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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC vs.
Revision 1.90 by sf-exg, Mon Mar 16 10:06:09 2015 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:X_RESOURCE:%.interval:seconds:minimum time between updates	5	#:META:RESOURCE:%.interval:seconds:minimum time between updates
6		6
7	=head1 NAME	7	=head1 NAME
8		8
9	background - manage terminal background	9	background - manage terminal background
10		10
11	=head1 SYNOPSIS	11	=head1 SYNOPSIS
12		12
13	urxvt --background-expr 'background expression'	13	urxvt --background-expr 'background expression'
14	--background-border	14	--background-border
15	--background-interval seconds	15	--background-interval seconds
16		16
		17	=head1 QUICK AND DIRTY CHEAT SHEET
		18
		19	Just load a random jpeg image and tile the background with it without
		20	scaling or anything else:
		21
		22	load "/path/to/img.jpg"
		23
		24	The same, but use mirroring/reflection instead of tiling:
		25
		26	mirror load "/path/to/img.jpg"
		27
		28	Load an image and scale it to exactly fill the terminal window:
		29
		30	scale keep { load "/path/to/img.jpg" }
		31
		32	Implement pseudo-transparency by using a suitably-aligned root pixmap
		33	as window background:
		34
		35	rootalign root
		36
		37	Likewise, but keep a blurred copy:
		38
		39	rootalign keep { blur 10, root }
		40
17	=head1 DESCRIPTION	41	=head1 DESCRIPTION
18		42
19	This extension manages the terminal background by creating a picture that	43	This extension manages the terminal background by creating a picture that
20	is behind the text, replacing the normal background colour.	44	is behind the text, replacing the normal background colour.
21		45
26	to be as simple as possible.	50	to be as simple as possible.
27		51
28	For example, to load an image and scale it to the window size, you would	52	For example, to load an image and scale it to the window size, you would
29	use:	53	use:
30		54
31	urxvt --background-expr 'scale load "/path/to/mybg.png"'	55	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
32		56
33	Or specified as a X resource:	57	Or specified as a X resource:
34		58
35	URxvt.background-expr: scale load "/path/to/mybg.png"	59	URxvt.background.expr: scale keep { load "/path/to/mybg.png" }
36		60
37	=head1 THEORY OF OPERATION	61	=head1 THEORY OF OPERATION
38		62
39	At startup, just before the window is mapped for the first time, the	63	At startup, just before the window is mapped for the first time, the
40	expression is evaluated and must yield an image. The image is then	64	expression is evaluated and must yield an image. The image is then
…		…
53	If any of the parameters that the expression relies on changes (when the	77	If any of the parameters that the expression relies on changes (when the
54	window is moved or resized, its position or size changes; when the root	78	window is moved or resized, its position or size changes; when the root
55	pixmap is replaced by another one the root background changes; or when the	79	pixmap is replaced by another one the root background changes; or when the
56	timer elapses), then the expression will be evaluated again.	80	timer elapses), then the expression will be evaluated again.
57		81
58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	82	For example, an expression such as C<scale keep { load "$HOME/mybg.png"
59	image to the window size, so it relies on the window size and will	83	}> scales the image to the window size, so it relies on the window size
60	be reevaluated each time it is changed, but not when it moves for	84	and will be reevaluated each time it is changed, but not when it moves for
61	example. That ensures that the picture always fills the terminal, even	85	example. That ensures that the picture always fills the terminal, even
62	after its size changes.	86	after its size changes.
63		87
64	=head2 EXPRESSIONS	88	=head2 EXPRESSIONS
65		89
66	Expressions are normal Perl expressions, in fact, they are Perl blocks -	90	Expressions are normal Perl expressions, in fact, they are Perl blocks -
67	which means you could use multiple lines and statements:	91	which means you could use multiple lines and statements:
68		92
		93	scale keep {
69	again 3600;	94	again 3600;
70	if (localtime now)[6]) {	95	if (localtime now)[6]) {
71	return scale load "$HOME/weekday.png";	96	return load "$HOME/weekday.png";
72	} else {	97	} else {
73	return scale load "$HOME/sunday.png";	98	return load "$HOME/sunday.png";
		99	}
74	}	100	}
75		101
76	This expression is evaluated once per hour. It will set F<sunday.png> as	102	This inner expression is evaluated once per hour (and whenever the
		103	terminal window is resized). It sets F<sunday.png> as background on
77	background on Sundays, and F<weekday.png> on all other days.	104	Sundays, and F<weekday.png> on all other days.
78		105
79	Fortunately, we expect that most expressions will be much simpler, with	106	Fortunately, we expect that most expressions will be much simpler, with
80	little Perl knowledge needed.	107	little Perl knowledge needed.
81		108
82	Basically, you always start with a function that "generates" an image	109	Basically, you always start with a function that "generates" an image
…		…
115	horizontal and vertical dimensions. For example, this halves the image	142	horizontal and vertical dimensions. For example, this halves the image
116	width and doubles the image height:	143	width and doubles the image height:
117		144
118	scale 0.5, 2, load "$HOME/mypic.png"	145	scale 0.5, 2, load "$HOME/mypic.png"
119		146
120	Other effects than scaling are also readily available, for example, you can	147	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:	148	because each time the terminal is resized, it loads the PNG image again
		149	and scales it. Scaling is usually fast (and unavoidable), but loading the
		150	image can be quite time consuming. This is where C<keep> comes in handy:
122		151
		152	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		153
		154	The C<keep> operator executes all the statements inside the braces only
		155	once, or when it thinks the outcome might change. In other cases it
		156	returns the last value computed by the brace block.
		157
		158	This means that the C<load> is only executed once, which makes it much
		159	faster, but also means that more memory is being used, because the loaded
		160	image must be kept in memory at all times. In this expression, the
		161	trade-off is likely worth it.
		162
		163	But back to effects: Other effects than scaling are also readily
		164	available, for example, you can tile the image to fill the whole window,
		165	instead of resizing it:
		166
123	tile load "$HOME/mypic.png"	167	tile keep { load "$HOME/mypic.png" }
124		168
125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	169	In fact, images returned by C<load> are in C<tile> mode by default, so the
126	is kind of superfluous.	170	C<tile> operator is kind of superfluous.
127		171
128	Another common effect is to mirror the image, so that the same edges touch:	172	Another common effect is to mirror the image, so that the same edges
		173	touch:
129		174
130	mirror load "$HOME/mypic.png"	175	mirror keep { load "$HOME/mypic.png" }
131		176
132	This is also a typical background expression:	177	Another common background expression is:
133		178
134	rootalign root	179	rootalign root
135		180
136	It first takes a snapshot of the screen background image, and then	181	This one first takes a snapshot of the screen background image, and then
137	moves it to the upper left corner of the screen - the result is	182	moves it to the upper left corner of the screen (as opposed to the upper
138	pseudo-transparency, as the image seems to be static while the window is	183	left corner of the terminal window)- the result is pseudo-transparency:
139	moved around.	184	the image seems to be static while the window is moved around.
140		185
141	=head2 CYCLES AND CACHING	186	=head2 COLOUR SPECIFICATIONS
142		187
143	As has been mentioned before, the expression might be evaluated multiple	188	Whenever an operator expects a "colour", then this can be specified in one
144	times. Each time the expression is reevaluated, a new cycle is said to	189	of two ways: Either as string with an X11 colour specification, such as:
145	have begun. Many operators cache their results till the next cycle.
146		190
147	For example, the C<load> operator keeps a copy of the image. If it is	191	"red" # named colour
148	asked to load the same image on the next cycle it will not load it again,	192	"#f00" # simple rgb
149	but return the cached copy.	193	"[50]red" # red with 50% alpha
		194	"TekHVC:300/50/50" # anything goes
150		195
151	This only works for one cycle though, so as long as you load the same	196	OR as an array reference with one, three or four components:
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		197
155	This allows you to either speed things up by keeping multiple images in	198	[0.5] # 50% gray, 100% alpha
156	memory, or conserve memory by loading images more often.	199	[0.5, 0, 0] # dark red, no green or blur, 100% alpha
		200	[0.5, 0, 0, 0.7] # same with explicit 70% alpha
157		201
158	For example, you can keep two images in memory and use a random one like	202	=head2 CACHING AND SENSITIVITY
159	this:
160		203
161	my $img1 = load "img1.png";	204	Since some operations (such as C<load> and C<blur>) can take a long time,
162	my $img2 = load "img2.png";	205	caching results can be very important for a smooth operation. Caching can
163	(0.5 > rand) ? $img1 : $img2	206	also be useful to reduce memory usage, though, for example, when an image
		207	is cached by C<load>, it could be shared by multiple terminal windows
		208	running inside urxvtd.
164		209
165	Since both images are "loaded" every time the expression is evaluated,	210	=head3 C<keep { ... }> caching
166	they are always kept in memory. Contrast this version:
167		211
168	my $path1 = "img1.png";	212	The most important way to cache expensive operations is to use C<keep {
169	my $path2 = "img2.png";	213	... }>. The C<keep> operator takes a block of multiple statements enclosed
170	load ((0.5 > rand) ? $path1 : $path2)	214	by C<{}> and keeps the return value in memory.
171		215
172	Here, a path is selected randomly, and load is only called for one image,	216	An expression can be "sensitive" to various external events, such as
173	so keeps only one image in memory. If, on the next evaluation, luck	217	scaling or moving the window, root background changes and timers. Simply
174	decides to use the other path, then it will have to load that image again.	218	using an expression (such as C<scale> without parameters) that depends on
		219	certain changing values (called "variables"), or using those variables
		220	directly, will make an expression sensitive to these events - for example,
		221	using C<scale> or C<TW> will make the expression sensitive to the terminal
		222	size, and thus to resizing events.
		223
		224	When such an event happens, C<keep> will automatically trigger a
		225	reevaluation of the whole expression with the new value of the expression.
		226
		227	C<keep> is most useful for expensive operations, such as C<blur>:
		228
		229	rootalign keep { blur 20, root }
		230
		231	This makes a blurred copy of the root background once, and on subsequent
		232	calls, just root-aligns it. Since C<blur> is usually quite slow and
		233	C<rootalign> is quite fast, this trades extra memory (for the cached
		234	blurred pixmap) with speed (blur only needs to be redone when root
		235	changes).
		236
		237	=head3 C<load> caching
		238
		239	The C<load> operator itself does not keep images in memory, but as long as
		240	the image is still in memory, C<load> will use the in-memory image instead
		241	of loading it freshly from disk.
		242
		243	That means that this expression:
		244
		245	keep { load "$HOME/path..." }
		246
		247	Not only caches the image in memory, other terminal instances that try to
		248	C<load> it can reuse that in-memory copy.
175		249
176	=head1 REFERENCE	250	=head1 REFERENCE
177		251
178	=head2 COMMAND LINE SWITCHES	252	=head2 COMMAND LINE SWITCHES
179		253
…		…
203	=back	277	=back
204		278
205	=cut	279	=cut
206		280
207	our %_IMG_CACHE;	281	our %_IMG_CACHE;
208	our %_ONCE_CACHE;
209	our $HOME;	282	our $HOME;
210	our ($self, $old, $new);	283	our ($self, $frame);
211	our ($x, $y, $w, $h);	284	our ($x, $y, $w, $h, $focus);
212		285
213	# enforce at least this interval between updates	286	# enforce at least this interval between updates
214	our $MIN_INTERVAL = 6/59.951;	287	our $MIN_INTERVAL = 6/59.951;
215		288
216	{	289	{
217	package urxvt::bgdsl; # background language	290	package urxvt::bgdsl; # background language
		291
		292	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		293	sub FR_CACHE () { 1 } # cached values
		294	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		295	sub FR_STATE () { 3 } # watchers etc.
218		296
219	use List::Util qw(min max sum shuffle);	297	use List::Util qw(min max sum shuffle);
220		298
221	=head2 PROVIDERS/GENERATORS	299	=head2 PROVIDERS/GENERATORS
222		300
…		…
229	=item load $path	307	=item load $path
230		308
231	Loads the image at the given C<$path>. The image is set to plane tiling	309	Loads the image at the given C<$path>. The image is set to plane tiling
232	mode.	310	mode.
233		311
234	Loaded images will be cached for one cycle, and shared between temrinals	312	If the image is already in memory (e.g. because another terminal instance
235	running in the same process (e.g. in C<urxvtd>).	313	uses it), then the in-memory copy is returned instead.
236		314
237	=item load_uc $path	315	=item load_uc $path
238		316
239	Load uncached - same as load, but does not cache the image. This function	317	Load uncached - same as load, but does not cache the image, which means it
240	is most useufl if you want to optimise a background expression in some	318	is I<always> loaded from the filesystem again, even if another copy of it
241	way.	319	is in memory at the time.
242		320
243	=cut	321	=cut
244		322
245	sub load_uc($) {	323	sub load_uc($) {
		324	$self->new_img_from_file ($_[0])
		325	}
		326
		327	sub load($) {
246	my ($path) = @_;	328	my ($path) = @_;
247		329
248	$_IMG_CACHE{$path} \|\| do {	330	$_IMG_CACHE{$path} \|\| do {
249	my $img = $self->new_img_from_file ($path);	331	my $img = load_uc $path;
250	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);	332	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
251	$img	333	$img
252	}	334	}
253	}	335	}
254		336
255	sub load($) {
256	my ($path) = @_;
257
258	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
259	}
260
261	=item root	337	=item root
262		338
263	Returns the root window pixmap, that is, hopefully, the background image	339	Returns the root window pixmap, that is, hopefully, the background image
264	of your screen. The image is set to extend mode.	340	of your screen.
265		341
266	This function makes your expression root sensitive, that means it will be	342	This function makes your expression root sensitive, that means it will be
267	reevaluated when the bg image changes.	343	reevaluated when the bg image changes.
268		344
269	=cut	345	=cut
270		346
271	sub root() {	347	sub root() {
272	$new->{rootpmap_sensitive} = 1;	348	$frame->[FR_AGAIN]{rootpmap} = 1;
273	$self->new_img_from_root	349	$self->new_img_from_root
274	}	350	}
275		351
276	=item solid $colour	352	=item solid $colour
277		353
…		…
286	=cut	362	=cut
287		363
288	sub solid($;$$) {	364	sub solid($;$$) {
289	my $colour = pop;	365	my $colour = pop;
290		366
291	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	367	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
292	$img->fill ($colour);	368	$img->fill ($colour);
293	$img	369	$img
294	}	370	}
295		371
296	=item clone $img	372	=item clone $img
…		…
301	=cut	377	=cut
302		378
303	sub clone($) {	379	sub clone($) {
304	$_[0]->clone	380	$_[0]->clone
305	}	381	}
		382
		383	=item merge $img ...
		384
		385	Takes any number of images and merges them together, creating a single
		386	image containing them all. The tiling mode of the first image is used as
		387	the tiling mode of the resulting image.
		388
		389	This function is called automatically when an expression returns multiple
		390	images.
		391
		392	=cut
		393
		394	sub merge(@) {
		395	return $_[0] unless $#_;
		396
		397	# rather annoyingly clumsy, but optimisation is for another time
		398
		399	my $x0 = +1e9;
		400	my $y0 = +1e9;
		401	my $x1 = -1e9;
		402	my $y1 = -1e9;
		403
		404	for (@_) {
		405	my ($x, $y, $w, $h) = $_->geometry;
		406
		407	$x0 = $x if $x0 > $x;
		408	$y0 = $y if $y0 > $y;
		409
		410	$x += $w;
		411	$y += $h;
		412
		413	$x1 = $x if $x1 < $x;
		414	$y1 = $y if $y1 < $y;
		415	}
		416
		417	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		418	$base->repeat_mode ($_[0]->repeat_mode);
		419	$base->fill ([0, 0, 0, 0]);
		420
		421	$base->draw ($_)
		422	for @_;
		423
		424	$base
		425	}
		426
		427	=back
306		428
307	=head2 TILING MODES	429	=head2 TILING MODES
308		430
309	The following operators modify the tiling mode of an image, that is, the	431	The following operators modify the tiling mode of an image, that is, the
310	way that pixels outside the image area are painted when the image is used.	432	way that pixels outside the image area are painted when the image is used.
…		…
402		524
403	Return the X and Y coordinates of the terminal window (the terminal	525	Return the X and Y coordinates of the terminal window (the terminal
404	window is the full window by default, and the character area only when in	526	window is the full window by default, and the character area only when in
405	border-respect mode).	527	border-respect mode).
406		528
407	Using these functions make your expression sensitive to window moves.	529	Using these functions makes your expression sensitive to window moves.
408		530
409	These functions are mainly useful to align images to the root window.	531	These functions are mainly useful to align images to the root window.
410		532
411	Example: load an image and align it so it looks as if anchored to the	533	Example: load an image and align it so it looks as if anchored to the
412	background.	534	background (that's exactly what C<rootalign> does btw.):
413		535
414	move -TX, -TY, load "mybg.png"	536	move -TX, -TY, keep { load "mybg.png" }
415		537
416	=item TW	538	=item TW
		539
		540	=item TH
417		541
418	Return the width (C<TW>) and height (C<TH>) of the terminal window (the	542	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
419	terminal window is the full window by default, and the character area only	543	terminal window is the full window by default, and the character area only
420	when in border-respect mode).	544	when in border-respect mode).
421		545
422	Using these functions make your expression sensitive to window resizes.	546	Using these functions makes your expression sensitive to window resizes.
423		547
424	These functions are mainly useful to scale images, or to clip images to	548	These functions are mainly useful to scale images, or to clip images to
425	the window size to conserve memory.	549	the window size to conserve memory.
426		550
427	Example: take the screen background, clip it to the window size, blur it a	551	Example: take the screen background, clip it to the window size, blur it a
428	bit, align it to the window position and use it as background.	552	bit, align it to the window position and use it as background.
429		553
430	clip move -TX, -TY, blur 5, root	554	clip move -TX, -TY, keep { blur 5, root }
431		555
432	=cut	556	=item FOCUS
433		557
434	sub TX() { $new->{position_sensitive} = 1; $x }	558	Returns a boolean indicating whether the terminal window has keyboard
435	sub TY() { $new->{position_sensitive} = 1; $y }	559	focus, in which case it returns true.
436	sub TW() { $new->{size_sensitive} = 1; $w }	560
437	sub TH() { $new->{size_sensitive} = 1; $h }	561	Using this function makes your expression sensitive to focus changes.
		562
		563	A common use case is to fade the background image when the terminal loses
		564	focus, often together with the C<-fade> command line option. In fact,
		565	there is a special function for just that use case: C<focus_fade>.
		566
		567	Example: use two entirely different background images, depending on
		568	whether the window has focus.
		569
		570	FOCUS ? keep { load "has_focus.jpg" } : keep { load "no_focus.jpg" }
		571
		572	=cut
		573
		574	sub TX () { $frame->[FR_AGAIN]{position} = 1; $x }
		575	sub TY () { $frame->[FR_AGAIN]{position} = 1; $y }
		576	sub TW () { $frame->[FR_AGAIN]{size} = 1; $w }
		577	sub TH () { $frame->[FR_AGAIN]{size} = 1; $h }
		578	sub FOCUS() { $frame->[FR_AGAIN]{focus} = 1; $focus }
438		579
439	=item now	580	=item now
440		581
441	Returns the current time as (fractional) seconds since the epoch.	582	Returns the current time as (fractional) seconds since the epoch.
442		583
…		…
449	C<$seconds> seconds.	590	C<$seconds> seconds.
450		591
451	Example: load some image and rotate it according to the time of day (as if it were	592	Example: load some image and rotate it according to the time of day (as if it were
452	the hour pointer of a clock). Update this image every minute.	593	the hour pointer of a clock). Update this image every minute.
453		594
		595	again 60;
454	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	596	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
455		597
456	=item counter $seconds	598	=item counter $seconds
457		599
458	Like C<again>, but also returns an increasing counter value, starting at	600	Like C<again>, but also returns an increasing counter value, starting at
459	0, which might be useful for some simple animation effects.	601	0, which might be useful for some simple animation effects.
…		…
461	=cut	603	=cut
462		604
463	sub now() { urxvt::NOW }	605	sub now() { urxvt::NOW }
464		606
465	sub again($) {	607	sub again($) {
466	$new->{again} = $_[0];	608	$frame->[FR_AGAIN]{time} = $_[0];
467	}	609	}
468		610
469	sub counter($) {	611	sub counter($) {
470	$new->{again} = $_[0];	612	$frame->[FR_AGAIN]{time} = $_[0];
471	$self->{counter} + 0	613	$frame->[FR_STATE]{counter} + 0
472	}	614	}
473		615
474	=back	616	=back
475		617
476	=head2 SHAPE CHANGING OPERATORS	618	=head2 SHAPE CHANGING OPERATORS
…		…
488	Clips an image to the given rectangle. If the rectangle is outside the	630	Clips an image to the given rectangle. If the rectangle is outside the
489	image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is	631	image area (e.g. when C<$x> or C<$y> are negative) or the rectangle is
490	larger than the image, then the tiling mode defines how the extra pixels	632	larger than the image, then the tiling mode defines how the extra pixels
491	will be filled.	633	will be filled.
492		634
493	If C<$x> an C<$y> are missing, then C<0> is assumed for both.	635	If C<$x> and C<$y> are missing, then C<0> is assumed for both.
494		636
495	If C<$width> and C<$height> are missing, then the window size will be	637	If C<$width> and C<$height> are missing, then the window size will be
496	assumed.	638	assumed.
497		639
498	Example: load an image, blur it, and clip it to the window size to save	640	Example: load an image, blur it, and clip it to the window size to save
499	memory.	641	memory.
500		642
501	clip blur 10, load "mybg.png"	643	clip keep { blur 10, load "mybg.png" }
502		644
503	=cut	645	=cut
504		646
505	sub clip($;$$;$$) {	647	sub clip($;$$;$$) {
506	my $img = pop;	648	my $img = pop;
…		…
516	=item scale $width_factor, $height_factor, $img	658	=item scale $width_factor, $height_factor, $img
517		659
518	Scales the image by the given factors in horizontal	660	Scales the image by the given factors in horizontal
519	(C<$width>) and vertical (C<$height>) direction.	661	(C<$width>) and vertical (C<$height>) direction.
520		662
521	If only one factor is give, it is used for both directions.	663	If only one factor is given, it is used for both directions.
522		664
523	If no factors are given, scales the image to the window size without	665	If no factors are given, scales the image to the window size without
524	keeping aspect.	666	keeping aspect.
525		667
526	=item resize $width, $height, $img	668	=item resize $width, $height, $img
…		…
600	the terminal window (or the box specified by C<$width> and C<$height> if	742	the terminal window (or the box specified by C<$width> and C<$height> if
601	given).	743	given).
602		744
603	Example: load an image and center it.	745	Example: load an image and center it.
604		746
605	center pad load "mybg.png"	747	center keep { pad load "mybg.png" }
606		748
607	=item rootalign $img	749	=item rootalign $img
608		750
609	Moves the image so that it appears glued to the screen as opposed to the	751	Moves the image so that it appears glued to the screen as opposed to the
610	window. This gives the illusion of a larger area behind the window. It is	752	window. This gives the illusion of a larger area behind the window. It is
611	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	753	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
612	top left of the screen.	754	top left of the screen.
613		755
614	Example: load a background image, put it in mirror mode and root align it.	756	Example: load a background image, put it in mirror mode and root align it.
615		757
616	rootalign mirror load "mybg.png"	758	rootalign keep { mirror load "mybg.png" }
617		759
618	Example: take the screen background and align it, giving the illusion of	760	Example: take the screen background and align it, giving the illusion of
619	transparency as long as the window isn't in front of other windows.	761	transparency as long as the window isn't in front of other windows.
620		762
621	rootalign root	763	rootalign root
…		…
646		788
647	sub rootalign($) {	789	sub rootalign($) {
648	move -TX, -TY, $_[0]	790	move -TX, -TY, $_[0]
649	}	791	}
650		792
651	=item rotate $center_x, $center_y, $degrees	793	=item rotate $center_x, $center_y, $degrees, $img
652		794
653	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	795	Rotates the image clockwise by C<$degrees> degrees, around the point at
654	pointer at C<$center_x> and C<$center_y> (specified as factor of image	796	C<$center_x> and C<$center_y> (specified as factor of image width/height).
655	width/height).
656		797
657	#TODO# new width, height, maybe more operators?
658
659	Example: rotate the image by 90 degrees	798	Example: rotate the image by 90 degrees around its center.
		799
		800	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
660		801
661	=cut	802	=cut
662		803
663	sub rotate($$$$) {	804	sub rotate($$$$) {
664	my $img = pop;	805	my $img = pop;
665	$img->rotate (	806	$img->rotate (
666	$_[0] * $img->w,	807	$_[0] * ($img->w + $img->x),
667	$_[1] * $img->h,	808	$_[1] * ($img->h + $img->y),
668	$_[2] * (3.14159265 / 180),	809	$_[2] * (3.14159265 / 180),
669	)	810	)
670	}	811	}
671		812
672	=back	813	=back
…		…
674	=head2 COLOUR MODIFICATIONS	815	=head2 COLOUR MODIFICATIONS
675		816
676	The following operators change the pixels of the image.	817	The following operators change the pixels of the image.
677		818
678	=over 4	819	=over 4
		820
		821	=item tint $color, $img
		822
		823	Tints the image in the given colour.
		824
		825	Example: tint the image red.
		826
		827	tint "red", load "rgb.png"
		828
		829	Example: the same, but specify the colour by component.
		830
		831	tint [1, 0, 0], load "rgb.png"
		832
		833	=cut
		834
		835	sub tint($$) {
		836	$_[1]->tint ($_[0])
		837	}
		838
		839	=item shade $factor, $img
		840
		841	Shade the image by the given factor.
		842
		843	=cut
		844
		845	sub shade($$) {
		846	$_[1]->shade ($_[0])
		847	}
679		848
680	=item contrast $factor, $img	849	=item contrast $factor, $img
681		850
682	=item contrast $r, $g, $b, $img	851	=item contrast $r, $g, $b, $img
683		852
…		…
713	latter in a white picture.	882	latter in a white picture.
714		883
715	Due to idiosyncrasies in the underlying XRender extension, biases less	884	Due to idiosyncrasies in the underlying XRender extension, biases less
716	than zero can be I<very> slow.	885	than zero can be I<very> slow.
717		886
		887	You can also try the experimental(!) C<muladd> operator.
		888
718	=cut	889	=cut
719		890
720	sub contrast($$;$$;$) {	891	sub contrast($$;$$;$) {
721	my $img = pop;	892	my $img = pop;
722	my ($r, $g, $b, $a) = @_;	893	my ($r, $g, $b, $a) = @_;
…		…
737	$a = 1 if @_ < 4;	908	$a = 1 if @_ < 4;
738		909
739	$img = $img->clone;	910	$img = $img->clone;
740	$img->brightness ($r, $g, $b, $a);	911	$img->brightness ($r, $g, $b, $a);
741	$img	912	$img
		913	}
		914
		915	=item muladd $mul, $add, $img # EXPERIMENTAL
		916
		917	First multiplies the pixels by C<$mul>, then adds C<$add>. This can be used
		918	to implement brightness and contrast at the same time, with a wider value
		919	range than contrast and brightness operators.
		920
		921	Due to numerous bugs in XRender implementations, it can also introduce a
		922	number of visual artifacts.
		923
		924	Example: increase contrast by a factor of C<$c> without changing image
		925	brightness too much.
		926
		927	muladd $c, (1 - $c) * 0.5, $img
		928
		929	=cut
		930
		931	sub muladd($$$) {
		932	$_[2]->muladd ($_[0], $_[1])
742	}	933	}
743		934
744	=item blur $radius, $img	935	=item blur $radius, $img
745		936
746	=item blur $radius_horz, $radius_vert, $img	937	=item blur $radius_horz, $radius_vert, $img
…		…
758	sub blur($$;$) {	949	sub blur($$;$) {
759	my $img = pop;	950	my $img = pop;
760	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	951	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
761	}	952	}
762		953
		954	=item focus_fade $img
		955
		956	=item focus_fade $factor, $img
		957
		958	=item focus_fade $factor, $color, $img
		959
		960	Fades the image by the given factor (and colour) when focus is lost (the
		961	same as the C<-fade>/C<-fadecolor> command line options, which also supply
		962	the default values for C<factor> and C<$color>. Unlike with C<-fade>, the
		963	C<$factor> is a real value, not a percentage value (that is, 0..1, not
		964	0..100).
		965
		966	Example: do the right thing when focus fading is requested.
		967
		968	focus_fade load "mybg.jpg";
		969
		970	=cut
		971
		972	sub focus_fade($;$$) {
		973	my $img = pop;
		974
		975	return $img
		976	if FOCUS;
		977
		978	my $fade = @_ >= 1 ? $_[0] : defined $self->resource ("fade") ? $self->resource ("fade") * 0.01 : 0;
		979	my $color = @_ >= 2 ? $_[1] : $self->resource ("color+" . urxvt::Color_fade);
		980
		981	$img = $img->tint ($color) if $color ne "rgb:00/00/00";
		982	$img = $img->muladd (1 - $fade, 0) if $fade;
		983
		984	$img
		985	}
		986
763	=back	987	=back
764		988
765	=head2 OTHER STUFF	989	=head2 OTHER STUFF
766		990
767	Anything that didn't fit any of the other categories, even after appliyng	991	Anything that didn't fit any of the other categories, even after applying
768	force and closing our eyes.	992	force and closing our eyes.
769		993
770	=over 4	994	=over 4
771		995
772	=item once { ... }	996	=item keep { ... }
773		997
774	This function takes a code block as argument, that is, one or more	998	This operator takes a code block as argument, that is, one or more
775	statements enclosed by braces.	999	statements enclosed by braces.
776		1000
777	The trick is that this code block is only evaluated once - future calls	1001	The trick is that this code block is only evaluated when the outcome
778	will simply return the original image (yes, it should only be used with	1002	changes - on other calls the C<keep> simply returns the image it computed
779	images).	1003	previously (yes, it should only be used with images). Or in other words,
		1004	C<keep> I<caches> the result of the code block so it doesn't need to be
		1005	computed again.
780		1006
781	This can be extremely useful to avoid redoign the same slow operations	1007	This can be extremely useful to avoid redoing slow operations - for
782	again and again- for example, if your background expression takes the root	1008	example, if your background expression takes the root background, blurs it
783	background, blurs it and then root-aligns it it would have to blur the	1009	and then root-aligns it it would have to blur the root background on every
784	root background on every window move or resize.	1010	window move or resize.
785		1011
		1012	Another example is C<load>, which can be quite slow.
		1013
		1014	In fact, urxvt itself encloses the whole expression in some kind of
		1015	C<keep> block so it only is reevaluated as required.
		1016
786	Putting the blur into a C<once> block will make sure the blur is only done	1017	Putting the blur into a C<keep> block will make sure the blur is only done
787	once:	1018	once, while the C<rootalign> is still done each time the window moves.
788		1019
789	rootlign once { blur 10, root }	1020	rootalign keep { blur 10, root }
790		1021
791	This leaves the question of how to force reevaluation of the block, in	1022	This leaves the question of how to force reevaluation of the block,
792	case the root background changes: Right now, all once blocks forget that	1023	in case the root background changes: If expression inside the block
793	they ahve been executed before each time the root background changes (if	1024	is sensitive to some event (root background changes, window geometry
794	the expression is sensitive to that) or when C<once_again> is called.	1025	changes), then it will be reevaluated automatically as needed.
795		1026
796	=item once_again
797
798	Resets all C<once> block as if they had never been called, i.e. on the
799	next call they will be reevaluated again.
800
801	=cut	1027	=cut
802		1028
803	sub once(&) {	1029	sub keep(&) {
804	$_ONCE_CACHE{$_[0]+0} \|\|= $_[0]()	1030	my $id = $_[0]+0;
		1031
		1032	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		1033
		1034	unless ($frame->[FR_CACHE]) {
		1035	$frame->[FR_CACHE] = [ $_[0]() ];
		1036
		1037	my $self = $self;
		1038	my $frame = $frame;
		1039	Scalar::Util::weaken $frame;
		1040	$self->compile_frame ($frame, sub {
		1041	# clear this frame cache, also for all parents
		1042	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		1043	undef $frame->[FR_CACHE];
		1044	}
		1045
		1046	$self->recalculate;
		1047	});
		1048	};
		1049
		1050	# in scalar context we always return the first original result, which
		1051	# is not quite how perl works.
		1052	wantarray
		1053	? @{ $frame->[FR_CACHE] }
		1054	: $frame->[FR_CACHE][0]
		1055	}
		1056
		1057	# sub keep_clear() {
		1058	# delete $self->{frame_cache};
805	}	1059	# }
806
807	sub once_again() {
808	%_ONCE_CACHE = ();
809	}
810		1060
811	=back	1061	=back
812		1062
813	=cut	1063	=cut
814		1064
815	}	1065	}
816		1066
817	sub parse_expr {	1067	sub parse_expr {
818	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	1068	my $expr = eval
		1069	"sub {\n"
		1070	. "package urxvt::bgdsl;\n"
		1071	. "#line 0 'background expression'\n"
		1072	. "$_[0]\n"
		1073	. "}";
819	die if $@;	1074	die if $@;
820	$expr	1075	$expr
821	}	1076	}
822		1077
823	# compiles a parsed expression	1078	# compiles a parsed expression
824	sub set_expr {	1079	sub set_expr {
825	my ($self, $expr) = @_;	1080	my ($self, $expr) = @_;
826		1081
		1082	$self->{root} = []; # the outermost frame
827	$self->{expr} = $expr;	1083	$self->{expr} = $expr;
828	$self->recalculate;	1084	$self->recalculate;
		1085	}
		1086
		1087	# takes a hash of sensitivity indicators and installs watchers
		1088	sub compile_frame {
		1089	my ($self, $frame, $cb) = @_;
		1090
		1091	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		1092	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		1093
		1094	# don't keep stuff alive
		1095	Scalar::Util::weaken $state;
		1096
		1097	if ($again->{nested}) {
		1098	$state->{nested} = 1;
		1099	} else {
		1100	delete $state->{nested};
		1101	}
		1102
		1103	if (my $interval = $again->{time}) {
		1104	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		1105	if $state->{time}[0] != $interval;
		1106
		1107	# callback might have changed, although we could just rule that out
		1108	$state->{time}[1]->cb (sub {
		1109	++$state->{counter};
		1110	$cb->();
		1111	});
		1112	} else {
		1113	delete $state->{time};
		1114	}
		1115
		1116	if ($again->{position}) {
		1117	$state->{position} = $self->on (position_change => $cb);
		1118	} else {
		1119	delete $state->{position};
		1120	}
		1121
		1122	if ($again->{size}) {
		1123	$state->{size} = $self->on (size_change => $cb);
		1124	} else {
		1125	delete $state->{size};
		1126	}
		1127
		1128	if ($again->{rootpmap}) {
		1129	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		1130	} else {
		1131	delete $state->{rootpmap};
		1132	}
		1133
		1134	if ($again->{focus}) {
		1135	$state->{focus} = $self->on (focus_in => $cb, focus_out => $cb);
		1136	} else {
		1137	delete $state->{focus};
		1138	}
829	}	1139	}
830		1140
831	# evaluate the current bg expression	1141	# evaluate the current bg expression
832	sub recalculate {	1142	sub recalculate {
833	my ($arg_self) = @_;	1143	my ($arg_self) = @_;
…		…
843		1153
844	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1154	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
845		1155
846	# set environment to evaluate user expression	1156	# set environment to evaluate user expression
847		1157
848	local $self = $arg_self;	1158	local $self = $arg_self;
849
850	local $HOME = $ENV{HOME};	1159	local $HOME = $ENV{HOME};
851	local $old = $self->{state};	1160	local $frame = $self->{root};
852	local $new = my $state = $self->{state} = {};
853		1161
854	($x, $y, $w, $h) =
855	$self->background_geometry ($self->{border});	1162	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
		1163	$focus = $self->focus;
856		1164
857	# evaluate user expression	1165	# evaluate user expression
858		1166
859	my $img = eval { $self->{expr}->() };	1167	my @img = eval { $self->{expr}->() };
860	warn $@ if $@;#d#	1168	die $@ if $@;
861	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";	1169	die "background-expr did not return anything.\n" unless @img;
		1170	die "background-expr: expected image(s), got something else.\n"
		1171	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
862		1172
863	$state->{size_sensitive} = 1	1173	my $img = urxvt::bgdsl::merge @img;
		1174
		1175	$frame->[FR_AGAIN]{size} = 1
864	if $img->repeat_mode != urxvt::RepeatNormal;	1176	if $img->repeat_mode != urxvt::RepeatNormal;
865		1177
866	# if the expression is sensitive to external events, prepare reevaluation then	1178	# if the expression is sensitive to external events, prepare reevaluation then
867		1179	$self->compile_frame ($frame, sub { $arg_self->recalculate });
868	my $repeat;
869
870	if (my $again = $state->{again}) {
871	$repeat = 1;
872	my $self = $self;
873	$state->{timer} = $again == $old->{again}
874	? $old->{timer}
875	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
876	++$self->{counter};
877	$self->recalculate
878	});
879	}
880
881	if (delete $state->{position_sensitive}) {
882	$repeat = 1;
883	$self->enable (position_change => sub { $_[0]->recalculate });
884	} else {
885	$self->disable ("position_change");
886	}
887
888	if (delete $state->{size_sensitive}) {
889	$repeat = 1;
890	$self->enable (size_change => sub { $_[0]->recalculate });
891	} else {
892	$self->disable ("size_change");
893	}
894
895	if (delete $state->{rootpmap_sensitive}) {
896	$repeat = 1;
897	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
898	} else {
899	$self->disable ("rootpmap_change");
900	}
901		1180
902	# clear stuff we no longer need	1181	# clear stuff we no longer need
903		1182
904	%$old = ();	1183	# unless (%{ $frame->[FR_STATE] }) {
905
906	unless ($repeat) {
907	delete $self->{state};	1184	# delete $self->{state};
908	delete $self->{expr};	1185	# delete $self->{expr};
909	}	1186	# }
910		1187
911	# set background pixmap	1188	# set background pixmap
912		1189
913	$self->set_background ($img, $self->{border});	1190	$self->set_background ($img, $self->{border});
914	$self->scr_recolour (0);	1191	$self->scr_recolor (0);
915	$self->want_refresh;	1192	$self->want_refresh;
916	}	1193	}
917		1194
918	sub on_start {	1195	sub on_start {
919	my ($self) = @_;	1196	my ($self) = @_;

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC vs. Revision 1.90 by sf-exg, Mon Mar 16 10:06:09 2015 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC vs.
Revision 1.90 by sf-exg, Mon Mar 16 10:06:09 2015 UTC