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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.40 by root, Fri Jun 8 22:19:21 2012 UTC vs.
Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC

…		…
1	#! perl	1	#! perl
2		2
3	#:META:X_RESOURCE:%.expr:string:background expression	3	#:META:X_RESOURCE:%.expr:string:background expression
4	#:META:X_RESOURCE:%.border.:boolean:respect the terminal border	4	#:META:X_RESOURCE:%.border:boolean:respect the terminal border
		5	#: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
…		…
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	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
118	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:
119		122
120	tile load "$HOME/mypic.png"	123	tile load "$HOME/mypic.png"
121		124
122	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
…		…
133	It first takes a snapshot of the screen background image, and then	136	It first takes a snapshot of the screen background image, and then
134	moves it to the upper left corner of the screen - the result is	137	moves it to the upper left corner of the screen - the result is
135	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
136	moved around.	139	moved around.
137		140
138	=head3 CYCLES AND CACHING	141	=head2 CYCLES AND CACHING
139		142
140	As has been mentioned before, the expression might be evaluated multiple	143	As has been mentioned before, the expression might be evaluated multiple
141	times. Each time the expression is reevaluated, a new cycle is said to	144	times. Each time the expression is reevaluated, a new cycle is said to
142	have begun. Many operators cache their results till the next cycle.	145	have begun. Many operators cache their results till the next cycle.
143		146
…		…
148	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
149	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
150	image, it will forget about the first one.	153	image, it will forget about the first one.
151		154
152	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
153	memory, or comserve memory by loading images more often.	156	memory, or conserve memory by loading images more often.
154		157
155	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
156	this:	159	this:
157		160
158	my $img1 = load "img1.png";	161	my $img1 = load "img1.png";
…		…
168		171
169	Here, a path is selected randomly, and load is only called for one image,	172	Here, a path is selected randomly, and load is only called for one image,
170	so keeps only one image in memory. If, on the next evaluation, luck	173	so keeps only one image in memory. If, on the next evaluation, luck
171	decides to use the other path, then it will have to load that image again.	174	decides to use the other path, then it will have to load that image again.
172		175
173	=head2 REFERENCE	176	=head1 REFERENCE
174		177
175	=head3 COMMAND LINE SWITCHES	178	=head2 COMMAND LINE SWITCHES
176		179
177	=over 4	180	=over 4
178		181
179	=item --background-expr perl-expression	182	=item --background-expr perl-expression
180		183
…		…
186	overwriting borders and any other areas, such as the scrollbar.	189	overwriting borders and any other areas, such as the scrollbar.
187		190
188	Specifying this flag changes the behaviour, so that the image only	191	Specifying this flag changes the behaviour, so that the image only
189	replaces the background of the character area.	192	replaces the background of the character area.
190		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
191	=back	203	=back
192		204
193	=cut	205	=cut
194		206
		207	our %_IMG_CACHE;
		208	our %_ONCE_CACHE;
195	our $HOME;	209	our $HOME;
196	our ($self, $old, $new);	210	our ($self, $old, $new);
197	our ($x, $y, $w, $h);	211	our ($x, $y, $w, $h);
198		212
199	# enforce at least this interval between updates	213	# enforce at least this interval between updates
200	our $MIN_INTERVAL = 1/100;	214	our $MIN_INTERVAL = 6/59.951;
201		215
202	{	216	{
203	package urxvt::bgdsl; # background language	217	package urxvt::bgdsl; # background language
		218
		219	use List::Util qw(min max sum shuffle);
204		220
205	=head2 PROVIDERS/GENERATORS	221	=head2 PROVIDERS/GENERATORS
206		222
207	These functions provide an image, by loading it from disk, grabbing it	223	These functions provide an image, by loading it from disk, grabbing it
208	from the root screen or by simply generating it. They are used as starting	224	from the root screen or by simply generating it. They are used as starting
…		…
213	=item load $path	229	=item load $path
214		230
215	Loads the image at the given C<$path>. The image is set to plane tiling	231	Loads the image at the given C<$path>. The image is set to plane tiling
216	mode.	232	mode.
217		233
218	Loaded images will be cached for one cycle.	234	Loaded images will be cached for one cycle, and shared between temrinals
		235	running in the same process (e.g. in C<urxvtd>).
219		236
		237	=item load_uc $path
		238
		239	Load uncached - same as load, but does not cache the image. This function
		240	is most useufl if you want to optimise a background expression in some
		241	way.
		242
220	=cut	243	=cut
		244
		245	sub load_uc($) {
		246	my ($path) = @_;
		247
		248	$_IMG_CACHE{$path} \|\| do {
		249	my $img = $self->new_img_from_file ($path);
		250	Scalar::Util::weaken ($_IMG_CACHE{$path} = $img);
		251	$img
		252	}
		253	}
221		254
222	sub load($) {	255	sub load($) {
223	my ($path) = @_;	256	my ($path) = @_;
224		257
225	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);	258	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
226	}	259	}
227		260
228	=item root	261	=item root
229		262
230	Returns the root window pixmap, that is, hopefully, the background image	263	Returns the root window pixmap, that is, hopefully, the background image
…		…
235		268
236	=cut	269	=cut
237		270
238	sub root() {	271	sub root() {
239	$new->{rootpmap_sensitive} = 1;	272	$new->{rootpmap_sensitive} = 1;
240	die "root op not supported, exg, we need you";	273	$self->new_img_from_root
241	}	274	}
242		275
243	=item solid $colour	276	=item solid $colour
244		277
245	=item solid $width, $height, $colour	278	=item solid $width, $height, $colour
…		…
250	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is	283	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
251	useful for solid backgrounds or for use in filtering effects.	284	useful for solid backgrounds or for use in filtering effects.
252		285
253	=cut	286	=cut
254		287
255	sub solid($$;$) {	288	sub solid($;$$) {
256	my $colour = pop;	289	my $colour = pop;
257		290
258	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);	291	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);
259	$img->fill ($colour);	292	$img->fill ($colour);
260	$img	293	$img
261	}	294	}
262		295
		296	=item clone $img
		297
		298	Returns an exact copy of the image. This is useful if you want to have
		299	multiple copies of the same image to apply different effects to.
		300
		301	=cut
		302
		303	sub clone($) {
		304	$_[0]->clone
		305	}
		306
		307	=head2 TILING MODES
		308
		309	The following operators modify the tiling mode of an image, that is, the
		310	way that pixels outside the image area are painted when the image is used.
		311
		312	=over 4
		313
		314	=item tile $img
		315
		316	Tiles the whole plane with the image and returns this new image - or in
		317	other words, it returns a copy of the image in plane tiling mode.
		318
		319	Example: load an image and tile it over the background, without
		320	resizing. The C<tile> call is superfluous because C<load> already defaults
		321	to tiling mode.
		322
		323	tile load "mybg.png"
		324
		325	=item mirror $img
		326
		327	Similar to tile, but reflects the image each time it uses a new copy, so
		328	that top edges always touch top edges, right edges always touch right
		329	edges and so on (with normal tiling, left edges always touch right edges
		330	and top always touch bottom edges).
		331
		332	Example: load an image and mirror it over the background, avoiding sharp
		333	edges at the image borders at the expense of mirroring the image itself
		334
		335	mirror load "mybg.png"
		336
		337	=item pad $img
		338
		339	Takes an image and modifies it so that all pixels outside the image area
		340	become transparent. This mode is most useful when you want to place an
		341	image over another image or the background colour while leaving all
		342	background pixels outside the image unchanged.
		343
		344	Example: load an image and display it in the upper left corner. The rest
		345	of the space is left "empty" (transparent or whatever your compositor does
		346	in alpha mode, else background colour).
		347
		348	pad load "mybg.png"
		349
		350	=item extend $img
		351
		352	Extends the image over the whole plane, using the closest pixel in the
		353	area outside the image. This mode is mostly useful when you use more complex
		354	filtering operations and want the pixels outside the image to have the
		355	same values as the pixels near the edge.
		356
		357	Example: just for curiosity, how does this pixel extension stuff work?
		358
		359	extend move 50, 50, load "mybg.png"
		360
		361	=cut
		362
		363	sub pad($) {
		364	my $img = $_[0]->clone;
		365	$img->repeat_mode (urxvt::RepeatNone);
		366	$img
		367	}
		368
		369	sub tile($) {
		370	my $img = $_[0]->clone;
		371	$img->repeat_mode (urxvt::RepeatNormal);
		372	$img
		373	}
		374
		375	sub mirror($) {
		376	my $img = $_[0]->clone;
		377	$img->repeat_mode (urxvt::RepeatReflect);
		378	$img
		379	}
		380
		381	sub extend($) {
		382	my $img = $_[0]->clone;
		383	$img->repeat_mode (urxvt::RepeatPad);
		384	$img
		385	}
		386
263	=back	387	=back
264		388
265	=head2 VARIABLES	389	=head2 VARIABLE VALUES
266		390
267	The following functions provide variable data such as the terminal	391	The following functions provide variable data such as the terminal window
		392	dimensions. They are not (Perl-) variables, they just return stuff that
268	window dimensions. Most of them make your expression sensitive to some	393	varies. Most of them make your expression sensitive to some events, for
269	events, for example using C<TW> (terminal width) means your expression is	394	example using C<TW> (terminal width) means your expression is evaluated
270	evaluated again when the terminal is resized.	395	again when the terminal is resized.
271		396
272	=over 4	397	=over 4
273		398
274	=item TX	399	=item TX
275		400
…		…
324	C<$seconds> seconds.	449	C<$seconds> seconds.
325		450
326	Example: load some image and rotate it according to the time of day (as if it were	451	Example: load some image and rotate it according to the time of day (as if it were
327	the hour pointer of a clock). Update this image every minute.	452	the hour pointer of a clock). Update this image every minute.
328		453
329	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"	454	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
330		455
331	=item counter $seconds	456	=item counter $seconds
332		457
333	Like C<again>, but also returns an increasing counter value, starting at	458	Like C<again>, but also returns an increasing counter value, starting at
334	0, which might be useful for some simple animation effects.	459	0, which might be useful for some simple animation effects.
…		…
346	$self->{counter} + 0	471	$self->{counter} + 0
347	}	472	}
348		473
349	=back	474	=back
350		475
351	=head2 TILING MODES	476	=head2 SHAPE CHANGING OPERATORS
352		477
353	The following operators modify the tiling mode of an image, that is, the	478	The following operators modify the shape, size or position of the image.
354	way that pixels outside the image area are painted when the image is used.
355		479
356	=over 4	480	=over 4
357
358	=item tile $img
359
360	Tiles the whole plane with the image and returns this new image - or in
361	other words, it returns a copy of the image in plane tiling mode.
362
363	Example: load an image and tile it over the background, without
364	resizing. The C<tile> call is superfluous because C<load> already defaults
365	to tiling mode.
366
367	tile load "mybg.png"
368
369	=item mirror $img
370
371	Similar to tile, but reflects the image each time it uses a new copy, so
372	that top edges always touch top edges, right edges always touch right
373	edges and so on (with normal tiling, left edges always touch right edges
374	and top always touch bottom edges).
375
376	Example: load an image and mirror it over the background, avoiding sharp
377	edges at the image borders at the expense of mirroring the image itself
378
379	mirror load "mybg.png"
380
381	=item pad $img
382
383	Takes an image and modifies it so that all pixels outside the image area
384	become transparent. This mode is most useful when you want to place an
385	image over another image or the background colour while leaving all
386	background pixels outside the image unchanged.
387
388	Example: load an image and display it in the upper left corner. The rest
389	of the space is left "empty" (transparent or wahtever your compisotr does
390	in alpha mode, else background colour).
391
392	pad load "mybg.png"
393
394	=item extend $img
395
396	Extends the image over the whole plane, using the closest pixel in the
397	area outside the image. This mode is mostly useful when you more complex
398	filtering operations and want the pixels outside the image to have the
399	same values as the pixels near the edge.
400
401	Example: just for curiosity, how does this pixel extension stuff work?
402
403	extend move 50, 50, load "mybg.png"
404
405	=cut
406
407	sub pad($) {
408	my $img = $_[0]->clone;
409	$img->repeat_mode (urxvt::RepeatNone);
410	$img
411	}
412
413	sub tile($) {
414	my $img = $_[0]->clone;
415	$img->repeat_mode (urxvt::RepeatNormal);
416	$img
417	}
418
419	sub mirror($) {
420	my $img = $_[0]->clone;
421	$img->repeat_mode (urxvt::RepeatReflect);
422	$img
423	}
424
425	sub extend($) {
426	my $img = $_[0]->clone;
427	$img->repeat_mode (urxvt::RepeatPad);
428	$img
429	}
430
431	=back
432
433	=head2 PIXEL OPERATORS
434
435	The following operators modify the image pixels in various ways.
436
437	=over 4
438
439	=item clone $img
440
441	Returns an exact copy of the image.
442
443	=cut
444
445	sub clone($) {
446	$_[0]->clone
447	}
448		481
449	=item clip $img	482	=item clip $img
450		483
451	=item clip $width, $height, $img	484	=item clip $width, $height, $img
452		485
…		…
476	$img->sub_rect ($_[0], $_[1], $w, $h)	509	$img->sub_rect ($_[0], $_[1], $w, $h)
477	}	510	}
478		511
479	=item scale $img	512	=item scale $img
480		513
481	=item scale $size_percent, $img	514	=item scale $size_factor, $img
482		515
483	=item scale $width_percent, $height_percent, $img	516	=item scale $width_factor, $height_factor, $img
484		517
485	Scales the image by the given percentages in horizontal	518	Scales the image by the given factors in horizontal
486	(C<$width_percent>) and vertical (C<$height_percent>) direction.	519	(C<$width>) and vertical (C<$height>) direction.
487		520
488	If only one percentage is give, it is used for both directions.	521	If only one factor is give, it is used for both directions.
489		522
490	If no percentages are given, scales the image to the window size without	523	If no factors are given, scales the image to the window size without
491	keeping aspect.	524	keeping aspect.
492		525
493	=item resize $width, $height, $img	526	=item resize $width, $height, $img
494		527
495	Resizes the image to exactly C<$width> times C<$height> pixels.	528	Resizes the image to exactly C<$width> times C<$height> pixels.
496		529
497	=cut	530	=item fit $img
498		531
499	#TODO: maximise, maximise_fill?	532	=item fit $width, $height, $img
		533
		534	Fits the image into the given C<$width> and C<$height> without changing
		535	aspect, or the terminal size. That means it will be shrunk or grown until
		536	the whole image fits into the given area, possibly leaving borders.
		537
		538	=item cover $img
		539
		540	=item cover $width, $height, $img
		541
		542	Similar to C<fit>, but shrinks or grows until all of the area is covered
		543	by the image, so instead of potentially leaving borders, it will cut off
		544	image data that doesn't fit.
		545
		546	=cut
500		547
501	sub scale($;$;$) {	548	sub scale($;$;$) {
502	my $img = pop;	549	my $img = pop;
503		550
504	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	551	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
505	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	552	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
506	: $img->scale (TW, TH)	553	: $img->scale (TW, TH)
507	}	554	}
508		555
509	sub resize($$$) {	556	sub resize($$$) {
510	my $img = pop;	557	my $img = pop;
511	$img->scale ($_[0], $_[1])	558	$img->scale ($_[0], $_[1])
		559	}
		560
		561	sub fit($;$$) {
		562	my $img = pop;
		563	my $w = ($_[0] \|\| TW) / $img->w;
		564	my $h = ($_[1] \|\| TH) / $img->h;
		565	scale +(min $w, $h), $img
		566	}
		567
		568	sub cover($;$$) {
		569	my $img = pop;
		570	my $w = ($_[0] \|\| TW) / $img->w;
		571	my $h = ($_[1] \|\| TH) / $img->h;
		572	scale +(max $w, $h), $img
512	}	573	}
513		574
514	=item move $dx, $dy, $img	575	=item move $dx, $dy, $img
515		576
516	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in	577	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
517	the vertical.	578	the vertical.
518		579
519	Example: move the image right by 20 pixels and down by 30.	580	Example: move the image right by 20 pixels and down by 30.
520		581
521	move 20, 30, ...	582	move 20, 30, ...
		583
		584	=item align $xalign, $yalign, $img
		585
		586	Aligns the image according to a factor - C<0> means the image is moved to
		587	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		588	exactly centered and C<1> means it touches the right or bottom edge.
		589
		590	Example: remove any visible border around an image, center it vertically but move
		591	it to the right hand side.
		592
		593	align 1, 0.5, pad $img
		594
		595	=item center $img
		596
		597	=item center $width, $height, $img
		598
		599	Centers the image, i.e. the center of the image is moved to the center of
		600	the terminal window (or the box specified by C<$width> and C<$height> if
		601	given).
		602
		603	Example: load an image and center it.
		604
		605	center pad load "mybg.png"
522		606
523	=item rootalign $img	607	=item rootalign $img
524		608
525	Moves the image so that it appears glued to the screen as opposed to the	609	Moves the image so that it appears glued to the screen as opposed to the
526	window. This gives the illusion of a larger area behind the window. It is	610	window. This gives the illusion of a larger area behind the window. It is
…		…
532	rootalign mirror load "mybg.png"	616	rootalign mirror load "mybg.png"
533		617
534	Example: take the screen background and align it, giving the illusion of	618	Example: take the screen background and align it, giving the illusion of
535	transparency as long as the window isn't in front of other windows.	619	transparency as long as the window isn't in front of other windows.
536		620
537	rootalign root	621	rootalign root
538		622
539	=cut	623	=cut
540		624
541	sub move($$;$) {	625	sub move($$;$) {
542	my $img = pop->clone;	626	my $img = pop->clone;
543	$img->move ($_[0], $_[1]);	627	$img->move ($_[0], $_[1]);
544	$img	628	$img
545	}	629	}
546		630
		631	sub align($;$$) {
		632	my $img = pop;
		633
		634	move $_[0] * (TW - $img->w),
		635	$_[1] * (TH - $img->h),
		636	$img
		637	}
		638
		639	sub center($;$$) {
		640	my $img = pop;
		641	my $w = $_[0] \|\| TW;
		642	my $h = $_[1] \|\| TH;
		643
		644	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		645	}
		646
547	sub rootalign($) {	647	sub rootalign($) {
548	move -TX, -TY, $_[0]	648	move -TX, -TY, $_[0]
549	}	649	}
550		650
		651	=item rotate $center_x, $center_y, $degrees
		652
		653	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		654	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		655	width/height).
		656
		657	#TODO# new width, height, maybe more operators?
		658
		659	Example: rotate the image by 90 degrees
		660
		661	=cut
		662
		663	sub rotate($$$$) {
		664	my $img = pop;
		665	$img->rotate (
		666	$_[0] * $img->w,
		667	$_[1] * $img->h,
		668	$_[2] * (3.14159265 / 180),
		669	)
		670	}
		671
		672	=back
		673
		674	=head2 COLOUR MODIFICATIONS
		675
		676	The following operators change the pixels of the image.
		677
		678	=over 4
		679
551	=item contrast $factor, $img	680	=item contrast $factor, $img
552		681
553	=item contrast $r, $g, $b, $img	682	=item contrast $r, $g, $b, $img
554		683
555	=item contrast $r, $g, $b, $a, $img	684	=item contrast $r, $g, $b, $a, $img
556		685
557	Adjusts the I<contrast> of an image.	686	Adjusts the I<contrast> of an image.
558		687
559	#TODO#	688	The first form applies a single C<$factor> to red, green and blue, the
		689	second form applies separate factors to each colour channel, and the last
		690	form includes the alpha channel.
560		691
		692	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		693	contrast.
		694
		695	Due to limitations in the underlying XRender extension, lowering contrast
		696	also reduces brightness, while increasing contrast currently also
		697	increases brightness.
		698
561	=item brightness $factor, $img	699	=item brightness $bias, $img
562		700
563	=item brightness $r, $g, $b, $img	701	=item brightness $r, $g, $b, $img
564		702
565	=item brightness $r, $g, $b, $a, $img	703	=item brightness $r, $g, $b, $a, $img
566		704
567	Adjusts the brightness of an image.	705	Adjusts the brightness of an image.
568		706
		707	The first form applies a single C<$bias> to red, green and blue, the
		708	second form applies separate biases to each colour channel, and the last
		709	form includes the alpha channel.
		710
		711	Values less than 0 reduce brightness, while values larger than 0 increase
		712	it. Useful range is from -1 to 1 - the former results in a black, the
		713	latter in a white picture.
		714
		715	Due to idiosyncrasies in the underlying XRender extension, biases less
		716	than zero can be I<very> slow.
		717
569	=cut	718	=cut
570		719
571	sub contrast($$;$$;$) {	720	sub contrast($$;$$;$) {
572	my $img = pop;	721	my $img = pop;
573	my ($r, $g, $b, $a) = @_;	722	my ($r, $g, $b, $a) = @_;
574		723
575	($g, $b) = ($r, $r) if @_ < 4;	724	($g, $b) = ($r, $r) if @_ < 3;
576	$a = 1 if @_ < 5;	725	$a = 1 if @_ < 4;
577		726
578	$img = $img->clone;	727	$img = $img->clone;
579	$img->contrast ($r, $g, $b, $a);	728	$img->contrast ($r, $g, $b, $a);
580	$img	729	$img
581	}	730	}
582		731
583	sub brightness($$;$$;$) {	732	sub brightness($$;$$;$) {
584	my $img = pop;	733	my $img = pop;
585	my ($r, $g, $b, $a) = @_;	734	my ($r, $g, $b, $a) = @_;
586		735
587	($g, $b) = ($r, $r) if @_ < 4;	736	($g, $b) = ($r, $r) if @_ < 3;
588	$a = 1 if @_ < 5;	737	$a = 1 if @_ < 4;
589		738
590	$img = $img->clone;	739	$img = $img->clone;
591	$img->brightness ($r, $g, $b, $a);	740	$img->brightness ($r, $g, $b, $a);
592	$img	741	$img
593	}	742	}
…		…
609	sub blur($$;$) {	758	sub blur($$;$) {
610	my $img = pop;	759	my $img = pop;
611	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])	760	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
612	}	761	}
613		762
614	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees	763	=back
615		764
616	Rotates the image by C<$degrees> degrees, counter-clockwise, around the	765	=head2 OTHER STUFF
617	pointer at C<$center_x> and C<$center_y> (specified as percentage of image
618	width/height), generating a new image with width C<$new_width> and height
619	C<$new_height>.
620		766
621	#TODO# new width, height, maybe more operators?	767	Anything that didn't fit any of the other categories, even after appliyng
		768	force and closing our eyes.
622		769
623	Example: rotate the image by 90 degrees	770	=over 4
624		771
625	=cut	772	=item once { ... }
626		773
627	sub rotate($$$$$$) {	774	This function takes a code block as argument, that is, one or more
628	my $img = pop;	775	statements enclosed by braces.
629	$img->rotate (	776
630	$_[0],	777	The trick is that this code block is only evaluated once - future calls
631	$_[1],	778	will simply return the original image (yes, it should only be used with
632	$_[2] * $img->w * .01,	779	images).
633	$_[3] * $img->h * .01,	780
634	$_[4] * (3.14159265 / 180),	781	This can be extremely useful to avoid redoign the same slow operations
635	)	782	again and again- for example, if your background expression takes the root
		783	background, blurs it and then root-aligns it it would have to blur the
		784	root background on every window move or resize.
		785
		786	Putting the blur into a C<once> block will make sure the blur is only done
		787	once:
		788
		789	rootlign once { blur 10, root }
		790
		791	This leaves the question of how to force reevaluation of the block, in
		792	case the root background changes: Right now, all once blocks forget that
		793	they ahve been executed before each time the root background changes (if
		794	the expression is sensitive to that) or when C<once_again> is called.
		795
		796	=item once_again
		797
		798	Resets all C<once> block as if they had never been called, i.e. on the
		799	next call they will be reevaluated again.
		800
		801	=cut
		802
		803	sub once(&) {
		804	$_ONCE_CACHE{$_[0]+0} \|\|= $_[0]()
		805	}
		806
		807	sub once_again() {
		808	%_ONCE_CACHE = ();
636	}	809	}
637		810
638	=back	811	=back
639		812
640	=cut	813	=cut
…		…
683		856
684	# evaluate user expression	857	# evaluate user expression
685		858
686	my $img = eval { $self->{expr}->() };	859	my $img = eval { $self->{expr}->() };
687	warn $@ if $@;#d#	860	warn $@ if $@;#d#
688	die if !UNIVERSAL::isa $img, "urxvt::img";	861	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
689		862
690	$state->{size_sensitive} = 1	863	$state->{size_sensitive} = 1
691	if $img->repeat_mode != urxvt::RepeatNormal;	864	if $img->repeat_mode != urxvt::RepeatNormal;
692		865
693	# if the expression is sensitive to external events, prepare reevaluation then	866	# if the expression is sensitive to external events, prepare reevaluation then
…		…
743	}	916	}
744		917
745	sub on_start {	918	sub on_start {
746	my ($self) = @_;	919	my ($self) = @_;
747		920
748	my $expr = $self->x_resource ("background.expr")	921	my $expr = $self->x_resource ("%.expr")
749	or return;	922	or return;
750		923
		924	$self->has_render
		925	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		926
751	$self->set_expr (parse_expr $expr);	927	$self->set_expr (parse_expr $expr);
752	$self->{border} = $self->x_resource_boolean ("background.border");	928	$self->{border} = $self->x_resource_boolean ("%.border");
		929
		930	$MIN_INTERVAL = $self->x_resource ("%.interval");
753		931
754	()	932	()
755	}	933	}
756		934

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.40 by root, Fri Jun 8 22:19:21 2012 UTC vs. Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.40 by root, Fri Jun 8 22:19:21 2012 UTC vs.
Revision 1.54 by root, Thu Jun 14 16:22:20 2012 UTC