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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.38 by root, Fri Jun 8 21:48:07 2012 UTC vs.
Revision 1.58 by root, Thu Jun 14 18:13:19 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	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
5		6
6	#TODO: once, rootalign	7	=head1 NAME
7		8
8	=head1 background - manage terminal background	9	background - manage terminal background
9		10
10	=head2 SYNOPSIS	11	=head1 SYNOPSIS
11		12
12	urxvt --background-expr 'background expression'	13	urxvt --background-expr 'background expression'
13	--background-border	14	--background-border
		15	--background-interval seconds
14		16
15	=head2 DESCRIPTION	17	=head1 DESCRIPTION
16		18
17	This extension manages the terminal background by creating a picture that	19	This extension manages the terminal background by creating a picture that
18	is behind the text, replacing the normal background colour.	20	is behind the text, replacing the normal background colour.
19		21
20	It does so by evaluating a Perl expression that I<calculates> the image on	22	It does so by evaluating a Perl expression that I<calculates> the image on
30		32
31	Or specified as a X resource:	33	Or specified as a X resource:
32		34
33	URxvt.background-expr: scale load "/path/to/mybg.png"	35	URxvt.background-expr: scale load "/path/to/mybg.png"
34		36
35	=head2 THEORY OF OPERATION	37	=head1 THEORY OF OPERATION
36		38
37	At startup, just before the window is mapped for the first time, the	39	At startup, just before the window is mapped for the first time, the
38	expression is evaluated and must yield an image. The image is then	40	expression is evaluated and must yield an image. The image is then
39	extended as necessary to cover the whole terminal window, and is set as a	41	extended as necessary to cover the whole terminal window, and is set as a
40	background pixmap.	42	background pixmap.
…		…
55		57
56	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
57	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
58	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
59	example. That ensures that the picture always fills the terminal, even	61	example. That ensures that the picture always fills the terminal, even
60	after it's size changes.	62	after its size changes.
61		63
62	=head3 EXPRESSIONS	64	=head2 EXPRESSIONS
63		65
64	Expressions are normal Perl expressions, in fact, they are Perl blocks -	66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
65	which means you could use multiple lines and statements:	67	which means you could use multiple lines and statements:
66		68
67	again 3600;	69	again 3600;
…		…
69	return scale load "$HOME/weekday.png";	71	return scale load "$HOME/weekday.png";
70	} else {	72	} else {
71	return scale load "$HOME/sunday.png";	73	return scale load "$HOME/sunday.png";
72	}	74	}
73		75
74	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
75	background on sundays, and F<weekday.png> on all other days.	77	background on Sundays, and F<weekday.png> on all other days.
76		78
77	Fortunately, we expect that most expressions will be much simpler, with	79	Fortunately, we expect that most expressions will be much simpler, with
78	little Perl knowledge needed.	80	little Perl knowledge needed.
79		81
80	Basically, you always start with a function that "generates" an image	82	Basically, you always start with a function that "generates" an image
…		…
97	its result becomes the argument to the C<scale> function.	99	its result becomes the argument to the C<scale> function.
98		100
99	Many operators also allow some parameters preceding the input image	101	Many operators also allow some parameters preceding the input image
100	that modify its behaviour. For example, C<scale> without any additional	102	that modify its behaviour. For example, C<scale> without any additional
101	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
102	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):
103		106
104	scale 200, load "$HOME/mypic.png"	107	scale 2, load "$HOME/mypic.png"
105		108
106	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>
107	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
108	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
109	commas.	112	commas.
110		113
111	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
112	horizontal and vertical dimensions. For example, this halves the image	115	horizontal and vertical dimensions. For example, this halves the image
113	width and doubles the image height:	116	width and doubles the image height:
114		117
115	scale 50, 200, load "$HOME/mypic.png"	118	scale 0.5, 2, load "$HOME/mypic.png"
116		119
117	TODO	120	Other effects than scaling are also readily available, for example, you can
		121	tile the image to fill the whole window, instead of resizing it:
118		122
		123	tile load "$HOME/mypic.png"
		124
		125	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator
		126	is kind of superfluous.
		127
		128	Another common effect is to mirror the image, so that the same edges touch:
		129
		130	mirror load "$HOME/mypic.png"
		131
		132	This is also a typical background expression:
		133
		134	rootalign root
		135
		136	It first takes a snapshot of the screen background image, and then
		137	moves it to the upper left corner of the screen - the result is
		138	pseudo-transparency, as the image seems to be static while the window is
		139	moved around.
		140
119	=head3 CYCLES AND CACHING	141	=head2 CYCLES AND CACHING
120		142
121	TODO	143	As has been mentioned before, the expression might be evaluated multiple
122
123	Each time the expression is reevaluated, a new cycle is said to have begun. Many operators	144	times. Each time the expression is reevaluated, a new cycle is said to
124	cache their results till the next cycle. For example	145	have begun. Many operators cache their results till the next cycle.
125		146
		147	For example, the C<load> operator keeps a copy of the image. If it is
		148	asked to load the same image on the next cycle it will not load it again,
		149	but return the cached copy.
		150
		151	This only works for one cycle though, so as long as you load the same
		152	image every time, it will always be cached, but when you load a different
		153	image, it will forget about the first one.
		154
		155	This allows you to either speed things up by keeping multiple images in
		156	memory, or conserve memory by loading images more often.
		157
		158	For example, you can keep two images in memory and use a random one like
		159	this:
		160
		161	my $img1 = load "img1.png";
		162	my $img2 = load "img2.png";
		163	(0.5 > rand) ? $img1 : $img2
		164
		165	Since both images are "loaded" every time the expression is evaluated,
		166	they are always kept in memory. Contrast this version:
		167
		168	my $path1 = "img1.png";
		169	my $path2 = "img2.png";
		170	load ((0.5 > rand) ? $path1 : $path2)
		171
		172	Here, a path is selected randomly, and load is only called for one image,
		173	so keeps only one image in memory. If, on the next evaluation, luck
		174	decides to use the other path, then it will have to load that image again.
		175
126	=head2 REFERENCE	176	=head1 REFERENCE
127		177
128	=head3 COMMAND LINE SWITCHES	178	=head2 COMMAND LINE SWITCHES
129		179
130	=over 4	180	=over 4
131		181
132	=item --background-expr perl-expression	182	=item --background-expr perl-expression
133		183
…		…
139	overwriting borders and any other areas, such as the scrollbar.	189	overwriting borders and any other areas, such as the scrollbar.
140		190
141	Specifying this flag changes the behaviour, so that the image only	191	Specifying this flag changes the behaviour, so that the image only
142	replaces the background of the character area.	192	replaces the background of the character area.
143		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
144	=back	203	=back
145		204
146	=cut	205	=cut
147		206
148	our $EXPR;#d#	207	our %_IMG_CACHE;
149	#$EXPR = 'move W * 0.1, -H * 0.1, resize W * 0.5, H * 0.5, repeat_none load "opensource.png"';
150	$EXPR = 'move -TX, -TY, load "argb.png"';
151	#$EXPR = '
152	# rotate W, H, 50, 50, counter 1/59.95, repeat_mirror,
153	# clip X, Y, W, H, repeat_mirror,
154	# load "/root/pix/das_fette_schwein.jpg"
155	#';
156	#$EXPR = 'solid "red"';
157	#$EXPR = 'blur root, 10, 10'
158	#$EXPR = 'blur move (root, -x, -y), 5, 5'
159	#resize load "/root/pix/das_fette_schwein.jpg", w, h
160
161	our $HOME;	208	our $HOME;
162	our ($self, $old, $new);	209	our ($self, $old, $new);
163	our ($x, $y, $w, $h);	210	our ($x, $y, $w, $h);
164		211
165	# enforce at least this interval between updates	212	# enforce at least this interval between updates
166	our $MIN_INTERVAL = 1/100;	213	our $MIN_INTERVAL = 6/59.951;
167		214
168	{	215	{
169	package urxvt::bgdsl; # background language	216	package urxvt::bgdsl; # background language
		217
		218	use List::Util qw(min max sum shuffle);
170		219
171	=head2 PROVIDERS/GENERATORS	220	=head2 PROVIDERS/GENERATORS
172		221
173	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
174	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
…		…
179	=item load $path	228	=item load $path
180		229
181	Loads the image at the given C<$path>. The image is set to plane tiling	230	Loads the image at the given C<$path>. The image is set to plane tiling
182	mode.	231	mode.
183		232
184	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>).
185		235
		236	=item load_uc $path
		237
		238	Load uncached - same as load, but does not cache the image. This function
		239	is most useufl if you want to optimise a background expression in some
		240	way.
		241
186	=cut	242	=cut
		243
		244	sub load_uc($) {
		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	$img
		251	}
		252	}
187		253
188	sub load($) {	254	sub load($) {
189	my ($path) = @_;	255	my ($path) = @_;
190		256
191	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	257	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
192	}	258	}
193		259
194	=item root	260	=item root
195		261
196	Returns the root window pixmap, that is, hopefully, the background image	262	Returns the root window pixmap, that is, hopefully, the background image
…		…
200	reevaluated when the bg image changes.	266	reevaluated when the bg image changes.
201		267
202	=cut	268	=cut
203		269
204	sub root() {	270	sub root() {
205	$new->{rootpmap_sensitive} = 1;	271	$new->{again}{rootpmap} = 1;
206	die "root op not supported, exg, we need you";	272	$self->new_img_from_root
207	}	273	}
208		274
209	=item solid $colour	275	=item solid $colour
210		276
211	=item solid $width, $height, $colour	277	=item solid $width, $height, $colour
212		278
213	Creates a new image and completely fills it with the given colour. The	279	Creates a new image and completely fills it with the given colour. The
214	image is set to tiling mode.	280	image is set to tiling mode.
215		281
216	If <$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
217	useful for solid backgrounds or for use in filtering effects.	283	useful for solid backgrounds or for use in filtering effects.
218		284
219	=cut	285	=cut
220		286
221	sub solid($$;$) {	287	sub solid($;$$) {
222	my $colour = pop;	288	my $colour = pop;
223		289
224	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	290	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);
225	$img->fill ($colour);	291	$img->fill ($colour);
226	$img	292	$img
227	}	293	}
228		294
229	=back	295	=item clone $img
230		296
231	=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.
232		299
233	The following functions provide variable data such as the terminal
234	window dimensions. Most of them make your expression sensitive to some
235	events, for example using C<TW> (terminal width) means your expression is
236	evaluated again when the terminal is resized.
237
238	=over 4
239
240	=item TX
241
242	=item TY
243
244	Return the X and Y coordinates of the terminal window (the terminal
245	window is the full window by default, and the character area only when in
246	border-respect mode).
247
248	Using these functions make your expression sensitive to window moves.
249
250	These functions are mainly useful to align images to the root window.
251
252	Example: load an image and align it so it looks as if anchored to the
253	background.
254
255	move -TX, -TY, load "mybg.png"
256
257	=item TW
258
259	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
260	terminal window is the full window by default, and the character area only
261	when in border-respect mode).
262
263	Using these functions make your expression sensitive to window resizes.
264
265	These functions are mainly useful to scale images, or to clip images to
266	the window size to conserve memory.
267
268	Example: take the screen background, clip it to the window size, blur it a
269	bit, align it to the window position and use it as background.
270
271	clip move -TX, -TY, blur 5, root
272
273	=cut	300	=cut
274		301
275	sub TX() { $new->{position_sensitive} = 1; $x }
276	sub TY() { $new->{position_sensitive} = 1; $y }
277	sub TW() { $new->{size_sensitive} = 1; $w }
278	sub TH() { $new->{size_sensitive} = 1; $h }
279
280	=item now
281
282	Returns the current time as (fractional) seconds since the epoch.
283
284	Using this expression does I<not> make your expression sensitive to time,
285	but the next two functions do.
286
287	=item again $seconds
288
289	When this function is used the expression will be reevaluated again in
290	C<$seconds> seconds.
291
292	Example: load some image and rotate it according to the time of day (as if it were
293	the hour pointer of a clock). Update this image every minute.
294
295	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
296
297	=item counter $seconds
298
299	Like C<again>, but also returns an increasing counter value, starting at
300	0, which might be useful for some simple animation effects.
301
302	=cut
303
304	sub now() { urxvt::NOW }
305
306	sub again($) {
307	$new->{again} = $_[0];
308	}
309
310	sub counter($) {	302	sub clone($) {
311	$new->{again} = $_[0];	303	$_[0]->clone
312	$self->{counter} + 0
313	}	304	}
314		305
315	=back	306	=item merge $img ...
		307
		308	Takes any number of images and merges them together, creating a single
		309	image containing them all.
		310
		311	=cut
		312
		313	sub merge(@) {
		314	# rather annoyingly clumsy, but optimisation is for another time
		315
		316	my $x0 = 1e9;
		317	my $y0 = 1e9;
		318	my $x1 = -1e9;
		319	my $y1 = -1e9;
		320
		321	for (@_) {
		322	my ($x, $y, $w, $h) = $_->geometry;
		323
		324	$x0 = $x if $x0 > $x;
		325	$y0 = $y if $y0 > $y;
		326
		327	$x += $w;
		328	$y += $h;
		329
		330	$x1 = $x if $x1 > $x;
		331	$y1 = $y if $y1 > $y;
		332	}
		333
		334	my $base = $self->new_img ($x0, $y0, $x1 - $x0, $y1 - $y0);
		335	$base->fill ([0, 0, 0, 0]);
		336
		337	$base->blend (1., $_)
		338	for @_;
		339
		340	$base
		341	}
316		342
317	=head2 TILING MODES	343	=head2 TILING MODES
318		344
319	The following operators modify the tiling mode of an image, that is, the	345	The following operators modify the tiling mode of an image, that is, the
320	way that pixels outside the image area are painted when the image is used.	346	way that pixels outside the image area are painted when the image is used.
…		…
350	become transparent. This mode is most useful when you want to place an	376	become transparent. This mode is most useful when you want to place an
351	image over another image or the background colour while leaving all	377	image over another image or the background colour while leaving all
352	background pixels outside the image unchanged.	378	background pixels outside the image unchanged.
353		379
354	Example: load an image and display it in the upper left corner. The rest	380	Example: load an image and display it in the upper left corner. The rest
355	of the space is left "empty" (transparent or wahtever your compisotr does	381	of the space is left "empty" (transparent or whatever your compositor does
356	in alpha mode, else background colour).	382	in alpha mode, else background colour).
357		383
358	pad load "mybg.png"	384	pad load "mybg.png"
359		385
360	=item extend $img	386	=item extend $img
361		387
362	Extends the image over the whole plane, using the closest pixel in the	388	Extends the image over the whole plane, using the closest pixel in the
363	area outside the image. This mode is mostly useful when you more complex	389	area outside the image. This mode is mostly useful when you use more complex
364	filtering operations and want the pixels outside the image to have the	390	filtering operations and want the pixels outside the image to have the
365	same values as the pixels near the edge.	391	same values as the pixels near the edge.
366		392
367	Example: just for curiosity, how does this pixel extension stuff work?	393	Example: just for curiosity, how does this pixel extension stuff work?
368		394
…		…
394	$img	420	$img
395	}	421	}
396		422
397	=back	423	=back
398		424
399	=head2 PIXEL OPERATORS	425	=head2 VARIABLE VALUES
400		426
401	The following operators modify the image pixels in various ways.	427	The following functions provide variable data such as the terminal window
		428	dimensions. They are not (Perl-) variables, they just return stuff that
		429	varies. Most of them make your expression sensitive to some events, for
		430	example using C<TW> (terminal width) means your expression is evaluated
		431	again when the terminal is resized.
402		432
403	=over 4	433	=over 4
404		434
405	=item clone $img	435	=item TX
406		436
407	Returns an exact copy of the image.	437	=item TY
408		438
409	=cut	439	Return the X and Y coordinates of the terminal window (the terminal
		440	window is the full window by default, and the character area only when in
		441	border-respect mode).
410		442
		443	Using these functions make your expression sensitive to window moves.
		444
		445	These functions are mainly useful to align images to the root window.
		446
		447	Example: load an image and align it so it looks as if anchored to the
		448	background.
		449
		450	move -TX, -TY, load "mybg.png"
		451
		452	=item TW
		453
		454	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		455	terminal window is the full window by default, and the character area only
		456	when in border-respect mode).
		457
		458	Using these functions make your expression sensitive to window resizes.
		459
		460	These functions are mainly useful to scale images, or to clip images to
		461	the window size to conserve memory.
		462
		463	Example: take the screen background, clip it to the window size, blur it a
		464	bit, align it to the window position and use it as background.
		465
		466	clip move -TX, -TY, once { blur 5, root }
		467
		468	=cut
		469
		470	sub TX() { $new->{again}{position} = 1; $x }
		471	sub TY() { $new->{again}{position} = 1; $y }
		472	sub TW() { $new->{again}{size} = 1; $w }
		473	sub TH() { $new->{again}{size} = 1; $h }
		474
		475	=item now
		476
		477	Returns the current time as (fractional) seconds since the epoch.
		478
		479	Using this expression does I<not> make your expression sensitive to time,
		480	but the next two functions do.
		481
		482	=item again $seconds
		483
		484	When this function is used the expression will be reevaluated again in
		485	C<$seconds> seconds.
		486
		487	Example: load some image and rotate it according to the time of day (as if it were
		488	the hour pointer of a clock). Update this image every minute.
		489
		490	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
		491
		492	=item counter $seconds
		493
		494	Like C<again>, but also returns an increasing counter value, starting at
		495	0, which might be useful for some simple animation effects.
		496
		497	=cut
		498
		499	sub now() { urxvt::NOW }
		500
		501	sub again($) {
		502	$new->{again}{time} = $_[0];
		503	}
		504
411	sub clone($) {	505	sub counter($) {
412	$_[0]->clone	506	$new->{again}{time} = $_[0];
		507	$self->{counter} + 0
413	}	508	}
		509
		510	=back
		511
		512	=head2 SHAPE CHANGING OPERATORS
		513
		514	The following operators modify the shape, size or position of the image.
		515
		516	=over 4
414		517
415	=item clip $img	518	=item clip $img
416		519
417	=item clip $width, $height, $img	520	=item clip $width, $height, $img
418		521
…		…
442	$img->sub_rect ($_[0], $_[1], $w, $h)	545	$img->sub_rect ($_[0], $_[1], $w, $h)
443	}	546	}
444		547
445	=item scale $img	548	=item scale $img
446		549
447	=item scale $size_percent, $img	550	=item scale $size_factor, $img
448		551
449	=item scale $width_percent, $height_percent, $img	552	=item scale $width_factor, $height_factor, $img
450		553
451	Scales the image by the given percentages in horizontal	554	Scales the image by the given factors in horizontal
452	(C<$width_percent>) and vertical (C<$height_percent>) direction.	555	(C<$width>) and vertical (C<$height>) direction.
453		556
454	If only one percentage is give, it is used for both directions.	557	If only one factor is give, it is used for both directions.
455		558
456	If no percentages are given, scales the image to the window size without	559	If no factors are given, scales the image to the window size without
457	keeping aspect.	560	keeping aspect.
458		561
459	=item resize $width, $height, $img	562	=item resize $width, $height, $img
460		563
461	Resizes the image to exactly C<$width> times C<$height> pixels.	564	Resizes the image to exactly C<$width> times C<$height> pixels.
462		565
463	=cut	566	=item fit $img
464		567
465	#TODO: maximise, maximise_fill?	568	=item fit $width, $height, $img
		569
		570	Fits the image into the given C<$width> and C<$height> without changing
		571	aspect, or the terminal size. That means it will be shrunk or grown until
		572	the whole image fits into the given area, possibly leaving borders.
		573
		574	=item cover $img
		575
		576	=item cover $width, $height, $img
		577
		578	Similar to C<fit>, but shrinks or grows until all of the area is covered
		579	by the image, so instead of potentially leaving borders, it will cut off
		580	image data that doesn't fit.
		581
		582	=cut
466		583
467	sub scale($;$;$) {	584	sub scale($;$;$) {
468	my $img = pop;	585	my $img = pop;
469		586
470	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	587	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
471	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	588	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
472	: $img->scale (TW, TH)	589	: $img->scale (TW, TH)
473	}	590	}
474		591
475	sub resize($$$) {	592	sub resize($$$) {
476	my $img = pop;	593	my $img = pop;
477	$img->scale ($_[0], $_[1])	594	$img->scale ($_[0], $_[1])
		595	}
		596
		597	sub fit($;$$) {
		598	my $img = pop;
		599	my $w = ($_[0] \|\| TW) / $img->w;
		600	my $h = ($_[1] \|\| TH) / $img->h;
		601	scale +(min $w, $h), $img
		602	}
		603
		604	sub cover($;$$) {
		605	my $img = pop;
		606	my $w = ($_[0] \|\| TW) / $img->w;
		607	my $h = ($_[1] \|\| TH) / $img->h;
		608	scale +(max $w, $h), $img
478	}	609	}
479		610
480	=item move $dx, $dy, $img	611	=item move $dx, $dy, $img
481		612
482	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	613	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
483	the vertical.	614	the vertical.
484		615
485	Example: move the image right by 20 pixels and down by 30.	616	Example: move the image right by 20 pixels and down by 30.
486		617
487	move 20, 30, ...	618	move 20, 30, ...
		619
		620	=item align $xalign, $yalign, $img
		621
		622	Aligns the image according to a factor - C<0> means the image is moved to
		623	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		624	exactly centered and C<1> means it touches the right or bottom edge.
		625
		626	Example: remove any visible border around an image, center it vertically but move
		627	it to the right hand side.
		628
		629	align 1, 0.5, pad $img
		630
		631	=item center $img
		632
		633	=item center $width, $height, $img
		634
		635	Centers the image, i.e. the center of the image is moved to the center of
		636	the terminal window (or the box specified by C<$width> and C<$height> if
		637	given).
		638
		639	Example: load an image and center it.
		640
		641	center pad load "mybg.png"
488		642
489	=item rootalign $img	643	=item rootalign $img
490		644
491	Moves the image so that it appears glued to the screen as opposed to the	645	Moves the image so that it appears glued to the screen as opposed to the
492	window. This gives the illusion of a larger area behind the window. It is	646	window. This gives the illusion of a larger area behind the window. It is
…		…
498	rootalign mirror load "mybg.png"	652	rootalign mirror load "mybg.png"
499		653
500	Example: take the screen background and align it, giving the illusion of	654	Example: take the screen background and align it, giving the illusion of
501	transparency as long as the window isn't in front of other windows.	655	transparency as long as the window isn't in front of other windows.
502		656
503	rootalign root	657	rootalign root
504		658
505	=cut	659	=cut
506		660
507	sub move($$;$) {	661	sub move($$;$) {
508	my $img = pop->clone;	662	my $img = pop->clone;
509	$img->move ($_[0], $_[1]);	663	$img->move ($_[0], $_[1]);
510	$img	664	$img
511	}	665	}
512		666
		667	sub align($;$$) {
		668	my $img = pop;
		669
		670	move $_[0] * (TW - $img->w),
		671	$_[1] * (TH - $img->h),
		672	$img
		673	}
		674
		675	sub center($;$$) {
		676	my $img = pop;
		677	my $w = $_[0] \|\| TW;
		678	my $h = $_[1] \|\| TH;
		679
		680	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		681	}
		682
513	sub rootalign($) {	683	sub rootalign($) {
514	move -TX, -TY, $_[0]	684	move -TX, -TY, $_[0]
515	}	685	}
516		686
		687	=item rotate $center_x, $center_y, $degrees
		688
		689	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		690	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		691	width/height).
		692
		693	#TODO# new width, height, maybe more operators?
		694
		695	Example: rotate the image by 90 degrees
		696
		697	=cut
		698
		699	sub rotate($$$$) {
		700	my $img = pop;
		701	$img->rotate (
		702	$_[0] * $img->w,
		703	$_[1] * $img->h,
		704	$_[2] * (3.14159265 / 180),
		705	)
		706	}
		707
		708	=back
		709
		710	=head2 COLOUR MODIFICATIONS
		711
		712	The following operators change the pixels of the image.
		713
		714	=over 4
		715
517	=item contrast $factor, $img	716	=item contrast $factor, $img
518		717
519	=item contrast $r, $g, $b, $img	718	=item contrast $r, $g, $b, $img
520		719
521	=item contrast $r, $g, $b, $a, $img	720	=item contrast $r, $g, $b, $a, $img
522		721
523	Adjusts the I<contrast> of an image.	722	Adjusts the I<contrast> of an image.
524		723
525	#TODO#	724	The first form applies a single C<$factor> to red, green and blue, the
		725	second form applies separate factors to each colour channel, and the last
		726	form includes the alpha channel.
526		727
		728	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		729	contrast.
		730
		731	Due to limitations in the underlying XRender extension, lowering contrast
		732	also reduces brightness, while increasing contrast currently also
		733	increases brightness.
		734
527	=item brightness $factor, $img	735	=item brightness $bias, $img
528		736
529	=item brightness $r, $g, $b, $img	737	=item brightness $r, $g, $b, $img
530		738
531	=item brightness $r, $g, $b, $a, $img	739	=item brightness $r, $g, $b, $a, $img
532		740
533	Adjusts the brightness of an image.	741	Adjusts the brightness of an image.
534		742
		743	The first form applies a single C<$bias> to red, green and blue, the
		744	second form applies separate biases to each colour channel, and the last
		745	form includes the alpha channel.
		746
		747	Values less than 0 reduce brightness, while values larger than 0 increase
		748	it. Useful range is from -1 to 1 - the former results in a black, the
		749	latter in a white picture.
		750
		751	Due to idiosyncrasies in the underlying XRender extension, biases less
		752	than zero can be I<very> slow.
		753
535	=cut	754	=cut
536		755
537	sub contrast($$;$$;$) {	756	sub contrast($$;$$;$) {
538	my $img = pop;	757	my $img = pop;
539	my ($r, $g, $b, $a) = @_;	758	my ($r, $g, $b, $a) = @_;
540		759
541	($g, $b) = ($r, $r) if @_ < 4;	760	($g, $b) = ($r, $r) if @_ < 3;
542	$a = 1 if @_ < 5;	761	$a = 1 if @_ < 4;
543		762
544	$img = $img->clone;	763	$img = $img->clone;
545	$img->contrast ($r, $g, $b, $a);	764	$img->contrast ($r, $g, $b, $a);
546	$img	765	$img
547	}	766	}
548		767
549	sub brightness($$;$$;$) {	768	sub brightness($$;$$;$) {
550	my $img = pop;	769	my $img = pop;
551	my ($r, $g, $b, $a) = @_;	770	my ($r, $g, $b, $a) = @_;
552		771
553	($g, $b) = ($r, $r) if @_ < 4;	772	($g, $b) = ($r, $r) if @_ < 3;
554	$a = 1 if @_ < 5;	773	$a = 1 if @_ < 4;
555		774
556	$img = $img->clone;	775	$img = $img->clone;
557	$img->brightness ($r, $g, $b, $a);	776	$img->brightness ($r, $g, $b, $a);
558	$img	777	$img
559	}	778	}
…		…
563	=item blur $radius_horz, $radius_vert, $img	782	=item blur $radius_horz, $radius_vert, $img
564		783
565	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii	784	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
566	can also be specified separately.	785	can also be specified separately.
567		786
		787	Blurring is often I<very> slow, at least compared or other
		788	operators. Larger blur radii are slower than smaller ones, too, so if you
		789	don't want to freeze your screen for long times, start experimenting with
		790	low values for radius (<5).
		791
568	=cut	792	=cut
569		793
570	sub blur($$;$) {	794	sub blur($$;$) {
571	my $img = pop;	795	my $img = pop;
572	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	796	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
573	}	797	}
574		798
575	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees	799	=back
576		800
577	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	801	=head2 OTHER STUFF
578	pointer at C<$center_x> and C<$center_y> (specified as percentage of image
579	width/height), generating a new image with width C<$new_width> and height
580	C<$new_height>.
581		802
582	#TODO# new width, height, maybe more operators?	803	Anything that didn't fit any of the other categories, even after applying
		804	force and closing our eyes.
583		805
584	Example: rotate the image by 90 degrees	806	=over 4
585		807
586	=cut	808	=item once { ... }
587		809
588	sub rotate($$$$$$) {	810	This function takes a code block as argument, that is, one or more
589	my $img = pop;	811	statements enclosed by braces.
590	$img->rotate (	812
591	$_[0],	813	The trick is that this code block is only evaluated once - future calls
592	$_[1],	814	will simply return the original image (yes, it should only be used with
593	$_[2] * $img->w * .01,	815	images).
594	$_[3] * $img->h * .01,	816
595	$_[4] * (3.14159265 / 180),	817	This can be extremely useful to avoid redoign the same slow operations
		818	again and again- for example, if your background expression takes the root
		819	background, blurs it and then root-aligns it it would have to blur the
		820	root background on every window move or resize.
		821
		822	Putting the blur into a C<once> block will make sure the blur is only done
		823	once:
		824
		825	rootlign once { blur 10, root }
		826
		827	This leaves the question of how to force reevaluation of the block, in
		828	case the root background changes: Right now, all once blocks forget that
		829	they ahve been executed before each time the root background changes (if
		830	the expression is sensitive to that) or when C<once_again> is called.
		831
		832	=item once_again
		833
		834	Resets all C<once> block as if they had never been called, i.e. on the
		835	next call they will be reevaluated again.
		836
		837	=cut
		838
		839	sub once(&) {
		840	my $once = $self->{once_cache}{$_[0]+0} \|\|= do {
		841	local $new->{again};
		842	my @res = $_[0]();
		843	[$new->{again}, \@res]
596	)	844	};
		845
		846	$new->{again} = {
		847	%{ $new->{again} },
		848	%{ $once->[0] }
		849	};
		850
		851	# in scalar context we always return the first original result, which
		852	# is not quite how perl works.
		853	wantarray
		854	? @{ $once->[1] }
		855	: $once->[1][0]
		856	}
		857
		858	sub once_again() {
		859	delete $self->{once_cache};
597	}	860	}
598		861
599	=back	862	=back
600		863
601	=cut	864	=cut
…		…
644		907
645	# evaluate user expression	908	# evaluate user expression
646		909
647	my $img = eval { $self->{expr}->() };	910	my $img = eval { $self->{expr}->() };
648	warn $@ if $@;#d#	911	warn $@ if $@;#d#
649	die if !UNIVERSAL::isa $img, "urxvt::img";	912	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
650		913
651	$state->{size_sensitive} = 1	914	# if the expression is sensitive to external events, prepare reevaluation then
		915
		916	my $again = delete $state->{again};
		917
		918	$again->{size} = 1
652	if $img->repeat_mode != urxvt::RepeatNormal;	919	if $img->repeat_mode != urxvt::RepeatNormal;
653		920
654	# if the expression is sensitive to external events, prepare reevaluation then
655
656	my $repeat;
657
658	if (my $again = $state->{again}) {	921	if (my $again = $again->{time}) {
659	$repeat = 1;
660	my $self = $self;	922	my $self = $self;
661	$state->{timer} = $again == $old->{again}	923	$state->{timer} = $again == $old->{again}
662	? $old->{timer}	924	? $old->{timer}
663	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {	925	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
664	++$self->{counter};	926	++$self->{counter};
665	$self->recalculate	927	$self->recalculate
666	});	928	});
667	}	929	}
668		930
669	if (delete $state->{position_sensitive}) {	931	if ($again->{position}) {
670	$repeat = 1;
671	$self->enable (position_change => sub { $_[0]->recalculate });	932	$self->enable (position_change => sub { $_[0]->recalculate });
672	} else {	933	} else {
673	$self->disable ("position_change");	934	$self->disable ("position_change");
674	}	935	}
675		936
676	if (delete $state->{size_sensitive}) {	937	if ($again->{size}) {
677	$repeat = 1;
678	$self->enable (size_change => sub { $_[0]->recalculate });	938	$self->enable (size_change => sub { $_[0]->recalculate });
679	} else {	939	} else {
680	$self->disable ("size_change");	940	$self->disable ("size_change");
681	}	941	}
682		942
683	if (delete $state->{rootpmap_sensitive}) {	943	if ($again->{rootpmap}) {
684	$repeat = 1;
685	$self->enable (rootpmap_change => sub { $_[0]->recalculate });	944	$self->enable (rootpmap_change => sub {
		945	delete $_[0]{once_cache}; # this will override once-block values from
		946	$_[0]->recalculate;
		947	});
686	} else {	948	} else {
687	$self->disable ("rootpmap_change");	949	$self->disable ("rootpmap_change");
688	}	950	}
689		951
690	# clear stuff we no longer need	952	# clear stuff we no longer need
691		953
692	%$old = ();	954	%$old = ();
693		955
694	unless ($repeat) {	956	unless (%$again) {
695	delete $self->{state};	957	delete $self->{state};
696	delete $self->{expr};	958	delete $self->{expr};
697	}	959	}
698		960
699	# set background pixmap	961	# set background pixmap
…		…
704	}	966	}
705		967
706	sub on_start {	968	sub on_start {
707	my ($self) = @_;	969	my ($self) = @_;
708		970
709	my $expr = $self->x_resource ("background.expr")	971	my $expr = $self->x_resource ("%.expr")
710	or return;	972	or return;
711		973
		974	$self->has_render
		975	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		976
712	$self->set_expr (parse_expr $expr);	977	$self->set_expr (parse_expr $expr);
713	$self->{border} = $self->x_resource_boolean ("background.border");	978	$self->{border} = $self->x_resource_boolean ("%.border");
		979
		980	$MIN_INTERVAL = $self->x_resource ("%.interval");
714		981
715	()	982	()
716	}	983	}
717		984

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.38 by root, Fri Jun 8 21:48:07 2012 UTC vs. Revision 1.58 by root, Thu Jun 14 18:13:19 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.38 by root, Fri Jun 8 21:48:07 2012 UTC vs.
Revision 1.58 by root, Thu Jun 14 18:13:19 2012 UTC