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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.49 by root, Sun Jun 10 15:29:18 2012 UTC vs.
Revision 1.68 by root, Sun Jul 1 21:47:07 2012 UTC

…		…
2		2
3	#:META:X_RESOURCE:%.expr:string:background expression	3	#:META:X_RESOURCE:%.expr:string:background expression
4	#:META:X_RESOURCE:%.border:boolean:respect the terminal border	4	#:META:X_RESOURCE:%.border:boolean:respect the terminal border
5	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates	5	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
6		6
7	#TODO: once, rootalign
8
9	=head1 NAME	7	=head1 NAME
10		8
11	background - manage terminal background	9	background - manage terminal background
12		10
13	=head1 SYNOPSIS	11	=head1 SYNOPSIS
…		…
28	to be as simple as possible.	26	to be as simple as possible.
29		27
30	For example, to load an image and scale it to the window size, you would	28	For example, to load an image and scale it to the window size, you would
31	use:	29	use:
32		30
33	urxvt --background-expr 'scale load "/path/to/mybg.png"'	31	urxvt --background-expr 'scale keep { load "/path/to/mybg.png" }'
34		32
35	Or specified as a X resource:	33	Or specified as a X resource:
36		34
37	URxvt.background-expr: scale load "/path/to/mybg.png"	35	URxvt.background-expr: scale keep { load "/path/to/mybg.png" }
38		36
39	=head1 THEORY OF OPERATION	37	=head1 THEORY OF OPERATION
40		38
41	At startup, just before the window is mapped for the first time, the	39	At startup, just before the window is mapped for the first time, the
42	expression is evaluated and must yield an image. The image is then	40	expression is evaluated and must yield an image. The image is then
…		…
55	If any of the parameters that the expression relies on changes (when the	53	If any of the parameters that the expression relies on changes (when the
56	window is moved or resized, its position or size changes; when the root	54	window is moved or resized, its position or size changes; when the root
57	pixmap is replaced by another one the root background changes; or when the	55	pixmap is replaced by another one the root background changes; or when the
58	timer elapses), then the expression will be evaluated again.	56	timer elapses), then the expression will be evaluated again.
59		57
60	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	58	For example, an expression such as C<scale keep { load "$HOME/mybg.png"
61	image to the window size, so it relies on the window size and will	59	}> scales the image to the window size, so it relies on the window size
62	be reevaluated each time it is changed, but not when it moves for	60	and will be reevaluated each time it is changed, but not when it moves for
63	example. That ensures that the picture always fills the terminal, even	61	example. That ensures that the picture always fills the terminal, even
64	after it's size changes.	62	after its size changes.
65		63
66	=head2 EXPRESSIONS	64	=head2 EXPRESSIONS
67		65
68	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
69	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
70		68
		69	scale keep {
71	again 3600;	70	again 3600;
72	if (localtime now)[6]) {	71	if (localtime now)[6]) {
73	return scale load "$HOME/weekday.png";	72	return load "$HOME/weekday.png";
74	} else {	73	} else {
75	return scale load "$HOME/sunday.png";	74	return load "$HOME/sunday.png";
		75	}
76	}	76	}
77		77
78	This expression gets evaluated once per hour. It will set F<sunday.png> as	78	This inner expression is evaluated once per hour (and whenever the
		79	temrinal window is resized). It sets F<sunday.png> as background on
79	background on Sundays, and F<weekday.png> on all other days.	80	Sundays, and F<weekday.png> on all other days.
80		81
81	Fortunately, we expect that most expressions will be much simpler, with	82	Fortunately, we expect that most expressions will be much simpler, with
82	little Perl knowledge needed.	83	little Perl knowledge needed.
83		84
84	Basically, you always start with a function that "generates" an image	85	Basically, you always start with a function that "generates" an image
…		…
117	horizontal and vertical dimensions. For example, this halves the image	118	horizontal and vertical dimensions. For example, this halves the image
118	width and doubles the image height:	119	width and doubles the image height:
119		120
120	scale 0.5, 2, load "$HOME/mypic.png"	121	scale 0.5, 2, load "$HOME/mypic.png"
121		122
122	Other effects than scalign are also readily available, for exmaple, you can	123	IF you try out these expressions, you might suffer from some sluggishness,
123	tile the image to fill the whole window, instead of resizing it:	124	because each time the terminal is resized, it loads the PNG image agin
		125	and scales it. Scaling is usually fast (and unavoidable), but loading the
		126	image can be quite time consuming. This is where C<keep> comes in handy:
124		127
		128	scale 0.5, 2, keep { load "$HOME/mypic.png" }
		129
		130	The C<keep> operator executes all the statements inside the braces only
		131	once, or when it thinks the outcome might change. In other cases it
		132	returns the last value computed by the brace block.
		133
		134	This means that the C<load> is only executed once, which makes it much
		135	faster, but also means that more memory is being used, because the loaded
		136	image must be kept in memory at all times. In this expression, the
		137	trade-off is likely worth it.
		138
		139	But back to effects: Other effects than scaling are also readily
		140	available, for example, you can tile the image to fill the whole window,
		141	instead of resizing it:
		142
125	tile load "$HOME/mypic.png"	143	tile keep { load "$HOME/mypic.png" }
126		144
127	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	145	In fact, images returned by C<load> are in C<tile> mode by default, so the
128	is kind of superfluous.	146	C<tile> operator is kind of superfluous.
129		147
130	Another common effect is to mirror the image, so that the same edges touch:	148	Another common effect is to mirror the image, so that the same edges
		149	touch:
131		150
132	mirror load "$HOME/mypic.png"	151	mirror keep { load "$HOME/mypic.png" }
133		152
134	This is also a typical background expression:	153	Another common background expression is:
135		154
136	rootalign root	155	rootalign root
137		156
138	It first takes a snapshot of the screen background image, and then	157	This one first takes a snapshot of the screen background image, and then
139	moves it to the upper left corner of the screen - the result is	158	moves it to the upper left corner of the screen (as opposed to the upper
140	pseudo-transparency, as the image seems to be static while the window is	159	left corner of the terminal window)- the result is pseudo-transparency:
141	moved around.	160	the image seems to be static while the window is moved around.
142		161
143	=head2 CYCLES AND CACHING	162	=head2 CACHING AND SENSITIVITY
144		163
145	As has been mentioned before, the expression might be evaluated multiple	164	Since some operations (such as C<load> and C<blur>) can take a long time,
146	times. Each time the expression is reevaluated, a new cycle is said to	165	caching results can be very important for a smooth operation. Caching can
147	have begun. Many operators cache their results till the next cycle.	166	also be useful to reduce memory usage, though, for example, when an image
		167	is cached by C<load>, it could be shared by multiple terminal windows
		168	running inside urxvtd.
148		169
149	For example, the C<load> operator keeps a copy of the image. If it is	170	=head3 C<keep { ... }> caching
150	asked to load the same image on the next cycle it will not load it again,
151	but return the cached copy.
152		171
153	This only works for one cycle though, so as long as you load the same	172	The most important way to cache expensive operations is to use C<keep {
154	image every time, it will always be cached, but when you load a different	173	... }>. The C<keep> operator takes a block of multiple statements enclosed
155	image, it will forget about the first one.	174	by C<{}> and keeps the return value in memory.
156		175
157	This allows you to either speed things up by keeping multiple images in	176	An expression can be "sensitive" to various external events, such as
158	memory, or comserve memory by loading images more often.	177	scaling or moving the window, root background changes and timers. Simply
		178	using an expression (such as C<scale> without parameters) that depends on
		179	certain changing values (called "variables"), or using those variables
		180	directly, will make an expression sensitive to these events - for example,
		181	using C<scale> or C<TW> will make the expression sensitive to the terminal
		182	size, and thus to resizing events.
159		183
160	For example, you can keep two images in memory and use a random one like	184	When such an event happens, C<keep> will automatically trigger a
161	this:	185	reevaluation of the whole expression with the new value of the expression.
162		186
163	my $img1 = load "img1.png";	187	C<keep> is most useful for expensive operations, such as C<blur>:
164	my $img2 = load "img2.png";
165	(0.5 > rand) ? $img1 : $img2
166		188
167	Since both images are "loaded" every time the expression is evaluated,	189	rootalign keep { blur 20, root }
168	they are always kept in memory. Contrast this version:
169		190
170	my $path1 = "img1.png";	191	This makes a blurred copy of the root background once, and on subsequent
171	my $path2 = "img2.png";	192	calls, just root-aligns it. Since C<blur> is usually quite slow and
172	load ((0.5 > rand) ? $path1 : $path2)	193	C<rootalign> is quite fast, this trades extra memory (for the cached
		194	blurred pixmap) with speed (blur only needs to be redone when root
		195	changes).
173		196
174	Here, a path is selected randomly, and load is only called for one image,	197	=head3 C<load> caching
175	so keeps only one image in memory. If, on the next evaluation, luck	198
176	decides to use the other path, then it will have to load that image again.	199	The C<load> operator itself does not keep images in memory, but as long as
		200	the image is still in memory, C<load> will use the in-memory image instead
		201	of loading it freshly from disk.
		202
		203	That means that this expression:
		204
		205	keep { load "$HOME/path..." }
		206
		207	Not only caches the image in memory, other terminal instances that try to
		208	C<load> it can reuse that in-memory copy.
177		209
178	=head1 REFERENCE	210	=head1 REFERENCE
179		211
180	=head2 COMMAND LINE SWITCHES	212	=head2 COMMAND LINE SWITCHES
181		213
…		…
193	Specifying this flag changes the behaviour, so that the image only	225	Specifying this flag changes the behaviour, so that the image only
194	replaces the background of the character area.	226	replaces the background of the character area.
195		227
196	=item --background-interval seconds	228	=item --background-interval seconds
197		229
198	Since some operations in the underlying XRender extension can effetively	230	Since some operations in the underlying XRender extension can effectively
199	freeze your X-server for prolonged time, this extension enforces a minimum	231	freeze your X-server for prolonged time, this extension enforces a minimum
200	time between updates, which is normally about 0.1 seconds.	232	time between updates, which is normally about 0.1 seconds.
201		233
202	If you want to do updates more often, you can decrease this safety	234	If you want to do updates more often, you can decrease this safety
203	interval with this switch.	235	interval with this switch.
204		236
205	=back	237	=back
206		238
207	=cut	239	=cut
208		240
209	our %_IMGCACHE;	241	our %_IMG_CACHE;
210	our $HOME;	242	our $HOME;
211	our ($self, $old, $new);	243	our ($self, $frame);
212	our ($x, $y, $w, $h);	244	our ($x, $y, $w, $h);
213		245
214	# enforce at least this interval between updates	246	# enforce at least this interval between updates
215	our $MIN_INTERVAL = 6/59.951;	247	our $MIN_INTERVAL = 6/59.951;
216		248
217	{	249	{
218	package urxvt::bgdsl; # background language	250	package urxvt::bgdsl; # background language
		251
		252	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		253	sub FR_CACHE () { 1 } # cached values
		254	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		255	sub FR_STATE () { 3 } # watchers etc.
219		256
220	use List::Util qw(min max sum shuffle);	257	use List::Util qw(min max sum shuffle);
221		258
222	=head2 PROVIDERS/GENERATORS	259	=head2 PROVIDERS/GENERATORS
223		260
…		…
230	=item load $path	267	=item load $path
231		268
232	Loads the image at the given C<$path>. The image is set to plane tiling	269	Loads the image at the given C<$path>. The image is set to plane tiling
233	mode.	270	mode.
234		271
235	Loaded images will be cached for one cycle.	272	If the image is already in memory (e.g. because another terminal instance
		273	uses it), then the in-memory copy us returned instead.
236		274
		275	=item load_uc $path
		276
		277	Load uncached - same as load, but does not cache the image, which means it
		278	is I<always> loaded from the filesystem again.
		279
237	=cut	280	=cut
		281
		282	sub load_uc($) {
		283	$self->new_img_from_file ($path)
		284	}
238		285
239	sub load($) {	286	sub load($) {
240	my ($path) = @_;	287	my ($path) = @_;
241		288
242	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	289	$_IMG_CACHE{$path} \|\| do {
		290	my $img = load_uc $path;
		291	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		292	$img
		293	}
243	}	294	}
244		295
245	=item root	296	=item root
246		297
247	Returns the root window pixmap, that is, hopefully, the background image	298	Returns the root window pixmap, that is, hopefully, the background image
248	of your screen. The image is set to extend mode.	299	of your screen.
249		300
250	This function makes your expression root sensitive, that means it will be	301	This function makes your expression root sensitive, that means it will be
251	reevaluated when the bg image changes.	302	reevaluated when the bg image changes.
252		303
253	=cut	304	=cut
254		305
255	sub root() {	306	sub root() {
256	$new->{rootpmap_sensitive} = 1;	307	$frame->[FR_AGAIN]{rootpmap} = 1;
257	die "root op not supported, exg, we need you";	308	$self->new_img_from_root
258	}	309	}
259		310
260	=item solid $colour	311	=item solid $colour
261		312
262	=item solid $width, $height, $colour	313	=item solid $width, $height, $colour
…		…
270	=cut	321	=cut
271		322
272	sub solid($;$$) {	323	sub solid($;$$) {
273	my $colour = pop;	324	my $colour = pop;
274		325
275	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	326	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
276	$img->fill ($colour);	327	$img->fill ($colour);
277	$img	328	$img
278	}	329	}
279		330
280	=item clone $img	331	=item clone $img
…		…
286		337
287	sub clone($) {	338	sub clone($) {
288	$_[0]->clone	339	$_[0]->clone
289	}	340	}
290		341
291	=back	342	=item merge $img ...
		343
		344	Takes any number of images and merges them together, creating a single
		345	image containing them all. The tiling mode of the first image is used as
		346	the tiling mode of the resulting image.
		347
		348	This function is called automatically when an expression returns multiple
		349	images.
		350
		351	=cut
		352
		353	sub merge(@) {
		354	return $_[0] unless $#_;
		355
		356	# rather annoyingly clumsy, but optimisation is for another time
		357
		358	my $x0 = +1e9;
		359	my $y0 = +1e9;
		360	my $x1 = -1e9;
		361	my $y1 = -1e9;
		362
		363	for (@_) {
		364	my ($x, $y, $w, $h) = $_->geometry;
		365
		366	$x0 = $x if $x0 > $x;
		367	$y0 = $y if $y0 > $y;
		368
		369	$x += $w;
		370	$y += $h;
		371
		372	$x1 = $x if $x1 < $x;
		373	$y1 = $y if $y1 < $y;
		374	}
		375
		376	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		377	$base->repeat_mode ($_[0]->repeat_mode);
		378	$base->fill ([0, 0, 0, 0]);
		379
		380	$base->draw ($_)
		381	for @_;
		382
		383	$base
		384	}
292		385
293	=head2 TILING MODES	386	=head2 TILING MODES
294		387
295	The following operators modify the tiling mode of an image, that is, the	388	The following operators modify the tiling mode of an image, that is, the
296	way that pixels outside the image area are painted when the image is used.	389	way that pixels outside the image area are painted when the image is used.
…		…
326	become transparent. This mode is most useful when you want to place an	419	become transparent. This mode is most useful when you want to place an
327	image over another image or the background colour while leaving all	420	image over another image or the background colour while leaving all
328	background pixels outside the image unchanged.	421	background pixels outside the image unchanged.
329		422
330	Example: load an image and display it in the upper left corner. The rest	423	Example: load an image and display it in the upper left corner. The rest
331	of the space is left "empty" (transparent or wahtever your compisotr does	424	of the space is left "empty" (transparent or whatever your compositor does
332	in alpha mode, else background colour).	425	in alpha mode, else background colour).
333		426
334	pad load "mybg.png"	427	pad load "mybg.png"
335		428
336	=item extend $img	429	=item extend $img
337		430
338	Extends the image over the whole plane, using the closest pixel in the	431	Extends the image over the whole plane, using the closest pixel in the
339	area outside the image. This mode is mostly useful when you more complex	432	area outside the image. This mode is mostly useful when you use more complex
340	filtering operations and want the pixels outside the image to have the	433	filtering operations and want the pixels outside the image to have the
341	same values as the pixels near the edge.	434	same values as the pixels near the edge.
342		435
343	Example: just for curiosity, how does this pixel extension stuff work?	436	Example: just for curiosity, how does this pixel extension stuff work?
344		437
…		…
393	Using these functions make your expression sensitive to window moves.	486	Using these functions make your expression sensitive to window moves.
394		487
395	These functions are mainly useful to align images to the root window.	488	These functions are mainly useful to align images to the root window.
396		489
397	Example: load an image and align it so it looks as if anchored to the	490	Example: load an image and align it so it looks as if anchored to the
398	background.	491	background (that's exactly what C<rootalign> does btw.):
399		492
400	move -TX, -TY, load "mybg.png"	493	move -TX, -TY, keep { load "mybg.png" }
401		494
402	=item TW	495	=item TW
403		496
404	Return the width (C<TW>) and height (C<TH>) of the terminal window (the	497	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
405	terminal window is the full window by default, and the character area only	498	terminal window is the full window by default, and the character area only
…		…
411	the window size to conserve memory.	504	the window size to conserve memory.
412		505
413	Example: take the screen background, clip it to the window size, blur it a	506	Example: take the screen background, clip it to the window size, blur it a
414	bit, align it to the window position and use it as background.	507	bit, align it to the window position and use it as background.
415		508
416	clip move -TX, -TY, blur 5, root	509	clip move -TX, -TY, keep { blur 5, root }
417		510
418	=cut	511	=cut
419		512
420	sub TX() { $new->{position_sensitive} = 1; $x }	513	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
421	sub TY() { $new->{position_sensitive} = 1; $y }	514	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
422	sub TW() { $new->{size_sensitive} = 1; $w }	515	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
423	sub TH() { $new->{size_sensitive} = 1; $h }	516	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
424		517
425	=item now	518	=item now
426		519
427	Returns the current time as (fractional) seconds since the epoch.	520	Returns the current time as (fractional) seconds since the epoch.
428		521
…		…
435	C<$seconds> seconds.	528	C<$seconds> seconds.
436		529
437	Example: load some image and rotate it according to the time of day (as if it were	530	Example: load some image and rotate it according to the time of day (as if it were
438	the hour pointer of a clock). Update this image every minute.	531	the hour pointer of a clock). Update this image every minute.
439		532
		533	again 60;
440	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	534	rotate 50, 50, (now % 86400) * -72 / 8640, scale keep { load "myclock.png" }
441		535
442	=item counter $seconds	536	=item counter $seconds
443		537
444	Like C<again>, but also returns an increasing counter value, starting at	538	Like C<again>, but also returns an increasing counter value, starting at
445	0, which might be useful for some simple animation effects.	539	0, which might be useful for some simple animation effects.
…		…
447	=cut	541	=cut
448		542
449	sub now() { urxvt::NOW }	543	sub now() { urxvt::NOW }
450		544
451	sub again($) {	545	sub again($) {
452	$new->{again} = $_[0];	546	$frame->[FR_AGAIN]{time} = $_[0];
453	}	547	}
454		548
455	sub counter($) {	549	sub counter($) {
456	$new->{again} = $_[0];	550	$frame->[FR_AGAIN]{time} = $_[0];
457	$self->{counter} + 0	551	$frame->[FR_STATE]{counter} + 0
458	}	552	}
459		553
460	=back	554	=back
461		555
462	=head2 SHAPE CHANGING OPERATORS	556	=head2 SHAPE CHANGING OPERATORS
…		…
482	assumed.	576	assumed.
483		577
484	Example: load an image, blur it, and clip it to the window size to save	578	Example: load an image, blur it, and clip it to the window size to save
485	memory.	579	memory.
486		580
487	clip blur 10, load "mybg.png"	581	clip keep { blur 10, load "mybg.png" }
488		582
489	=cut	583	=cut
490		584
491	sub clip($;$$;$$) {	585	sub clip($;$$;$$) {
492	my $img = pop;	586	my $img = pop;
…		…
586	the terminal window (or the box specified by C<$width> and C<$height> if	680	the terminal window (or the box specified by C<$width> and C<$height> if
587	given).	681	given).
588		682
589	Example: load an image and center it.	683	Example: load an image and center it.
590		684
591	center pad load "mybg.png"	685	center keep { pad load "mybg.png" }
592		686
593	=item rootalign $img	687	=item rootalign $img
594		688
595	Moves the image so that it appears glued to the screen as opposed to the	689	Moves the image so that it appears glued to the screen as opposed to the
596	window. This gives the illusion of a larger area behind the window. It is	690	window. This gives the illusion of a larger area behind the window. It is
597	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the	691	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
598	top left of the screen.	692	top left of the screen.
599		693
600	Example: load a background image, put it in mirror mode and root align it.	694	Example: load a background image, put it in mirror mode and root align it.
601		695
602	rootalign mirror load "mybg.png"	696	rootalign keep { mirror load "mybg.png" }
603		697
604	Example: take the screen background and align it, giving the illusion of	698	Example: take the screen background and align it, giving the illusion of
605	transparency as long as the window isn't in front of other windows.	699	transparency as long as the window isn't in front of other windows.
606		700
607	rootalign root	701	rootalign root
…		…
632		726
633	sub rootalign($) {	727	sub rootalign($) {
634	move -TX, -TY, $_[0]	728	move -TX, -TY, $_[0]
635	}	729	}
636		730
		731	=item rotate $center_x, $center_y, $degrees, $img
		732
		733	Rotates the image clockwise by C<$degrees> degrees, around the point at
		734	C<$center_x> and C<$center_y> (specified as factor of image width/height).
		735
		736	Example: rotate the image by 90 degrees around it's center.
		737
		738	rotate 0.5, 0.5, 90, keep { load "$HOME/mybg.png" }
		739
		740	=cut
		741
		742	sub rotate($$$$) {
		743	my $img = pop;
		744	$img->rotate (
		745	$_[0] * ($img->w + $img->x),
		746	$_[1] * ($img->h + $img->y),
		747	$_[2] * (3.14159265 / 180),
		748	)
		749	}
		750
637	=back	751	=back
638		752
639	=head2 COLOUR MODIFICATIONS	753	=head2 COLOUR MODIFICATIONS
640		754
641	The following operators change the pixels of the image.	755	The following operators change the pixels of the image.
…		…
675		789
676	Values less than 0 reduce brightness, while values larger than 0 increase	790	Values less than 0 reduce brightness, while values larger than 0 increase
677	it. Useful range is from -1 to 1 - the former results in a black, the	791	it. Useful range is from -1 to 1 - the former results in a black, the
678	latter in a white picture.	792	latter in a white picture.
679		793
680	Due to idiosynchrasies in the underlying XRender extension, biases less	794	Due to idiosyncrasies in the underlying XRender extension, biases less
681	than zero can be I<very> slow.	795	than zero can be I<very> slow.
682		796
683	=cut	797	=cut
684		798
685	sub contrast($$;$$;$) {	799	sub contrast($$;$$;$) {
…		…
723	sub blur($$;$) {	837	sub blur($$;$) {
724	my $img = pop;	838	my $img = pop;
725	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	839	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
726	}	840	}
727		841
728	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
729
730	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
731	pointer at C<$center_x> and C<$center_y> (specified as factor of image
732	width/height), generating a new image with width C<$new_width> and height
733	C<$new_height>.
734
735	#TODO# new width, height, maybe more operators?
736
737	Example: rotate the image by 90 degrees
738
739	=cut
740
741	sub rotate($$$$$$) {
742	my $img = pop;
743	$img->rotate (
744	$_[0],
745	$_[1],
746	$_[2] * $img->w,
747	$_[3] * $img->h,
748	$_[4] * (3.14159265 / 180),
749	)
750	}
751
752	=back	842	=back
753		843
		844	=head2 OTHER STUFF
		845
		846	Anything that didn't fit any of the other categories, even after applying
		847	force and closing our eyes.
		848
		849	=over 4
		850
		851	=item keep { ... }
		852
		853	This operator takes a code block as argument, that is, one or more
		854	statements enclosed by braces.
		855
		856	The trick is that this code block is only evaluated when the outcome
		857	changes - on other calls the C<keep> simply returns the image it computed
		858	previously (yes, it should only be used with images). Or in other words,
		859	C<keep> I<caches> the result of the code block so it doesn't need to be
		860	computed again.
		861
		862	This can be extremely useful to avoid redoing slow operations - for
		863	example, if your background expression takes the root background, blurs it
		864	and then root-aligns it it would have to blur the root background on every
		865	window move or resize.
		866
		867	Another example is C<load>, which can be quite slow.
		868
		869	In fact, urxvt itself encloses the whole expression in some kind of
		870	C<keep> block so it only is reevaluated as required.
		871
		872	Putting the blur into a C<keep> block will make sure the blur is only done
		873	once, while the C<rootalign> is still done each time the window moves.
		874
		875	rootlign keep { blur 10, root }
		876
		877	This leaves the question of how to force reevaluation of the block,
		878	in case the root background changes: If expression inside the block
		879	is sensitive to some event (root background changes, window geometry
		880	changes), then it will be reevaluated automatically as needed.
		881
		882	=cut
		883
		884	sub keep(&) {
		885	my $id = $_[0]+0;
		886
		887	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		888
		889	unless ($frame->[FR_CACHE]) {
		890	$frame->[FR_CACHE] = [ $_[0]() ];
		891
		892	my $self = $self;
		893	my $frame = $frame;
		894	Scalar::Util::weaken $frame;
		895	$self->compile_frame ($frame, sub {
		896	# clear this frame cache, also for all parents
		897	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		898	undef $frame->[FR_CACHE];
		899	}
		900
		901	$self->recalculate;
		902	});
		903	};
		904
		905	# in scalar context we always return the first original result, which
		906	# is not quite how perl works.
		907	wantarray
		908	? @{ $frame->[FR_CACHE] }
		909	: $frame->[FR_CACHE][0]
		910	}
		911
		912	# sub keep_clear() {
		913	# delete $self->{frame_cache};
		914	# }
		915
		916	=back
		917
754	=cut	918	=cut
755		919
756	}	920	}
757		921
758	sub parse_expr {	922	sub parse_expr {
759	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	923	my $expr = eval
		924	"sub {\n"
		925	. "package urxvt::bgdsl;\n"
		926	. "#line 0 'background expression'\n"
		927	. "$_[0]\n"
		928	. "}";
760	die if $@;	929	die if $@;
761	$expr	930	$expr
762	}	931	}
763		932
764	# compiles a parsed expression	933	# compiles a parsed expression
765	sub set_expr {	934	sub set_expr {
766	my ($self, $expr) = @_;	935	my ($self, $expr) = @_;
767		936
		937	$self->{root} = [];
768	$self->{expr} = $expr;	938	$self->{expr} = $expr;
769	$self->recalculate;	939	$self->recalculate;
		940	}
		941
		942	# takes a hash of sensitivity indicators and installs watchers
		943	sub compile_frame {
		944	my ($self, $frame, $cb) = @_;
		945
		946	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		947	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		948
		949	# don't keep stuff alive
		950	Scalar::Util::weaken $state;
		951
		952	if ($again->{nested}) {
		953	$state->{nested} = 1;
		954	} else {
		955	delete $state->{nested};
		956	}
		957
		958	if (my $interval = $again->{time}) {
		959	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		960	if $state->{time}[0] != $interval;
		961
		962	# callback might have changed, although we could just rule that out
		963	$state->{time}[1]->cb (sub {
		964	++$state->{counter};
		965	$cb->();
		966	});
		967	} else {
		968	delete $state->{time};
		969	}
		970
		971	if ($again->{position}) {
		972	$state->{position} = $self->on (position_change => $cb);
		973	} else {
		974	delete $state->{position};
		975	}
		976
		977	if ($again->{size}) {
		978	$state->{size} = $self->on (size_change => $cb);
		979	} else {
		980	delete $state->{size};
		981	}
		982
		983	if ($again->{rootpmap}) {
		984	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		985	} else {
		986	delete $state->{rootpmap};
		987	}
770	}	988	}
771		989
772	# evaluate the current bg expression	990	# evaluate the current bg expression
773	sub recalculate {	991	sub recalculate {
774	my ($arg_self) = @_;	992	my ($arg_self) = @_;
…		…
784		1002
785	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	1003	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
786		1004
787	# set environment to evaluate user expression	1005	# set environment to evaluate user expression
788		1006
789	local $self = $arg_self;	1007	local $self = $arg_self;
790
791	local $HOME = $ENV{HOME};	1008	local $HOME = $ENV{HOME};
792	local $old = $self->{state};	1009	local $frame = [];
793	local $new = my $state = $self->{state} = {};
794		1010
795	($x, $y, $w, $h) =
796	$self->background_geometry ($self->{border});	1011	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
797		1012
798	# evaluate user expression	1013	# evaluate user expression
799		1014
800	my $img = eval { $self->{expr}->() };	1015	my @img = eval { $self->{expr}->() };
801	warn $@ if $@;#d#	1016	die $@ if $@;
802	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";	1017	die "background-expr did not return anything.\n" unless @img;
		1018	die "background-expr: expected image(s), got something else.\n"
		1019	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
803		1020
804	$state->{size_sensitive} = 1	1021	my $img = urxvt::bgdsl::merge @img;
		1022
		1023	$frame->[FR_AGAIN]{size} = 1
805	if $img->repeat_mode != urxvt::RepeatNormal;	1024	if $img->repeat_mode != urxvt::RepeatNormal;
806		1025
807	# if the expression is sensitive to external events, prepare reevaluation then	1026	# if the expression is sensitive to external events, prepare reevaluation then
808		1027	$self->compile_frame ($frame, sub { $arg_self->recalculate });
809	my $repeat;
810
811	if (my $again = $state->{again}) {
812	$repeat = 1;
813	my $self = $self;
814	$state->{timer} = $again == $old->{again}
815	? $old->{timer}
816	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
817	++$self->{counter};
818	$self->recalculate
819	});
820	}
821
822	if (delete $state->{position_sensitive}) {
823	$repeat = 1;
824	$self->enable (position_change => sub { $_[0]->recalculate });
825	} else {
826	$self->disable ("position_change");
827	}
828
829	if (delete $state->{size_sensitive}) {
830	$repeat = 1;
831	$self->enable (size_change => sub { $_[0]->recalculate });
832	} else {
833	$self->disable ("size_change");
834	}
835
836	if (delete $state->{rootpmap_sensitive}) {
837	$repeat = 1;
838	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
839	} else {
840	$self->disable ("rootpmap_change");
841	}
842		1028
843	# clear stuff we no longer need	1029	# clear stuff we no longer need
844		1030
845	%$old = ();	1031	# unless (%{ $frame->[FR_STATE] }) {
846
847	unless ($repeat) {
848	delete $self->{state};	1032	# delete $self->{state};
849	delete $self->{expr};	1033	# delete $self->{expr};
850	}	1034	# }
851		1035
852	# set background pixmap	1036	# set background pixmap
853		1037
854	$self->set_background ($img, $self->{border});	1038	$self->set_background ($img, $self->{border});
855	$self->scr_recolour (0);	1039	$self->scr_recolour (0);

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.49 by root, Sun Jun 10 15:29:18 2012 UTC vs. Revision 1.68 by root, Sun Jul 1 21:47:07 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.49 by root, Sun Jun 10 15:29:18 2012 UTC vs.
Revision 1.68 by root, Sun Jul 1 21:47:07 2012 UTC