[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 1.54 by root, Thu Jun 14 16:22:20 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
…		…
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
…		…
215	=item load $path	229	=item load $path
216		230
217	Loads the image at the given C<$path>. The image is set to plane tiling	231	Loads the image at the given C<$path>. The image is set to plane tiling
218	mode.	232	mode.
219		233
220	Loaded images will be cached for one cycle.	234	Loaded images will be cached for one cycle, and shared between temrinals
		235	running in the same process (e.g. in C<urxvtd>).
221		236
		237	=item load_uc $path
		238
		239	Load uncached - same as load, but does not cache the image. This function
		240	is most useufl if you want to optimise a background expression in some
		241	way.
		242
222	=cut	243	=cut
		244
		245	sub load_uc($) {
		246	my ($path) = @_;
		247
		248	$_IMG_CACHE{$path} \|\| do {
		249	my $img = $self->new_img_from_file ($path);
		250	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		251	$img
		252	}
		253	}
223		254
224	sub load($) {	255	sub load($) {
225	my ($path) = @_;	256	my ($path) = @_;
226		257
227	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	258	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
228	}	259	}
229		260
230	=item root	261	=item root
231		262
232	Returns the root window pixmap, that is, hopefully, the background image	263	Returns the root window pixmap, that is, hopefully, the background image
…		…
237		268
238	=cut	269	=cut
239		270
240	sub root() {	271	sub root() {
241	$new->{rootpmap_sensitive} = 1;	272	$new->{rootpmap_sensitive} = 1;
242	die "root op not supported, exg, we need you";	273	$self->new_img_from_root
243	}	274	}
244		275
245	=item solid $colour	276	=item solid $colour
246		277
247	=item solid $width, $height, $colour	278	=item solid $width, $height, $colour
…		…
260	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	291	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);
261	$img->fill ($colour);	292	$img->fill ($colour);
262	$img	293	$img
263	}	294	}
264		295
		296	=item clone $img
		297
		298	Returns an exact copy of the image. This is useful if you want to have
		299	multiple copies of the same image to apply different effects to.
		300
		301	=cut
		302
		303	sub clone($) {
		304	$_[0]->clone
		305	}
		306
		307	=head2 TILING MODES
		308
		309	The following operators modify the tiling mode of an image, that is, the
		310	way that pixels outside the image area are painted when the image is used.
		311
		312	=over 4
		313
		314	=item tile $img
		315
		316	Tiles the whole plane with the image and returns this new image - or in
		317	other words, it returns a copy of the image in plane tiling mode.
		318
		319	Example: load an image and tile it over the background, without
		320	resizing. The C<tile> call is superfluous because C<load> already defaults
		321	to tiling mode.
		322
		323	tile load "mybg.png"
		324
		325	=item mirror $img
		326
		327	Similar to tile, but reflects the image each time it uses a new copy, so
		328	that top edges always touch top edges, right edges always touch right
		329	edges and so on (with normal tiling, left edges always touch right edges
		330	and top always touch bottom edges).
		331
		332	Example: load an image and mirror it over the background, avoiding sharp
		333	edges at the image borders at the expense of mirroring the image itself
		334
		335	mirror load "mybg.png"
		336
		337	=item pad $img
		338
		339	Takes an image and modifies it so that all pixels outside the image area
		340	become transparent. This mode is most useful when you want to place an
		341	image over another image or the background colour while leaving all
		342	background pixels outside the image unchanged.
		343
		344	Example: load an image and display it in the upper left corner. The rest
		345	of the space is left "empty" (transparent or whatever your compositor does
		346	in alpha mode, else background colour).
		347
		348	pad load "mybg.png"
		349
		350	=item extend $img
		351
		352	Extends the image over the whole plane, using the closest pixel in the
		353	area outside the image. This mode is mostly useful when you use more complex
		354	filtering operations and want the pixels outside the image to have the
		355	same values as the pixels near the edge.
		356
		357	Example: just for curiosity, how does this pixel extension stuff work?
		358
		359	extend move 50, 50, load "mybg.png"
		360
		361	=cut
		362
		363	sub pad($) {
		364	my $img = $_[0]->clone;
		365	$img->repeat_mode (urxvt::RepeatNone);
		366	$img
		367	}
		368
		369	sub tile($) {
		370	my $img = $_[0]->clone;
		371	$img->repeat_mode (urxvt::RepeatNormal);
		372	$img
		373	}
		374
		375	sub mirror($) {
		376	my $img = $_[0]->clone;
		377	$img->repeat_mode (urxvt::RepeatReflect);
		378	$img
		379	}
		380
		381	sub extend($) {
		382	my $img = $_[0]->clone;
		383	$img->repeat_mode (urxvt::RepeatPad);
		384	$img
		385	}
		386
265	=back	387	=back
266		388
267	=head2 VARIABLES	389	=head2 VARIABLE VALUES
268		390
269	The following functions provide variable data such as the terminal window	391	The following functions provide variable data such as the terminal window
270	dimensions. They are not (Perl-) variables, they jsut return stuff that	392	dimensions. They are not (Perl-) variables, they just return stuff that
271	varies. Most of them make your expression sensitive to some events, for	393	varies. Most of them make your expression sensitive to some events, for
272	example using C<TW> (terminal width) means your expression is evaluated	394	example using C<TW> (terminal width) means your expression is evaluated
273	again when the terminal is resized.	395	again when the terminal is resized.
274		396
275	=over 4	397	=over 4
…		…
327	C<$seconds> seconds.	449	C<$seconds> seconds.
328		450
329	Example: load some image and rotate it according to the time of day (as if it were	451	Example: load some image and rotate it according to the time of day (as if it were
330	the hour pointer of a clock). Update this image every minute.	452	the hour pointer of a clock). Update this image every minute.
331		453
332	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	454	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
333		455
334	=item counter $seconds	456	=item counter $seconds
335		457
336	Like C<again>, but also returns an increasing counter value, starting at	458	Like C<again>, but also returns an increasing counter value, starting at
337	0, which might be useful for some simple animation effects.	459	0, which might be useful for some simple animation effects.
…		…
349	$self->{counter} + 0	471	$self->{counter} + 0
350	}	472	}
351		473
352	=back	474	=back
353		475
354	=head2 TILING MODES	476	=head2 SHAPE CHANGING OPERATORS
355		477
356	The following operators modify the tiling mode of an image, that is, the	478	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		479
359	=over 4	480	=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		481
452	=item clip $img	482	=item clip $img
453		483
454	=item clip $width, $height, $img	484	=item clip $width, $height, $img
455		485
…		…
479	$img->sub_rect ($_[0], $_[1], $w, $h)	509	$img->sub_rect ($_[0], $_[1], $w, $h)
480	}	510	}
481		511
482	=item scale $img	512	=item scale $img
483		513
484	=item scale $size_percent, $img	514	=item scale $size_factor, $img
485		515
486	=item scale $width_percent, $height_percent, $img	516	=item scale $width_factor, $height_factor, $img
487		517
488	Scales the image by the given percentages in horizontal	518	Scales the image by the given factors in horizontal
489	(C<$width_percent>) and vertical (C<$height_percent>) direction.	519	(C<$width>) and vertical (C<$height>) direction.
490		520
491	If only one percentage is give, it is used for both directions.	521	If only one factor is give, it is used for both directions.
492		522
493	If no percentages are given, scales the image to the window size without	523	If no factors are given, scales the image to the window size without
494	keeping aspect.	524	keeping aspect.
495		525
496	=item resize $width, $height, $img	526	=item resize $width, $height, $img
497		527
498	Resizes the image to exactly C<$width> times C<$height> pixels.	528	Resizes the image to exactly C<$width> times C<$height> pixels.
499		529
500	=cut	530	=item fit $img
501		531
502	#TODO: maximise, maximise_fill?	532	=item fit $width, $height, $img
		533
		534	Fits the image into the given C<$width> and C<$height> without changing
		535	aspect, or the terminal size. That means it will be shrunk or grown until
		536	the whole image fits into the given area, possibly leaving borders.
		537
		538	=item cover $img
		539
		540	=item cover $width, $height, $img
		541
		542	Similar to C<fit>, but shrinks or grows until all of the area is covered
		543	by the image, so instead of potentially leaving borders, it will cut off
		544	image data that doesn't fit.
		545
		546	=cut
503		547
504	sub scale($;$;$) {	548	sub scale($;$;$) {
505	my $img = pop;	549	my $img = pop;
506		550
507	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	551	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
508	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	552	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
509	: $img->scale (TW, TH)	553	: $img->scale (TW, TH)
510	}	554	}
511		555
512	sub resize($$$) {	556	sub resize($$$) {
513	my $img = pop;	557	my $img = pop;
514	$img->scale ($_[0], $_[1])	558	$img->scale ($_[0], $_[1])
		559	}
		560
		561	sub fit($;$$) {
		562	my $img = pop;
		563	my $w = ($_[0] \|\| TW) / $img->w;
		564	my $h = ($_[1] \|\| TH) / $img->h;
		565	scale +(min $w, $h), $img
		566	}
		567
		568	sub cover($;$$) {
		569	my $img = pop;
		570	my $w = ($_[0] \|\| TW) / $img->w;
		571	my $h = ($_[1] \|\| TH) / $img->h;
		572	scale +(max $w, $h), $img
515	}	573	}
516		574
517	=item move $dx, $dy, $img	575	=item move $dx, $dy, $img
518		576
519	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	577	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
520	the vertical.	578	the vertical.
521		579
522	Example: move the image right by 20 pixels and down by 30.	580	Example: move the image right by 20 pixels and down by 30.
523		581
524	move 20, 30, ...	582	move 20, 30, ...
		583
		584	=item align $xalign, $yalign, $img
		585
		586	Aligns the image according to a factor - C<0> means the image is moved to
		587	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		588	exactly centered and C<1> means it touches the right or bottom edge.
		589
		590	Example: remove any visible border around an image, center it vertically but move
		591	it to the right hand side.
		592
		593	align 1, 0.5, pad $img
		594
		595	=item center $img
		596
		597	=item center $width, $height, $img
		598
		599	Centers the image, i.e. the center of the image is moved to the center of
		600	the terminal window (or the box specified by C<$width> and C<$height> if
		601	given).
		602
		603	Example: load an image and center it.
		604
		605	center pad load "mybg.png"
525		606
526	=item rootalign $img	607	=item rootalign $img
527		608
528	Moves the image so that it appears glued to the screen as opposed to the	609	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	610	window. This gives the illusion of a larger area behind the window. It is
…		…
535	rootalign mirror load "mybg.png"	616	rootalign mirror load "mybg.png"
536		617
537	Example: take the screen background and align it, giving the illusion of	618	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.	619	transparency as long as the window isn't in front of other windows.
539		620
540	rootalign root	621	rootalign root
541		622
542	=cut	623	=cut
543		624
544	sub move($$;$) {	625	sub move($$;$) {
545	my $img = pop->clone;	626	my $img = pop->clone;
546	$img->move ($_[0], $_[1]);	627	$img->move ($_[0], $_[1]);
547	$img	628	$img
548	}	629	}
549		630
		631	sub align($;$$) {
		632	my $img = pop;
		633
		634	move $_[0] * (TW - $img->w),
		635	$_[1] * (TH - $img->h),
		636	$img
		637	}
		638
		639	sub center($;$$) {
		640	my $img = pop;
		641	my $w = $_[0] \|\| TW;
		642	my $h = $_[1] \|\| TH;
		643
		644	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		645	}
		646
550	sub rootalign($) {	647	sub rootalign($) {
551	move -TX, -TY, $_[0]	648	move -TX, -TY, $_[0]
552	}	649	}
553		650
		651	=item rotate $center_x, $center_y, $degrees
		652
		653	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		654	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		655	width/height).
		656
		657	#TODO# new width, height, maybe more operators?
		658
		659	Example: rotate the image by 90 degrees
		660
		661	=cut
		662
		663	sub rotate($$$$) {
		664	my $img = pop;
		665	$img->rotate (
		666	$_[0] * $img->w,
		667	$_[1] * $img->h,
		668	$_[2] * (3.14159265 / 180),
		669	)
		670	}
		671
		672	=back
		673
		674	=head2 COLOUR MODIFICATIONS
		675
		676	The following operators change the pixels of the image.
		677
		678	=over 4
		679
554	=item contrast $factor, $img	680	=item contrast $factor, $img
555		681
556	=item contrast $r, $g, $b, $img	682	=item contrast $r, $g, $b, $img
557		683
558	=item contrast $r, $g, $b, $a, $img	684	=item contrast $r, $g, $b, $a, $img
559		685
560	Adjusts the I<contrast> of an image.	686	Adjusts the I<contrast> of an image.
561		687
562	#TODO#	688	The first form applies a single C<$factor> to red, green and blue, the
		689	second form applies separate factors to each colour channel, and the last
		690	form includes the alpha channel.
563		691
		692	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		693	contrast.
		694
		695	Due to limitations in the underlying XRender extension, lowering contrast
		696	also reduces brightness, while increasing contrast currently also
		697	increases brightness.
		698
564	=item brightness $factor, $img	699	=item brightness $bias, $img
565		700
566	=item brightness $r, $g, $b, $img	701	=item brightness $r, $g, $b, $img
567		702
568	=item brightness $r, $g, $b, $a, $img	703	=item brightness $r, $g, $b, $a, $img
569		704
570	Adjusts the brightness of an image.	705	Adjusts the brightness of an image.
571		706
		707	The first form applies a single C<$bias> to red, green and blue, the
		708	second form applies separate biases to each colour channel, and the last
		709	form includes the alpha channel.
		710
		711	Values less than 0 reduce brightness, while values larger than 0 increase
		712	it. Useful range is from -1 to 1 - the former results in a black, the
		713	latter in a white picture.
		714
		715	Due to idiosyncrasies in the underlying XRender extension, biases less
		716	than zero can be I<very> slow.
		717
572	=cut	718	=cut
573		719
574	sub contrast($$;$$;$) {	720	sub contrast($$;$$;$) {
575	my $img = pop;	721	my $img = pop;
576	my ($r, $g, $b, $a) = @_;	722	my ($r, $g, $b, $a) = @_;
577		723
578	($g, $b) = ($r, $r) if @_ < 4;	724	($g, $b) = ($r, $r) if @_ < 3;
579	$a = 1 if @_ < 5;	725	$a = 1 if @_ < 4;
580		726
581	$img = $img->clone;	727	$img = $img->clone;
582	$img->contrast ($r, $g, $b, $a);	728	$img->contrast ($r, $g, $b, $a);
583	$img	729	$img
584	}	730	}
585		731
586	sub brightness($$;$$;$) {	732	sub brightness($$;$$;$) {
587	my $img = pop;	733	my $img = pop;
588	my ($r, $g, $b, $a) = @_;	734	my ($r, $g, $b, $a) = @_;
589		735
590	($g, $b) = ($r, $r) if @_ < 4;	736	($g, $b) = ($r, $r) if @_ < 3;
591	$a = 1 if @_ < 5;	737	$a = 1 if @_ < 4;
592		738
593	$img = $img->clone;	739	$img = $img->clone;
594	$img->brightness ($r, $g, $b, $a);	740	$img->brightness ($r, $g, $b, $a);
595	$img	741	$img
596	}	742	}
…		…
612	sub blur($$;$) {	758	sub blur($$;$) {
613	my $img = pop;	759	my $img = pop;
614	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	760	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
615	}	761	}
616		762
617	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees	763	=back
618		764
619	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	765	=head2 OTHER STUFF
620	pointer at C<$center_x> and C<$center_y> (specified as percentage of image
621	width/height), generating a new image with width C<$new_width> and height
622	C<$new_height>.
623		766
624	#TODO# new width, height, maybe more operators?	767	Anything that didn't fit any of the other categories, even after appliyng
		768	force and closing our eyes.
625		769
626	Example: rotate the image by 90 degrees	770	=over 4
627		771
628	=cut	772	=item once { ... }
629		773
630	sub rotate($$$$$$) {	774	This function takes a code block as argument, that is, one or more
631	my $img = pop;	775	statements enclosed by braces.
632	$img->rotate (	776
633	$_[0],	777	The trick is that this code block is only evaluated once - future calls
634	$_[1],	778	will simply return the original image (yes, it should only be used with
635	$_[2] * $img->w * .01,	779	images).
636	$_[3] * $img->h * .01,	780
637	$_[4] * (3.14159265 / 180),	781	This can be extremely useful to avoid redoign the same slow operations
638	)	782	again and again- for example, if your background expression takes the root
		783	background, blurs it and then root-aligns it it would have to blur the
		784	root background on every window move or resize.
		785
		786	Putting the blur into a C<once> block will make sure the blur is only done
		787	once:
		788
		789	rootlign once { blur 10, root }
		790
		791	This leaves the question of how to force reevaluation of the block, in
		792	case the root background changes: Right now, all once blocks forget that
		793	they ahve been executed before each time the root background changes (if
		794	the expression is sensitive to that) or when C<once_again> is called.
		795
		796	=item once_again
		797
		798	Resets all C<once> block as if they had never been called, i.e. on the
		799	next call they will be reevaluated again.
		800
		801	=cut
		802
		803	sub once(&) {
		804	$_ONCE_CACHE{$_[0]+0} \|\|= $_[0]()
		805	}
		806
		807	sub once_again() {
		808	%_ONCE_CACHE = ();
639	}	809	}
640		810
641	=back	811	=back
642		812
643	=cut	813	=cut
…		…
686		856
687	# evaluate user expression	857	# evaluate user expression
688		858
689	my $img = eval { $self->{expr}->() };	859	my $img = eval { $self->{expr}->() };
690	warn $@ if $@;#d#	860	warn $@ if $@;#d#
691	die if !UNIVERSAL::isa $img, "urxvt::img";	861	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
692		862
693	$state->{size_sensitive} = 1	863	$state->{size_sensitive} = 1
694	if $img->repeat_mode != urxvt::RepeatNormal;	864	if $img->repeat_mode != urxvt::RepeatNormal;
695		865
696	# if the expression is sensitive to external events, prepare reevaluation then	866	# if the expression is sensitive to external events, prepare reevaluation then
…		…
746	}	916	}
747		917
748	sub on_start {	918	sub on_start {
749	my ($self) = @_;	919	my ($self) = @_;
750		920
751	my $expr = $self->x_resource ("background.expr")	921	my $expr = $self->x_resource ("%.expr")
752	or return;	922	or return;
753		923
		924	$self->has_render
		925	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		926
754	$self->set_expr (parse_expr $expr);	927	$self->set_expr (parse_expr $expr);
755	$self->{border} = $self->x_resource_boolean ("background.border");	928	$self->{border} = $self->x_resource_boolean ("%.border");
		929
		930	$MIN_INTERVAL = $self->x_resource ("%.interval");
756		931
757	()	932	()
758	}	933	}
759		934

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs. Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.42 by root, Sun Jun 10 10:42:19 2012 UTC vs.
Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC