item root	347	=item root
234		348
235	Returns the root window pixmap, that is, hopefully, the background image	349	Returns the root window pixmap, that is, hopefully, the background image
236	of your screen. The image is set to extend mode.	350	of your screen.
237		351
238	This function makes your expression root sensitive, that means it will be	352	This function makes your expression root sensitive, that means it will be
239	reevaluated when the bg image changes.	353	reevaluated when the bg image changes.
240		354
241	=cut	355	=cut
242		356
243	sub root() {	357	sub root() {
244	$new->{rootpmap_sensitive} = 1;	358	$frame->[FR_AGAIN]{rootpmap} = 1;
245	die "root op not supported, exg, we need you";	359	$self->new_img_from_root
246	}	360	}
247		361
248	=item solid $colour	362	=item solid $colour
249		363
250	=item solid $width, $height, $colour	364	=item solid $width, $height, $colour
…		…
258	=cut	372	=cut
259		373
260	sub solid($;$$) {	374	sub solid($;$$) {
261	my $colour = pop;	375	my $colour = pop;
262		376
263	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] || 1, $_[1] || 1);	377	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] || 1, $_[1] || 1);
264	$img->fill ($colour);	378	$img->fill ($colour);
265	$img	379	$img
266	}	380	}
267		381
268	=back	382	=item clone $img
269		383
270	=head2 VARIABLES	384	Returns an exact copy of the image. This is useful if you want to have
		385	multiple copies of the same image to apply different effects to.
271		386
272	The following functions provide variable data such as the terminal window
273	dimensions. They are not (Perl-) variables, they jsut return stuff that
274	varies. Most of them make your expression sensitive to some events, for
275	example using C<TW> (terminal width) means your expression is evaluated
276	again when the terminal is resized.
277
278	=over 4
279
280	=item TX
281
282	=item TY
283
284	Return the X and Y coordinates of the terminal window (the terminal
285	window is the full window by default, and the character area only when in
286	border-respect mode).
287
288	Using these functions make your expression sensitive to window moves.
289
290	These functions are mainly useful to align images to the root window.
291
292	Example: load an image and align it so it looks as if anchored to the
293	background.
294
295	move -TX, -TY, load "mybg.png"
296
297	=item TW
298
299	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
300	terminal window is the full window by default, and the character area only
301	when in border-respect mode).
302
303	Using these functions make your expression sensitive to window resizes.
304
305	These functions are mainly useful to scale images, or to clip images to
306	the window size to conserve memory.
307
308	Example: take the screen background, clip it to the window size, blur it a
309	bit, align it to the window position and use it as background.
310
311	clip move -TX, -TY, blur 5, root
312
313	=cut	387	=cut
314		388
315	sub TX() { $new->{position_sensitive} = 1; $x }
316	sub TY() { $new->{position_sensitive} = 1; $y }
317	sub TW() { $new->{size_sensitive} = 1; $w }
318	sub TH() { $new->{size_sensitive} = 1; $h }
319
320	=item now
321
322	Returns the current time as (fractional) seconds since the epoch.
323
324	Using this expression does I<not> make your expression sensitive to time,
325	but the next two functions do.
326
327	=item again $seconds
328
329	When this function is used the expression will be reevaluated again in
330	C<$seconds> seconds.
331
332	Example: load some image and rotate it according to the time of day (as if it were
333	the hour pointer of a clock). Update this image every minute.
334
335	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
336
337	=item counter $seconds
338
339	Like C<again>, but also returns an increasing counter value, starting at
340	0, which might be useful for some simple animation effects.
341
342	=cut
343
344	sub now() { urxvt::NOW }
345
346	sub again($) {
347	$new->{again} = $_[0];
348	}
349
350	sub counter($) {	389	sub clone($) {
351	$new->{again} = $_[0];	390	$_[0]->clone
352	$self->{counter} + 0	391	}
		392
		393	=item merge $img ...
		394
		395	Takes any number of images and merges them together, creating a single
		396	image containing them all. The tiling mode of the first image is used as
		397	the tiling mode of the resulting image.
		398
		399	This function is called automatically when an expression returns multiple
		400	images.
		401
		402	=cut
		403
		404	sub merge(@) {
		405	return $_[0] unless $#_;
		406
		407	# rather annoyingly clumsy, but optimisation is for another time
		408
		409	my $x0 = +1e9;
		410	my $y0 = +1e9;
		411	my $x1 = -1e9;
		412	my $y1 = -1e9;
		413
		414	for (@_) {
		415	my ($x, $y, $w, $h) = $_->geometry;
		416
		417	$x0 = $x if $x0 > $x;
		418	$y0 = $y if $y0 > $y;
		419
		420	$x += $w;
		421	$y += $h;
		422
		423	$x1 = $x if $x1 < $x;
		424	$y1 = $y if $y1 < $y;
		425	}
		426
		427	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		428	$base->repeat_mode ($_[0]->repeat_mode);
		429	$base->fill ([0, 0, 0, 0]);
		430
		431	$base->draw ($_)
		432	for @_;
		433
		434	$base
353	}	435	}
354		436
355	=back	437	=back
356		438
357	=head2 TILING MODES	439	=head2 TILING MODES
…		…
390	become transparent. This mode is most useful when you want to place an	472	become transparent. This mode is most useful when you want to place an
391	image over another image or the background colour while leaving all	473	image over another image or the background colour while leaving all
392	background pixels outside the image unchanged.	474	background pixels outside the image unchanged.
393		475
394	Example: load an image and display it in the upper left corner. The rest	476	Example: load an image and display it in the upper left corner. The rest
395	of the space is left "empty" (transparent or wahtever your compisotr does	477	of the space is left "empty" (transparent or whatever your compositor does
396	in alpha mode, else background colour).	478	in alpha mode, else background colour).
397		479
398	pad load "mybg.png"	480	pad load "mybg.png"
399		481
400	=item extend $img	482	=item extend $img
401		483
402	Extends the image over the whole plane, using the closest pixel in the	484	Extends the image over the whole plane, using the closest pixel in the
403	area outside the image. This mode is mostly useful when you more complex	485	area outside the image. This mode is mostly useful when you use more complex
404	filtering operations and want the pixels outside the image to have the	486	filtering operations and want the pixels outside the image to have the
405	same values as the pixels near the edge.	487	same values as the pixels near the edge.
406		488
407	Example: just for curiosity, how does this pixel extension stuff work?	489	Example: just for curiosity, how does this pixel extension stuff work?
408		490
…		…
434	$img	516	$img
435	}	517	}
436		518
437	=back	519	=back
438		520
439	=head2 PIXEL OPERATORS	521	=head2 VARIABLE VALUES
440		522
441	The following operators modify the image pixels in various ways.	523	The following functions provide variable data such as the terminal window
		524	dimensions. They are not (Perl-) variables, they just return stuff that
		525	varies. Most of them make your expression sensitive to some events, for
		526	example using C<TW> (terminal width) means your expression is evaluated
		527	again when the terminal is resized.
442		528
443	=over 4	529	=over 4
444		530
445	=item clone $img	531	=item TX
446		532
447	Returns an exact copy of the image.	533	=item TY
448		534
449	=cut	535	Return the X and Y coordinates of the terminal window (the terminal
		536	window is the full window by default, and the character area only when in
		537	border-respect mode).
450		538
		539	Using these functions makes your expression sensitive to window moves.
		540
		541	These functions are mainly useful to align images to the root window.
		542
		543	Example: load an image and align it so it looks as if anchored to the
		544	background (that's exactly what C<rootalign> does btw.):
		545
		546	move -TX, -TY, keep { load "mybg.png" }
		547
		548	=item TW
		549
		550	=item TH
		551
		552	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		553	terminal window is the full window by default, and the character area only
		554	when in border-respect mode).
		555
		556	Using these functions makes your expression sensitive to window resizes.
		557
		558	These functions are mainly useful to scale images, or to clip images to
		559	the window size to conserve memory.
		560
		561	Example: take the screen background, clip it to the window size, blur it a
		562	bit, align it to the window position and use it as background.
		563
		564	clip move -TX, -TY, keep { blur 5, root }
		565
		566	=item FOCUS
		567
		568	Returns a boolean indicating whether the terminal window has keyboard
		569	focus, in which case it returns true.
		570
		571	Using this function makes your expression sensitive to focus changes.
		572
		573	A common use case is to fade the background image when the terminal loses
		574	focus, often together with the C<-fade> command line option. In fact,
		575	there is a special function for just that use case: C<focus_fade>.
		576
		577	Example: use two entirely different background images, depending on
		578	whether the window has focus.
		579
		580	FOCUS ? keep { load "has_focus.jpg" } : keep { load "no_focus.jpg" }
		581
		582	=cut
		583
		584	sub TX () { $frame->[FR_AGAIN]{position} = 1; $x }
		585	sub TY () { $frame->[FR_AGAIN]{position} = 1; $y }
		586	sub TW () { $frame->[FR_AGAIN]{size} = 1; $w }
		587	sub TH () { $frame->[FR_AGAIN]{size} = 1; $h }
		588	sub FOCUS() { $frame->[FR_AGAIN]{focus} = 1; $focus }
		589
		590	=item now
		591
		592	Returns the current time as (fractional) seconds since the epoch.
		593
		594	Using this expression does I<not> make your expression sensitive to time,
		595	but the next two functions do.
		596
		597	=item again $seconds
		598
		599	When this function is used the expression will be reevaluated again in
		600	C<$seconds> seconds.
		601
		602	Example: load some image and rotate it according to the time of day (as if it were
		603	the hour pointer of a clock). Update this image every minute.
		604
		605	again 60;
		606	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
		607
		608	=item counter $seconds
		609
		610	Like C<again>, but also returns an increasing counter value, starting at
		611	0, which might be useful for some simple animation effects.
		612
		613	=cut
		614
		615	sub now() { urxvt::NOW }
		616
		617	sub again($) {
		618	$frame->[FR_AGAIN]{time} = $_[0];
		619	}
		620
451	sub clone($) {	621	sub counter($) {
452	$_[0]->clone	622	$frame->[FR_AGAIN]{time} = $_[0];
		623	$frame->[FR_STATE]{counter} + 0
453	}	624	}
		625
		626	=back
		627
		628	=head2 SHAPE CHANGING OPERATORS
		629
		630	The following operators modify the shape, size or position of the image.
		631
		632	=over 4
454		633
455	=item clip $img	634	=item clip $img
456		635
457	=item clip $width, $height, $img	636	=item clip $width, $height, $img
458		637
…		…
461	Clips an image to the given rectangle. If the rectangle is outside the	640	Clips an image to the given rectangle. If the rectangle is outside the
462	image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is	641	image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is
463	larger than the image, then the tiling mode defines how the extra pixels	642	larger than the image, then the tiling mode defines how the extra pixels
464	will be filled.	643	will be filled.
465		644
466	If C<$x> an C<$y> are missing, then C<0> is assumed for both.	645	If C<$x> and C<$y> are missing, then C<0> is assumed for both.
467		646
468	If C<$width> and C<$height> are missing, then the window size will be	647	If C<$width> and C<$height> are missing, then the window size will be
469	assumed.	648	assumed.
470		649
471	Example: load an image, blur it, and clip it to the window size to save	650	Example: load an image, blur it, and clip it to the window size to save
472	memory.	651	memory.
473		652
474	clip blur 10, load "mybg.png"	653	clip keep { blur 10, load "mybg.png" }
475		654
476	=cut	655	=cut
477		656
478	sub clip($;$$;$$) {	657	sub clip($;$$;$$) {
479	my $img = pop;	658	my $img = pop;
…		…
489	=item scale $width_factor, $height_factor, $img	668	=item scale $width_factor, $height_factor, $img
490		669
491	Scales the image by the given factors in horizontal	670	Scales the image by the given factors in horizontal
492	(C<$width>) and vertical (C<$height>) direction.	671	(C<$width>) and vertical (C<$height>) direction.
493		672
494	If only one factor is give, it is used for both directions.	673	If only one factor is given, it is used for both directions.
495		674
496	If no factors are given, scales the image to the window size without	675	If no factors are given, scales the image to the window size without
497	keeping aspect.	676	keeping aspect.
498		677
499	=item resize $width, $height, $img	678	=item resize $width, $height, $img
…		…
552		731
553	Example: move the image right by 20 pixels and down by 30.	732	Example: move the image right by 20 pixels and down by 30.
554		733
555	move 20, 30, ...	734	move 20, 30, ...
556		735
		736	=item align $xalign, $yalign, $img
		737
		738	Aligns the image according to a factor - C<0> means the image is moved to
		739	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		740	exactly centered and C<1> means it touches the right or bottom edge.
		741
		742	Example: remove any visible border around an image, center it vertically but move
		743	it to the right hand side.
		744
		745	align 1, 0.5, pad $img
		746
		747	=item center $img
		748
		749	=item center $width, $height, $img
		750
		751	Centers the image, i.e. the center of the image is moved to the center of
		752	the terminal window (or the box specified by C<$width> and C<$height> if
		753	given).
		754
		755	Example: load an image and center it.
		756
		757	center keep { pad load "mybg.png" }
		758
557	=item rootalign $img	759	=item rootalign $img
558		760
559	Moves the image so that it appears glued to the screen as opposed to the	761	Moves the image so that it appears glued to the screen as opposed to the
560	window. This gives the illusion of a larger area behind the window. It is	762	window. This gives the illusion of a larger area behind the window. It is
561	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	763	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
562	top left of the screen.	764	top left of the screen.
563		765
564	Example: load a background image, put it in mirror mode and root align it.	766	Example: load a background image, put it in mirror mode and root align it.
565		767
566	rootalign mirror load "mybg.png"	768	rootalign keep { mirror load "mybg.png" }
567		769
568	Example: take the screen background and align it, giving the illusion of	770	Example: take the screen background and align it, giving the illusion of
569	transparency as long as the window isn't in front of other windows.	771	transparency as long as the window isn't in front of other windows.
570		772
571	rootalign root	773	rootalign root
572		774
573	=cut	775	=cut
574		776
575	sub move($$;$) {	777	sub move($$;$) {
576	my $img = pop->clone;	778	my $img = pop->clone;
577	$img->move ($_[0], $_[1]);	779	$img->move ($_[0], $_[1]);
578	$img	780	$img
579	}	781	}
580		782
		783	sub align($;$$) {
		784	my $img = pop;
		785
		786	move $_[0] * (TW - $img->w),
		787	$_[1] * (TH - $img->h),
		788	$img
		789	}
		790
		791	sub center($;$$) {
		792	my $img = pop;
		793	my $w = $_[0] || TW;
		794	my $h = $_[1] || TH;
		795
		796	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		797	}
		798
581	sub rootalign($) {	799	sub rootalign($) {
582	move -TX, -TY, $_[0]	800	move -TX, -TY, $_[0]
583	}	801	}
584		802
		803	=item rotate $center_x, $center_y, $degrees, $img
		804
		805	Rotates the image clockwise by C<$degrees> degrees, around the point at
		806	C<$center_x> and C<$center_y> (specified as factor of image width/height).
		807
		808	Example: rotate the image by 90 degrees around its center.
		809
		810	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
		811
		812	=cut
		813
		814	sub rotate($$$$) {
		815	my $img = pop;
		816	$img->rotate (
		817	$_[0] * ($img->w + $img->x),
		818	$_[1] * ($img->h + $img->y),
		819	$_[2] * (3.14159265 / 180),
		820	)
		821	}
		822
		823	=back
		824
		825	=head2 COLOUR MODIFICATIONS
		826
		827	The following operators change the pixels of the image.
		828
		829	=over 4
		830
		831	=item tint $color, $img
		832
		833	Tints the image in the given colour.
		834
		835	Example: tint the image red.
		836
		837	tint "red", load "rgb.png"
		838
		839	Example: the same, but specify the colour by component.
		840
		841	tint [1, 0, 0], load "rgb.png"
		842
		843	=cut
		844
		845	sub tint($$) {
		846	$_[1]->tint ($_[0])
		847	}
		848
		849	=item shade $factor, $img
		850
		851	Shade the image by the given factor.
		852
		853	=cut
		854
		855	sub shade($$) {
		856	$_[1]->shade ($_[0])
		857	}
		858
585	=item contrast $factor, $img	859	=item contrast $factor, $img
586		860
587	=item contrast $r, $g, $b, $img	861	=item contrast $r, $g, $b, $img
588		862
589	=item contrast $r, $g, $b, $a, $img	863	=item contrast $r, $g, $b, $a, $img
590		864
591	Adjusts the I<contrast> of an image.	865	Adjusts the I<contrast> of an image.
592		866
593	#TODO#	867	The first form applies a single C<$factor> to red, green and blue, the
		868	second form applies separate factors to each colour channel, and the last
		869	form includes the alpha channel.
594		870
		871	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		872	contrast.
		873
		874	Due to limitations in the underlying XRender extension, lowering contrast
		875	also reduces brightness, while increasing contrast currently also
		876	increases brightness.
		877
595	=item brightness $factor, $img	878	=item brightness $bias, $img
596		879
597	=item brightness $r, $g, $b, $img	880	=item brightness $r, $g, $b, $img
598		881
599	=item brightness $r, $g, $b, $a, $img	882	=item brightness $r, $g, $b, $a, $img
600		883
601	Adjusts the brightness of an image.	884	Adjusts the brightness of an image.
		885
		886	The first form applies a single C<$bias> to red, green and blue, the
		887	second form applies separate biases to each colour channel, and the last
		888	form includes the alpha channel.
		889
		890	Values less than 0 reduce brightness, while values larger than 0 increase
		891	it. Useful range is from -1 to 1 - the former results in a black, the
		892	latter in a white picture.
		893
		894	Due to idiosyncrasies in the underlying XRender extension, biases less
		895	than zero can be I<very> slow.
		896
		897	You can also try the experimental(!) C<muladd> operator.
602		898
603	=cut	899	=cut
604		900
605	sub contrast($$;$$;$) {	901	sub contrast($$;$$;$) {
606	my $img = pop;	902	my $img = pop;
607	my ($r, $g, $b, $a) = @_;	903	my ($r, $g, $b, $a) = @_;
608		904
609	($g, $b) = ($r, $r) if @_ < 4;	905	($g, $b) = ($r, $r) if @_ < 3;
610	$a = 1 if @_ < 5;	906	$a = 1 if @_ < 4;
611		907
612	$img = $img->clone;	908	$img = $img->clone;
613	$img->contrast ($r, $g, $b, $a);	909	$img->contrast ($r, $g, $b, $a);
614	$img	910	$img
615	}	911	}
616		912
617	sub brightness($$;$$;$) {	913	sub brightness($$;$$;$) {
618	my $img = pop;	914	my $img = pop;
619	my ($r, $g, $b, $a) = @_;	915	my ($r, $g, $b, $a) = @_;
620		916
621	($g, $b) = ($r, $r) if @_ < 4;	917	($g, $b) = ($r, $r) if @_ < 3;
622	$a = 1 if @_ < 5;	918	$a = 1 if @_ < 4;
623		919
624	$img = $img->clone;	920	$img = $img->clone;
625	$img->brightness ($r, $g, $b, $a);	921	$img->brightness ($r, $g, $b, $a);
626	$img	922	$img
		923	}
		924
		925	=item muladd $mul, $add, $img # EXPERIMENTAL
		926
		927	First multiplies the pixels by C<$mul>, then adds C<$add>. This can be used
		928	to implement brightness and contrast at the same time, with a wider value
		929	range than contrast and brightness operators.
		930
		931	Due to numerous bugs in XRender implementations, it can also introduce a
		932	number of visual artifacts.
		933
		934	Example: increase contrast by a factor of C<$c> without changing image
		935	brightness too much.
		936
		937	muladd $c, (1 - $c) * 0.5, $img
		938
		939	=cut
		940
		941	sub muladd($$$) {
		942	$_[2]->muladd ($_[0], $_[1])
627	}	943	}
628		944
629	=item blur $radius, $img	945	=item blur $radius, $img
630		946
631	=item blur $radius_horz, $radius_vert, $img	947	=item blur $radius_horz, $radius_vert, $img
…		…
643	sub blur($$;$) {	959	sub blur($$;$) {
644	my $img = pop;	960	my $img = pop;
645	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	961	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
646	}	962	}
647		963
648	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees	964	=item focus_fade $img
649		965
650	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	966	=item focus_fade $factor, $img
651	pointer at C<$center_x> and C<$center_y> (specified as factor of image
652	width/height), generating a new image with width C<$new_width> and height
653	C<$new_height>.
654		967
655	#TODO# new width, height, maybe more operators?	968	=item focus_fade $factor, $color, $img
656		969
657	Example: rotate the image by 90 degrees	970	Fades the image by the given factor (and colour) when focus is lost (the
		971	same as the C<-fade>/C<-fadecolor> command line options, which also supply
		972	the default values for C<factor> and C<$color>. Unlike with C<-fade>, the
		973	C<$factor> is a real value, not a percentage value (that is, 0..1, not
		974	0..100).
658		975
659	=cut	976	Example: do the right thing when focus fading is requested.
660		977
661	sub rotate($$$$$$) {	978	focus_fade load "mybg.jpg";
		979
		980	=cut
		981
		982	sub focus_fade($;$$) {
662	my $img = pop;	983	my $img = pop;
663	$img->rotate (	984
664	$_[0],	985	return $img
665	$_[1],	986	if FOCUS;
666	$_[2] * $img->w,	987
667	$_[3] * $img->h,	988	my $fade = @_ >= 1 ? $_[0] : defined $self->resource ("fade") ? $self->resource ("fade") * 0.01 : 0;
668	$_[4] * (3.14159265 / 180),	989	my $color = @_ >= 2 ? $_[1] : $self->resource ("color+" . urxvt::Color_fade);
669	)	990
		991	$img = $img->tint ($color) if $color ne "rgb:00/00/00";
		992	$img = $img->muladd (1 - $fade, 0) if $fade;
		993
		994	$img
670	}	995	}
671		996
672	=back	997	=back
673		998
		999	=head2 OTHER STUFF
		1000
		1001	Anything that didn't fit any of the other categories, even after applying
		1002	force and closing our eyes.
		1003
		1004	=over 4
		1005
		1006	=item keep { ... }
		1007
		1008	This operator takes a code block as argument, that is, one or more
		1009	statements enclosed by braces.
		1010
		1011	The trick is that this code block is only evaluated when the outcome
		1012	changes - on other calls the C<keep> simply returns the image it computed
		1013	previously (yes, it should only be used with images). Or in other words,
		1014	C<keep> I<caches> the result of the code block so it doesn't need to be
		1015	computed again.
		1016
		1017	This can be extremely useful to avoid redoing slow operations - for
		1018	example, if your background expression takes the root background, blurs it
		1019	and then root-aligns it it would have to blur the root background on every
		1020	window move or resize.
		1021
		1022	Another example is C<load>, which can be quite slow.
		1023
		1024	In fact, urxvt itself encloses the whole expression in some kind of
		1025	C<keep> block so it only is reevaluated as required.
		1026
		1027	Putting the blur into a C<keep> block will make sure the blur is only done
		1028	once, while the C<rootalign> is still done each time the window moves.
		1029
		1030	rootalign keep { blur 10, root }
		1031
		1032	This leaves the question of how to force reevaluation of the block,
		1033	in case the root background changes: If expression inside the block
		1034	is sensitive to some event (root background changes, window geometry
		1035	changes), then it will be reevaluated automatically as needed.
		1036
		1037	=back
		1038
		1039	=head1 OLD BACKGROUND IMAGE SETTINGS
		1040
		1041	This extension also provides support for the old options/resources and
		1042	OSC sequences for setting a background image. These settings are
		1043	B<deprecated> and will be removed in future versions.
		1044
		1045	=head2 OPTIONS AND RESOURCES
		1046
		1047	=over 4
		1048
		1049	=item B<-pixmap> I<file[;oplist]>
		1050
		1051	=item B<backgroundPixmap:> I<file[;oplist]>
		1052
		1053	Use the specified image file as the window's background and also
		1054	optionally specify a colon separated list of operations to modify it.
		1055	Note that you may need to quote the C<;> character when using the
		1056	command line option, as C<;> is usually a metacharacter in shells.
		1057	Supported operations are:
		1058
		1059	=over 4
		1060
		1061	=item B<WxH+X+Y>
		1062
		1063	sets scale and position. B<"W" / "H"> specify the horizontal/vertical
		1064	scale (percent), and B<"X" / "Y"> locate the image centre (percent). A
		1065	scale of 0 disables scaling.
		1066
		1067	=item B<op=tile>
		1068
		1069	enables tiling
		1070
		1071	=item B<op=keep-aspect>
		1072
		1073	maintain the image aspect ratio when scaling
		1074
		1075	=item B<op=root-align>
		1076
		1077	use the position of the terminal window relative to the root window as
		1078	the image offset, simulating a root window background
		1079
		1080	=back
		1081
		1082	The default scale and position setting is C<100x100+50+50>.
		1083	Alternatively, a predefined set of templates can be used to achieve
		1084	the most common setups:
		1085
		1086	=over 4
		1087
		1088	=item B<style=tiled>
		1089
		1090	the image is tiled with no scaling. Equivalent to 0x0+0+0:op=tile
		1091
		1092	=item B<style=aspect-stretched>
		1093
		1094	the image is scaled to fill the whole window maintaining the aspect
		1095	ratio and centered. Equivalent to 100x100+50+50:op=keep-aspect
		1096
		1097	=item B<style=stretched>
		1098
		1099	the image is scaled to fill the whole window. Equivalent to 100x100
		1100
		1101	=item B<style=centered>
		1102
		1103	the image is centered with no scaling. Equivalent to 0x0+50+50
		1104
		1105	=item B<style=root-tiled>
		1106
		1107	the image is tiled with no scaling and using 'root' positioning.
		1108	Equivalent to 0x0:op=tile:op=root-align
		1109
		1110	=back
		1111
		1112	If multiple templates are specified the last one wins. Note that a
		1113	template overrides all the scale, position and operations settings.
		1114
		1115	If used in conjunction with pseudo-transparency, the specified image
		1116	will be blended over the transparent background using alpha-blending.
		1117
		1118	=item B<-tr>|B<+tr>
		1119
		1120	=item B<transparent:> I<boolean>
		1121
		1122	Turn on/off pseudo-transparency by using the root pixmap as background.
		1123
		1124	=item B<-tint> I<colour>
		1125
		1126	=item B<tintColor:> I<colour>
		1127
		1128	Tint the transparent background with the given colour. Note that a
		1129	black tint yields a completely black image while a white tint yields
		1130	the image unchanged.
		1131
		1132	=item B<-sh> I<number>
		1133
		1134	=item B<shading:> I<number>
		1135
		1136	Darken (0 .. 99) or lighten (101 .. 200) the transparent background.
		1137	A value of 100 means no shading.
		1138
		1139	=item B<-blr> I<HxV>
		1140
		1141	=item B<blurRadius:> I<HxV>
		1142
		1143	Apply gaussian blur with the specified radius to the transparent
		1144	background. If a single number is specified, the vertical and
		1145	horizontal radii are considered to be the same. Setting one of the
		1146	radii to 1 and the other to a large number creates interesting effects
		1147	on some backgrounds. The maximum radius value is 128. An horizontal or
		1148	vertical radius of 0 disables blurring.
		1149
		1150	=back
		1151
		1152	=head2 OSC sequences
		1153
		1154	=over 4
		1155
		1156	=item B<< C<ESC ] 705 ; Pt ST> >> Change transparent background tint colour to B<< C<Pt> >>.
		1157
		1158	=item B<< C<ESC ] 20 ; Pt ST> >> Change/Query background image
		1159	parameters: the value of B<< C<Pt> >> can be one of the following
		1160	commands:
		1161
		1162	=over 4
		1163
		1164	=item B<< C<?> >>
		1165
		1166	display scale and position in the title
		1167
		1168	=item B<< C<;WxH+X+Y> >>
		1169
		1170	change scale and/or position
		1171
		1172	=item B<< C<FILE;WxH+X+Y> >>
		1173
		1174	change background image
		1175
		1176	=back
		1177
		1178	=cut
		1179
		1180	sub keep(&) {
		1181	my $id = $_[0]+0;
		1182
		1183	local $frame = $self->{frame_cache}{$id} ||= [$frame];
		1184
		1185	unless ($frame->[FR_CACHE]) {
		1186	$frame->[FR_CACHE] = [ $_[0]() ];
		1187
		1188	my $self = $self;
		1189	my $frame = $frame;
		1190	Scalar::Util::weaken $frame;
		1191	$self->compile_frame ($frame, sub {
		1192	# clear this frame cache, also for all parents
		1193	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		1194	undef $frame->[FR_CACHE];
		1195	}
		1196
		1197	$self->recalculate;
		1198	});
		1199	};
		1200
		1201	# in scalar context we always return the first original result, which
		1202	# is not quite how perl works.
		1203	wantarray
		1204	? @{ $frame->[FR_CACHE] }
		1205	: $frame->[FR_CACHE][0]
		1206	}
		1207
		1208	# sub keep_clear() {
		1209	# delete $self->{frame_cache};
		1210	# }
		1211
		1212	=back
		1213
674	=cut	1214	=cut
675		1215
676	}	1216	}
677		1217
678	sub parse_expr {	1218	sub parse_expr {
679	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	1219	my $expr = eval
		1220	"sub {\n"
		1221	. "package urxvt::bgdsl;\n"
		1222	. "#line 0 'background expression'\n"
		1223	. "$_[0]\n"
		1224	. "}";
680	die if $@;	1225	die if $@;
681	$expr	1226	$expr
682	}	1227	}
683		1228
684	# compiles a parsed expression	1229	# compiles a parsed expression
685	sub set_expr {	1230	sub set_expr {
686	my ($self, $expr) = @_;	1231	my ($self, $expr) = @_;
687		1232
		1233	$self->{root} = []; # the outermost frame
688	$self->{expr} = $expr;	1234	$self->{expr} = $expr;
689	$self->recalculate;	1235	$self->recalculate;
		1236	}
		1237
		1238	# takes a hash of sensitivity indicators and installs watchers
		1239	sub compile_frame {
		1240	my ($self, $frame, $cb) = @_;
		1241
		1242	my $state = $frame->[urxvt::bgdsl::FR_STATE] ||= {};
		1243	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		1244
		1245	# don't keep stuff alive
		1246	Scalar::Util::weaken $state;
		1247
		1248	if ($again->{nested}) {
		1249	$state->{nested} = 1;
		1250	} else {
		1251	delete $state->{nested};
		1252	}
		1253
		1254	if (my $interval = $again->{time}) {
		1255	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		1256	if $state->{time}[0] != $interval;
		1257
		1258	# callback *might* have changed, although we could just rule that out
		1259	$state->{time}[1]->cb (sub {
		1260	++$state->{counter};
		1261	$cb->();
		1262	});
		1263	} else {
		1264	delete $state->{time};
		1265	}
		1266
		1267	if ($again->{position}) {
		1268	$state->{position} = $self->on (position_change => $cb);
		1269	} else {
		1270	delete $state->{position};
		1271	}
		1272
		1273	if ($again->{size}) {
		1274	$state->{size} = $self->on (size_change => $cb);
		1275	} else {
		1276	delete $state->{size};
		1277	}
		1278
		1279	if ($again->{rootpmap}) {
		1280	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		1281	} else {
		1282	delete $state->{rootpmap};
		1283	}
		1284
		1285	if ($again->{focus}) {
		1286	$state->{focus} = $self->on (focus_in => $cb, focus_out => $cb);
		1287	} else {
		1288	delete $state->{focus};
		1289	}
690	}	1290	}
691		1291
692	# evaluate the current bg expression	1292	# evaluate the current bg expression
693	sub recalculate {	1293	sub recalculate {
694	my ($arg_self) = @_;	1294	my ($arg_self) = @_;
…		…
704		1304
705	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1305	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
706		1306
707	# set environment to evaluate user expression	1307	# set environment to evaluate user expression
708		1308
709	local $self = $arg_self;	1309	local $self = $arg_self;
710
711	local $HOME = $ENV{HOME};	1310	local $HOME = $ENV{HOME};
712	local $old = $self->{state};	1311	local $frame = $self->{root};
713	local $new = my $state = $self->{state} = {};
714		1312
715	($x, $y, $w, $h) =
716	$self->background_geometry ($self->{border});	1313	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
		1314	$focus = $self->focus;
717		1315
718	# evaluate user expression	1316	# evaluate user expression
719		1317
720	my $img = eval { $self->{expr}->() };	1318	my @img = eval { $self->{expr}->() };
721	warn $@ if $@;#d#	1319	die $@ if $@;
		1320	die "background-expr did not return anything.\n" unless @img;
		1321	die "background-expr: expected image(s), got something else.\n"
722	die if !UNIVERSAL::isa $img, "urxvt::img";	1322	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
723		1323
724	$state->{size_sensitive} = 1	1324	my $img = urxvt::bgdsl::merge @img;
		1325
		1326	$frame->[FR_AGAIN]{size} = 1
725	if $img->repeat_mode != urxvt::RepeatNormal;	1327	if $img->repeat_mode != urxvt::RepeatNormal;
726		1328
727	# if the expression is sensitive to external events, prepare reevaluation then	1329	# if the expression is sensitive to external events, prepare reevaluation then
728		1330	$self->compile_frame ($frame, sub { $arg_self->recalculate });
729	my $repeat;
730
731	if (my $again = $state->{again}) {
732	$repeat = 1;
733	my $self = $self;
734	$state->{timer} = $again == $old->{again}
735	? $old->{timer}
736	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
737	++$self->{counter};
738	$self->recalculate
739	});
740	}
741
742	if (delete $state->{position_sensitive}) {
743	$repeat = 1;
744	$self->enable (position_change => sub { $_[0]->recalculate });
745	} else {
746	$self->disable ("position_change");
747	}
748
749	if (delete $state->{size_sensitive}) {
750	$repeat = 1;
751	$self->enable (size_change => sub { $_[0]->recalculate });
752	} else {
753	$self->disable ("size_change");
754	}
755
756	if (delete $state->{rootpmap_sensitive}) {
757	$repeat = 1;
758	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
759	} else {
760	$self->disable ("rootpmap_change");
761	}
762		1331
763	# clear stuff we no longer need	1332	# clear stuff we no longer need
764		1333
765	%$old = ();	1334	# unless (%{ $frame->[FR_STATE] }) {
766
767	unless ($repeat) {
768	delete $self->{state};	1335	# delete $self->{state};
769	delete $self->{expr};	1336	# delete $self->{expr};
770	}	1337	# }
771		1338
772	# set background pixmap	1339	# set background pixmap
773		1340
774	$self->set_background ($img, $self->{border});	1341	$self->set_background ($img, $self->{border});
775	$self->scr_recolour (0);	1342	$self->scr_recolor (0);
776	$self->want_refresh;	1343	$self->want_refresh;
777	}	1344	}
778		1345
		1346	sub old_bg_opts {
		1347	my ($self, $arg) = @_;
		1348
		1349	$arg or return;
		1350
		1351	my @str = split /;/, $arg;
		1352
		1353	return unless $str[0] or $self->{bg_opts}->{path};
		1354
		1355	my $bg_opts = $self->{bg_opts};
		1356
		1357	if ($str[0]) {
		1358	$bg_opts->{tile} = 0;
		1359	$bg_opts->{keep_aspect} = 0;
		1360	$bg_opts->{root_align} = 0;
		1361	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 100;
		1362	$bg_opts->{h_align} = $bg_opts->{v_align} = 50;
		1363	$bg_opts->{path} = unpack "H*", $str[0];
		1364	}
		1365
		1366	my @oplist = split /:/, $str[1];
		1367
		1368	for (@oplist) {
		1369	if (/style=tiled/i) {
		1370	$bg_opts->{tile} = 1;
		1371	$bg_opts->{keep_aspect} = 0;
		1372	$bg_opts->{root_align} = 0;
		1373	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 0;
		1374	$bg_opts->{h_align} = $bg_opts->{v_align} = 0;
		1375	} elsif (/style=aspect-stretched/i) {
		1376	$bg_opts->{tile} = 0;
		1377	$bg_opts->{keep_aspect} = 1;
		1378	$bg_opts->{root_align} = 0;
		1379	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 100;
		1380	$bg_opts->{h_align} = $bg_opts->{v_align} = 50;
		1381	} elsif (/style=stretched/i) {
		1382	$bg_opts->{tile} = 0;
		1383	$bg_opts->{keep_aspect} = 0;
		1384	$bg_opts->{root_align} = 0;
		1385	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 100;
		1386	$bg_opts->{h_align} = $bg_opts->{v_align} = 50;
		1387	} elsif (/style=centered/i) {
		1388	$bg_opts->{tile} = 0;
		1389	$bg_opts->{keep_aspect} = 0;
		1390	$bg_opts->{root_align} = 0;
		1391	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 0;
		1392	$bg_opts->{h_align} = $bg_opts->{v_align} = 50;
		1393	} elsif (/style=root-tiled/i) {
		1394	$bg_opts->{tile} = 1;
		1395	$bg_opts->{keep_aspect} = 0;
		1396	$bg_opts->{root_align} = 1;
		1397	$bg_opts->{h_scale} = $bg_opts->{v_scale} = 0;
		1398	$bg_opts->{h_align} = $bg_opts->{v_align} = 0;
		1399	} elsif (/op=tile/i) {
		1400	$bg_opts->{tile} = 1;
		1401	} elsif (/op=keep_aspect/i) {
		1402	$bg_opts->{keep_aspect} = 1;
		1403	} elsif (/op=root_align/i) {
		1404	$bg_opts->{root_align} = 1;
		1405	} elsif (/^ =? ([0-9]+)? (?:[xX] ([0-9]+))? ([+-][0-9]+)? ([+-][0-9]+)? $/x) {
		1406	my ($w, $h, $x, $y) = ($1, $2, $3, $4);
		1407
		1408	if ($str[0]) {
		1409	$w = $h unless defined $w;
		1410	$h = $w unless defined $h;
		1411	$y = $x unless defined $y;
		1412	}
		1413
		1414	$bg_opts->{h_scale} = $w if defined $w;
		1415	$bg_opts->{v_scale} = $h if defined $h;
		1416	$bg_opts->{h_align} = $x if defined $x;
		1417	$bg_opts->{v_align} = $y if defined $y;
		1418	}
		1419	}
		1420	}
		1421
		1422	sub old_bg_expr {
		1423	my ($self) = @_;
		1424
		1425	my $expr;
		1426
		1427	my $bg_opts = $self->{bg_opts};
		1428
		1429	if ($bg_opts->{root}) {
		1430	$expr .= "tile (";
		1431
		1432	my $shade = $bg_opts->{shade};
		1433
		1434	if ($shade) {
		1435	$shade = List::Util::min $shade, 200;
		1436	$shade = List::Util::max $shade, -100;
		1437	$shade = 200 - (100 + $shade) if $shade < 0;
		1438
		1439	$shade = $shade * 0.01 - 1;
		1440	$expr .= "shade $shade, ";
		1441	}
		1442
		1443	my $tint = $bg_opts->{tint};
		1444
		1445	if ($tint) {
		1446	$expr .= "tint $tint, ";
		1447	}
		1448
		1449	my $blur = $bg_opts->{blur};
		1450
		1451	if ($blur and $blur =~ /^ =? ([0-9]+)? (?:[xX] ([0-9]+))? $/x) {
		1452	my $hr = defined $1 ? $1 : 1;
		1453	my $vr = defined $2 ? $2 : $hr;
		1454
		1455	if ($hr != 0 and $vr != 0) {
		1456	$expr .= "blur $hr, $vr, ";
		1457	}
		1458	}
		1459
		1460	$expr .= "rootalign root)";
		1461	}
		1462
		1463	if ($bg_opts->{path}) {
		1464	my $file_expr;
		1465	my $h_scale = $bg_opts->{h_scale} * 0.01;
		1466	my $v_scale = $bg_opts->{v_scale} * 0.01;
		1467	my $h_align = $bg_opts->{h_align} * 0.01;
		1468	my $v_align = $bg_opts->{v_align} * 0.01;
		1469
		1470	if (!$bg_opts->{tile}) {
		1471	$file_expr .= "pad (";
		1472	} else {
		1473	$file_expr .= "tile (";
		1474	}
		1475
		1476	if ($bg_opts->{root_align}) {
		1477	$file_expr .= "rootalign ";
		1478	} else {
		1479	$file_expr .= "align $h_align, $v_align, ";
		1480	}
		1481
		1482	if ($h_scale != 0 and $v_scale != 0) {
		1483	my $op = $bg_opts->{keep_aspect} ? "fit" : "resize";
		1484	$file_expr .= "$op TW * $h_scale, TH * $v_scale, ";
		1485	}
		1486
		1487	$file_expr .= "keep { load pack \"H*\", \"$bg_opts->{path}\" })";
		1488
		1489	if ($expr) {
		1490	$expr .= ", tint (\"[50]white\", $file_expr)";
		1491	} else {
		1492	$expr = $file_expr;
		1493	}
		1494	}
		1495
		1496	$expr
		1497	}
		1498
		1499	sub on_osc_seq {
		1500	my ($self, $op, $arg) = @_;
		1501
		1502	$self->{bg_opts} or return;
		1503
		1504	$op =~ /^(20|705)$/ or return;
		1505
		1506	if ($op eq "20") {
		1507	if ($arg eq "?") {
		1508	my $h_scale = $self->{bg_opts}->{h_scale};
		1509	my $v_scale = $self->{bg_opts}->{v_scale};
		1510	my $h_align = $self->{bg_opts}->{h_align};
		1511	my $v_align = $self->{bg_opts}->{v_align};
		1512	$self->cmd_parse ("\033]2;[${h_scale}x${v_scale}+${h_align}+${v_align}]\007");
		1513	} else {
		1514	$self->old_bg_opts ($arg);
		1515	my $expr = $self->old_bg_expr;
		1516	$self->set_expr (parse_expr $expr) if $expr;
		1517	}
		1518	} elsif ($op eq "705") {
		1519	$self->{bg_opts}->{tint} = $arg;
		1520	my $expr = $self->old_bg_expr;
		1521	$self->set_expr (parse_expr $expr) if $expr;
		1522	}
		1523
		1524	1
		1525	}
		1526
		1527	sub find_resource {
		1528	my ($self, $a, $b) = @_;
		1529
		1530	my $v = $self->x_resource ($a);
		1531	$v = $self->x_resource ($b) unless defined $v;
		1532
		1533	$v
		1534	}
		1535
779	sub on_start {	1536	sub on_start {
780	my ($self) = @_;	1537	my ($self) = @_;
781		1538
782	my $expr = $self->x_resource ("background.expr")	1539	my $expr = $self->x_resource ("%.expr");
		1540
		1541	if (!$expr) {
		1542	$self->{bg_opts} = { h_scale => 100, v_scale => 100,
		1543	h_align => 50, v_align => 50 };
		1544
		1545	$self->{bg_opts}->{shade} = $self->find_resource ("shading", "sh");
		1546	$self->{bg_opts}->{tint} = $self->find_resource ("tintColor", "tint");
		1547	$self->{bg_opts}->{blur} = $self->find_resource ("blurRadius", "blr");
		1548	if ($self->x_resource_boolean ("transparent")
		1549	or $self->x_resource_boolean ("tr")) {
		1550	$self->{bg_opts}->{root} = 1;
		1551	}
		1552
		1553	$self->old_bg_opts ($self->find_resource ("backgroundPixmap", "pixmap"));
		1554	$expr = $self->old_bg_expr;
		1555	}
		1556
783	or return;	1557	$expr or return;
		1558
		1559	$self->has_render
		1560	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
784		1561
785	$self->set_expr (parse_expr $expr);	1562	$self->set_expr (parse_expr $expr);
786	$self->{border} = $self->x_resource_boolean ("background.border");	1563	$self->{border} = $self->x_resource_boolean ("%.border");
		1564
		1565	$MIN_INTERVAL = $self->x_resource ("%.interval");
787		1566
788	()	1567	()
789	}	1568	}
790		1569

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