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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.44 by root, Sun Jun 10 11:31:22 2012 UTC vs.
Revision 1.61 by root, Fri Jun 15 19:50:56 2012 UTC

…		…
1	#! perl	1	#! perl
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		5	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
6	#TODO: once, rootalign
7		6
8	=head1 NAME	7	=head1 NAME
9		8
10	background - manage terminal background	9	background - manage terminal background
11		10
12	=head1 SYNOPSIS	11	=head1 SYNOPSIS
13		12
14	urxvt --background-expr 'background expression'	13	urxvt --background-expr 'background expression'
15	--background-border	14	--background-border
		15	--background-interval seconds
16		16
17	=head1 DESCRIPTION	17	=head1 DESCRIPTION
18		18
19	This extension manages the terminal background by creating a picture that	19	This extension manages the terminal background by creating a picture that
20	is behind the text, replacing the normal background colour.	20	is behind the text, replacing the normal background colour.
57		57
58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the
59	image to the window size, so it relies on the window size and will	59	image to the window size, so it relies on the window size and will
60	be reevaluated each time it is changed, but not when it moves for	60	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	61	example. That ensures that the picture always fills the terminal, even
62	after it's size changes.	62	after its size changes.
63		63
64	=head2 EXPRESSIONS	64	=head2 EXPRESSIONS
65		65
66	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
67	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
…		…
71	return scale load "$HOME/weekday.png";	71	return scale load "$HOME/weekday.png";
72	} else {	72	} else {
73	return scale load "$HOME/sunday.png";	73	return scale load "$HOME/sunday.png";
74	}	74	}
75		75
76	This expression gets evaluated once per hour. It will set F<sunday.png> as	76	This expression is evaluated once per hour. It will set F<sunday.png> as
77	background on Sundays, and F<weekday.png> on all other days.	77	background on Sundays, and F<weekday.png> on all other days.
78		78
79	Fortunately, we expect that most expressions will be much simpler, with	79	Fortunately, we expect that most expressions will be much simpler, with
80	little Perl knowledge needed.	80	little Perl knowledge needed.
81		81
…		…
115	horizontal and vertical dimensions. For example, this halves the image	115	horizontal and vertical dimensions. For example, this halves the image
116	width and doubles the image height:	116	width and doubles the image height:
117		117
118	scale 0.5, 2, load "$HOME/mypic.png"	118	scale 0.5, 2, load "$HOME/mypic.png"
119		119
120	Other effects than scalign are also readily available, for exmaple, you can	120	Other effects than scaling are also readily available, for example, you can
121	tile the image to fill the whole window, instead of resizing it:	121	tile the image to fill the whole window, instead of resizing it:
122		122
123	tile load "$HOME/mypic.png"	123	tile load "$HOME/mypic.png"
124		124
125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator	125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator
…		…
151	This only works for one cycle though, so as long as you load the same	151	This only works for one cycle though, so as long as you load the same
152	image every time, it will always be cached, but when you load a different	152	image every time, it will always be cached, but when you load a different
153	image, it will forget about the first one.	153	image, it will forget about the first one.
154		154
155	This allows you to either speed things up by keeping multiple images in	155	This allows you to either speed things up by keeping multiple images in
156	memory, or comserve memory by loading images more often.	156	memory, or conserve memory by loading images more often.
157		157
158	For example, you can keep two images in memory and use a random one like	158	For example, you can keep two images in memory and use a random one like
159	this:	159	this:
160		160
161	my $img1 = load "img1.png";	161	my $img1 = load "img1.png";
…		…
189	overwriting borders and any other areas, such as the scrollbar.	189	overwriting borders and any other areas, such as the scrollbar.
190		190
191	Specifying this flag changes the behaviour, so that the image only	191	Specifying this flag changes the behaviour, so that the image only
192	replaces the background of the character area.	192	replaces the background of the character area.
193		193
		194	=item --background-interval seconds
		195
		196	Since some operations in the underlying XRender extension can effectively
		197	freeze your X-server for prolonged time, this extension enforces a minimum
		198	time between updates, which is normally about 0.1 seconds.
		199
		200	If you want to do updates more often, you can decrease this safety
		201	interval with this switch.
		202
194	=back	203	=back
195		204
196	=cut	205	=cut
197		206
		207	our %_IMG_CACHE;
198	our $HOME;	208	our $HOME;
199	our ($self, $old, $new);	209	our ($self, $old, $new);
200	our ($x, $y, $w, $h);	210	our ($x, $y, $w, $h);
201		211
202	# enforce at least this interval between updates	212	# enforce at least this interval between updates
203	our $MIN_INTERVAL = 1/100;	213	our $MIN_INTERVAL = 6/59.951;
204		214
205	{	215	{
206	package urxvt::bgdsl; # background language	216	package urxvt::bgdsl; # background language
207		217
208	use List::Util qw(min max sum shuffle);	218	use List::Util qw(min max sum shuffle);
…		…
218	=item load $path	228	=item load $path
219		229
220	Loads the image at the given C<$path>. The image is set to plane tiling	230	Loads the image at the given C<$path>. The image is set to plane tiling
221	mode.	231	mode.
222		232
223	Loaded images will be cached for one cycle.	233	Loaded images will be cached for one cycle, and shared between temrinals
		234	running in the same process (e.g. in C<urxvtd>).
224		235
		236	=item load_uc $path
		237
		238	Load uncached - same as load, but does not cache the image. This function
		239	is most useufl if you want to optimise a background expression in some
		240	way.
		241
225	=cut	242	=cut
		243
		244	sub load_uc($) {
		245	my ($path) = @_;
		246
		247	$_IMG_CACHE{$path} \|\| do {
		248	my $img = $self->new_img_from_file ($path);
		249	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		250	$img
		251	}
		252	}
226		253
227	sub load($) {	254	sub load($) {
228	my ($path) = @_;	255	my ($path) = @_;
229		256
230	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	257	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
231	}	258	}
232		259
233	=item root	260	=item root
234		261
235	Returns the root window pixmap, that is, hopefully, the background image	262	Returns the root window pixmap, that is, hopefully, the background image
…		…
239	reevaluated when the bg image changes.	266	reevaluated when the bg image changes.
240		267
241	=cut	268	=cut
242		269
243	sub root() {	270	sub root() {
244	$new->{rootpmap_sensitive} = 1;	271	$new->{again}{rootpmap} = 1;
245	die "root op not supported, exg, we need you";	272	$self->new_img_from_root
246	}	273	}
247		274
248	=item solid $colour	275	=item solid $colour
249		276
250	=item solid $width, $height, $colour	277	=item solid $width, $height, $colour
…		…
258	=cut	285	=cut
259		286
260	sub solid($;$$) {	287	sub solid($;$$) {
261	my $colour = pop;	288	my $colour = pop;
262		289
263	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	290	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
264	$img->fill ($colour);	291	$img->fill ($colour);
265	$img	292	$img
266	}	293	}
267		294
268	=back	295	=item clone $img
269		296
270	=head2 VARIABLES	297	Returns an exact copy of the image. This is useful if you want to have
		298	multiple copies of the same image to apply different effects to.
271		299
272	The following functions provide variable data such as the terminal window
273	dimensions. They are not (Perl-) variables, they jsut return stuff that
274	varies. Most of them make your expression sensitive to some events, for
275	example using C<TW> (terminal width) means your expression is evaluated
276	again when the terminal is resized.
277
278	=over 4
279
280	=item TX
281
282	=item TY
283
284	Return the X and Y coordinates of the terminal window (the terminal
285	window is the full window by default, and the character area only when in
286	border-respect mode).
287
288	Using these functions make your expression sensitive to window moves.
289
290	These functions are mainly useful to align images to the root window.
291
292	Example: load an image and align it so it looks as if anchored to the
293	background.
294
295	move -TX, -TY, load "mybg.png"
296
297	=item TW
298
299	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
300	terminal window is the full window by default, and the character area only
301	when in border-respect mode).
302
303	Using these functions make your expression sensitive to window resizes.
304
305	These functions are mainly useful to scale images, or to clip images to
306	the window size to conserve memory.
307
308	Example: take the screen background, clip it to the window size, blur it a
309	bit, align it to the window position and use it as background.
310
311	clip move -TX, -TY, blur 5, root
312
313	=cut	300	=cut
314		301
315	sub TX() { $new->{position_sensitive} = 1; $x }
316	sub TY() { $new->{position_sensitive} = 1; $y }
317	sub TW() { $new->{size_sensitive} = 1; $w }
318	sub TH() { $new->{size_sensitive} = 1; $h }
319
320	=item now
321
322	Returns the current time as (fractional) seconds since the epoch.
323
324	Using this expression does I<not> make your expression sensitive to time,
325	but the next two functions do.
326
327	=item again $seconds
328
329	When this function is used the expression will be reevaluated again in
330	C<$seconds> seconds.
331
332	Example: load some image and rotate it according to the time of day (as if it were
333	the hour pointer of a clock). Update this image every minute.
334
335	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
336
337	=item counter $seconds
338
339	Like C<again>, but also returns an increasing counter value, starting at
340	0, which might be useful for some simple animation effects.
341
342	=cut
343
344	sub now() { urxvt::NOW }
345
346	sub again($) {
347	$new->{again} = $_[0];
348	}
349
350	sub counter($) {	302	sub clone($) {
351	$new->{again} = $_[0];	303	$_[0]->clone
352	$self->{counter} + 0
353	}	304	}
354		305
355	=back	306	=item merge $img ...
		307
		308	Takes any number of images and merges them together, creating a single
		309	image containing them all.
		310
		311	This function is called automatically when an expression returns multiple
		312	images.
		313
		314	=cut
		315
		316	sub merge(@) {
		317	return $_[0] unless $#_;
		318
		319	# rather annoyingly clumsy, but optimisation is for another time
		320
		321	my $x0 = +1e9;
		322	my $y0 = +1e9;
		323	my $x1 = -1e9;
		324	my $y1 = -1e9;
		325
		326	for (@_) {
		327	my ($x, $y, $w, $h) = $_->geometry;
		328
		329	$x0 = $x if $x0 > $x;
		330	$y0 = $y if $y0 > $y;
		331
		332	$x += $w;
		333	$y += $h;
		334
		335	$x1 = $x if $x1 < $x;
		336	$y1 = $y if $y1 < $y;
		337	}
		338
		339	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		340	$base->fill ([0, 0, 0, 0]);
		341
		342	$base->draw ($_)
		343	for @_;
		344
		345	$base
		346	}
356		347
357	=head2 TILING MODES	348	=head2 TILING MODES
358		349
359	The following operators modify the tiling mode of an image, that is, the	350	The following operators modify the tiling mode of an image, that is, the
360	way that pixels outside the image area are painted when the image is used.	351	way that pixels outside the image area are painted when the image is used.
…		…
390	become transparent. This mode is most useful when you want to place an	381	become transparent. This mode is most useful when you want to place an
391	image over another image or the background colour while leaving all	382	image over another image or the background colour while leaving all
392	background pixels outside the image unchanged.	383	background pixels outside the image unchanged.
393		384
394	Example: load an image and display it in the upper left corner. The rest	385	Example: load an image and display it in the upper left corner. The rest
395	of the space is left "empty" (transparent or wahtever your compisotr does	386	of the space is left "empty" (transparent or whatever your compositor does
396	in alpha mode, else background colour).	387	in alpha mode, else background colour).
397		388
398	pad load "mybg.png"	389	pad load "mybg.png"
399		390
400	=item extend $img	391	=item extend $img
401		392
402	Extends the image over the whole plane, using the closest pixel in the	393	Extends the image over the whole plane, using the closest pixel in the
403	area outside the image. This mode is mostly useful when you more complex	394	area outside the image. This mode is mostly useful when you use more complex
404	filtering operations and want the pixels outside the image to have the	395	filtering operations and want the pixels outside the image to have the
405	same values as the pixels near the edge.	396	same values as the pixels near the edge.
406		397
407	Example: just for curiosity, how does this pixel extension stuff work?	398	Example: just for curiosity, how does this pixel extension stuff work?
408		399
…		…
434	$img	425	$img
435	}	426	}
436		427
437	=back	428	=back
438		429
439	=head2 PIXEL OPERATORS	430	=head2 VARIABLE VALUES
440		431
441	The following operators modify the image pixels in various ways.	432	The following functions provide variable data such as the terminal window
		433	dimensions. They are not (Perl-) variables, they just return stuff that
		434	varies. Most of them make your expression sensitive to some events, for
		435	example using C<TW> (terminal width) means your expression is evaluated
		436	again when the terminal is resized.
442		437
443	=over 4	438	=over 4
444		439
445	=item clone $img	440	=item TX
446		441
447	Returns an exact copy of the image.	442	=item TY
448		443
449	=cut	444	Return the X and Y coordinates of the terminal window (the terminal
		445	window is the full window by default, and the character area only when in
		446	border-respect mode).
450		447
		448	Using these functions make your expression sensitive to window moves.
		449
		450	These functions are mainly useful to align images to the root window.
		451
		452	Example: load an image and align it so it looks as if anchored to the
		453	background.
		454
		455	move -TX, -TY, load "mybg.png"
		456
		457	=item TW
		458
		459	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		460	terminal window is the full window by default, and the character area only
		461	when in border-respect mode).
		462
		463	Using these functions make your expression sensitive to window resizes.
		464
		465	These functions are mainly useful to scale images, or to clip images to
		466	the window size to conserve memory.
		467
		468	Example: take the screen background, clip it to the window size, blur it a
		469	bit, align it to the window position and use it as background.
		470
		471	clip move -TX, -TY, once { blur 5, root }
		472
		473	=cut
		474
		475	sub TX() { $new->{again}{position} = 1; $x }
		476	sub TY() { $new->{again}{position} = 1; $y }
		477	sub TW() { $new->{again}{size} = 1; $w }
		478	sub TH() { $new->{again}{size} = 1; $h }
		479
		480	=item now
		481
		482	Returns the current time as (fractional) seconds since the epoch.
		483
		484	Using this expression does I<not> make your expression sensitive to time,
		485	but the next two functions do.
		486
		487	=item again $seconds
		488
		489	When this function is used the expression will be reevaluated again in
		490	C<$seconds> seconds.
		491
		492	Example: load some image and rotate it according to the time of day (as if it were
		493	the hour pointer of a clock). Update this image every minute.
		494
		495	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
		496
		497	=item counter $seconds
		498
		499	Like C<again>, but also returns an increasing counter value, starting at
		500	0, which might be useful for some simple animation effects.
		501
		502	=cut
		503
		504	sub now() { urxvt::NOW }
		505
		506	sub again($) {
		507	$new->{again}{time} = $_[0];
		508	}
		509
451	sub clone($) {	510	sub counter($) {
452	$_[0]->clone	511	$new->{again}{time} = $_[0];
		512	$self->{counter} + 0
453	}	513	}
		514
		515	=back
		516
		517	=head2 SHAPE CHANGING OPERATORS
		518
		519	The following operators modify the shape, size or position of the image.
		520
		521	=over 4
454		522
455	=item clip $img	523	=item clip $img
456		524
457	=item clip $width, $height, $img	525	=item clip $width, $height, $img
458		526
…		…
552		620
553	Example: move the image right by 20 pixels and down by 30.	621	Example: move the image right by 20 pixels and down by 30.
554		622
555	move 20, 30, ...	623	move 20, 30, ...
556		624
		625	=item align $xalign, $yalign, $img
		626
		627	Aligns the image according to a factor - C<0> means the image is moved to
		628	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		629	exactly centered and C<1> means it touches the right or bottom edge.
		630
		631	Example: remove any visible border around an image, center it vertically but move
		632	it to the right hand side.
		633
		634	align 1, 0.5, pad $img
		635
557	=item center $img	636	=item center $img
558		637
559	=item center $width, $height, $img	638	=item center $width, $height, $img
560		639
561	Centers the image, i.e. the center of the image is moved to the center of	640	Centers the image, i.e. the center of the image is moved to the center of
562	the terminal window (or the box specified by C<$width> and C<$height> if	641	the terminal window (or the box specified by C<$width> and C<$height> if
563	given).	642	given).
		643
		644	Example: load an image and center it.
		645
		646	center pad load "mybg.png"
564		647
565	=item rootalign $img	648	=item rootalign $img
566		649
567	Moves the image so that it appears glued to the screen as opposed to the	650	Moves the image so that it appears glued to the screen as opposed to the
568	window. This gives the illusion of a larger area behind the window. It is	651	window. This gives the illusion of a larger area behind the window. It is
…		…
574	rootalign mirror load "mybg.png"	657	rootalign mirror load "mybg.png"
575		658
576	Example: take the screen background and align it, giving the illusion of	659	Example: take the screen background and align it, giving the illusion of
577	transparency as long as the window isn't in front of other windows.	660	transparency as long as the window isn't in front of other windows.
578		661
579	rootalign root	662	rootalign root
580		663
581	=cut	664	=cut
582		665
583	sub move($$;$) {	666	sub move($$;$) {
584	my $img = pop->clone;	667	my $img = pop->clone;
585	$img->move ($_[0], $_[1]);	668	$img->move ($_[0], $_[1]);
586	$img	669	$img
587	}	670	}
588		671
		672	sub align($;$$) {
		673	my $img = pop;
		674
		675	move $_[0] * (TW - $img->w),
		676	$_[1] * (TH - $img->h),
		677	$img
		678	}
		679
589	sub center($;$$) {	680	sub center($;$$) {
590	my $img = pop;	681	my $img = pop;
591	my $w = $_[0] \|\| TW;	682	my $w = $_[0] \|\| TW;
592	my $h = $_[0] \|\| TH;	683	my $h = $_[1] \|\| TH;
593		684
594	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img	685	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
595	}	686	}
596		687
597	sub rootalign($) {	688	sub rootalign($) {
598	move -TX, -TY, $_[0]	689	move -TX, -TY, $_[0]
599	}	690	}
600		691
		692	=item rotate $center_x, $center_y, $degrees
		693
		694	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		695	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		696	width/height).
		697
		698	#TODO# new width, height, maybe more operators?
		699
		700	Example: rotate the image by 90 degrees
		701
		702	=cut
		703
		704	sub rotate($$$$) {
		705	my $img = pop;
		706	$img->rotate (
		707	$_[0] * ($img->w + $img->x),
		708	$_[1] * ($img->h + $img->y),
		709	$_[2] * (3.14159265 / 180),
		710	)
		711	}
		712
		713	=back
		714
		715	=head2 COLOUR MODIFICATIONS
		716
		717	The following operators change the pixels of the image.
		718
		719	=over 4
		720
601	=item contrast $factor, $img	721	=item contrast $factor, $img
602		722
603	=item contrast $r, $g, $b, $img	723	=item contrast $r, $g, $b, $img
604		724
605	=item contrast $r, $g, $b, $a, $img	725	=item contrast $r, $g, $b, $a, $img
606		726
607	Adjusts the I<contrast> of an image.	727	Adjusts the I<contrast> of an image.
608		728
609	#TODO#	729	The first form applies a single C<$factor> to red, green and blue, the
		730	second form applies separate factors to each colour channel, and the last
		731	form includes the alpha channel.
610		732
		733	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		734	contrast.
		735
		736	Due to limitations in the underlying XRender extension, lowering contrast
		737	also reduces brightness, while increasing contrast currently also
		738	increases brightness.
		739
611	=item brightness $factor, $img	740	=item brightness $bias, $img
612		741
613	=item brightness $r, $g, $b, $img	742	=item brightness $r, $g, $b, $img
614		743
615	=item brightness $r, $g, $b, $a, $img	744	=item brightness $r, $g, $b, $a, $img
616		745
617	Adjusts the brightness of an image.	746	Adjusts the brightness of an image.
618		747
		748	The first form applies a single C<$bias> to red, green and blue, the
		749	second form applies separate biases to each colour channel, and the last
		750	form includes the alpha channel.
		751
		752	Values less than 0 reduce brightness, while values larger than 0 increase
		753	it. Useful range is from -1 to 1 - the former results in a black, the
		754	latter in a white picture.
		755
		756	Due to idiosyncrasies in the underlying XRender extension, biases less
		757	than zero can be I<very> slow.
		758
619	=cut	759	=cut
620		760
621	sub contrast($$;$$;$) {	761	sub contrast($$;$$;$) {
622	my $img = pop;	762	my $img = pop;
623	my ($r, $g, $b, $a) = @_;	763	my ($r, $g, $b, $a) = @_;
624		764
625	($g, $b) = ($r, $r) if @_ < 4;	765	($g, $b) = ($r, $r) if @_ < 3;
626	$a = 1 if @_ < 5;	766	$a = 1 if @_ < 4;
627		767
628	$img = $img->clone;	768	$img = $img->clone;
629	$img->contrast ($r, $g, $b, $a);	769	$img->contrast ($r, $g, $b, $a);
630	$img	770	$img
631	}	771	}
632		772
633	sub brightness($$;$$;$) {	773	sub brightness($$;$$;$) {
634	my $img = pop;	774	my $img = pop;
635	my ($r, $g, $b, $a) = @_;	775	my ($r, $g, $b, $a) = @_;
636		776
637	($g, $b) = ($r, $r) if @_ < 4;	777	($g, $b) = ($r, $r) if @_ < 3;
638	$a = 1 if @_ < 5;	778	$a = 1 if @_ < 4;
639		779
640	$img = $img->clone;	780	$img = $img->clone;
641	$img->brightness ($r, $g, $b, $a);	781	$img->brightness ($r, $g, $b, $a);
642	$img	782	$img
643	}	783	}
…		…
659	sub blur($$;$) {	799	sub blur($$;$) {
660	my $img = pop;	800	my $img = pop;
661	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	801	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
662	}	802	}
663		803
664	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees	804	=back
665		805
666	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	806	=head2 OTHER STUFF
667	pointer at C<$center_x> and C<$center_y> (specified as factor of image
668	width/height), generating a new image with width C<$new_width> and height
669	C<$new_height>.
670		807
671	#TODO# new width, height, maybe more operators?	808	Anything that didn't fit any of the other categories, even after applying
		809	force and closing our eyes.
672		810
673	Example: rotate the image by 90 degrees	811	=over 4
674		812
675	=cut	813	=item once { ... }
676		814
677	sub rotate($$$$$$) {	815	This function takes a code block as argument, that is, one or more
678	my $img = pop;	816	statements enclosed by braces.
679	$img->rotate (	817
680	$_[0],	818	The trick is that this code block is only evaluated once - future calls
681	$_[1],	819	will simply return the original image (yes, it should only be used with
682	$_[2] * $img->w,	820	images).
683	$_[3] * $img->h,	821
684	$_[4] * (3.14159265 / 180),	822	This can be extremely useful to avoid redoign the same slow operations
		823	again and again- for example, if your background expression takes the root
		824	background, blurs it and then root-aligns it it would have to blur the
		825	root background on every window move or resize.
		826
		827	Putting the blur into a C<once> block will make sure the blur is only done
		828	once:
		829
		830	rootlign once { blur 10, root }
		831
		832	This leaves the question of how to force reevaluation of the block, in
		833	case the root background changes: Right now, all once blocks forget that
		834	they ahve been executed before each time the root background changes (if
		835	the expression is sensitive to that) or when C<once_again> is called.
		836
		837	=item once_again
		838
		839	Resets all C<once> block as if they had never been called, i.e. on the
		840	next call they will be reevaluated again.
		841
		842	=cut
		843
		844	sub once(&) {
		845	my $once = $self->{once_cache}{$_[0]+0} \|\|= do {
		846	local $new->{again};
		847	my @res = $_[0]();
		848	[$new->{again}, \@res]
685	)	849	};
		850
		851	$new->{again} = {
		852	%{ $new->{again} },
		853	%{ $once->[0] }
		854	};
		855
		856	# in scalar context we always return the first original result, which
		857	# is not quite how perl works.
		858	wantarray
		859	? @{ $once->[1] }
		860	: $once->[1][0]
		861	}
		862
		863	sub once_again() {
		864	delete $self->{once_cache};
686	}	865	}
687		866
688	=back	867	=back
689		868
690	=cut	869	=cut
…		…
731	($x, $y, $w, $h) =	910	($x, $y, $w, $h) =
732	$self->background_geometry ($self->{border});	911	$self->background_geometry ($self->{border});
733		912
734	# evaluate user expression	913	# evaluate user expression
735		914
736	my $img = eval { $self->{expr}->() };	915	my $img = eval { urxvt::bgdsl::merge $self->{expr}->() };
737	warn $@ if $@;#d#	916	die $@ if $@;
738	die if !UNIVERSAL::isa $img, "urxvt::img";	917	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
739		918
740	$state->{size_sensitive} = 1	919	# if the expression is sensitive to external events, prepare reevaluation then
		920
		921	my $again = delete $state->{again};
		922
		923	$again->{size} = 1
741	if $img->repeat_mode != urxvt::RepeatNormal;	924	if $img->repeat_mode != urxvt::RepeatNormal;
742		925
743	# if the expression is sensitive to external events, prepare reevaluation then
744
745	my $repeat;
746
747	if (my $again = $state->{again}) {	926	if (my $again = $again->{time}) {
748	$repeat = 1;
749	my $self = $self;	927	my $self = $self;
750	$state->{timer} = $again == $old->{again}	928	$state->{timer} = $again == $old->{again}
751	? $old->{timer}	929	? $old->{timer}
752	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {	930	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
753	++$self->{counter};	931	++$self->{counter};
754	$self->recalculate	932	$self->recalculate
755	});	933	});
756	}	934	}
757		935
758	if (delete $state->{position_sensitive}) {	936	if ($again->{position}) {
759	$repeat = 1;
760	$self->enable (position_change => sub { $_[0]->recalculate });	937	$self->enable (position_change => sub { $_[0]->recalculate });
761	} else {	938	} else {
762	$self->disable ("position_change");	939	$self->disable ("position_change");
763	}	940	}
764		941
765	if (delete $state->{size_sensitive}) {	942	if ($again->{size}) {
766	$repeat = 1;
767	$self->enable (size_change => sub { $_[0]->recalculate });	943	$self->enable (size_change => sub { $_[0]->recalculate });
768	} else {	944	} else {
769	$self->disable ("size_change");	945	$self->disable ("size_change");
770	}	946	}
771		947
772	if (delete $state->{rootpmap_sensitive}) {	948	if ($again->{rootpmap}) {
773	$repeat = 1;
774	$self->enable (rootpmap_change => sub { $_[0]->recalculate });	949	$self->enable (rootpmap_change => sub {
		950	delete $_[0]{once_cache}; # this will override once-block values from
		951	$_[0]->recalculate;
		952	});
775	} else {	953	} else {
776	$self->disable ("rootpmap_change");	954	$self->disable ("rootpmap_change");
777	}	955	}
778		956
779	# clear stuff we no longer need	957	# clear stuff we no longer need
780		958
781	%$old = ();	959	%$old = ();
782		960
783	unless ($repeat) {	961	unless (%$again) {
784	delete $self->{state};	962	delete $self->{state};
785	delete $self->{expr};	963	delete $self->{expr};
786	}	964	}
787		965
788	# set background pixmap	966	# set background pixmap
…		…
793	}	971	}
794		972
795	sub on_start {	973	sub on_start {
796	my ($self) = @_;	974	my ($self) = @_;
797		975
798	my $expr = $self->x_resource ("background.expr")	976	my $expr = $self->x_resource ("%.expr")
799	or return;	977	or return;
800		978
		979	$self->has_render
		980	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		981
801	$self->set_expr (parse_expr $expr);	982	$self->set_expr (parse_expr $expr);
802	$self->{border} = $self->x_resource_boolean ("background.border");	983	$self->{border} = $self->x_resource_boolean ("%.border");
		984
		985	$MIN_INTERVAL = $self->x_resource ("%.interval");
803		986
804	()	987	()
805	}	988	}
806		989

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.44 by root, Sun Jun 10 11:31:22 2012 UTC vs. Revision 1.61 by root, Fri Jun 15 19:50:56 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.44 by root, Sun Jun 10 11:31:22 2012 UTC vs.
Revision 1.61 by root, Fri Jun 15 19:50:56 2012 UTC