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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.41 by root, Fri Jun 8 22:21:48 2012 UTC vs.
Revision 1.57 by root, Thu Jun 14 18:06:15 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;
197	our $HOME;	208	our $HOME;
198	our ($self, $old, $new);	209	our ($self, $old, $new);
199	our ($x, $y, $w, $h);	210	our ($x, $y, $w, $h);
200		211
201	# enforce at least this interval between updates	212	# enforce at least this interval between updates
202	our $MIN_INTERVAL = 1/100;	213	our $MIN_INTERVAL = 6/59.951;
203		214
204	{	215	{
205	package urxvt::bgdsl; # background language	216	package urxvt::bgdsl; # background language
		217
		218	use List::Util qw(min max sum shuffle);
206		219
207	=head2 PROVIDERS/GENERATORS	220	=head2 PROVIDERS/GENERATORS
208		221
209	These functions provide an image, by loading it from disk, grabbing it	222	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	223	from the root screen or by simply generating it. They are used as starting
…		…
215	=item load $path	228	=item load $path
216		229
217	Loads the image at the given C<$path>. The image is set to plane tiling	230	Loads the image at the given C<$path>. The image is set to plane tiling
218	mode.	231	mode.
219		232
220	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>).
221		235
		236	=item load_uc $path
		237
		238	Load uncached - same as load, but does not cache the image. This function
		239	is most useufl if you want to optimise a background expression in some
		240	way.
		241
222	=cut	242	=cut
		243
		244	sub load_uc($) {
		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	$img
		251	}
		252	}
223		253
224	sub load($) {	254	sub load($) {
225	my ($path) = @_;	255	my ($path) = @_;
226		256
227	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	257	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
228	}	258	}
229		259
230	=item root	260	=item root
231		261
232	Returns the root window pixmap, that is, hopefully, the background image	262	Returns the root window pixmap, that is, hopefully, the background image
…		…
236	reevaluated when the bg image changes.	266	reevaluated when the bg image changes.
237		267
238	=cut	268	=cut
239		269
240	sub root() {	270	sub root() {
241	$new->{rootpmap_sensitive} = 1;	271	$new->{again}{rootpmap} = 1;
242	die "root op not supported, exg, we need you";	272	$self->new_img_from_root
243	}	273	}
244		274
245	=item solid $colour	275	=item solid $colour
246		276
247	=item solid $width, $height, $colour	277	=item solid $width, $height, $colour
…		…
252	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is	282	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
253	useful for solid backgrounds or for use in filtering effects.	283	useful for solid backgrounds or for use in filtering effects.
254		284
255	=cut	285	=cut
256		286
257	sub solid($$;$) {	287	sub solid($;$$) {
258	my $colour = pop;	288	my $colour = pop;
259		289
260	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	290	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);
261	$img->fill ($colour);	291	$img->fill ($colour);
262	$img	292	$img
263	}	293	}
264		294
265	=back	295	=item clone $img
266		296
267	=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.
268		299
269	The following functions provide variable data such as the terminal window
270	dimensions. They are not (Perl-) variables, they jsut return stuff that
271	varies. Most of them make your expression sensitive to some events, for
272	example using C<TW> (terminal width) means your expression is evaluated
273	again when the terminal is resized.
274
275	=over 4
276
277	=item TX
278
279	=item TY
280
281	Return the X and Y coordinates of the terminal window (the terminal
282	window is the full window by default, and the character area only when in
283	border-respect mode).
284
285	Using these functions make your expression sensitive to window moves.
286
287	These functions are mainly useful to align images to the root window.
288
289	Example: load an image and align it so it looks as if anchored to the
290	background.
291
292	move -TX, -TY, load "mybg.png"
293
294	=item TW
295
296	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
297	terminal window is the full window by default, and the character area only
298	when in border-respect mode).
299
300	Using these functions make your expression sensitive to window resizes.
301
302	These functions are mainly useful to scale images, or to clip images to
303	the window size to conserve memory.
304
305	Example: take the screen background, clip it to the window size, blur it a
306	bit, align it to the window position and use it as background.
307
308	clip move -TX, -TY, blur 5, root
309
310	=cut	300	=cut
311		301
312	sub TX() { $new->{position_sensitive} = 1; $x }
313	sub TY() { $new->{position_sensitive} = 1; $y }
314	sub TW() { $new->{size_sensitive} = 1; $w }
315	sub TH() { $new->{size_sensitive} = 1; $h }
316
317	=item now
318
319	Returns the current time as (fractional) seconds since the epoch.
320
321	Using this expression does I<not> make your expression sensitive to time,
322	but the next two functions do.
323
324	=item again $seconds
325
326	When this function is used the expression will be reevaluated again in
327	C<$seconds> seconds.
328
329	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.
331
332	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
333
334	=item counter $seconds
335
336	Like C<again>, but also returns an increasing counter value, starting at
337	0, which might be useful for some simple animation effects.
338
339	=cut
340
341	sub now() { urxvt::NOW }
342
343	sub again($) {
344	$new->{again} = $_[0];
345	}
346
347	sub counter($) {	302	sub clone($) {
348	$new->{again} = $_[0];	303	$_[0]->clone
349	$self->{counter} + 0
350	}	304	}
351		305
352	=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	#TODO
		315	}
353		316
354	=head2 TILING MODES	317	=head2 TILING MODES
355		318
356	The following operators modify the tiling mode of an image, that is, the	319	The following operators modify the tiling mode of an image, that is, the
357	way that pixels outside the image area are painted when the image is used.	320	way that pixels outside the image area are painted when the image is used.
…		…
387	become transparent. This mode is most useful when you want to place an	350	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	351	image over another image or the background colour while leaving all
389	background pixels outside the image unchanged.	352	background pixels outside the image unchanged.
390		353
391	Example: load an image and display it in the upper left corner. The rest	354	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	355	of the space is left "empty" (transparent or whatever your compositor does
393	in alpha mode, else background colour).	356	in alpha mode, else background colour).
394		357
395	pad load "mybg.png"	358	pad load "mybg.png"
396		359
397	=item extend $img	360	=item extend $img
398		361
399	Extends the image over the whole plane, using the closest pixel in the	362	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	363	area outside the image. This mode is mostly useful when you use more complex
401	filtering operations and want the pixels outside the image to have the	364	filtering operations and want the pixels outside the image to have the
402	same values as the pixels near the edge.	365	same values as the pixels near the edge.
403		366
404	Example: just for curiosity, how does this pixel extension stuff work?	367	Example: just for curiosity, how does this pixel extension stuff work?
405		368
…		…
431	$img	394	$img
432	}	395	}
433		396
434	=back	397	=back
435		398
436	=head2 PIXEL OPERATORS	399	=head2 VARIABLE VALUES
437		400
438	The following operators modify the image pixels in various ways.	401	The following functions provide variable data such as the terminal window
		402	dimensions. They are not (Perl-) variables, they just return stuff that
		403	varies. Most of them make your expression sensitive to some events, for
		404	example using C<TW> (terminal width) means your expression is evaluated
		405	again when the terminal is resized.
439		406
440	=over 4	407	=over 4
441		408
442	=item clone $img	409	=item TX
443		410
444	Returns an exact copy of the image.	411	=item TY
445		412
446	=cut	413	Return the X and Y coordinates of the terminal window (the terminal
		414	window is the full window by default, and the character area only when in
		415	border-respect mode).
447		416
		417	Using these functions make your expression sensitive to window moves.
		418
		419	These functions are mainly useful to align images to the root window.
		420
		421	Example: load an image and align it so it looks as if anchored to the
		422	background.
		423
		424	move -TX, -TY, load "mybg.png"
		425
		426	=item TW
		427
		428	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		429	terminal window is the full window by default, and the character area only
		430	when in border-respect mode).
		431
		432	Using these functions make your expression sensitive to window resizes.
		433
		434	These functions are mainly useful to scale images, or to clip images to
		435	the window size to conserve memory.
		436
		437	Example: take the screen background, clip it to the window size, blur it a
		438	bit, align it to the window position and use it as background.
		439
		440	clip move -TX, -TY, once { blur 5, root }
		441
		442	=cut
		443
		444	sub TX() { $new->{again}{position} = 1; $x }
		445	sub TY() { $new->{again}{position} = 1; $y }
		446	sub TW() { $new->{again}{size} = 1; $w }
		447	sub TH() { $new->{again}{size} = 1; $h }
		448
		449	=item now
		450
		451	Returns the current time as (fractional) seconds since the epoch.
		452
		453	Using this expression does I<not> make your expression sensitive to time,
		454	but the next two functions do.
		455
		456	=item again $seconds
		457
		458	When this function is used the expression will be reevaluated again in
		459	C<$seconds> seconds.
		460
		461	Example: load some image and rotate it according to the time of day (as if it were
		462	the hour pointer of a clock). Update this image every minute.
		463
		464	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
		465
		466	=item counter $seconds
		467
		468	Like C<again>, but also returns an increasing counter value, starting at
		469	0, which might be useful for some simple animation effects.
		470
		471	=cut
		472
		473	sub now() { urxvt::NOW }
		474
		475	sub again($) {
		476	$new->{again}{time} = $_[0];
		477	}
		478
448	sub clone($) {	479	sub counter($) {
449	$_[0]->clone	480	$new->{again}{time} = $_[0];
		481	$self->{counter} + 0
450	}	482	}
		483
		484	=back
		485
		486	=head2 SHAPE CHANGING OPERATORS
		487
		488	The following operators modify the shape, size or position of the image.
		489
		490	=over 4
451		491
452	=item clip $img	492	=item clip $img
453		493
454	=item clip $width, $height, $img	494	=item clip $width, $height, $img
455		495
…		…
479	$img->sub_rect ($_[0], $_[1], $w, $h)	519	$img->sub_rect ($_[0], $_[1], $w, $h)
480	}	520	}
481		521
482	=item scale $img	522	=item scale $img
483		523
484	=item scale $size_percent, $img	524	=item scale $size_factor, $img
485		525
486	=item scale $width_percent, $height_percent, $img	526	=item scale $width_factor, $height_factor, $img
487		527
488	Scales the image by the given percentages in horizontal	528	Scales the image by the given factors in horizontal
489	(C<$width_percent>) and vertical (C<$height_percent>) direction.	529	(C<$width>) and vertical (C<$height>) direction.
490		530
491	If only one percentage is give, it is used for both directions.	531	If only one factor is give, it is used for both directions.
492		532
493	If no percentages are given, scales the image to the window size without	533	If no factors are given, scales the image to the window size without
494	keeping aspect.	534	keeping aspect.
495		535
496	=item resize $width, $height, $img	536	=item resize $width, $height, $img
497		537
498	Resizes the image to exactly C<$width> times C<$height> pixels.	538	Resizes the image to exactly C<$width> times C<$height> pixels.
499		539
500	=cut	540	=item fit $img
501		541
502	#TODO: maximise, maximise_fill?	542	=item fit $width, $height, $img
		543
		544	Fits the image into the given C<$width> and C<$height> without changing
		545	aspect, or the terminal size. That means it will be shrunk or grown until
		546	the whole image fits into the given area, possibly leaving borders.
		547
		548	=item cover $img
		549
		550	=item cover $width, $height, $img
		551
		552	Similar to C<fit>, but shrinks or grows until all of the area is covered
		553	by the image, so instead of potentially leaving borders, it will cut off
		554	image data that doesn't fit.
		555
		556	=cut
503		557
504	sub scale($;$;$) {	558	sub scale($;$;$) {
505	my $img = pop;	559	my $img = pop;
506		560
507	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	561	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
508	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	562	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
509	: $img->scale (TW, TH)	563	: $img->scale (TW, TH)
510	}	564	}
511		565
512	sub resize($$$) {	566	sub resize($$$) {
513	my $img = pop;	567	my $img = pop;
514	$img->scale ($_[0], $_[1])	568	$img->scale ($_[0], $_[1])
		569	}
		570
		571	sub fit($;$$) {
		572	my $img = pop;
		573	my $w = ($_[0] \|\| TW) / $img->w;
		574	my $h = ($_[1] \|\| TH) / $img->h;
		575	scale +(min $w, $h), $img
		576	}
		577
		578	sub cover($;$$) {
		579	my $img = pop;
		580	my $w = ($_[0] \|\| TW) / $img->w;
		581	my $h = ($_[1] \|\| TH) / $img->h;
		582	scale +(max $w, $h), $img
515	}	583	}
516		584
517	=item move $dx, $dy, $img	585	=item move $dx, $dy, $img
518		586
519	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	587	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
520	the vertical.	588	the vertical.
521		589
522	Example: move the image right by 20 pixels and down by 30.	590	Example: move the image right by 20 pixels and down by 30.
523		591
524	move 20, 30, ...	592	move 20, 30, ...
		593
		594	=item align $xalign, $yalign, $img
		595
		596	Aligns the image according to a factor - C<0> means the image is moved to
		597	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		598	exactly centered and C<1> means it touches the right or bottom edge.
		599
		600	Example: remove any visible border around an image, center it vertically but move
		601	it to the right hand side.
		602
		603	align 1, 0.5, pad $img
		604
		605	=item center $img
		606
		607	=item center $width, $height, $img
		608
		609	Centers the image, i.e. the center of the image is moved to the center of
		610	the terminal window (or the box specified by C<$width> and C<$height> if
		611	given).
		612
		613	Example: load an image and center it.
		614
		615	center pad load "mybg.png"
525		616
526	=item rootalign $img	617	=item rootalign $img
527		618
528	Moves the image so that it appears glued to the screen as opposed to the	619	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	620	window. This gives the illusion of a larger area behind the window. It is
…		…
535	rootalign mirror load "mybg.png"	626	rootalign mirror load "mybg.png"
536		627
537	Example: take the screen background and align it, giving the illusion of	628	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.	629	transparency as long as the window isn't in front of other windows.
539		630
540	rootalign root	631	rootalign root
541		632
542	=cut	633	=cut
543		634
544	sub move($$;$) {	635	sub move($$;$) {
545	my $img = pop->clone;	636	my $img = pop->clone;
546	$img->move ($_[0], $_[1]);	637	$img->move ($_[0], $_[1]);
547	$img	638	$img
548	}	639	}
549		640
		641	sub align($;$$) {
		642	my $img = pop;
		643
		644	move $_[0] * (TW - $img->w),
		645	$_[1] * (TH - $img->h),
		646	$img
		647	}
		648
		649	sub center($;$$) {
		650	my $img = pop;
		651	my $w = $_[0] \|\| TW;
		652	my $h = $_[1] \|\| TH;
		653
		654	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		655	}
		656
550	sub rootalign($) {	657	sub rootalign($) {
551	move -TX, -TY, $_[0]	658	move -TX, -TY, $_[0]
552	}	659	}
553		660
		661	=item rotate $center_x, $center_y, $degrees
		662
		663	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		664	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		665	width/height).
		666
		667	#TODO# new width, height, maybe more operators?
		668
		669	Example: rotate the image by 90 degrees
		670
		671	=cut
		672
		673	sub rotate($$$$) {
		674	my $img = pop;
		675	$img->rotate (
		676	$_[0] * $img->w,
		677	$_[1] * $img->h,
		678	$_[2] * (3.14159265 / 180),
		679	)
		680	}
		681
		682	=back
		683
		684	=head2 COLOUR MODIFICATIONS
		685
		686	The following operators change the pixels of the image.
		687
		688	=over 4
		689
554	=item contrast $factor, $img	690	=item contrast $factor, $img
555		691
556	=item contrast $r, $g, $b, $img	692	=item contrast $r, $g, $b, $img
557		693
558	=item contrast $r, $g, $b, $a, $img	694	=item contrast $r, $g, $b, $a, $img
559		695
560	Adjusts the I<contrast> of an image.	696	Adjusts the I<contrast> of an image.
561		697
562	#TODO#	698	The first form applies a single C<$factor> to red, green and blue, the
		699	second form applies separate factors to each colour channel, and the last
		700	form includes the alpha channel.
563		701
		702	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		703	contrast.
		704
		705	Due to limitations in the underlying XRender extension, lowering contrast
		706	also reduces brightness, while increasing contrast currently also
		707	increases brightness.
		708
564	=item brightness $factor, $img	709	=item brightness $bias, $img
565		710
566	=item brightness $r, $g, $b, $img	711	=item brightness $r, $g, $b, $img
567		712
568	=item brightness $r, $g, $b, $a, $img	713	=item brightness $r, $g, $b, $a, $img
569		714
570	Adjusts the brightness of an image.	715	Adjusts the brightness of an image.
571		716
		717	The first form applies a single C<$bias> to red, green and blue, the
		718	second form applies separate biases to each colour channel, and the last
		719	form includes the alpha channel.
		720
		721	Values less than 0 reduce brightness, while values larger than 0 increase
		722	it. Useful range is from -1 to 1 - the former results in a black, the
		723	latter in a white picture.
		724
		725	Due to idiosyncrasies in the underlying XRender extension, biases less
		726	than zero can be I<very> slow.
		727
572	=cut	728	=cut
573		729
574	sub contrast($$;$$;$) {	730	sub contrast($$;$$;$) {
575	my $img = pop;	731	my $img = pop;
576	my ($r, $g, $b, $a) = @_;	732	my ($r, $g, $b, $a) = @_;
577		733
578	($g, $b) = ($r, $r) if @_ < 4;	734	($g, $b) = ($r, $r) if @_ < 3;
579	$a = 1 if @_ < 5;	735	$a = 1 if @_ < 4;
580		736
581	$img = $img->clone;	737	$img = $img->clone;
582	$img->contrast ($r, $g, $b, $a);	738	$img->contrast ($r, $g, $b, $a);
583	$img	739	$img
584	}	740	}
585		741
586	sub brightness($$;$$;$) {	742	sub brightness($$;$$;$) {
587	my $img = pop;	743	my $img = pop;
588	my ($r, $g, $b, $a) = @_;	744	my ($r, $g, $b, $a) = @_;
589		745
590	($g, $b) = ($r, $r) if @_ < 4;	746	($g, $b) = ($r, $r) if @_ < 3;
591	$a = 1 if @_ < 5;	747	$a = 1 if @_ < 4;
592		748
593	$img = $img->clone;	749	$img = $img->clone;
594	$img->brightness ($r, $g, $b, $a);	750	$img->brightness ($r, $g, $b, $a);
595	$img	751	$img
596	}	752	}
…		…
612	sub blur($$;$) {	768	sub blur($$;$) {
613	my $img = pop;	769	my $img = pop;
614	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	770	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
615	}	771	}
616		772
617	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees	773	=back
618		774
619	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	775	=head2 OTHER STUFF
620	pointer at C<$center_x> and C<$center_y> (specified as percentage of image
621	width/height), generating a new image with width C<$new_width> and height
622	C<$new_height>.
623		776
624	#TODO# new width, height, maybe more operators?	777	Anything that didn't fit any of the other categories, even after applying
		778	force and closing our eyes.
625		779
626	Example: rotate the image by 90 degrees	780	=over 4
627		781
628	=cut	782	=item once { ... }
629		783
630	sub rotate($$$$$$) {	784	This function takes a code block as argument, that is, one or more
631	my $img = pop;	785	statements enclosed by braces.
632	$img->rotate (	786
633	$_[0],	787	The trick is that this code block is only evaluated once - future calls
634	$_[1],	788	will simply return the original image (yes, it should only be used with
635	$_[2] * $img->w * .01,	789	images).
636	$_[3] * $img->h * .01,	790
637	$_[4] * (3.14159265 / 180),	791	This can be extremely useful to avoid redoign the same slow operations
		792	again and again- for example, if your background expression takes the root
		793	background, blurs it and then root-aligns it it would have to blur the
		794	root background on every window move or resize.
		795
		796	Putting the blur into a C<once> block will make sure the blur is only done
		797	once:
		798
		799	rootlign once { blur 10, root }
		800
		801	This leaves the question of how to force reevaluation of the block, in
		802	case the root background changes: Right now, all once blocks forget that
		803	they ahve been executed before each time the root background changes (if
		804	the expression is sensitive to that) or when C<once_again> is called.
		805
		806	=item once_again
		807
		808	Resets all C<once> block as if they had never been called, i.e. on the
		809	next call they will be reevaluated again.
		810
		811	=cut
		812
		813	sub once(&) {
		814	my $once = $self->{once_cache}{$_[0]+0} \|\|= do {
		815	local $new->{again};
		816	my @res = $_[0]();
		817	[$new->{again}, \@res]
638	)	818	};
		819
		820	$new->{again} = {
		821	%{ $new->{again} },
		822	%{ $once->[0] }
		823	};
		824
		825	# in scalar context we always return the first original result, which
		826	# is not quite how perl works.
		827	wantarray
		828	? @{ $once->[1] }
		829	: $once->[1][0]
		830	}
		831
		832	sub once_again() {
		833	delete $self->{once_cache};
639	}	834	}
640		835
641	=back	836	=back
642		837
643	=cut	838	=cut
…		…
686		881
687	# evaluate user expression	882	# evaluate user expression
688		883
689	my $img = eval { $self->{expr}->() };	884	my $img = eval { $self->{expr}->() };
690	warn $@ if $@;#d#	885	warn $@ if $@;#d#
691	die if !UNIVERSAL::isa $img, "urxvt::img";	886	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
692		887
693	$state->{size_sensitive} = 1	888	# if the expression is sensitive to external events, prepare reevaluation then
		889
		890	my $again = delete $state->{again};
		891
		892	$again->{size} = 1
694	if $img->repeat_mode != urxvt::RepeatNormal;	893	if $img->repeat_mode != urxvt::RepeatNormal;
695		894
696	# if the expression is sensitive to external events, prepare reevaluation then
697
698	my $repeat;
699
700	if (my $again = $state->{again}) {	895	if (my $again = $again->{time}) {
701	$repeat = 1;
702	my $self = $self;	896	my $self = $self;
703	$state->{timer} = $again == $old->{again}	897	$state->{timer} = $again == $old->{again}
704	? $old->{timer}	898	? $old->{timer}
705	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {	899	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
706	++$self->{counter};	900	++$self->{counter};
707	$self->recalculate	901	$self->recalculate
708	});	902	});
709	}	903	}
710		904
711	if (delete $state->{position_sensitive}) {	905	if ($again->{position}) {
712	$repeat = 1;
713	$self->enable (position_change => sub { $_[0]->recalculate });	906	$self->enable (position_change => sub { $_[0]->recalculate });
714	} else {	907	} else {
715	$self->disable ("position_change");	908	$self->disable ("position_change");
716	}	909	}
717		910
718	if (delete $state->{size_sensitive}) {	911	if ($again->{size}) {
719	$repeat = 1;
720	$self->enable (size_change => sub { $_[0]->recalculate });	912	$self->enable (size_change => sub { $_[0]->recalculate });
721	} else {	913	} else {
722	$self->disable ("size_change");	914	$self->disable ("size_change");
723	}	915	}
724		916
725	if (delete $state->{rootpmap_sensitive}) {	917	if ($again->{rootpmap}) {
726	$repeat = 1;
727	$self->enable (rootpmap_change => sub { $_[0]->recalculate });	918	$self->enable (rootpmap_change => sub {
		919	delete $_[0]{once_cache}; # this will override once-block values from
		920	$_[0]->recalculate;
		921	});
728	} else {	922	} else {
729	$self->disable ("rootpmap_change");	923	$self->disable ("rootpmap_change");
730	}	924	}
731		925
732	# clear stuff we no longer need	926	# clear stuff we no longer need
733		927
734	%$old = ();	928	%$old = ();
735		929
736	unless ($repeat) {	930	unless (%$again) {
737	delete $self->{state};	931	delete $self->{state};
738	delete $self->{expr};	932	delete $self->{expr};
739	}	933	}
740		934
741	# set background pixmap	935	# set background pixmap
…		…
746	}	940	}
747		941
748	sub on_start {	942	sub on_start {
749	my ($self) = @_;	943	my ($self) = @_;
750		944
751	my $expr = $self->x_resource ("background.expr")	945	my $expr = $self->x_resource ("%.expr")
752	or return;	946	or return;
753		947
		948	$self->has_render
		949	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		950
754	$self->set_expr (parse_expr $expr);	951	$self->set_expr (parse_expr $expr);
755	$self->{border} = $self->x_resource_boolean ("background.border");	952	$self->{border} = $self->x_resource_boolean ("%.border");
		953
		954	$MIN_INTERVAL = $self->x_resource ("%.interval");
756		955
757	()	956	()
758	}	957	}
759		958

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.41 by root, Fri Jun 8 22:21:48 2012 UTC vs. Revision 1.57 by root, Thu Jun 14 18:06:15 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.41 by root, Fri Jun 8 22:21:48 2012 UTC vs.
Revision 1.57 by root, Thu Jun 14 18:06:15 2012 UTC