[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 1.63 by root, Tue Jun 19 18:17:56 2012 UTC

…		…
1	#! perl	1	#! perl
2		2
3	#:META:X_RESOURCE:%.expr:string:background expression	3	#:META:X_RESOURCE:%.expr:string:background expression
4	#:META:X_RESOURCE:%.border.:boolean:respect the terminal border	4	#:META:X_RESOURCE:%.border:boolean:respect the terminal border
5		5	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
6	#TODO: once, rootalign
7		6
8	=head1 NAME	7	=head1 NAME
9		8
10	background - manage terminal background	9	background - manage terminal background
11		10
12	=head1 SYNOPSIS	11	=head1 SYNOPSIS
13		12
14	urxvt --background-expr 'background expression'	13	urxvt --background-expr 'background expression'
15	--background-border	14	--background-border
		15	--background-interval seconds
16		16
17	=head1 DESCRIPTION	17	=head1 DESCRIPTION
18		18
19	This extension manages the terminal background by creating a picture that	19	This extension manages the terminal background by creating a picture that
20	is behind the text, replacing the normal background colour.	20	is behind the text, replacing the normal background colour.
57		57
58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the	58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the
59	image to the window size, so it relies on the window size and will	59	image to the window size, so it relies on the window size and will
60	be reevaluated each time it is changed, but not when it moves for	60	be reevaluated each time it is changed, but not when it moves for
61	example. That ensures that the picture always fills the terminal, even	61	example. That ensures that the picture always fills the terminal, even
62	after it's size changes.	62	after its size changes.
63		63
64	=head2 EXPRESSIONS	64	=head2 EXPRESSIONS
65		65
66	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
67	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
…		…
71	return scale load "$HOME/weekday.png";	71	return scale load "$HOME/weekday.png";
72	} else {	72	} else {
73	return scale load "$HOME/sunday.png";	73	return scale load "$HOME/sunday.png";
74	}	74	}
75		75
76	This expression gets evaluated once per hour. It will set F<sunday.png> as	76	This expression is evaluated once per hour. It will set F<sunday.png> as
77	background on Sundays, and F<weekday.png> on all other days.	77	background on Sundays, and F<weekday.png> on all other days.
78		78
79	Fortunately, we expect that most expressions will be much simpler, with	79	Fortunately, we expect that most expressions will be much simpler, with
80	little Perl knowledge needed.	80	little Perl knowledge needed.
81		81
…		…
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
…		…
137	pseudo-transparency, as the image seems to be static while the window is	138	pseudo-transparency, as the image seems to be static while the window is
138	moved around.	139	moved around.
139		140
140	=head2 CYCLES AND CACHING	141	=head2 CYCLES AND CACHING
141		142
		143	=head3 C<load> et al.
		144
142	As has been mentioned before, the expression might be evaluated multiple	145	As has been mentioned before, the expression might be evaluated multiple
143	times. Each time the expression is reevaluated, a new cycle is said to	146	times. Each time the expression is reevaluated, a new cycle is said to
144	have begun. Many operators cache their results till the next cycle.	147	have begun. Many operators cache their results till the next cycle.
145		148
146	For example, the C<load> operator keeps a copy of the image. If it is	149	For example, the C<load> operator keeps a copy of the image. If it is
…		…
150	This only works for one cycle though, so as long as you load the same	153	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	154	image every time, it will always be cached, but when you load a different
152	image, it will forget about the first one.	155	image, it will forget about the first one.
153		156
154	This allows you to either speed things up by keeping multiple images in	157	This allows you to either speed things up by keeping multiple images in
155	memory, or comserve memory by loading images more often.	158	memory, or conserve memory by loading images more often.
156		159
157	For example, you can keep two images in memory and use a random one like	160	For example, you can keep two images in memory and use a random one like
158	this:	161	this:
159		162
160	my $img1 = load "img1.png";	163	my $img1 = load "img1.png";
…		…
170		173
171	Here, a path is selected randomly, and load is only called for one image,	174	Here, a path is selected randomly, and load is only called for one image,
172	so keeps only one image in memory. If, on the next evaluation, luck	175	so keeps only one image in memory. If, on the next evaluation, luck
173	decides to use the other path, then it will have to load that image again.	176	decides to use the other path, then it will have to load that image again.
174		177
		178	=head3 C<once { ... }>
		179
		180	Another way to cache expensive operations is to use C<once { ... }>. The
		181	C<once> operator takes a block of multiple statements enclosed by C<{}>
		182	and evaluates it only.. once, returning any images the last statement
		183	returned. Further calls simply produce the values from the cache.
		184
		185	This is most useful for expensive operations, such as C<blur>:
		186
		187	rootalign once { blur 20, root }
		188
		189	This makes a blurred copy of the root background once, and on subsequent
		190	calls, just root-aligns it. Since C<blur> is usually quite slow and
		191	C<rootalign> is quite fast, this trades extra memory (For the cached
		192	blurred pixmap) with speed (blur only needs to be redone when root
		193	changes).
		194
175	=head1 REFERENCE	195	=head1 REFERENCE
176		196
177	=head2 COMMAND LINE SWITCHES	197	=head2 COMMAND LINE SWITCHES
178		198
179	=over 4	199	=over 4
…		…
188	overwriting borders and any other areas, such as the scrollbar.	208	overwriting borders and any other areas, such as the scrollbar.
189		209
190	Specifying this flag changes the behaviour, so that the image only	210	Specifying this flag changes the behaviour, so that the image only
191	replaces the background of the character area.	211	replaces the background of the character area.
192		212
		213	=item --background-interval seconds
		214
		215	Since some operations in the underlying XRender extension can effectively
		216	freeze your X-server for prolonged time, this extension enforces a minimum
		217	time between updates, which is normally about 0.1 seconds.
		218
		219	If you want to do updates more often, you can decrease this safety
		220	interval with this switch.
		221
193	=back	222	=back
194		223
195	=cut	224	=cut
196		225
		226	our %_IMG_CACHE;
197	our $HOME;	227	our $HOME;
198	our ($self, $old, $new);	228	our ($self, $frame);
199	our ($x, $y, $w, $h);	229	our ($x, $y, $w, $h);
200		230
201	# enforce at least this interval between updates	231	# enforce at least this interval between updates
202	our $MIN_INTERVAL = 1/100;	232	our $MIN_INTERVAL = 6/59.951;
203		233
204	{	234	{
205	package urxvt::bgdsl; # background language	235	package urxvt::bgdsl; # background language
		236
		237	sub FR_PARENT() { 0 } # parent frame, if any - must be #0
		238	sub FR_CACHE () { 1 } # cached values
		239	sub FR_AGAIN () { 2 } # what this expr is sensitive to
		240	sub FR_STATE () { 3 } # watchers etc.
		241
		242	use List::Util qw(min max sum shuffle);
206		243
207	=head2 PROVIDERS/GENERATORS	244	=head2 PROVIDERS/GENERATORS
208		245
209	These functions provide an image, by loading it from disk, grabbing it	246	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	247	from the root screen or by simply generating it. They are used as starting
…		…
215	=item load $path	252	=item load $path
216		253
217	Loads the image at the given C<$path>. The image is set to plane tiling	254	Loads the image at the given C<$path>. The image is set to plane tiling
218	mode.	255	mode.
219		256
220	Loaded images will be cached for one cycle.	257	Loaded images will be cached for one cycle, and shared between temrinals
		258	running in the same process (e.g. in C<urxvtd>).
		259
		260	#=item load_uc $path
		261	#
		262	#Load uncached - same as load, but does not cache the image. This function
		263	#is most useufl if you want to optimise a background expression in some
		264	#way.
221		265
222	=cut	266	=cut
223		267
224	sub load($) {	268	sub load($) {
225	my ($path) = @_;	269	my ($path) = @_;
226		270
227	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	271	$_IMG_CACHE{$path} \|\| do {
		272	my $img = $self->new_img_from_file ($path);
		273	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		274	$img
		275	}
228	}	276	}
229		277
230	=item root	278	=item root
231		279
232	Returns the root window pixmap, that is, hopefully, the background image	280	Returns the root window pixmap, that is, hopefully, the background image
233	of your screen. The image is set to extend mode.	281	of your screen.
234		282
235	This function makes your expression root sensitive, that means it will be	283	This function makes your expression root sensitive, that means it will be
236	reevaluated when the bg image changes.	284	reevaluated when the bg image changes.
237		285
238	=cut	286	=cut
239		287
240	sub root() {	288	sub root() {
241	$new->{rootpmap_sensitive} = 1;	289	$frame->[FR_AGAIN]{rootpmap} = 1;
242	die "root op not supported, exg, we need you";	290	$self->new_img_from_root
243	}	291	}
244		292
245	=item solid $colour	293	=item solid $colour
246		294
247	=item solid $width, $height, $colour	295	=item solid $width, $height, $colour
…		…
255	=cut	303	=cut
256		304
257	sub solid($;$$) {	305	sub solid($;$$) {
258	my $colour = pop;	306	my $colour = pop;
259		307
260	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	308	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
261	$img->fill ($colour);	309	$img->fill ($colour);
262	$img	310	$img
263	}	311	}
264		312
265	=back	313	=item clone $img
266		314
267	=head2 VARIABLES	315	Returns an exact copy of the image. This is useful if you want to have
		316	multiple copies of the same image to apply different effects to.
268		317
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	318	=cut
311		319
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} = $_[0];
345	}
346
347	sub counter($) {	320	sub clone($) {
348	$new->{again} = $_[0];	321	$_[0]->clone
349	$self->{counter} + 0
350	}	322	}
351		323
352	=back	324	=item merge $img ...
		325
		326	Takes any number of images and merges them together, creating a single
		327	image containing them all. The tiling mode of the first image is used as
		328	the tiling mdoe of the resulting image.
		329
		330	This function is called automatically when an expression returns multiple
		331	images.
		332
		333	=cut
		334
		335	sub merge(@) {
		336	return $_[0] unless $#_;
		337
		338	# rather annoyingly clumsy, but optimisation is for another time
		339
		340	my $x0 = +1e9;
		341	my $y0 = +1e9;
		342	my $x1 = -1e9;
		343	my $y1 = -1e9;
		344
		345	for (@_) {
		346	my ($x, $y, $w, $h) = $_->geometry;
		347
		348	$x0 = $x if $x0 > $x;
		349	$y0 = $y if $y0 > $y;
		350
		351	$x += $w;
		352	$y += $h;
		353
		354	$x1 = $x if $x1 < $x;
		355	$y1 = $y if $y1 < $y;
		356	}
		357
		358	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		359	$base->repeat_mode ($_[0]->repeat_mode);
		360	$base->fill ([0, 0, 0, 0]);
		361
		362	$base->draw ($_)
		363	for @_;
		364
		365	$base
		366	}
353		367
354	=head2 TILING MODES	368	=head2 TILING MODES
355		369
356	The following operators modify the tiling mode of an image, that is, the	370	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.	371	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	401	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	402	image over another image or the background colour while leaving all
389	background pixels outside the image unchanged.	403	background pixels outside the image unchanged.
390		404
391	Example: load an image and display it in the upper left corner. The rest	405	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	406	of the space is left "empty" (transparent or whatever your compositor does
393	in alpha mode, else background colour).	407	in alpha mode, else background colour).
394		408
395	pad load "mybg.png"	409	pad load "mybg.png"
396		410
397	=item extend $img	411	=item extend $img
398		412
399	Extends the image over the whole plane, using the closest pixel in the	413	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	414	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	415	filtering operations and want the pixels outside the image to have the
402	same values as the pixels near the edge.	416	same values as the pixels near the edge.
403		417
404	Example: just for curiosity, how does this pixel extension stuff work?	418	Example: just for curiosity, how does this pixel extension stuff work?
405		419
…		…
431	$img	445	$img
432	}	446	}
433		447
434	=back	448	=back
435		449
436	=head2 PIXEL OPERATORS	450	=head2 VARIABLE VALUES
437		451
438	The following operators modify the image pixels in various ways.	452	The following functions provide variable data such as the terminal window
		453	dimensions. They are not (Perl-) variables, they just return stuff that
		454	varies. Most of them make your expression sensitive to some events, for
		455	example using C<TW> (terminal width) means your expression is evaluated
		456	again when the terminal is resized.
439		457
440	=over 4	458	=over 4
441		459
442	=item clone $img	460	=item TX
443		461
444	Returns an exact copy of the image.	462	=item TY
445		463
446	=cut	464	Return the X and Y coordinates of the terminal window (the terminal
		465	window is the full window by default, and the character area only when in
		466	border-respect mode).
447		467
		468	Using these functions make your expression sensitive to window moves.
		469
		470	These functions are mainly useful to align images to the root window.
		471
		472	Example: load an image and align it so it looks as if anchored to the
		473	background.
		474
		475	move -TX, -TY, load "mybg.png"
		476
		477	=item TW
		478
		479	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		480	terminal window is the full window by default, and the character area only
		481	when in border-respect mode).
		482
		483	Using these functions make your expression sensitive to window resizes.
		484
		485	These functions are mainly useful to scale images, or to clip images to
		486	the window size to conserve memory.
		487
		488	Example: take the screen background, clip it to the window size, blur it a
		489	bit, align it to the window position and use it as background.
		490
		491	clip move -TX, -TY, once { blur 5, root }
		492
		493	=cut
		494
		495	sub TX() { $frame->[FR_AGAIN]{position} = 1; $x }
		496	sub TY() { $frame->[FR_AGAIN]{position} = 1; $y }
		497	sub TW() { $frame->[FR_AGAIN]{size} = 1; $w }
		498	sub TH() { $frame->[FR_AGAIN]{size} = 1; $h }
		499
		500	=item now
		501
		502	Returns the current time as (fractional) seconds since the epoch.
		503
		504	Using this expression does I<not> make your expression sensitive to time,
		505	but the next two functions do.
		506
		507	=item again $seconds
		508
		509	When this function is used the expression will be reevaluated again in
		510	C<$seconds> seconds.
		511
		512	Example: load some image and rotate it according to the time of day (as if it were
		513	the hour pointer of a clock). Update this image every minute.
		514
		515	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
		516
		517	=item counter $seconds
		518
		519	Like C<again>, but also returns an increasing counter value, starting at
		520	0, which might be useful for some simple animation effects.
		521
		522	=cut
		523
		524	sub now() { urxvt::NOW }
		525
		526	sub again($) {
		527	$frame->[FR_AGAIN]{time} = $_[0];
		528	}
		529
448	sub clone($) {	530	sub counter($) {
449	$_[0]->clone	531	$frame->[FR_AGAIN]{time} = $_[0];
		532	$frame->[FR_STATE]{counter} + 0
450	}	533	}
		534
		535	=back
		536
		537	=head2 SHAPE CHANGING OPERATORS
		538
		539	The following operators modify the shape, size or position of the image.
		540
		541	=over 4
451		542
452	=item clip $img	543	=item clip $img
453		544
454	=item clip $width, $height, $img	545	=item clip $width, $height, $img
455		546
…		…
479	$img->sub_rect ($_[0], $_[1], $w, $h)	570	$img->sub_rect ($_[0], $_[1], $w, $h)
480	}	571	}
481		572
482	=item scale $img	573	=item scale $img
483		574
484	=item scale $size_percent, $img	575	=item scale $size_factor, $img
485		576
486	=item scale $width_percent, $height_percent, $img	577	=item scale $width_factor, $height_factor, $img
487		578
488	Scales the image by the given percentages in horizontal	579	Scales the image by the given factors in horizontal
489	(C<$width_percent>) and vertical (C<$height_percent>) direction.	580	(C<$width>) and vertical (C<$height>) direction.
490		581
491	If only one percentage is give, it is used for both directions.	582	If only one factor is give, it is used for both directions.
492		583
493	If no percentages are given, scales the image to the window size without	584	If no factors are given, scales the image to the window size without
494	keeping aspect.	585	keeping aspect.
495		586
496	=item resize $width, $height, $img	587	=item resize $width, $height, $img
497		588
498	Resizes the image to exactly C<$width> times C<$height> pixels.	589	Resizes the image to exactly C<$width> times C<$height> pixels.
499		590
500	=cut	591	=item fit $img
501		592
502	#TODO: maximise, maximise_fill?	593	=item fit $width, $height, $img
		594
		595	Fits the image into the given C<$width> and C<$height> without changing
		596	aspect, or the terminal size. That means it will be shrunk or grown until
		597	the whole image fits into the given area, possibly leaving borders.
		598
		599	=item cover $img
		600
		601	=item cover $width, $height, $img
		602
		603	Similar to C<fit>, but shrinks or grows until all of the area is covered
		604	by the image, so instead of potentially leaving borders, it will cut off
		605	image data that doesn't fit.
		606
		607	=cut
503		608
504	sub scale($;$;$) {	609	sub scale($;$;$) {
505	my $img = pop;	610	my $img = pop;
506		611
507	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	612	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
508	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	613	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
509	: $img->scale (TW, TH)	614	: $img->scale (TW, TH)
510	}	615	}
511		616
512	sub resize($$$) {	617	sub resize($$$) {
513	my $img = pop;	618	my $img = pop;
514	$img->scale ($_[0], $_[1])	619	$img->scale ($_[0], $_[1])
515	}	620	}
516		621
		622	sub fit($;$$) {
		623	my $img = pop;
		624	my $w = ($_[0] \|\| TW) / $img->w;
		625	my $h = ($_[1] \|\| TH) / $img->h;
		626	scale +(min $w, $h), $img
		627	}
		628
		629	sub cover($;$$) {
		630	my $img = pop;
		631	my $w = ($_[0] \|\| TW) / $img->w;
		632	my $h = ($_[1] \|\| TH) / $img->h;
		633	scale +(max $w, $h), $img
		634	}
		635
517	=item move $dx, $dy, $img	636	=item move $dx, $dy, $img
518		637
519	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	638	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
520	the vertical.	639	the vertical.
521		640
522	Example: move the image right by 20 pixels and down by 30.	641	Example: move the image right by 20 pixels and down by 30.
523		642
524	move 20, 30, ...	643	move 20, 30, ...
		644
		645	=item align $xalign, $yalign, $img
		646
		647	Aligns the image according to a factor - C<0> means the image is moved to
		648	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		649	exactly centered and C<1> means it touches the right or bottom edge.
		650
		651	Example: remove any visible border around an image, center it vertically but move
		652	it to the right hand side.
		653
		654	align 1, 0.5, pad $img
		655
		656	=item center $img
		657
		658	=item center $width, $height, $img
		659
		660	Centers the image, i.e. the center of the image is moved to the center of
		661	the terminal window (or the box specified by C<$width> and C<$height> if
		662	given).
		663
		664	Example: load an image and center it.
		665
		666	center pad load "mybg.png"
525		667
526	=item rootalign $img	668	=item rootalign $img
527		669
528	Moves the image so that it appears glued to the screen as opposed to the	670	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	671	window. This gives the illusion of a larger area behind the window. It is
…		…
535	rootalign mirror load "mybg.png"	677	rootalign mirror load "mybg.png"
536		678
537	Example: take the screen background and align it, giving the illusion of	679	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.	680	transparency as long as the window isn't in front of other windows.
539		681
540	rootalign root	682	rootalign root
541		683
542	=cut	684	=cut
543		685
544	sub move($$;$) {	686	sub move($$;$) {
545	my $img = pop->clone;	687	my $img = pop->clone;
546	$img->move ($_[0], $_[1]);	688	$img->move ($_[0], $_[1]);
547	$img	689	$img
548	}	690	}
549		691
		692	sub align($;$$) {
		693	my $img = pop;
		694
		695	move $_[0] * (TW - $img->w),
		696	$_[1] * (TH - $img->h),
		697	$img
		698	}
		699
		700	sub center($;$$) {
		701	my $img = pop;
		702	my $w = $_[0] \|\| TW;
		703	my $h = $_[1] \|\| TH;
		704
		705	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		706	}
		707
550	sub rootalign($) {	708	sub rootalign($) {
551	move -TX, -TY, $_[0]	709	move -TX, -TY, $_[0]
552	}	710	}
553		711
		712	=item rotate $center_x, $center_y, $degrees
		713
		714	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		715	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		716	width/height).
		717
		718	#TODO# new width, height, maybe more operators?
		719
		720	Example: rotate the image by 90 degrees
		721
		722	=cut
		723
		724	sub rotate($$$$) {
		725	my $img = pop;
		726	$img->rotate (
		727	$_[0] * ($img->w + $img->x),
		728	$_[1] * ($img->h + $img->y),
		729	$_[2] * (3.14159265 / 180),
		730	)
		731	}
		732
		733	=back
		734
		735	=head2 COLOUR MODIFICATIONS
		736
		737	The following operators change the pixels of the image.
		738
		739	=over 4
		740
554	=item contrast $factor, $img	741	=item contrast $factor, $img
555		742
556	=item contrast $r, $g, $b, $img	743	=item contrast $r, $g, $b, $img
557		744
558	=item contrast $r, $g, $b, $a, $img	745	=item contrast $r, $g, $b, $a, $img
559		746
560	Adjusts the I<contrast> of an image.	747	Adjusts the I<contrast> of an image.
561		748
562	#TODO#	749	The first form applies a single C<$factor> to red, green and blue, the
		750	second form applies separate factors to each colour channel, and the last
		751	form includes the alpha channel.
563		752
		753	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		754	contrast.
		755
		756	Due to limitations in the underlying XRender extension, lowering contrast
		757	also reduces brightness, while increasing contrast currently also
		758	increases brightness.
		759
564	=item brightness $factor, $img	760	=item brightness $bias, $img
565		761
566	=item brightness $r, $g, $b, $img	762	=item brightness $r, $g, $b, $img
567		763
568	=item brightness $r, $g, $b, $a, $img	764	=item brightness $r, $g, $b, $a, $img
569		765
570	Adjusts the brightness of an image.	766	Adjusts the brightness of an image.
		767
		768	The first form applies a single C<$bias> to red, green and blue, the
		769	second form applies separate biases to each colour channel, and the last
		770	form includes the alpha channel.
		771
		772	Values less than 0 reduce brightness, while values larger than 0 increase
		773	it. Useful range is from -1 to 1 - the former results in a black, the
		774	latter in a white picture.
		775
		776	Due to idiosyncrasies in the underlying XRender extension, biases less
		777	than zero can be I<very> slow.
571		778
572	=cut	779	=cut
573		780
574	sub contrast($$;$$;$) {	781	sub contrast($$;$$;$) {
575	my $img = pop;	782	my $img = pop;
576	my ($r, $g, $b, $a) = @_;	783	my ($r, $g, $b, $a) = @_;
577		784
578	($g, $b) = ($r, $r) if @_ < 4;	785	($g, $b) = ($r, $r) if @_ < 3;
579	$a = 1 if @_ < 5;	786	$a = 1 if @_ < 4;
580		787
581	$img = $img->clone;	788	$img = $img->clone;
582	$img->contrast ($r, $g, $b, $a);	789	$img->contrast ($r, $g, $b, $a);
583	$img	790	$img
584	}	791	}
585		792
586	sub brightness($$;$$;$) {	793	sub brightness($$;$$;$) {
587	my $img = pop;	794	my $img = pop;
588	my ($r, $g, $b, $a) = @_;	795	my ($r, $g, $b, $a) = @_;
589		796
590	($g, $b) = ($r, $r) if @_ < 4;	797	($g, $b) = ($r, $r) if @_ < 3;
591	$a = 1 if @_ < 5;	798	$a = 1 if @_ < 4;
592		799
593	$img = $img->clone;	800	$img = $img->clone;
594	$img->brightness ($r, $g, $b, $a);	801	$img->brightness ($r, $g, $b, $a);
595	$img	802	$img
596	}	803	}
…		…
612	sub blur($$;$) {	819	sub blur($$;$) {
613	my $img = pop;	820	my $img = pop;
614	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	821	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
615	}	822	}
616		823
617	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
618
619	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
620	pointer at C<$center_x> and C<$center_y> (specified as percentage of image
621	width/height), generating a new image with width C<$new_width> and height
622	C<$new_height>.
623
624	#TODO# new width, height, maybe more operators?
625
626	Example: rotate the image by 90 degrees
627
628	=cut
629
630	sub rotate($$$$$$) {
631	my $img = pop;
632	$img->rotate (
633	$_[0],
634	$_[1],
635	$_[2] * $img->w * .01,
636	$_[3] * $img->h * .01,
637	$_[4] * (3.14159265 / 180),
638	)
639	}
640
641	=back	824	=back
642		825
		826	=head2 OTHER STUFF
		827
		828	Anything that didn't fit any of the other categories, even after applying
		829	force and closing our eyes.
		830
		831	=over 4
		832
		833	=item once { ... }
		834
		835	This function takes a code block as argument, that is, one or more
		836	statements enclosed by braces.
		837
		838	The trick is that this code block is only evaluated once - future calls
		839	will simply return the original image (yes, it should only be used with
		840	images).
		841
		842	This can be extremely useful to avoid redoing the same slow operations
		843	again and again- for example, if your background expression takes the root
		844	background, blurs it and then root-aligns it it would have to blur the
		845	root background on every window move or resize.
		846
		847	In fact, urxvt itself encloses the whole expression in some kind of
		848	C<once> block so it only is reevaluated as required.
		849
		850	Putting the blur into a C<once> block will make sure the blur is only done
		851	once:
		852
		853	rootlign once { blur 10, root }
		854
		855	This leaves the question of how to force reevaluation of the block,
		856	in case the root background changes: If expression inside the block
		857	is sensitive to some event (root background changes, window geometry
		858	changes), then it will be reevaluated automatically as needed.
		859
		860	=item once_again
		861
		862	Resets all C<once> block as if they had never been called, i.e. on the
		863	next call they will be reevaluated again.
		864
		865	=cut
		866
		867	sub once(&) {
		868	my $id = $_[0]+0;
		869
		870	local $frame = $self->{frame_cache}{$id} \|\|= [$frame];
		871
		872	unless ($frame->[FR_CACHE]) {
		873	$frame->[FR_CACHE] = [ $_[0]() ];
		874
		875	my $self = $self;
		876	my $frame = $frame;
		877	Scalar::Util::weaken $frame;
		878	$self->compile_frame ($frame, sub {
		879	# clear this frame cache, also for all parents
		880	for (my $frame = $frame; $frame; $frame = $frame->[0]) {
		881	undef $frame->[FR_CACHE];
		882	}
		883
		884	unless ($self->{term}) {
		885	use Data::Dump;
		886	ddx $frame;
		887	exit;
		888	}
		889
		890	$self->recalculate;
		891	});
		892	};
		893
		894	# in scalar context we always return the first original result, which
		895	# is not quite how perl works.
		896	wantarray
		897	? @{ $frame->[FR_CACHE] }
		898	: $frame->[FR_CACHE][0]
		899	}
		900
		901	sub once_again() {
		902	delete $self->{frame_cache};
		903	}
		904
		905	=back
		906
643	=cut	907	=cut
644		908
645	}	909	}
646		910
647	sub parse_expr {	911	sub parse_expr {
648	my $expr = eval "sub {\npackage urxvt::bgdsl;\n#line 0 'background expression'\n$_[0]\n}";	912	my $expr = eval
		913	"sub {\n"
		914	. "package urxvt::bgdsl;\n"
		915	. "#line 0 'background expression'\n"
		916	. "$_[0]\n"
		917	. "}";
649	die if $@;	918	die if $@;
650	$expr	919	$expr
651	}	920	}
652		921
653	# compiles a parsed expression	922	# compiles a parsed expression
654	sub set_expr {	923	sub set_expr {
655	my ($self, $expr) = @_;	924	my ($self, $expr) = @_;
656		925
		926	$self->{root} = [];
657	$self->{expr} = $expr;	927	$self->{expr} = $expr;
658	$self->recalculate;	928	$self->recalculate;
		929	}
		930
		931	# takes a hash of sensitivity indicators and installs watchers
		932	sub compile_frame {
		933	my ($self, $frame, $cb) = @_;
		934
		935	my $state = $frame->[urxvt::bgdsl::FR_STATE] \|\|= {};
		936	my $again = $frame->[urxvt::bgdsl::FR_AGAIN];
		937
		938	# don't keep stuff alive
		939	Scalar::Util::weaken $state;
		940
		941	if ($again->{nested}) {
		942	$state->{nested} = 1;
		943	} else {
		944	delete $state->{nested};
		945	}
		946
		947	if (my $interval = $again->{time}) {
		948	$state->{time} = [$interval, urxvt::timer->new->after ($interval)->interval ($interval)]
		949	if $state->{time}[0] != $interval;
		950
		951	# callback might have changed, although we could just rule that out
		952	$state->{time}[1]->cb (sub {
		953	++$state->{counter};
		954	$cb->();
		955	});
		956	} else {
		957	delete $state->{time};
		958	}
		959
		960	if ($again->{position}) {
		961	$state->{position} = $self->on (position_change => $cb);
		962	} else {
		963	delete $state->{position};
		964	}
		965
		966	if ($again->{size}) {
		967	$state->{size} = $self->on (size_change => $cb);
		968	} else {
		969	delete $state->{size};
		970	}
		971
		972	if ($again->{rootpmap}) {
		973	$state->{rootpmap} = $self->on (rootpmap_change => $cb);
		974	} else {
		975	delete $state->{rootpmap};
		976	}
659	}	977	}
660		978
661	# evaluate the current bg expression	979	# evaluate the current bg expression
662	sub recalculate {	980	sub recalculate {
663	my ($arg_self) = @_;	981	my ($arg_self) = @_;
…		…
673		991
674	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	992	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
675		993
676	# set environment to evaluate user expression	994	# set environment to evaluate user expression
677		995
678	local $self = $arg_self;	996	local $self = $arg_self;
679
680	local $HOME = $ENV{HOME};	997	local $HOME = $ENV{HOME};
681	local $old = $self->{state};	998	local $frame = [];
682	local $new = my $state = $self->{state} = {};
683		999
684	($x, $y, $w, $h) =
685	$self->background_geometry ($self->{border});	1000	($x, $y, $w, $h) = $self->background_geometry ($self->{border});
686		1001
687	# evaluate user expression	1002	# evaluate user expression
688		1003
689	my $img = eval { $self->{expr}->() };	1004	my @img = eval { $self->{expr}->() };
690	warn $@ if $@;#d#	1005	die $@ if $@;
		1006	die "background-expr did not return anything.\n" unless @img;
		1007	die "background-expr: expected image(s), got something else.\n"
691	die if !UNIVERSAL::isa $img, "urxvt::img";	1008	if grep { !UNIVERSAL::isa $_, "urxvt::img" } @img;
692		1009
693	$state->{size_sensitive} = 1	1010	my $img = urxvt::bgdsl::merge @img;
		1011
		1012	$frame->[FR_AGAIN]{size} = 1
694	if $img->repeat_mode != urxvt::RepeatNormal;	1013	if $img->repeat_mode != urxvt::RepeatNormal;
695		1014
696	# if the expression is sensitive to external events, prepare reevaluation then	1015	# if the expression is sensitive to external events, prepare reevaluation then
697		1016	$self->compile_frame ($frame, sub { $arg_self->recalculate });
698	my $repeat;
699
700	if (my $again = $state->{again}) {
701	$repeat = 1;
702	my $self = $self;
703	$state->{timer} = $again == $old->{again}
704	? $old->{timer}
705	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
706	++$self->{counter};
707	$self->recalculate
708	});
709	}
710
711	if (delete $state->{position_sensitive}) {
712	$repeat = 1;
713	$self->enable (position_change => sub { $_[0]->recalculate });
714	} else {
715	$self->disable ("position_change");
716	}
717
718	if (delete $state->{size_sensitive}) {
719	$repeat = 1;
720	$self->enable (size_change => sub { $_[0]->recalculate });
721	} else {
722	$self->disable ("size_change");
723	}
724
725	if (delete $state->{rootpmap_sensitive}) {
726	$repeat = 1;
727	$self->enable (rootpmap_change => sub { $_[0]->recalculate });
728	} else {
729	$self->disable ("rootpmap_change");
730	}
731		1017
732	# clear stuff we no longer need	1018	# clear stuff we no longer need
733		1019
734	%$old = ();	1020	# unless (%{ $frame->[FR_STATE] }) {
735
736	unless ($repeat) {
737	delete $self->{state};	1021	# delete $self->{state};
738	delete $self->{expr};	1022	# delete $self->{expr};
739	}	1023	# }
740		1024
741	# set background pixmap	1025	# set background pixmap
742		1026
743	$self->set_background ($img, $self->{border});	1027	$self->set_background ($img, $self->{border});
744	$self->scr_recolour (0);	1028	$self->scr_recolour (0);
…		…
746	}	1030	}
747		1031
748	sub on_start {	1032	sub on_start {
749	my ($self) = @_;	1033	my ($self) = @_;
750		1034
751	my $expr = $self->x_resource ("background.expr")	1035	my $expr = $self->x_resource ("%.expr")
752	or return;	1036	or return;
753		1037
		1038	$self->has_render
		1039	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		1040
754	$self->set_expr (parse_expr $expr);	1041	$self->set_expr (parse_expr $expr);
755	$self->{border} = $self->x_resource_boolean ("background.border");	1042	$self->{border} = $self->x_resource_boolean ("%.border");
		1043
		1044	$MIN_INTERVAL = $self->x_resource ("%.interval");
756		1045
757	()	1046	()
758	}	1047	}
759		1048

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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 1.63 by root, Tue Jun 19 18:17:56 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 1.63 by root, Tue Jun 19 18:17:56 2012 UTC