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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs.
Revision 1.52 by root, Tue Jun 12 10:45:53 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:
…		…
99	its result becomes the argument to the C<scale> function.	99	its result becomes the argument to the C<scale> function.
100		100
101	Many operators also allow some parameters preceding the input image	101	Many operators also allow some parameters preceding the input image
102	that modify its behaviour. For example, C<scale> without any additional	102	that modify its behaviour. For example, C<scale> without any additional
103	arguments scales the image to size of the terminal window. If you specify	103	arguments scales the image to size of the terminal window. If you specify
104	an additional argument, it uses it as a percentage:	104	an additional argument, it uses it as a scale factor (multiply by 100 to
		105	get a percentage):
105		106
106	scale 200, load "$HOME/mypic.png"	107	scale 2, load "$HOME/mypic.png"
107		108
108	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>	109	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
109	has now two arguments, the C<200> and the C<load> expression, while	110	has now two arguments, the C<200> and the C<load> expression, while
110	C<load> only has one argument. Arguments are separated from each other by	111	C<load> only has one argument. Arguments are separated from each other by
111	commas.	112	commas.
112		113
113	Scale also accepts two arguments, which are then separate factors for both	114	Scale also accepts two arguments, which are then separate factors for both
114	horizontal and vertical dimensions. For example, this halves the image	115	horizontal and vertical dimensions. For example, this halves the image
115	width and doubles the image height:	116	width and doubles the image height:
116		117
117	scale 50, 200, load "$HOME/mypic.png"	118	scale 0.5, 2, load "$HOME/mypic.png"
118		119
119	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
120	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:
121		122
122	tile load "$HOME/mypic.png"	123	tile load "$HOME/mypic.png"
123		124
124	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
…		…
150	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
151	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
152	image, it will forget about the first one.	153	image, it will forget about the first one.
153		154
154	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
155	memory, or comserve memory by loading images more often.	156	memory, or conserve memory by loading images more often.
156		157
157	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
158	this:	159	this:
159		160
160	my $img1 = load "img1.png";	161	my $img1 = load "img1.png";
…		…
188	overwriting borders and any other areas, such as the scrollbar.	189	overwriting borders and any other areas, such as the scrollbar.
189		190
190	Specifying this flag changes the behaviour, so that the image only	191	Specifying this flag changes the behaviour, so that the image only
191	replaces the background of the character area.	192	replaces the background of the character area.
192		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
193	=back	203	=back
194		204
195	=cut	205	=cut
196		206
		207	our %_IMG_CACHE;
		208	our %_ONCE_CACHE;
197	our $HOME;	209	our $HOME;
198	our ($self, $old, $new);	210	our ($self, $old, $new);
199	our ($x, $y, $w, $h);	211	our ($x, $y, $w, $h);
200		212
201	# enforce at least this interval between updates	213	# enforce at least this interval between updates
202	our $MIN_INTERVAL = 1/100;	214	our $MIN_INTERVAL = 6/59.951;
203		215
204	{	216	{
205	package urxvt::bgdsl; # background language	217	package urxvt::bgdsl; # background language
		218
		219	use List::Util qw(min max sum shuffle);
206		220
207	=head2 PROVIDERS/GENERATORS	221	=head2 PROVIDERS/GENERATORS
208		222
209	These functions provide an image, by loading it from disk, grabbing it	223	These functions provide an image, by loading it from disk, grabbing it
210	from the root screen or by simply generating it. They are used as starting	224	from the root screen or by simply generating it. They are used as starting
…		…
237		251
238	=cut	252	=cut
239		253
240	sub root() {	254	sub root() {
241	$new->{rootpmap_sensitive} = 1;	255	$new->{rootpmap_sensitive} = 1;
242	die "root op not supported, exg, we need you";	256	$self->new_img_from_root
243	}	257	}
244		258
245	=item solid $colour	259	=item solid $colour
246		260
247	=item solid $width, $height, $colour	261	=item solid $width, $height, $colour
…		…
260	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	274	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);
261	$img->fill ($colour);	275	$img->fill ($colour);
262	$img	276	$img
263	}	277	}
264		278
		279	=item clone $img
		280
		281	Returns an exact copy of the image. This is useful if you want to have
		282	multiple copies of the same image to apply different effects to.
		283
		284	=cut
		285
		286	sub clone($) {
		287	$_[0]->clone
		288	}
		289
		290	=head2 TILING MODES
		291
		292	The following operators modify the tiling mode of an image, that is, the
		293	way that pixels outside the image area are painted when the image is used.
		294
		295	=over 4
		296
		297	=item tile $img
		298
		299	Tiles the whole plane with the image and returns this new image - or in
		300	other words, it returns a copy of the image in plane tiling mode.
		301
		302	Example: load an image and tile it over the background, without
		303	resizing. The C<tile> call is superfluous because C<load> already defaults
		304	to tiling mode.
		305
		306	tile load "mybg.png"
		307
		308	=item mirror $img
		309
		310	Similar to tile, but reflects the image each time it uses a new copy, so
		311	that top edges always touch top edges, right edges always touch right
		312	edges and so on (with normal tiling, left edges always touch right edges
		313	and top always touch bottom edges).
		314
		315	Example: load an image and mirror it over the background, avoiding sharp
		316	edges at the image borders at the expense of mirroring the image itself
		317
		318	mirror load "mybg.png"
		319
		320	=item pad $img
		321
		322	Takes an image and modifies it so that all pixels outside the image area
		323	become transparent. This mode is most useful when you want to place an
		324	image over another image or the background colour while leaving all
		325	background pixels outside the image unchanged.
		326
		327	Example: load an image and display it in the upper left corner. The rest
		328	of the space is left "empty" (transparent or whatever your compositor does
		329	in alpha mode, else background colour).
		330
		331	pad load "mybg.png"
		332
		333	=item extend $img
		334
		335	Extends the image over the whole plane, using the closest pixel in the
		336	area outside the image. This mode is mostly useful when you use more complex
		337	filtering operations and want the pixels outside the image to have the
		338	same values as the pixels near the edge.
		339
		340	Example: just for curiosity, how does this pixel extension stuff work?
		341
		342	extend move 50, 50, load "mybg.png"
		343
		344	=cut
		345
		346	sub pad($) {
		347	my $img = $_[0]->clone;
		348	$img->repeat_mode (urxvt::RepeatNone);
		349	$img
		350	}
		351
		352	sub tile($) {
		353	my $img = $_[0]->clone;
		354	$img->repeat_mode (urxvt::RepeatNormal);
		355	$img
		356	}
		357
		358	sub mirror($) {
		359	my $img = $_[0]->clone;
		360	$img->repeat_mode (urxvt::RepeatReflect);
		361	$img
		362	}
		363
		364	sub extend($) {
		365	my $img = $_[0]->clone;
		366	$img->repeat_mode (urxvt::RepeatPad);
		367	$img
		368	}
		369
265	=back	370	=back
266		371
267	=head2 VARIABLES	372	=head2 VARIABLE VALUES
268		373
269	The following functions provide variable data such as the terminal window	374	The following functions provide variable data such as the terminal window
270	dimensions. They are not (Perl-) variables, they jsut return stuff that	375	dimensions. They are not (Perl-) variables, they just return stuff that
271	varies. Most of them make your expression sensitive to some events, for	376	varies. Most of them make your expression sensitive to some events, for
272	example using C<TW> (terminal width) means your expression is evaluated	377	example using C<TW> (terminal width) means your expression is evaluated
273	again when the terminal is resized.	378	again when the terminal is resized.
274		379
275	=over 4	380	=over 4
…		…
349	$self->{counter} + 0	454	$self->{counter} + 0
350	}	455	}
351		456
352	=back	457	=back
353		458
354	=head2 TILING MODES	459	=head2 SHAPE CHANGING OPERATORS
355		460
356	The following operators modify the tiling mode of an image, that is, the	461	The following operators modify the shape, size or position of the image.
357	way that pixels outside the image area are painted when the image is used.
358		462
359	=over 4	463	=over 4
360
361	=item tile $img
362
363	Tiles the whole plane with the image and returns this new image - or in
364	other words, it returns a copy of the image in plane tiling mode.
365
366	Example: load an image and tile it over the background, without
367	resizing. The C<tile> call is superfluous because C<load> already defaults
368	to tiling mode.
369
370	tile load "mybg.png"
371
372	=item mirror $img
373
374	Similar to tile, but reflects the image each time it uses a new copy, so
375	that top edges always touch top edges, right edges always touch right
376	edges and so on (with normal tiling, left edges always touch right edges
377	and top always touch bottom edges).
378
379	Example: load an image and mirror it over the background, avoiding sharp
380	edges at the image borders at the expense of mirroring the image itself
381
382	mirror load "mybg.png"
383
384	=item pad $img
385
386	Takes an image and modifies it so that all pixels outside the image area
387	become transparent. This mode is most useful when you want to place an
388	image over another image or the background colour while leaving all
389	background pixels outside the image unchanged.
390
391	Example: load an image and display it in the upper left corner. The rest
392	of the space is left "empty" (transparent or wahtever your compisotr does
393	in alpha mode, else background colour).
394
395	pad load "mybg.png"
396
397	=item extend $img
398
399	Extends the image over the whole plane, using the closest pixel in the
400	area outside the image. This mode is mostly useful when you more complex
401	filtering operations and want the pixels outside the image to have the
402	same values as the pixels near the edge.
403
404	Example: just for curiosity, how does this pixel extension stuff work?
405
406	extend move 50, 50, load "mybg.png"
407
408	=cut
409
410	sub pad($) {
411	my $img = $_[0]->clone;
412	$img->repeat_mode (urxvt::RepeatNone);
413	$img
414	}
415
416	sub tile($) {
417	my $img = $_[0]->clone;
418	$img->repeat_mode (urxvt::RepeatNormal);
419	$img
420	}
421
422	sub mirror($) {
423	my $img = $_[0]->clone;
424	$img->repeat_mode (urxvt::RepeatReflect);
425	$img
426	}
427
428	sub extend($) {
429	my $img = $_[0]->clone;
430	$img->repeat_mode (urxvt::RepeatPad);
431	$img
432	}
433
434	=back
435
436	=head2 PIXEL OPERATORS
437
438	The following operators modify the image pixels in various ways.
439
440	=over 4
441
442	=item clone $img
443
444	Returns an exact copy of the image.
445
446	=cut
447
448	sub clone($) {
449	$_[0]->clone
450	}
451		464
452	=item clip $img	465	=item clip $img
453		466
454	=item clip $width, $height, $img	467	=item clip $width, $height, $img
455		468
…		…
479	$img->sub_rect ($_[0], $_[1], $w, $h)	492	$img->sub_rect ($_[0], $_[1], $w, $h)
480	}	493	}
481		494
482	=item scale $img	495	=item scale $img
483		496
484	=item scale $size_percent, $img	497	=item scale $size_factor, $img
485		498
486	=item scale $width_percent, $height_percent, $img	499	=item scale $width_factor, $height_factor, $img
487		500
488	Scales the image by the given percentages in horizontal	501	Scales the image by the given factors in horizontal
489	(C<$width_percent>) and vertical (C<$height_percent>) direction.	502	(C<$width>) and vertical (C<$height>) direction.
490		503
491	If only one percentage is give, it is used for both directions.	504	If only one factor is give, it is used for both directions.
492		505
493	If no percentages are given, scales the image to the window size without	506	If no factors are given, scales the image to the window size without
494	keeping aspect.	507	keeping aspect.
495		508
496	=item resize $width, $height, $img	509	=item resize $width, $height, $img
497		510
498	Resizes the image to exactly C<$width> times C<$height> pixels.	511	Resizes the image to exactly C<$width> times C<$height> pixels.
499		512
500	=cut	513	=item fit $img
501		514
502	#TODO: maximise, maximise_fill?	515	=item fit $width, $height, $img
		516
		517	Fits the image into the given C<$width> and C<$height> without changing
		518	aspect, or the terminal size. That means it will be shrunk or grown until
		519	the whole image fits into the given area, possibly leaving borders.
		520
		521	=item cover $img
		522
		523	=item cover $width, $height, $img
		524
		525	Similar to C<fit>, but shrinks or grows until all of the area is covered
		526	by the image, so instead of potentially leaving borders, it will cut off
		527	image data that doesn't fit.
		528
		529	=cut
503		530
504	sub scale($;$;$) {	531	sub scale($;$;$) {
505	my $img = pop;	532	my $img = pop;
506		533
507	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	534	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
508	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	535	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
509	: $img->scale (TW, TH)	536	: $img->scale (TW, TH)
510	}	537	}
511		538
512	sub resize($$$) {	539	sub resize($$$) {
513	my $img = pop;	540	my $img = pop;
514	$img->scale ($_[0], $_[1])	541	$img->scale ($_[0], $_[1])
		542	}
		543
		544	sub fit($;$$) {
		545	my $img = pop;
		546	my $w = ($_[0] \|\| TW) / $img->w;
		547	my $h = ($_[1] \|\| TH) / $img->h;
		548	scale +(min $w, $h), $img
		549	}
		550
		551	sub cover($;$$) {
		552	my $img = pop;
		553	my $w = ($_[0] \|\| TW) / $img->w;
		554	my $h = ($_[1] \|\| TH) / $img->h;
		555	scale +(max $w, $h), $img
515	}	556	}
516		557
517	=item move $dx, $dy, $img	558	=item move $dx, $dy, $img
518		559
519	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	560	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
520	the vertical.	561	the vertical.
521		562
522	Example: move the image right by 20 pixels and down by 30.	563	Example: move the image right by 20 pixels and down by 30.
523		564
524	move 20, 30, ...	565	move 20, 30, ...
		566
		567	=item align $xalign, $yalign, $img
		568
		569	Aligns the image according to a factor - C<0> means the image is moved to
		570	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		571	exactly centered and C<1> means it touches the right or bottom edge.
		572
		573	Example: remove any visible border around an image, center it vertically but move
		574	it to the right hand side.
		575
		576	align 1, 0.5, pad $img
		577
		578	=item center $img
		579
		580	=item center $width, $height, $img
		581
		582	Centers the image, i.e. the center of the image is moved to the center of
		583	the terminal window (or the box specified by C<$width> and C<$height> if
		584	given).
		585
		586	Example: load an image and center it.
		587
		588	center pad load "mybg.png"
525		589
526	=item rootalign $img	590	=item rootalign $img
527		591
528	Moves the image so that it appears glued to the screen as opposed to the	592	Moves the image so that it appears glued to the screen as opposed to the
529	window. This gives the illusion of a larger area behind the window. It is	593	window. This gives the illusion of a larger area behind the window. It is
…		…
535	rootalign mirror load "mybg.png"	599	rootalign mirror load "mybg.png"
536		600
537	Example: take the screen background and align it, giving the illusion of	601	Example: take the screen background and align it, giving the illusion of
538	transparency as long as the window isn't in front of other windows.	602	transparency as long as the window isn't in front of other windows.
539		603
540	rootalign root	604	rootalign root
541		605
542	=cut	606	=cut
543		607
544	sub move($$;$) {	608	sub move($$;$) {
545	my $img = pop->clone;	609	my $img = pop->clone;
546	$img->move ($_[0], $_[1]);	610	$img->move ($_[0], $_[1]);
547	$img	611	$img
548	}	612	}
549		613
		614	sub align($;$$) {
		615	my $img = pop;
		616
		617	move $_[0] * (TW - $img->w),
		618	$_[1] * (TH - $img->h),
		619	$img
		620	}
		621
		622	sub center($;$$) {
		623	my $img = pop;
		624	my $w = $_[0] \|\| TW;
		625	my $h = $_[1] \|\| TH;
		626
		627	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		628	}
		629
550	sub rootalign($) {	630	sub rootalign($) {
551	move -TX, -TY, $_[0]	631	move -TX, -TY, $_[0]
552	}	632	}
553		633
		634	=item rotate $center_x, $center_y, $degrees, $new_width, $new_height
		635
		636	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		637	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		638	width/height), generating a new image with width C<$new_width> and height
		639	C<$new_height>.
		640
		641	#TODO# new width, height, maybe more operators?
		642
		643	Example: rotate the image by 90 degrees
		644
		645	=cut
		646
		647	sub rotate($$$$$$) {
		648	my $img = pop;
		649	$img->rotate (
		650	$_[0] * $img->w,
		651	$_[1] * $img->h,
		652	$_[2] * (3.14159265 / 180),
		653	$_[3],
		654	$_[4],
		655	)
		656	}
		657
		658	=back
		659
		660	=head2 COLOUR MODIFICATIONS
		661
		662	The following operators change the pixels of the image.
		663
		664	=over 4
		665
554	=item contrast $factor, $img	666	=item contrast $factor, $img
555		667
556	=item contrast $r, $g, $b, $img	668	=item contrast $r, $g, $b, $img
557		669
558	=item contrast $r, $g, $b, $a, $img	670	=item contrast $r, $g, $b, $a, $img
559		671
560	Adjusts the I<contrast> of an image.	672	Adjusts the I<contrast> of an image.
561		673
562	#TODO#	674	The first form applies a single C<$factor> to red, green and blue, the
		675	second form applies separate factors to each colour channel, and the last
		676	form includes the alpha channel.
563		677
		678	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		679	contrast.
		680
		681	Due to limitations in the underlying XRender extension, lowering contrast
		682	also reduces brightness, while increasing contrast currently also
		683	increases brightness.
		684
564	=item brightness $factor, $img	685	=item brightness $bias, $img
565		686
566	=item brightness $r, $g, $b, $img	687	=item brightness $r, $g, $b, $img
567		688
568	=item brightness $r, $g, $b, $a, $img	689	=item brightness $r, $g, $b, $a, $img
569		690
570	Adjusts the brightness of an image.	691	Adjusts the brightness of an image.
571		692
		693	The first form applies a single C<$bias> to red, green and blue, the
		694	second form applies separate biases to each colour channel, and the last
		695	form includes the alpha channel.
		696
		697	Values less than 0 reduce brightness, while values larger than 0 increase
		698	it. Useful range is from -1 to 1 - the former results in a black, the
		699	latter in a white picture.
		700
		701	Due to idiosyncrasies in the underlying XRender extension, biases less
		702	than zero can be I<very> slow.
		703
572	=cut	704	=cut
573		705
574	sub contrast($$;$$;$) {	706	sub contrast($$;$$;$) {
575	my $img = pop;	707	my $img = pop;
576	my ($r, $g, $b, $a) = @_;	708	my ($r, $g, $b, $a) = @_;
577		709
578	($g, $b) = ($r, $r) if @_ < 4;	710	($g, $b) = ($r, $r) if @_ < 3;
579	$a = 1 if @_ < 5;	711	$a = 1 if @_ < 4;
580		712
581	$img = $img->clone;	713	$img = $img->clone;
582	$img->contrast ($r, $g, $b, $a);	714	$img->contrast ($r, $g, $b, $a);
583	$img	715	$img
584	}	716	}
585		717
586	sub brightness($$;$$;$) {	718	sub brightness($$;$$;$) {
587	my $img = pop;	719	my $img = pop;
588	my ($r, $g, $b, $a) = @_;	720	my ($r, $g, $b, $a) = @_;
589		721
590	($g, $b) = ($r, $r) if @_ < 4;	722	($g, $b) = ($r, $r) if @_ < 3;
591	$a = 1 if @_ < 5;	723	$a = 1 if @_ < 4;
592		724
593	$img = $img->clone;	725	$img = $img->clone;
594	$img->brightness ($r, $g, $b, $a);	726	$img->brightness ($r, $g, $b, $a);
595	$img	727	$img
596	}	728	}
…		…
612	sub blur($$;$) {	744	sub blur($$;$) {
613	my $img = pop;	745	my $img = pop;
614	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	746	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
615	}	747	}
616		748
617	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees	749	=back
618		750
619	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	751	=head2 OTHER STUFF
620	pointer at C<$center_x> and C<$center_y> (specified as percentage of image
621	width/height), generating a new image with width C<$new_width> and height
622	C<$new_height>.
623		752
624	#TODO# new width, height, maybe more operators?	753	Anything that didn't fit any of the other categories, even after appliyng
		754	force and closing our eyes.
625		755
626	Example: rotate the image by 90 degrees	756	=over 4
627		757
628	=cut	758	=item once { ... }
629		759
630	sub rotate($$$$$$) {	760	This function takes a code block as argument, that is, one or more
631	my $img = pop;	761	statements enclosed by braces.
632	$img->rotate (	762
633	$_[0],	763	The trick is that this code block is only evaluated once - future calls
634	$_[1],	764	will simply return the original image (yes, it should only be used with
635	$_[2] * $img->w * .01,	765	images).
636	$_[3] * $img->h * .01,	766
637	$_[4] * (3.14159265 / 180),	767	This can be extremely useful to avoid redoign the same slow operations
638	)	768	again and again- for example, if your background expression takes the root
		769	background, blurs it and then root-aligns it it would have to blur the
		770	root background on every window move or resize.
		771
		772	Putting the blur into a C<once> block will make sure the blur is only done
		773	once:
		774
		775	rootlign once { blur 10, root }
		776
		777	This leaves the question of how to force reevaluation of the block, in
		778	case the root background changes: Right now, all once blocks forget that
		779	they ahve been executed before each time the root background changes (if
		780	the expression is sensitive to that) or when C<once_again> is called.
		781
		782	=item once_again
		783
		784	Resets all C<once> block as if they had never been called, i.e. on the
		785	next call they will be reevaluated again.
		786
		787	=cut
		788
		789	sub once(&) {
		790	$_ONCE_CACHE{$_[0]+0} \|\|= $_[0]()
		791	}
		792
		793	sub once_again() {
		794	%_ONCE_CACHE = ();
639	}	795	}
640		796
641	=back	797	=back
642		798
643	=cut	799	=cut
…		…
686		842
687	# evaluate user expression	843	# evaluate user expression
688		844
689	my $img = eval { $self->{expr}->() };	845	my $img = eval { $self->{expr}->() };
690	warn $@ if $@;#d#	846	warn $@ if $@;#d#
691	die if !UNIVERSAL::isa $img, "urxvt::img";	847	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
692		848
693	$state->{size_sensitive} = 1	849	$state->{size_sensitive} = 1
694	if $img->repeat_mode != urxvt::RepeatNormal;	850	if $img->repeat_mode != urxvt::RepeatNormal;
695		851
696	# if the expression is sensitive to external events, prepare reevaluation then	852	# if the expression is sensitive to external events, prepare reevaluation then
…		…
746	}	902	}
747		903
748	sub on_start {	904	sub on_start {
749	my ($self) = @_;	905	my ($self) = @_;
750		906
751	my $expr = $self->x_resource ("background.expr")	907	my $expr = $self->x_resource ("%.expr")
752	or return;	908	or return;
753		909
		910	$self->has_render
		911	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		912
754	$self->set_expr (parse_expr $expr);	913	$self->set_expr (parse_expr $expr);
755	$self->{border} = $self->x_resource_boolean ("background.border");	914	$self->{border} = $self->x_resource_boolean ("%.border");
		915
		916	$MIN_INTERVAL = $self->x_resource ("%.interval");
756		917
757	()	918	()
758	}	919	}
759		920

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs. Revision 1.52 by root, Tue Jun 12 10:45:53 2012 UTC

Diff Legend

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs.
Revision 1.52 by root, Tue Jun 12 10:45:53 2012 UTC