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Revision 1.37 by root, Fri Jun 8 20:35:43 2012 UTC vs.
Revision 1.95 by root, Tue Sep 17 17:29:16 2019 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
		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
5		16
6	#TODO: once, rootalign	17	=head1 NAME
7		18
8	=head1 background - manage terminal background	19	background - manage terminal background
9		20
10	=head2 SYNOPSIS	21	=head1 SYNOPSIS
11		22
12	urxvt --background-expr 'background expression'	23	urxvt --background-expr 'background expression'
13	--background-border	24	--background-border
		25	--background-interval seconds
14		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 }
		50
15	=head2 DESCRIPTION	51	=head1 DESCRIPTION
16		52
17	This extension manages the terminal background by creating a picture that	53	This extension manages the terminal background by creating a picture that
18	is behind the text, replacing the normal background colour.	54	is behind the text, replacing the normal background colour.
19		55
20	It does so by evaluating a Perl expression that I<calculates> the image on	56	It does so by evaluating a Perl expression that I<calculates> the image on
…		…
24	to be as simple as possible.	60	to be as simple as possible.
25		61
26	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
27	use:	63	use:
28		64
29	urxvt --background-expr 'scale load "/path/to/mybg.png"'	65	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
30		66
31	Or specified as a X resource:	67	Or specified as a X resource:
32		68
33	URxvt.background-expr: scale load "/path/to/mybg.png"	69	URxvt.background.expr: scale keep { load "/path/to/mybg.png" }
34		70
35	=head2 THEORY OF OPERATION	71	=head1 THEORY OF OPERATION
36		72
37	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
38	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
39	extended as necessary to cover the whole terminal window, and is set as a	75	extended as necessary to cover the whole terminal window, and is set as a
40	background pixmap.	76	background pixmap.
…		…
51	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
52	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
53	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
54	timer elapses), then the expression will be evaluated again.	90	timer elapses), then the expression will be evaluated again.
55		91
56	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"
57	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
58	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
59	example. That ensures that the picture always fills the terminal, even	95	example. That ensures that the picture always fills the terminal, even
60	after it's size changes.	96	after its size changes.
61		97
62	=head3 EXPRESSIONS	98	=head2 EXPRESSIONS
63		99
64	Expressions are normal Perl expressions, in fact, they are Perl blocks -	100	Expressions are normal Perl expressions, in fact, they are Perl blocks -
65	which means you could use multiple lines and statements:	101	which means you could use multiple lines and statements:
66		102
		103	scale keep {
67	again 3600;	104	again 3600;
68	if (localtime now)[6]) {	105	if (localtime now)[6]) {
69	return scale load "$HOME/weekday.png";	106	return load "$HOME/weekday.png";
70	} else {	107	} else {
71	return scale load "$HOME/sunday.png";	108	return load "$HOME/sunday.png";
		109	}
72	}	110	}
73		111
74	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
75	background on sundays, and F<weekday.png> on all other days.	114	Sundays, and F<weekday.png> on all other days.
76		115
77	Fortunately, we expect that most expressions will be much simpler, with	116	Fortunately, we expect that most expressions will be much simpler, with
78	little Perl knowledge needed.	117	little Perl knowledge needed.
79		118
80	Basically, you always start with a function that "generates" an image	119	Basically, you always start with a function that "generates" an image
…		…
97	its result becomes the argument to the C<scale> function.	136	its result becomes the argument to the C<scale> function.
98		137
99	Many operators also allow some parameters preceding the input image	138	Many operators also allow some parameters preceding the input image
100	that modify its behaviour. For example, C<scale> without any additional	139	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	140	arguments scales the image to size of the terminal window. If you specify
102	an additional argument, it uses it as a percentage:	141	an additional argument, it uses it as a scale factor (multiply by 100 to
		142	get a percentage):
103		143
104	scale 200, load "$HOME/mypic.png"	144	scale 2, load "$HOME/mypic.png"
105		145
106	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>
107	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
108	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
109	commas.	149	commas.
110		150
111	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
112	horizontal and vertical dimensions. For example, this halves the image	152	horizontal and vertical dimensions. For example, this halves the image
113	width and doubles the image height:	153	width and doubles the image height:
114		154
115	scale 50, 200, load "$HOME/mypic.png"	155	scale 0.5, 2, load "$HOME/mypic.png"
116		156
117	TODO	157	IF you try out these expressions, you might suffer from some sluggishness,
		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:
118		161
119	=head3 CYCLES AND CACHING	162	scale 0.5, 2, keep { load "$HOME/mypic.png" }
120		163
121	TODO	164	The C<keep> operator executes all the statements inside the braces only
		165	once, or when it thinks the outcome might change. In other cases it
		166	returns the last value computed by the brace block.
122		167
123	Each time the expression is reevaluated, a new cycle is said to have begun. Many operators	168	This means that the C<load> is only executed once, which makes it much
124	cache their results till the next cycle. For example	169	faster, but also means that more memory is being used, because the loaded
		170	image must be kept in memory at all times. In this expression, the
		171	trade-off is likely worth it.
125		172
		173	But back to effects: Other effects than scaling are also readily
		174	available, for example, you can tile the image to fill the whole window,
		175	instead of resizing it:
		176
		177	tile keep { load "$HOME/mypic.png" }
		178
		179	In fact, images returned by C<load> are in C<tile> mode by default, so the
		180	C<tile> operator is kind of superfluous.
		181
		182	Another common effect is to mirror the image, so that the same edges
		183	touch:
		184
		185	mirror keep { load "$HOME/mypic.png" }
		186
		187	Another common background expression is:
		188
		189	rootalign root
		190
		191	This one first takes a snapshot of the screen background image, and then
		192	moves it to the upper left corner of the screen (as opposed to the upper
		193	left corner of the terminal window)- the result is pseudo-transparency:
		194	the image seems to be static while the window is moved around.
		195
		196	=head2 COLOUR SPECIFICATIONS
		197
		198	Whenever an operator expects a "colour", then this can be specified in one
		199	of two ways: Either as string with an X11 colour specification, such as:
		200
		201	"red" # named colour
		202	"#f00" # simple rgb
		203	"[50]red" # red with 50% alpha
		204	"TekHVC:300/50/50" # anything goes
		205
		206	OR as an array reference with one, three or four components:
		207
		208	[0.5] # 50% gray, 100% alpha
		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
		211
		212	=head2 CACHING AND SENSITIVITY
		213
		214	Since some operations (such as C<load> and C<blur>) can take a long time,
		215	caching results can be very important for a smooth operation. Caching can
		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.
		219
		220	=head3 C<keep { ... }> caching
		221
		222	The most important way to cache expensive operations is to use C<keep {
		223	... }>. The C<keep> operator takes a block of multiple statements enclosed
		224	by C<{}> and keeps the return value in memory.
		225
		226	An expression can be "sensitive" to various external events, such as
		227	scaling or moving the window, root background changes and timers. Simply
		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.
		259
126	=head2 REFERENCE	260	=head1 REFERENCE
127		261
128	=head3 COMMAND LINE SWITCHES	262	=head2 COMMAND LINE SWITCHES
129		263
130	=over 4	264	=over 4
131		265
132	=item --background-expr perl-expression	266	=item --background-expr perl-expression
133		267
…		…
139	overwriting borders and any other areas, such as the scrollbar.	273	overwriting borders and any other areas, such as the scrollbar.
140		274
141	Specifying this flag changes the behaviour, so that the image only	275	Specifying this flag changes the behaviour, so that the image only
142	replaces the background of the character area.	276	replaces the background of the character area.
143		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
144	=back	287	=back
145		288
146	=cut	289	=cut
147		290
148	our $EXPR;#d#	291	our %_IMG_CACHE;
149	#$EXPR = 'move W * 0.1, -H * 0.1, resize W * 0.5, H * 0.5, repeat_none load "opensource.png"';
150	$EXPR = 'move -TX, -TY, load "argb.png"';
151	#$EXPR = '
152	# rotate W, H, 50, 50, counter 1/59.95, repeat_mirror,
153	# clip X, Y, W, H, repeat_mirror,
154	# load "/root/pix/das_fette_schwein.jpg"
155	#';
156	#$EXPR = 'solid "red"';
157	#$EXPR = 'blur root, 10, 10'
158	#$EXPR = 'blur move (root, -x, -y), 5, 5'
159	#resize load "/root/pix/das_fette_schwein.jpg", w, h
160
161	our $HOME;	292	our $HOME;
162	our ($self, $old, $new);	293	our ($self, $frame);
163	our ($x, $y, $w, $h);	294	our ($x, $y, $w, $h, $focus);
164		295
165	# enforce at least this interval between updates	296	# enforce at least this interval between updates
166	our $MIN_INTERVAL = 1/100;	297	our $MIN_INTERVAL = 6/59.951;
167		298
168	{	299	{
169	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.
		306
		307	use List::Util qw(min max sum shuffle);
170		308
171	=head2 PROVIDERS/GENERATORS	309	=head2 PROVIDERS/GENERATORS
172		310
173	These functions provide an image, by loading it from disk, grabbing it	311	These functions provide an image, by loading it from disk, grabbing it
174	from the root screen or by simply generating it. They are used as starting	312	from the root screen or by simply generating it. They are used as starting
…		…
179	=item load $path	317	=item load $path
180		318
181	Loads the image at the given C<$path>. The image is set to plane tiling	319	Loads the image at the given C<$path>. The image is set to plane tiling
182	mode.	320	mode.
183		321
184	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.
185		324
		325	=item load_uc $path
		326
		327	Load uncached - same as load, but does not cache the image, which means it
		328	is I<always> loaded from the filesystem again, even if another copy of it
		329	is in memory at the time.
		330
186	=cut	331	=cut
		332
		333	sub load_uc($) {
		334	$self->new_img_from_file ($_[0])
		335	}
187		336
188	sub load($) {	337	sub load($) {
189	my ($path) = @_;	338	my ($path) = @_;
190		339
191	$new->{load}{$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	}
192	}	345	}
193		346
194	=item root	347	=item root
195		348
196	Returns the root window pixmap, that is, hopefully, the background image	349	Returns the root window pixmap, that is, hopefully, the background image
197	of your screen. The image is set to extend mode.	350	of your screen.
198		351
199	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
200	reevaluated when the bg image changes.	353	reevaluated when the bg image changes.
201		354
202	=cut	355	=cut
203		356
204	sub root() {	357	sub root() {
205	$new->{rootpmap_sensitive} = 1;	358	$frame->[FR_AGAIN]{rootpmap} = 1;
206	die "root op not supported, exg, we need you";	359	$self->new_img_from_root
207	}	360	}
208		361
209	=item solid $colour	362	=item solid $colour
210		363
211	=item solid $width, $height, $colour	364	=item solid $width, $height, $colour
212		365
213	Creates a new image and completely fills it with the given colour. The	366	Creates a new image and completely fills it with the given colour. The
214	image is set to tiling mode.	367	image is set to tiling mode.
215		368
216	If <$width> and C<$height> are omitted, it creates a 1x1 image, which is	369	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
217	useful for solid backgrounds or for use in filtering effects.	370	useful for solid backgrounds or for use in filtering effects.
218		371
219	=cut	372	=cut
220		373
221	sub solid($$;$) {	374	sub solid($;$$) {
222	my $colour = pop;	375	my $colour = pop;
223		376
224	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);
225	$img->fill ($colour);	378	$img->fill ($colour);
226	$img	379	$img
227	}	380	}
228		381
229	=back	382	=item clone $img
230		383
231	=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.
232		386
233	The following functions provide variable data such as the terminal
234	window dimensions. Most of them make your expression sensitive to some
235	events, for example using C<TW> (terminal width) means your expression is
236	evaluated again when the terminal is resized.
237
238	=over 4
239
240	=item TX
241
242	=item TY
243
244	Return the X and Y coordinates of the terminal window (the terminal
245	window is the full window by default, and the character area only when in
246	border-respect mode).
247
248	Using these functions make your expression sensitive to window moves.
249
250	These functions are mainly useful to align images to the root window.
251
252	Example: load an image and align it so it looks as if anchored to the
253	background.
254
255	move -TX, -TY, load "mybg.png"
256
257	=item TW
258
259	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
260	terminal window is the full window by default, and the character area only
261	when in border-respect mode).
262
263	Using these functions make your expression sensitive to window resizes.
264
265	These functions are mainly useful to scale images, or to clip images to
266	the window size to conserve memory.
267
268	Example: take the screen background, clip it to the window size, blur it a
269	bit, align it to the window position and use it as background.
270
271	clip move -TX, -TY, blur 5, root
272
273	=cut	387	=cut
274		388
275	sub TX() { $new->{position_sensitive} = 1; $x }
276	sub TY() { $new->{position_sensitive} = 1; $y }
277	sub TW() { $new->{size_sensitive} = 1; $w }
278	sub TH() { $new->{size_sensitive} = 1; $h }
279
280	=item now
281
282	Returns the current time as (fractional) seconds since the epoch.
283
284	Using this expression does I<not> make your expression sensitive to time,
285	but the next two functions do.
286
287	=item again $seconds
288
289	When this function is used the expression will be reevaluated again in
290	C<$seconds> seconds.
291
292	Example: load some image and rotate it according to the time of day (as if it were
293	the hour pointer of a clock). Update this image every minute.
294
295	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
296
297	=item counter $seconds
298
299	Like C<again>, but also returns an increasing counter value, starting at
300	0, which might be useful for some simple animation effects.
301
302	=cut
303
304	sub now() { urxvt::NOW }
305
306	sub again($) {
307	$new->{again} = $_[0];
308	}
309
310	sub counter($) {	389	sub clone($) {
311	$new->{again} = $_[0];	390	$_[0]->clone
312	$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
313	}	435	}
314		436
315	=back	437	=back
316		438
317	=head2 TILING MODES	439	=head2 TILING MODES
…		…
350	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
351	image over another image or the background colour while leaving all	473	image over another image or the background colour while leaving all
352	background pixels outside the image unchanged.	474	background pixels outside the image unchanged.
353		475
354	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
355	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
356	in alpha mode, else background colour).	478	in alpha mode, else background colour).
357		479
358	pad load "mybg.png"	480	pad load "mybg.png"
359		481
360	=item extend $img	482	=item extend $img
361		483
362	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
363	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
364	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
365	same values as the pixels near the edge.	487	same values as the pixels near the edge.
366		488
367	Example: just for curiosity, how does this pixel extension stuff work?	489	Example: just for curiosity, how does this pixel extension stuff work?
368		490
…		…
394	$img	516	$img
395	}	517	}
396		518
397	=back	519	=back
398		520
399	=head2 PIXEL OPERATORS	521	=head2 VARIABLE VALUES
400		522
401	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.
402		528
403	=over 4	529	=over 4
404		530
405	=item clone $img	531	=item TX
406		532
407	Returns an exact copy of the image.	533	=item TY
408		534
409	=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).
410		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} = $_[0];
		619	}
		620
411	sub clone($) {	621	sub counter($) {
412	$_[0]->clone	622	$frame->[FR_AGAIN]{time} = $_[0];
		623	$frame->[FR_STATE]{counter} + 0
413	}	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
414		633
415	=item clip $img	634	=item clip $img
416		635
417	=item clip $width, $height, $img	636	=item clip $width, $height, $img
418		637
…		…
421	Clips an image to the given rectangle. If the rectangle is outside the	640	Clips an image to the given rectangle. If the rectangle is outside the
422	image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is	641	image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is
423	larger than the image, then the tiling mode defines how the extra pixels	642	larger than the image, then the tiling mode defines how the extra pixels
424	will be filled.	643	will be filled.
425		644
426	If C<$x> an C<$y> are missing, then C<0> is assumed for both.	645	If C<$x> and C<$y> are missing, then C<0> is assumed for both.
427		646
428	If C<$width> and C<$height> are missing, then the window size will be	647	If C<$width> and C<$height> are missing, then the window size will be
429	assumed.	648	assumed.
430		649
431	Example: load an image, blur it, and clip it to the window size to save	650	Example: load an image, blur it, and clip it to the window size to save
432	memory.	651	memory.
433		652
434	clip blur 10, load "mybg.png"	653	clip keep { blur 10, load "mybg.png" }
435		654
436	=cut	655	=cut
437		656
438	sub clip($;$$;$$) {	657	sub clip($;$$;$$) {
439	my $img = pop;	658	my $img = pop;
…		…
442	$img->sub_rect ($_[0], $_[1], $w, $h)	661	$img->sub_rect ($_[0], $_[1], $w, $h)
443	}	662	}
444		663
445	=item scale $img	664	=item scale $img
446		665
447	=item scale $size_percent, $img	666	=item scale $size_factor, $img
448		667
449	=item scale $width_percent, $height_percent, $img	668	=item scale $width_factor, $height_factor, $img
450		669
451	Scales the image by the given percentages in horizontal	670	Scales the image by the given factors in horizontal
452	(C<$width_percent>) and vertical (C<$height_percent>) direction.	671	(C<$width>) and vertical (C<$height>) direction.
453		672
454	If only one percentage is give, it is used for both directions.	673	If only one factor is given, it is used for both directions.
455		674
456	If no percentages are given, scales the image to the window size without	675	If no factors are given, scales the image to the window size without
457	keeping aspect.	676	keeping aspect.
458		677
459	=item resize $width, $height, $img	678	=item resize $width, $height, $img
460		679
461	Resizes the image to exactly C<$width> times C<$height> pixels.	680	Resizes the image to exactly C<$width> times C<$height> pixels.
462		681
463	=cut	682	=item fit $img
464		683
465	#TODO: maximise, maximise_fill?	684	=item fit $width, $height, $img
		685
		686	Fits the image into the given C<$width> and C<$height> without changing
		687	aspect, or the terminal size. That means it will be shrunk or grown until
		688	the whole image fits into the given area, possibly leaving borders.
		689
		690	=item cover $img
		691
		692	=item cover $width, $height, $img
		693
		694	Similar to C<fit>, but shrinks or grows until all of the area is covered
		695	by the image, so instead of potentially leaving borders, it will cut off
		696	image data that doesn't fit.
		697
		698	=cut
466		699
467	sub scale($;$;$) {	700	sub scale($;$;$) {
468	my $img = pop;	701	my $img = pop;
469		702
470	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	703	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
471	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	704	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
472	: $img->scale (TW, TH)	705	: $img->scale (TW, TH)
473	}	706	}
474		707
475	sub resize($$$) {	708	sub resize($$$) {
476	my $img = pop;	709	my $img = pop;
477	$img->scale ($_[0], $_[1])	710	$img->scale ($_[0], $_[1])
478	}	711	}
479		712
		713	sub fit($;$$) {
		714	my $img = pop;
		715	my $w = ($_[0] || TW) / $img->w;
		716	my $h = ($_[1] || TH) / $img->h;
		717	scale +(min $w, $h), $img
		718	}
		719
		720	sub cover($;$$) {
		721	my $img = pop;
		722	my $w = ($_[0] || TW) / $img->w;
		723	my $h = ($_[1] || TH) / $img->h;
		724	scale +(max $w, $h), $img
		725	}
		726
480	=item move $dx, $dy, $img	727	=item move $dx, $dy, $img
481		728
482	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	729	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
483	the vertical.	730	the vertical.
484		731
485	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.
486		733
487	move 20, 30, ...	734	move 20, 30, ...
		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" }
488		758
489	=item rootalign $img	759	=item rootalign $img
490		760
491	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
492	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
493	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
494	top left of the screen.	764	top left of the screen.
495		765
496	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.
497		767
498	rootalign mirror load "mybg.png"	768	rootalign keep { mirror load "mybg.png" }
499		769
500	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
501	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.
502		772
503	rootalign root	773	rootalign root
504		774
505	=cut	775	=cut
506		776
507	sub move($$;$) {	777	sub move($$;$) {
508	my $img = pop->clone;	778	my $img = pop->clone;
509	$img->move ($_[0], $_[1]);	779	$img->move ($_[0], $_[1]);
510	$img	780	$img
511	}	781	}
512		782
		783	sub align($;$$) {
		784	my $img = pop;
		785
		786	move $_[0] * (TW - $img->w),
		787	$_[1] * (TH - $img->h),
		788	$img
		789	}
		790
		791	sub center($;$$) {
		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), $img
		797	}
		798
513	sub rootalign($) {	799	sub rootalign($) {
514	move -TX, -TY, $_[0]	800	move -TX, -TY, $_[0]
515	}	801	}
516		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($$) {
		856	$_[1]->shade ($_[0])
		857	}
		858
517	=item contrast $factor, $img	859	=item contrast $factor, $img
518		860
519	=item contrast $r, $g, $b, $img	861	=item contrast $r, $g, $b, $img
520		862
521	=item contrast $r, $g, $b, $a, $img	863	=item contrast $r, $g, $b, $a, $img
522		864
523	Adjusts the I<contrast> of an image.	865	Adjusts the I<contrast> of an image.
524		866
		867	The first form applies a single C<$factor> to red, green and blue, the
		868	second form applies separate factors to each colour channel, and the last
		869	form includes the alpha channel.
		870
		871	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		872	contrast.
		873
		874	Due to limitations in the underlying XRender extension, lowering contrast
		875	also reduces brightness, while increasing contrast currently also
		876	increases brightness.
		877
525	=item brightness $factor, $img	878	=item brightness $bias, $img
526		879
527	=item brightness $r, $g, $b, $img	880	=item brightness $r, $g, $b, $img
528		881
529	=item brightness $r, $g, $b, $a, $img	882	=item brightness $r, $g, $b, $a, $img
		883
		884	Adjusts the brightness of an image.
		885
		886	The first form applies a single C<$bias> to red, green and blue, the
		887	second form applies separate biases to each colour channel, and the last
		888	form includes the alpha channel.
		889
		890	Values less than 0 reduce brightness, while values larger than 0 increase
		891	it. Useful range is from -1 to 1 - the former results in a black, the
		892	latter in a white picture.
		893
		894	Due to idiosyncrasies in the underlying XRender extension, biases less
		895	than zero can be I<very> slow.
		896
		897	You can also try the experimental(!) C<muladd> operator.
530		898
531	=cut	899	=cut
532		900
533	sub contrast($$;$$;$) {	901	sub contrast($$;$$;$) {
534	my $img = pop;	902	my $img = pop;
535	my ($r, $g, $b, $a) = @_;	903	my ($r, $g, $b, $a) = @_;
536		904
537	($g, $b) = ($r, $r) if @_ < 4;	905	($g, $b) = ($r, $r) if @_ < 3;
538	$a = 1 if @_ < 5;	906	$a = 1 if @_ < 4;
539		907
540	$img = $img->clone;	908	$img = $img->clone;
541	$img->contrast ($r, $g, $b, $a);	909	$img->contrast ($r, $g, $b, $a);
542	$img	910	$img
543	}	911	}
544		912
545	sub brightness($$;$$;$) {	913	sub brightness($$;$$;$) {
546	my $img = pop;	914	my $img = pop;
547	my ($r, $g, $b, $a) = @_;	915	my ($r, $g, $b, $a) = @_;
548		916
549	($g, $b) = ($r, $r) if @_ < 4;	917	($g, $b) = ($r, $r) if @_ < 3;
550	$a = 1 if @_ < 5;	918	$a = 1 if @_ < 4;
551		919
552	$img = $img->clone;	920	$img = $img->clone;
553	$img->brightness ($r, $g, $b, $a);	921	$img->brightness ($r, $g, $b, $a);
554	$img	922	$img
555	}	923	}
556		924
		925	=item muladd $mul, $add, $img # EXPERIMENTAL
		926
		927	First multiplies the pixels by C<$mul>, then adds C<$add>. This can be used
		928	to implement brightness and contrast at the same time, with a wider value
		929	range than contrast and brightness operators.
		930
		931	Due to numerous bugs in XRender implementations, it can also introduce a
		932	number of visual artifacts.
		933
		934	Example: increase contrast by a factor of C<$c> without changing image
		935	brightness too much.
		936
		937	muladd $c, (1 - $c) * 0.5, $img
		938
		939	=cut
		940
		941	sub muladd($$$) {
		942	$_[2]->muladd ($_[0], $_[1])
		943	}
		944
		945	=item blur $radius, $img
		946
		947	=item blur $radius_horz, $radius_vert, $img
		948
		949	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
		950	can also be specified separately.
		951
		952	Blurring is often I<very> slow, at least compared or other
		953	operators. Larger blur radii are slower than smaller ones, too, so if you
		954	don't want to freeze your screen for long times, start experimenting with
		955	low values for radius (<5).
		956
		957	=cut
		958
557	sub blur($$;$) {	959	sub blur($$;$) {
558	my $img = pop;	960	my $img = pop;
559	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	961	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
560	}	962	}
561		963
562	sub rotate($$$$$$) {	964	=item focus_fade $img
		965
		966	=item focus_fade $factor, $img
		967
		968	=item focus_fade $factor, $color, $img
		969
		970	Fades the image by the given factor (and colour) when focus is lost (the
		971	same as the C<-fade>/C<-fadecolor> command line options, which also supply
		972	the default values for C<factor> and C<$color>. Unlike with C<-fade>, the
		973	C<$factor> is a real value, not a percentage value (that is, 0..1, not
		974	0..100).
		975
		976	Example: do the right thing when focus fading is requested.
		977
		978	focus_fade load "mybg.jpg";
		979
		980	=cut
		981
		982	sub focus_fade($;$$) {
563	my $img = pop;	983	my $img = pop;
564	$img->rotate (	984
565	$_[0],	985	return $img
566	$_[1],	986	if FOCUS;
567	$_[2] * $img->w * .01,	987
568	$_[3] * $img->h * .01,	988	my $fade = @_ >= 1 ? $_[0] : defined $self->resource ("fade") ? $self->resource ("fade") * 0.01 : 0;
569	$_[4] * (3.14159265 / 180),	989	my $color = @_ >= 2 ? $_[1] : $self->resource ("color+" . urxvt::Color_fade);
570	)	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
571	}	995	}
572		996
573	=back	997	=back
574		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
575	=cut	1214	=cut
576		1215
577	}	1216	}
578		1217
579	sub parse_expr {	1218	sub parse_expr {
580	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	. "}";
581	die if $@;	1225	die if $@;
582	$expr	1226	$expr
583	}	1227	}
584		1228
585	# compiles a parsed expression	1229	# compiles a parsed expression
586	sub set_expr {	1230	sub set_expr {
587	my ($self, $expr) = @_;	1231	my ($self, $expr) = @_;
588		1232
		1233	$self->{root} = []; # the outermost frame
589	$self->{expr} = $expr;	1234	$self->{expr} = $expr;
590	$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 $state->{focus};
		1289	}
591	}	1290	}
592		1291
593	# evaluate the current bg expression	1292	# evaluate the current bg expression
594	sub recalculate {	1293	sub recalculate {
595	my ($arg_self) = @_;	1294	my ($arg_self) = @_;
…		…
605		1304
606	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1305	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
607		1306
608	# set environment to evaluate user expression	1307	# set environment to evaluate user expression
609		1308
610	local $self = $arg_self;	1309	local $self = $arg_self;
611
612	local $HOME = $ENV{HOME};	1310	local $HOME = $ENV{HOME};
613	local $old = $self->{state};	1311	local $frame = $self->{root};
614	local $new = my $state = $self->{state} = {};
615		1312
616	($x, $y, $w, $h) =
617	$self->background_geometry ($self->{border});	1313	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
		1314	$focus = $self->focus;
618		1315
619	# evaluate user expression	1316	# evaluate user expression
620		1317
621	my $img = eval { $self->{expr}->() };	1318	my @img = eval { $self->{expr}->() };
622	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"
623	die if !UNIVERSAL::isa $img, "urxvt::img";	1322	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
624		1323
625	$state->{size_sensitive} = 1	1324	my $img = urxvt::bgdsl::merge @img;
		1325
		1326	$frame->[FR_AGAIN]{size} = 1
626	if $img->repeat_mode != urxvt::RepeatNormal;	1327	if $img->repeat_mode != urxvt::RepeatNormal;
627		1328
628	# if the expression is sensitive to external events, prepare reevaluation then	1329	# if the expression is sensitive to external events, prepare reevaluation then
629		1330	$self->compile_frame ($frame, sub { $arg_self->recalculate });
630	my $repeat;
631
632	if (my $again = $state->{again}) {
633	$repeat = 1;
634	my $self = $self;
635	$state->{timer} = $again == $old->{again}
636	? $old->{timer}
637	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
638	++$self->{counter};
639	$self->recalculate
640	});
641	}
642
643	if (delete $state->{position_sensitive}) {
644	$repeat = 1;
645	$self->enable (position_change => sub { $_[0]->recalculate });
646	} else {
647	$self->disable ("position_change");
648	}
649
650	if (delete $state->{size_sensitive}) {
651	$repeat = 1;
652	$self->enable (size_change => sub { $_[0]->recalculate });
653	} else {
654	$self->disable ("size_change");
655	}
656
657	if (delete $state->{rootpmap_sensitive}) {
658	$repeat = 1;
659	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
660	} else {
661	$self->disable ("rootpmap_change");
662	}
663		1331
664	# clear stuff we no longer need	1332	# clear stuff we no longer need
665		1333
666	%$old = ();	1334	# unless (%{ $frame->[FR_STATE] }) {
667
668	unless ($repeat) {
669	delete $self->{state};	1335	# delete $self->{state};
670	delete $self->{expr};	1336	# delete $self->{expr};
671	}	1337	# }
672		1338
673	# set background pixmap	1339	# set background pixmap
674		1340
675	$self->set_background ($img, $self->{border});	1341	$self->set_background ($img, $self->{border});
676	$self->scr_recolour (0);	1342	$self->scr_recolor (0);
677	$self->want_refresh;	1343	$self->want_refresh;
678	}	1344	}
679		1345
		1346	sub old_bg_opts {
		1347	my ($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} =~ /^\s*(?:true|yes|on|1)\s*$/i) {
		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, $res, $opt) = @_;
		1529
		1530	my $v = $self->x_resource ($opt);
		1531	$v = $self->x_resource ($res) unless defined $v;
		1532
		1533	$v
		1534	}
		1535
680	sub on_start {	1536	sub on_start {
681	my ($self) = @_;	1537	my ($self) = @_;
682		1538
683	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	$self->{bg_opts}->{root} = $self->find_resource ("transparent", "tr");
		1549
		1550	$self->old_bg_opts ($self->find_resource ("backgroundPixmap", "pixmap"));
		1551	$expr = $self->old_bg_expr;
		1552	}
		1553
684	or return;	1554	$expr or return;
		1555
		1556	$self->has_render
		1557	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
685		1558
686	$self->set_expr (parse_expr $expr);	1559	$self->set_expr (parse_expr $expr);
687	$self->{border} = $self->x_resource_boolean ("background.border");	1560	$self->{border} = $self->x_resource_boolean ("%.border");
		1561
		1562	$MIN_INTERVAL = $self->x_resource ("%.interval");
688		1563
689	()	1564	()
690	}	1565	}
691		1566

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