[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 1.59 by root, Thu Jun 14 19:31:17 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	=cut
		312
		313	sub merge(@) {
		314	# rather annoyingly clumsy, but optimisation is for another time
		315
		316	my $x0 = +1e9;
		317	my $y0 = +1e9;
		318	my $x1 = -1e9;
		319	my $y1 = -1e9;
		320
		321	for (@_) {
		322	my ($x, $y, $w, $h) = $_->geometry;
		323
		324	$x0 = $x if $x0 > $x;
		325	$y0 = $y if $y0 > $y;
		326
		327	$x += $w;
		328	$y += $h;
		329
		330	$x1 = $x if $x1 < $x;
		331	$y1 = $y if $y1 < $y;
		332	}
		333
		334	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		335	$base->fill ([0, 0, 0, 0]);
		336
		337	$base->draw ($_)
		338	for @_;
		339
		340	$base
		341	}
356		342
357	=head2 TILING MODES	343	=head2 TILING MODES
358		344
359	The following operators modify the tiling mode of an image, that is, the	345	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.	346	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	376	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	377	image over another image or the background colour while leaving all
392	background pixels outside the image unchanged.	378	background pixels outside the image unchanged.
393		379
394	Example: load an image and display it in the upper left corner. The rest	380	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	381	of the space is left "empty" (transparent or whatever your compositor does
396	in alpha mode, else background colour).	382	in alpha mode, else background colour).
397		383
398	pad load "mybg.png"	384	pad load "mybg.png"
399		385
400	=item extend $img	386	=item extend $img
401		387
402	Extends the image over the whole plane, using the closest pixel in the	388	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	389	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	390	filtering operations and want the pixels outside the image to have the
405	same values as the pixels near the edge.	391	same values as the pixels near the edge.
406		392
407	Example: just for curiosity, how does this pixel extension stuff work?	393	Example: just for curiosity, how does this pixel extension stuff work?
408		394
…		…
434	$img	420	$img
435	}	421	}
436		422
437	=back	423	=back
438		424
439	=head2 PIXEL OPERATORS	425	=head2 VARIABLE VALUES
440		426
441	The following operators modify the image pixels in various ways.	427	The following functions provide variable data such as the terminal window
		428	dimensions. They are not (Perl-) variables, they just return stuff that
		429	varies. Most of them make your expression sensitive to some events, for
		430	example using C<TW> (terminal width) means your expression is evaluated
		431	again when the terminal is resized.
442		432
443	=over 4	433	=over 4
444		434
445	=item clone $img	435	=item TX
446		436
447	Returns an exact copy of the image.	437	=item TY
448		438
449	=cut	439	Return the X and Y coordinates of the terminal window (the terminal
		440	window is the full window by default, and the character area only when in
		441	border-respect mode).
450		442
		443	Using these functions make your expression sensitive to window moves.
		444
		445	These functions are mainly useful to align images to the root window.
		446
		447	Example: load an image and align it so it looks as if anchored to the
		448	background.
		449
		450	move -TX, -TY, load "mybg.png"
		451
		452	=item TW
		453
		454	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		455	terminal window is the full window by default, and the character area only
		456	when in border-respect mode).
		457
		458	Using these functions make your expression sensitive to window resizes.
		459
		460	These functions are mainly useful to scale images, or to clip images to
		461	the window size to conserve memory.
		462
		463	Example: take the screen background, clip it to the window size, blur it a
		464	bit, align it to the window position and use it as background.
		465
		466	clip move -TX, -TY, once { blur 5, root }
		467
		468	=cut
		469
		470	sub TX() { $new->{again}{position} = 1; $x }
		471	sub TY() { $new->{again}{position} = 1; $y }
		472	sub TW() { $new->{again}{size} = 1; $w }
		473	sub TH() { $new->{again}{size} = 1; $h }
		474
		475	=item now
		476
		477	Returns the current time as (fractional) seconds since the epoch.
		478
		479	Using this expression does I<not> make your expression sensitive to time,
		480	but the next two functions do.
		481
		482	=item again $seconds
		483
		484	When this function is used the expression will be reevaluated again in
		485	C<$seconds> seconds.
		486
		487	Example: load some image and rotate it according to the time of day (as if it were
		488	the hour pointer of a clock). Update this image every minute.
		489
		490	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
		491
		492	=item counter $seconds
		493
		494	Like C<again>, but also returns an increasing counter value, starting at
		495	0, which might be useful for some simple animation effects.
		496
		497	=cut
		498
		499	sub now() { urxvt::NOW }
		500
		501	sub again($) {
		502	$new->{again}{time} = $_[0];
		503	}
		504
451	sub clone($) {	505	sub counter($) {
452	$_[0]->clone	506	$new->{again}{time} = $_[0];
		507	$self->{counter} + 0
453	}	508	}
		509
		510	=back
		511
		512	=head2 SHAPE CHANGING OPERATORS
		513
		514	The following operators modify the shape, size or position of the image.
		515
		516	=over 4
454		517
455	=item clip $img	518	=item clip $img
456		519
457	=item clip $width, $height, $img	520	=item clip $width, $height, $img
458		521
…		…
552		615
553	Example: move the image right by 20 pixels and down by 30.	616	Example: move the image right by 20 pixels and down by 30.
554		617
555	move 20, 30, ...	618	move 20, 30, ...
556		619
		620	=item align $xalign, $yalign, $img
		621
		622	Aligns the image according to a factor - C<0> means the image is moved to
		623	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		624	exactly centered and C<1> means it touches the right or bottom edge.
		625
		626	Example: remove any visible border around an image, center it vertically but move
		627	it to the right hand side.
		628
		629	align 1, 0.5, pad $img
		630
557	=item center $img	631	=item center $img
558		632
559	=item center $width, $height, $img	633	=item center $width, $height, $img
560		634
561	Centers the image, i.e. the center of the image is moved to the center of	635	Centers the image, i.e. the center of the image is moved to the center of
562	the terminal window (or the box specified by C<$width> and C<$height> if	636	the terminal window (or the box specified by C<$width> and C<$height> if
563	given).	637	given).
		638
		639	Example: load an image and center it.
		640
		641	center pad load "mybg.png"
564		642
565	=item rootalign $img	643	=item rootalign $img
566		644
567	Moves the image so that it appears glued to the screen as opposed to the	645	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	646	window. This gives the illusion of a larger area behind the window. It is
…		…
574	rootalign mirror load "mybg.png"	652	rootalign mirror load "mybg.png"
575		653
576	Example: take the screen background and align it, giving the illusion of	654	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.	655	transparency as long as the window isn't in front of other windows.
578		656
579	rootalign root	657	rootalign root
580		658
581	=cut	659	=cut
582		660
583	sub move($$;$) {	661	sub move($$;$) {
584	my $img = pop->clone;	662	my $img = pop->clone;
585	$img->move ($_[0], $_[1]);	663	$img->move ($_[0], $_[1]);
586	$img	664	$img
587	}	665	}
588		666
		667	sub align($;$$) {
		668	my $img = pop;
		669
		670	move $_[0] * (TW - $img->w),
		671	$_[1] * (TH - $img->h),
		672	$img
		673	}
		674
589	sub center($;$$) {	675	sub center($;$$) {
590	my $img = pop;	676	my $img = pop;
591	my $w = $_[0] \|\| TW;	677	my $w = $_[0] \|\| TW;
592	my $h = $_[0] \|\| TH;	678	my $h = $_[1] \|\| TH;
593		679
594	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img	680	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
595	}	681	}
596		682
597	sub rootalign($) {	683	sub rootalign($) {
598	move -TX, -TY, $_[0]	684	move -TX, -TY, $_[0]
599	}	685	}
600		686
		687	=item rotate $center_x, $center_y, $degrees
		688
		689	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		690	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		691	width/height).
		692
		693	#TODO# new width, height, maybe more operators?
		694
		695	Example: rotate the image by 90 degrees
		696
		697	=cut
		698
		699	sub rotate($$$$) {
		700	my $img = pop;
		701	$img->rotate (
		702	$_[0] * $img->w,
		703	$_[1] * $img->h,
		704	$_[2] * (3.14159265 / 180),
		705	)
		706	}
		707
		708	=back
		709
		710	=head2 COLOUR MODIFICATIONS
		711
		712	The following operators change the pixels of the image.
		713
		714	=over 4
		715
601	=item contrast $factor, $img	716	=item contrast $factor, $img
602		717
603	=item contrast $r, $g, $b, $img	718	=item contrast $r, $g, $b, $img
604		719
605	=item contrast $r, $g, $b, $a, $img	720	=item contrast $r, $g, $b, $a, $img
606		721
607	Adjusts the I<contrast> of an image.	722	Adjusts the I<contrast> of an image.
608		723
609	#TODO#	724	The first form applies a single C<$factor> to red, green and blue, the
		725	second form applies separate factors to each colour channel, and the last
		726	form includes the alpha channel.
610		727
		728	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		729	contrast.
		730
		731	Due to limitations in the underlying XRender extension, lowering contrast
		732	also reduces brightness, while increasing contrast currently also
		733	increases brightness.
		734
611	=item brightness $factor, $img	735	=item brightness $bias, $img
612		736
613	=item brightness $r, $g, $b, $img	737	=item brightness $r, $g, $b, $img
614		738
615	=item brightness $r, $g, $b, $a, $img	739	=item brightness $r, $g, $b, $a, $img
616		740
617	Adjusts the brightness of an image.	741	Adjusts the brightness of an image.
618		742
		743	The first form applies a single C<$bias> to red, green and blue, the
		744	second form applies separate biases to each colour channel, and the last
		745	form includes the alpha channel.
		746
		747	Values less than 0 reduce brightness, while values larger than 0 increase
		748	it. Useful range is from -1 to 1 - the former results in a black, the
		749	latter in a white picture.
		750
		751	Due to idiosyncrasies in the underlying XRender extension, biases less
		752	than zero can be I<very> slow.
		753
619	=cut	754	=cut
620		755
621	sub contrast($$;$$;$) {	756	sub contrast($$;$$;$) {
622	my $img = pop;	757	my $img = pop;
623	my ($r, $g, $b, $a) = @_;	758	my ($r, $g, $b, $a) = @_;
624		759
625	($g, $b) = ($r, $r) if @_ < 4;	760	($g, $b) = ($r, $r) if @_ < 3;
626	$a = 1 if @_ < 5;	761	$a = 1 if @_ < 4;
627		762
628	$img = $img->clone;	763	$img = $img->clone;
629	$img->contrast ($r, $g, $b, $a);	764	$img->contrast ($r, $g, $b, $a);
630	$img	765	$img
631	}	766	}
632		767
633	sub brightness($$;$$;$) {	768	sub brightness($$;$$;$) {
634	my $img = pop;	769	my $img = pop;
635	my ($r, $g, $b, $a) = @_;	770	my ($r, $g, $b, $a) = @_;
636		771
637	($g, $b) = ($r, $r) if @_ < 4;	772	($g, $b) = ($r, $r) if @_ < 3;
638	$a = 1 if @_ < 5;	773	$a = 1 if @_ < 4;
639		774
640	$img = $img->clone;	775	$img = $img->clone;
641	$img->brightness ($r, $g, $b, $a);	776	$img->brightness ($r, $g, $b, $a);
642	$img	777	$img
643	}	778	}
…		…
659	sub blur($$;$) {	794	sub blur($$;$) {
660	my $img = pop;	795	my $img = pop;
661	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	796	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
662	}	797	}
663		798
664	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees	799	=back
665		800
666	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	801	=head2 OTHER STUFF
667	pointer at C<$center_x> and C<$center_y> (specified as factor of image
668	width/height), generating a new image with width C<$new_width> and height
669	C<$new_height>.
670		802
671	#TODO# new width, height, maybe more operators?	803	Anything that didn't fit any of the other categories, even after applying
		804	force and closing our eyes.
672		805
673	Example: rotate the image by 90 degrees	806	=over 4
674		807
675	=cut	808	=item once { ... }
676		809
677	sub rotate($$$$$$) {	810	This function takes a code block as argument, that is, one or more
678	my $img = pop;	811	statements enclosed by braces.
679	$img->rotate (	812
680	$_[0],	813	The trick is that this code block is only evaluated once - future calls
681	$_[1],	814	will simply return the original image (yes, it should only be used with
682	$_[2] * $img->w,	815	images).
683	$_[3] * $img->h,	816
684	$_[4] * (3.14159265 / 180),	817	This can be extremely useful to avoid redoign the same slow operations
		818	again and again- for example, if your background expression takes the root
		819	background, blurs it and then root-aligns it it would have to blur the
		820	root background on every window move or resize.
		821
		822	Putting the blur into a C<once> block will make sure the blur is only done
		823	once:
		824
		825	rootlign once { blur 10, root }
		826
		827	This leaves the question of how to force reevaluation of the block, in
		828	case the root background changes: Right now, all once blocks forget that
		829	they ahve been executed before each time the root background changes (if
		830	the expression is sensitive to that) or when C<once_again> is called.
		831
		832	=item once_again
		833
		834	Resets all C<once> block as if they had never been called, i.e. on the
		835	next call they will be reevaluated again.
		836
		837	=cut
		838
		839	sub once(&) {
		840	my $once = $self->{once_cache}{$_[0]+0} \|\|= do {
		841	local $new->{again};
		842	my @res = $_[0]();
		843	[$new->{again}, \@res]
685	)	844	};
		845
		846	$new->{again} = {
		847	%{ $new->{again} },
		848	%{ $once->[0] }
		849	};
		850
		851	# in scalar context we always return the first original result, which
		852	# is not quite how perl works.
		853	wantarray
		854	? @{ $once->[1] }
		855	: $once->[1][0]
		856	}
		857
		858	sub once_again() {
		859	delete $self->{once_cache};
686	}	860	}
687		861
688	=back	862	=back
689		863
690	=cut	864	=cut
…		…
733		907
734	# evaluate user expression	908	# evaluate user expression
735		909
736	my $img = eval { $self->{expr}->() };	910	my $img = eval { $self->{expr}->() };
737	warn $@ if $@;#d#	911	warn $@ if $@;#d#
738	die if !UNIVERSAL::isa $img, "urxvt::img";	912	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
739		913
740	$state->{size_sensitive} = 1	914	# if the expression is sensitive to external events, prepare reevaluation then
		915
		916	my $again = delete $state->{again};
		917
		918	$again->{size} = 1
741	if $img->repeat_mode != urxvt::RepeatNormal;	919	if $img->repeat_mode != urxvt::RepeatNormal;
742		920
743	# if the expression is sensitive to external events, prepare reevaluation then
744
745	my $repeat;
746
747	if (my $again = $state->{again}) {	921	if (my $again = $again->{time}) {
748	$repeat = 1;
749	my $self = $self;	922	my $self = $self;
750	$state->{timer} = $again == $old->{again}	923	$state->{timer} = $again == $old->{again}
751	? $old->{timer}	924	? $old->{timer}
752	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {	925	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
753	++$self->{counter};	926	++$self->{counter};
754	$self->recalculate	927	$self->recalculate
755	});	928	});
756	}	929	}
757		930
758	if (delete $state->{position_sensitive}) {	931	if ($again->{position}) {
759	$repeat = 1;
760	$self->enable (position_change => sub { $_[0]->recalculate });	932	$self->enable (position_change => sub { $_[0]->recalculate });
761	} else {	933	} else {
762	$self->disable ("position_change");	934	$self->disable ("position_change");
763	}	935	}
764		936
765	if (delete $state->{size_sensitive}) {	937	if ($again->{size}) {
766	$repeat = 1;
767	$self->enable (size_change => sub { $_[0]->recalculate });	938	$self->enable (size_change => sub { $_[0]->recalculate });
768	} else {	939	} else {
769	$self->disable ("size_change");	940	$self->disable ("size_change");
770	}	941	}
771		942
772	if (delete $state->{rootpmap_sensitive}) {	943	if ($again->{rootpmap}) {
773	$repeat = 1;
774	$self->enable (rootpmap_change => sub { $_[0]->recalculate });	944	$self->enable (rootpmap_change => sub {
		945	delete $_[0]{once_cache}; # this will override once-block values from
		946	$_[0]->recalculate;
		947	});
775	} else {	948	} else {
776	$self->disable ("rootpmap_change");	949	$self->disable ("rootpmap_change");
777	}	950	}
778		951
779	# clear stuff we no longer need	952	# clear stuff we no longer need
780		953
781	%$old = ();	954	%$old = ();
782		955
783	unless ($repeat) {	956	unless (%$again) {
784	delete $self->{state};	957	delete $self->{state};
785	delete $self->{expr};	958	delete $self->{expr};
786	}	959	}
787		960
788	# set background pixmap	961	# set background pixmap
…		…
793	}	966	}
794		967
795	sub on_start {	968	sub on_start {
796	my ($self) = @_;	969	my ($self) = @_;
797		970
798	my $expr = $self->x_resource ("background.expr")	971	my $expr = $self->x_resource ("%.expr")
799	or return;	972	or return;
800		973
		974	$self->has_render
		975	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		976
801	$self->set_expr (parse_expr $expr);	977	$self->set_expr (parse_expr $expr);
802	$self->{border} = $self->x_resource_boolean ("background.border");	978	$self->{border} = $self->x_resource_boolean ("%.border");
		979
		980	$MIN_INTERVAL = $self->x_resource ("%.interval");
803		981
804	()	982	()
805	}	983	}
806		984

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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 1.59 by root, Thu Jun 14 19:31:17 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 1.59 by root, Thu Jun 14 19:31:17 2012 UTC