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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.28 by root, Thu Jun 7 12:56:27 2012 UTC vs.
Revision 1.62 by root, Sun Jun 17 21:58:18 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:%.enable:boolean:some boolean	4	#:META:X_RESOURCE:%.border:boolean:respect the terminal border
5	#:META:X_RESOURCE:%.extra.:value:extra config	5	#:META:X_RESOURCE:%.interval:seconds:minimum time between updates
6		6
7	our $EXPR;	7	=head1 NAME
8	#$EXPR = 'move W * 0.1, -H * 0.1, resize W * 0.5, H * 0.5, repeat_none load "opensource.png"';
9	$EXPR = 'border; move -X, -Y, load "argb.png"';
10	#$EXPR = '
11	# rotate W, H, 50, 50, counter 1/59.95, repeat_mirror,
12	# clip X, Y, W, H, repeat_mirror,
13	# load "/root/pix/das_fette_schwein.jpg"
14	#';
15	#$EXPR = 'solid "red"';
16	#$EXPR = 'blur root, 10, 10'
17	#$EXPR = 'blur move (root, -x, -y), 5, 5'
18	#resize load "/root/pix/das_fette_schwein.jpg", w, h
19		8
20	use Safe;	9	background - manage terminal background
21		10
22	our $border;	11	=head1 SYNOPSIS
		12
		13	urxvt --background-expr 'background expression'
		14	--background-border
		15	--background-interval seconds
		16
		17	=head1 DESCRIPTION
		18
		19	This extension manages the terminal background by creating a picture that
		20	is behind the text, replacing the normal background colour.
		21
		22	It does so by evaluating a Perl expression that I<calculates> the image on
		23	the fly, for example, by grabbing the root background or loading a file.
		24
		25	While the full power of Perl is available, the operators have been design
		26	to be as simple as possible.
		27
		28	For example, to load an image and scale it to the window size, you would
		29	use:
		30
		31	urxvt --background-expr 'scale load "/path/to/mybg.png"'
		32
		33	Or specified as a X resource:
		34
		35	URxvt.background-expr: scale load "/path/to/mybg.png"
		36
		37	=head1 THEORY OF OPERATION
		38
		39	At startup, just before the window is mapped for the first time, the
		40	expression is evaluated and must yield an image. The image is then
		41	extended as necessary to cover the whole terminal window, and is set as a
		42	background pixmap.
		43
		44	If the image contains an alpha channel, then it will be used as-is in
		45	visuals that support alpha channels (for example, for a compositing
		46	manager). In other visuals, the terminal background colour will be used to
		47	replace any transparency.
		48
		49	When the expression relies, directly or indirectly, on the window size,
		50	position, the root pixmap, or a timer, then it will be remembered. If not,
		51	then it will be removed.
		52
		53	If any of the parameters that the expression relies on changes (when the
		54	window is moved or resized, its position or size changes; when the root
		55	pixmap is replaced by another one the root background changes; or when the
		56	timer elapses), then the expression will be evaluated again.
		57
		58	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the
		59	image to the window size, so it relies on the window size and will
		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
		62	after its size changes.
		63
		64	=head2 EXPRESSIONS
		65
		66	Expressions are normal Perl expressions, in fact, they are Perl blocks -
		67	which means you could use multiple lines and statements:
		68
		69	again 3600;
		70	if (localtime now)[6]) {
		71	return scale load "$HOME/weekday.png";
		72	} else {
		73	return scale load "$HOME/sunday.png";
		74	}
		75
		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.
		78
		79	Fortunately, we expect that most expressions will be much simpler, with
		80	little Perl knowledge needed.
		81
		82	Basically, you always start with a function that "generates" an image
		83	object, such as C<load>, which loads an image from disk, or C<root>, which
		84	returns the root window background image:
		85
		86	load "$HOME/mypic.png"
		87
		88	The path is usually specified as a quoted string (the exact rules can be
		89	found in the L<perlop> manpage). The F<$HOME> at the beginning of the
		90	string is expanded to the home directory.
		91
		92	Then you prepend one or more modifiers or filtering expressions, such as
		93	C<scale>:
		94
		95	scale load "$HOME/mypic.png"
		96
		97	Just like a mathematical expression with functions, you should read these
		98	expressions from right to left, as the C<load> is evaluated first, and
		99	its result becomes the argument to the C<scale> function.
		100
		101	Many operators also allow some parameters preceding the input image
		102	that modify its behaviour. For example, C<scale> without any additional
		103	arguments scales the image to size of the terminal window. If you specify
		104	an additional argument, it uses it as a scale factor (multiply by 100 to
		105	get a percentage):
		106
		107	scale 2, load "$HOME/mypic.png"
		108
		109	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
		110	has now two arguments, the C<200> and the C<load> expression, while
		111	C<load> only has one argument. Arguments are separated from each other by
		112	commas.
		113
		114	Scale also accepts two arguments, which are then separate factors for both
		115	horizontal and vertical dimensions. For example, this halves the image
		116	width and doubles the image height:
		117
		118	scale 0.5, 2, load "$HOME/mypic.png"
		119
		120	Other effects than scaling are also readily available, for example, you can
		121	tile the image to fill the whole window, instead of resizing it:
		122
		123	tile load "$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
		141	=head2 CYCLES AND CACHING
		142
		143	As has been mentioned before, the expression might be evaluated multiple
		144	times. Each time the expression is reevaluated, a new cycle is said to
		145	have begun. Many operators cache their results till the next cycle.
		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
		176	=head1 REFERENCE
		177
		178	=head2 COMMAND LINE SWITCHES
		179
		180	=over 4
		181
		182	=item --background-expr perl-expression
		183
		184	Specifies the Perl expression to evaluate.
		185
		186	=item --background-border
		187
		188	By default, the expression creates an image that fills the full window,
		189	overwriting borders and any other areas, such as the scrollbar.
		190
		191	Specifying this flag changes the behaviour, so that the image only
		192	replaces the background of the character area.
		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
		203	=back
		204
		205	=cut
		206
		207	our %_IMG_CACHE;
		208	our $HOME;
23	our ($bgdsl_self, $old, $new);	209	our ($self, $old, $new);
24	our ($l, $t, $w, $h);	210	our ($x, $y, $w, $h);
25		211
26	# enforce at least this interval between updates	212	# enforce at least this interval between updates
27	our $MIN_INTERVAL = 1/100;	213	our $MIN_INTERVAL = 6/59.951;
28		214
29	{	215	{
30	package urxvt::bgdsl; # background language	216	package urxvt::bgdsl; # background language
31		217
32	# *repeat_empty = \&urxvt::RepeatNone;	218	use List::Util qw(min max sum shuffle);
33	# *repeat_tile = \&urxvt::RepeatNormal;
34	# *repeat_pad = \&urxvt::RepeatPad;
35	# *repeat_mirror = \&urxvt::RepeatReflect;
36		219
37	=head2 PROVIDERS/GENERATORS	220	=head2 PROVIDERS/GENERATORS
38		221
		222	These functions provide an image, by loading it from disk, grabbing it
		223	from the root screen or by simply generating it. They are used as starting
		224	points to get an image you can play with.
		225
39	=over 4	226	=over 4
40		227
41	=item load $path	228	=item load $path
42		229
		230	Loads the image at the given C<$path>. The image is set to plane tiling
		231	mode.
		232
		233	Loaded images will be cached for one cycle, and shared between temrinals
		234	running in the same process (e.g. in C<urxvtd>).
		235
		236	=item load_uc $path
		237
		238	Load uncached - same as load, but does not cache the image. This function
		239	is most useufl if you want to optimise a background expression in some
		240	way.
		241
43	=cut	242	=cut
		243
		244	sub load_uc($) {
		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	$img
		251	}
		252	}
44		253
45	sub load($) {	254	sub load($) {
46	my ($path) = @_;	255	my ($path) = @_;
47		256
48	$new->{load}{$path} = $old->{load}{$path} \|\| $bgdsl_self->new_img_from_file ($path);	257	$new->{load}{$path} = $old->{load}{$path} \|\| load_uc $path;
49	}	258	}
		259
		260	=item root
		261
		262	Returns the root window pixmap, that is, hopefully, the background image
		263	of your screen.
		264
		265	This function makes your expression root sensitive, that means it will be
		266	reevaluated when the bg image changes.
		267
		268	=cut
50		269
51	sub root() {	270	sub root() {
52	$new->{rootpmap_sensitive} = 1;	271	$new->{again}{rootpmap} = 1;
53	die "root op not supported, exg, we need you";	272	$self->new_img_from_root
54	}	273	}
		274
		275	=item solid $colour
		276
		277	=item solid $width, $height, $colour
		278
		279	Creates a new image and completely fills it with the given colour. The
		280	image is set to tiling mode.
		281
		282	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
		283	useful for solid backgrounds or for use in filtering effects.
		284
		285	=cut
55		286
56	sub solid($;$$) {	287	sub solid($;$$) {
		288	my $colour = pop;
		289
57	my $img = $bgdsl_self->new_img (urxvt::PictStandardARGB32, $_[1] \|\| 1, $_[2] \|\| 1);	290	my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] \|\| 1, $_[1] \|\| 1);
58	$img->fill ($_[0]);	291	$img->fill ($colour);
59	$img	292	$img
60	}	293	}
61		294
62	=back	295	=item clone $img
63		296
64	=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.
65		299
66	=over 4
67
68	=cut	300	=cut
69		301
70	sub X() { $new->{position_sensitive} = 1; $l }
71	sub Y() { $new->{position_sensitive} = 1; $t }
72	sub W() { $new->{size_sensitive} = 1; $w }
73	sub H() { $new->{size_sensitive} = 1; $h }
74
75	sub now() { urxvt::NOW }
76
77	sub again($) {
78	$new->{again} = $_[0];
79	}
80
81	sub counter($) {	302	sub clone($) {
82	$new->{again} = $_[0];	303	$_[0]->clone
83	$bgdsl_self->{counter} + 0
84	}	304	}
85		305
86	=back	306	=item merge $img ...
		307
		308	Takes any number of images and merges them together, creating a single
		309	image containing them all. The tiling mode of the first image is used as
		310	the tiling mdoe of the resulting image.
		311
		312	This function is called automatically when an expression returns multiple
		313	images.
		314
		315	=cut
		316
		317	sub merge(@) {
		318	return $_[0] unless $#_;
		319
		320	# rather annoyingly clumsy, but optimisation is for another time
		321
		322	my $x0 = +1e9;
		323	my $y0 = +1e9;
		324	my $x1 = -1e9;
		325	my $y1 = -1e9;
		326
		327	for (@_) {
		328	my ($x, $y, $w, $h) = $_->geometry;
		329
		330	$x0 = $x if $x0 > $x;
		331	$y0 = $y if $y0 > $y;
		332
		333	$x += $w;
		334	$y += $h;
		335
		336	$x1 = $x if $x1 < $x;
		337	$y1 = $y if $y1 < $y;
		338	}
		339
		340	my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
		341	$base->repeat_mode ($_[0]->repeat_mode);
		342	$base->fill ([0, 0, 0, 0]);
		343
		344	$base->draw ($_)
		345	for @_;
		346
		347	$base
		348	}
87		349
88	=head2 TILING MODES	350	=head2 TILING MODES
89		351
90	The following operators modify the tiling mode of an image, that is, the	352	The following operators modify the tiling mode of an image, that is, the
91	way that pixels outside the image area are painted when the image is used.	353	way that pixels outside the image area are painted when the image is used.
94		356
95	=item tile $img	357	=item tile $img
96		358
97	Tiles the whole plane with the image and returns this new image - or in	359	Tiles the whole plane with the image and returns this new image - or in
98	other words, it returns a copy of the image in plane tiling mode.	360	other words, it returns a copy of the image in plane tiling mode.
		361
		362	Example: load an image and tile it over the background, without
		363	resizing. The C<tile> call is superfluous because C<load> already defaults
		364	to tiling mode.
		365
		366	tile load "mybg.png"
99		367
100	=item mirror $img	368	=item mirror $img
101		369
102	Similar to tile, but reflects the image each time it uses a new copy, so	370	Similar to tile, but reflects the image each time it uses a new copy, so
103	that top edges always touch top edges, right edges always touch right	371	that top edges always touch top edges, right edges always touch right
104	edges and so on (with normal tiling, left edges always touch right edges	372	edges and so on (with normal tiling, left edges always touch right edges
105	and top always touch bottom edges).	373	and top always touch bottom edges).
106		374
		375	Example: load an image and mirror it over the background, avoiding sharp
		376	edges at the image borders at the expense of mirroring the image itself
		377
		378	mirror load "mybg.png"
		379
107	=item pad $img	380	=item pad $img
108		381
109	Takes an image and modifies it so that all pixels outside the image area	382	Takes an image and modifies it so that all pixels outside the image area
110	become transparent. This mode is most useful when you want to place an	383	become transparent. This mode is most useful when you want to place an
111	image over another image or the background colour while leaving all	384	image over another image or the background colour while leaving all
112	background pixels outside the image unchanged.	385	background pixels outside the image unchanged.
113		386
		387	Example: load an image and display it in the upper left corner. The rest
		388	of the space is left "empty" (transparent or whatever your compositor does
		389	in alpha mode, else background colour).
		390
		391	pad load "mybg.png"
		392
114	=item extend $img	393	=item extend $img
115		394
116	Extends the image over the whole plane, using the closest pixel in the	395	Extends the image over the whole plane, using the closest pixel in the
117	area outside the image. This mode is mostly useful when you more complex	396	area outside the image. This mode is mostly useful when you use more complex
118	filtering operations and want the pixels outside the image to have the	397	filtering operations and want the pixels outside the image to have the
119	same values as the pixels near the edge.	398	same values as the pixels near the edge.
		399
		400	Example: just for curiosity, how does this pixel extension stuff work?
		401
		402	extend move 50, 50, load "mybg.png"
120		403
121	=cut	404	=cut
122		405
123	sub pad($) {	406	sub pad($) {
124	my $img = $_[0]->clone;	407	my $img = $_[0]->clone;
…		…
144	$img	427	$img
145	}	428	}
146		429
147	=back	430	=back
148		431
149	=head2 PIXEL OPERATORS	432	=head2 VARIABLE VALUES
150		433
151	The following operators modify the image pixels in various ways.	434	The following functions provide variable data such as the terminal window
		435	dimensions. They are not (Perl-) variables, they just return stuff that
		436	varies. Most of them make your expression sensitive to some events, for
		437	example using C<TW> (terminal width) means your expression is evaluated
		438	again when the terminal is resized.
152		439
153	=over 4	440	=over 4
154		441
155	=item clone $img	442	=item TX
156		443
157	Returns an exact copy of the image.	444	=item TY
158		445
159	=cut	446	Return the X and Y coordinates of the terminal window (the terminal
		447	window is the full window by default, and the character area only when in
		448	border-respect mode).
160		449
		450	Using these functions make your expression sensitive to window moves.
		451
		452	These functions are mainly useful to align images to the root window.
		453
		454	Example: load an image and align it so it looks as if anchored to the
		455	background.
		456
		457	move -TX, -TY, load "mybg.png"
		458
		459	=item TW
		460
		461	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		462	terminal window is the full window by default, and the character area only
		463	when in border-respect mode).
		464
		465	Using these functions make your expression sensitive to window resizes.
		466
		467	These functions are mainly useful to scale images, or to clip images to
		468	the window size to conserve memory.
		469
		470	Example: take the screen background, clip it to the window size, blur it a
		471	bit, align it to the window position and use it as background.
		472
		473	clip move -TX, -TY, once { blur 5, root }
		474
		475	=cut
		476
		477	sub TX() { $new->{again}{position} = 1; $x }
		478	sub TY() { $new->{again}{position} = 1; $y }
		479	sub TW() { $new->{again}{size} = 1; $w }
		480	sub TH() { $new->{again}{size} = 1; $h }
		481
		482	=item now
		483
		484	Returns the current time as (fractional) seconds since the epoch.
		485
		486	Using this expression does I<not> make your expression sensitive to time,
		487	but the next two functions do.
		488
		489	=item again $seconds
		490
		491	When this function is used the expression will be reevaluated again in
		492	C<$seconds> seconds.
		493
		494	Example: load some image and rotate it according to the time of day (as if it were
		495	the hour pointer of a clock). Update this image every minute.
		496
		497	again 60; rotate 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
		498
		499	=item counter $seconds
		500
		501	Like C<again>, but also returns an increasing counter value, starting at
		502	0, which might be useful for some simple animation effects.
		503
		504	=cut
		505
		506	sub now() { urxvt::NOW }
		507
		508	sub again($) {
		509	$new->{again}{time} = $_[0];
		510	}
		511
161	sub clone($) {	512	sub counter($) {
162	$_[0]->clone	513	$new->{again}{time} = $_[0];
		514	$self->{counter} + 0
163	}	515	}
		516
		517	=back
		518
		519	=head2 SHAPE CHANGING OPERATORS
		520
		521	The following operators modify the shape, size or position of the image.
		522
		523	=over 4
164		524
165	=item clip $img	525	=item clip $img
166		526
167	=item clip $width, $height, $img	527	=item clip $width, $height, $img
168		528
…		…
185		545
186	=cut	546	=cut
187		547
188	sub clip($;$$;$$) {	548	sub clip($;$$;$$) {
189	my $img = pop;	549	my $img = pop;
190	my $h = pop \|\| H;	550	my $h = pop \|\| TH;
191	my $w = pop \|\| W;	551	my $w = pop \|\| TW;
192	$img->sub_rect ($_[0], $_[1], $w, $h)	552	$img->sub_rect ($_[0], $_[1], $w, $h)
193	}	553	}
194		554
195	=item scale $img	555	=item scale $img
196		556
197	=item scale $size_percent, $img	557	=item scale $size_factor, $img
198		558
199	=item scale $width_percent, $height_percent, $img	559	=item scale $width_factor, $height_factor, $img
200		560
201	Scales the image by the given percentages in horizontal	561	Scales the image by the given factors in horizontal
202	(C<$width_percent>) and vertical (C<$height_percent>) direction.	562	(C<$width>) and vertical (C<$height>) direction.
203		563
204	If only one percentage is give, it is used for both directions.	564	If only one factor is give, it is used for both directions.
205		565
206	If no percentages are given, scales the image to the window size without	566	If no factors are given, scales the image to the window size without
207	keeping aspect.	567	keeping aspect.
208		568
209	=item resize $width, $height, $img	569	=item resize $width, $height, $img
210		570
211	Resizes the image to exactly C<$width> times C<$height> pixels.	571	Resizes the image to exactly C<$width> times C<$height> pixels.
212		572
213	=cut	573	=item fit $img
214		574
215	#TODO: maximise, maximise_fill?	575	=item fit $width, $height, $img
216		576
		577	Fits the image into the given C<$width> and C<$height> without changing
		578	aspect, or the terminal size. That means it will be shrunk or grown until
		579	the whole image fits into the given area, possibly leaving borders.
		580
		581	=item cover $img
		582
		583	=item cover $width, $height, $img
		584
		585	Similar to C<fit>, but shrinks or grows until all of the area is covered
		586	by the image, so instead of potentially leaving borders, it will cut off
		587	image data that doesn't fit.
		588
		589	=cut
		590
217	sub scale($$$) {	591	sub scale($;$;$) {
218	my $img = pop;	592	my $img = pop;
219		593
220	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	594	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
221	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	595	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
222	: $img->scale (W, H)	596	: $img->scale (TW, TH)
223	}	597	}
224		598
225	sub resize($$$) {	599	sub resize($$$) {
226	my $img = pop;	600	my $img = pop;
227	$img->scale ($_[0], $_[1])	601	$img->scale ($_[0], $_[1])
228	}	602	}
229		603
230	# TODO: ugly	604	sub fit($;$$) {
		605	my $img = pop;
		606	my $w = ($_[0] \|\| TW) / $img->w;
		607	my $h = ($_[1] \|\| TH) / $img->h;
		608	scale +(min $w, $h), $img
		609	}
		610
		611	sub cover($;$$) {
		612	my $img = pop;
		613	my $w = ($_[0] \|\| TW) / $img->w;
		614	my $h = ($_[1] \|\| TH) / $img->h;
		615	scale +(max $w, $h), $img
		616	}
		617
		618	=item move $dx, $dy, $img
		619
		620	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
		621	the vertical.
		622
		623	Example: move the image right by 20 pixels and down by 30.
		624
		625	move 20, 30, ...
		626
		627	=item align $xalign, $yalign, $img
		628
		629	Aligns the image according to a factor - C<0> means the image is moved to
		630	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		631	exactly centered and C<1> means it touches the right or bottom edge.
		632
		633	Example: remove any visible border around an image, center it vertically but move
		634	it to the right hand side.
		635
		636	align 1, 0.5, pad $img
		637
		638	=item center $img
		639
		640	=item center $width, $height, $img
		641
		642	Centers the image, i.e. the center of the image is moved to the center of
		643	the terminal window (or the box specified by C<$width> and C<$height> if
		644	given).
		645
		646	Example: load an image and center it.
		647
		648	center pad load "mybg.png"
		649
		650	=item rootalign $img
		651
		652	Moves the image so that it appears glued to the screen as opposed to the
		653	window. This gives the illusion of a larger area behind the window. It is
		654	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
		655	top left of the screen.
		656
		657	Example: load a background image, put it in mirror mode and root align it.
		658
		659	rootalign mirror load "mybg.png"
		660
		661	Example: take the screen background and align it, giving the illusion of
		662	transparency as long as the window isn't in front of other windows.
		663
		664	rootalign root
		665
		666	=cut
		667
231	sub move($$;$) {	668	sub move($$;$) {
232	my $img = pop->clone;	669	my $img = pop->clone;
233	$img->move ($_[0], $_[1]);	670	$img->move ($_[0], $_[1]);
234	$img	671	$img
		672	}
		673
		674	sub align($;$$) {
235	# my $img = pop;	675	my $img = pop;
236	# $img->sub_rect (
237	# $_[0], $_[1],
238	# $img->w, $img->h,
239	# $_[2],
240	# )
241	}
242		676
		677	move $_[0] * (TW - $img->w),
		678	$_[1] * (TH - $img->h),
		679	$img
		680	}
		681
		682	sub center($;$$) {
		683	my $img = pop;
		684	my $w = $_[0] \|\| TW;
		685	my $h = $_[1] \|\| TH;
		686
		687	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		688	}
		689
		690	sub rootalign($) {
		691	move -TX, -TY, $_[0]
		692	}
		693
		694	=item rotate $center_x, $center_y, $degrees
		695
		696	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		697	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		698	width/height).
		699
		700	#TODO# new width, height, maybe more operators?
		701
		702	Example: rotate the image by 90 degrees
		703
		704	=cut
		705
243	sub rotate($$$$$$) {	706	sub rotate($$$$) {
244	my $img = pop;	707	my $img = pop;
245	$img->rotate (	708	$img->rotate (
246	$_[0],	709	$_[0] * ($img->w + $img->x),
247	$_[1],	710	$_[1] * ($img->h + $img->y),
248	$_[2] * $img->w * .01,
249	$_[3] * $img->h * .01,
250	$_[4] * (3.14159265 / 180),	711	$_[2] * (3.14159265 / 180),
251	)	712	)
252	}	713	}
253		714
254	sub blur($$;$) {	715	=back
255	my $img = pop;
256		716
257	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0]);	717	=head2 COLOUR MODIFICATIONS
258	}	718
		719	The following operators change the pixels of the image.
		720
		721	=over 4
		722
		723	=item contrast $factor, $img
		724
		725	=item contrast $r, $g, $b, $img
		726
		727	=item contrast $r, $g, $b, $a, $img
		728
		729	Adjusts the I<contrast> of an image.
		730
		731	The first form applies a single C<$factor> to red, green and blue, the
		732	second form applies separate factors to each colour channel, and the last
		733	form includes the alpha channel.
		734
		735	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		736	contrast.
		737
		738	Due to limitations in the underlying XRender extension, lowering contrast
		739	also reduces brightness, while increasing contrast currently also
		740	increases brightness.
		741
		742	=item brightness $bias, $img
		743
		744	=item brightness $r, $g, $b, $img
		745
		746	=item brightness $r, $g, $b, $a, $img
		747
		748	Adjusts the brightness of an image.
		749
		750	The first form applies a single C<$bias> to red, green and blue, the
		751	second form applies separate biases to each colour channel, and the last
		752	form includes the alpha channel.
		753
		754	Values less than 0 reduce brightness, while values larger than 0 increase
		755	it. Useful range is from -1 to 1 - the former results in a black, the
		756	latter in a white picture.
		757
		758	Due to idiosyncrasies in the underlying XRender extension, biases less
		759	than zero can be I<very> slow.
		760
		761	=cut
259		762
260	sub contrast($$;$$;$) {	763	sub contrast($$;$$;$) {
261	my $img = pop;	764	my $img = pop;
262	my ($r, $g, $b, $a) = @_;	765	my ($r, $g, $b, $a) = @_;
263		766
264	($g, $b) = ($r, $r) if @_ < 4;	767	($g, $b) = ($r, $r) if @_ < 3;
265	$a = 1 if @_ < 5;	768	$a = 1 if @_ < 4;
266		769
267	$img = $img->clone;	770	$img = $img->clone;
268	$img->contrast ($r, $g, $b, $a);	771	$img->contrast ($r, $g, $b, $a);
269	$img	772	$img
270	}	773	}
271		774
272	sub brightness($$;$$;$) {	775	sub brightness($$;$$;$) {
273	my $img = pop;	776	my $img = pop;
274	my ($r, $g, $b, $a) = @_;	777	my ($r, $g, $b, $a) = @_;
275		778
276	($g, $b) = ($r, $r) if @_ < 4;	779	($g, $b) = ($r, $r) if @_ < 3;
277	$a = 1 if @_ < 5;	780	$a = 1 if @_ < 4;
278		781
279	$img = $img->clone;	782	$img = $img->clone;
280	$img->brightness ($r, $g, $b, $a);	783	$img->brightness ($r, $g, $b, $a);
281	$img	784	$img
282	}	785	}
283		786
		787	=item blur $radius, $img
		788
		789	=item blur $radius_horz, $radius_vert, $img
		790
		791	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
		792	can also be specified separately.
		793
		794	Blurring is often I<very> slow, at least compared or other
		795	operators. Larger blur radii are slower than smaller ones, too, so if you
		796	don't want to freeze your screen for long times, start experimenting with
		797	low values for radius (<5).
		798
		799	=cut
		800
		801	sub blur($$;$) {
		802	my $img = pop;
		803	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
		804	}
		805
284	=back	806	=back
285		807
286	=head2 SETTINGS	808	=head2 OTHER STUFF
		809
		810	Anything that didn't fit any of the other categories, even after applying
		811	force and closing our eyes.
287		812
288	=over 4	813	=over 4
289		814
290	=item border $respect_border=1	815	=item once { ... }
291		816
292	Sets whether the image should respect the terminal border (argument true	817	This function takes a code block as argument, that is, one or more
293	or missing), or whether it should fill the whole window (the default).	818	statements enclosed by braces.
294		819
295	By default, the image will cover the whole toplevel window. If C<border>	820	The trick is that this code block is only evaluated once - future calls
296	is enabled, then it will only fill the character area and leave a normal	821	will simply return the original image (yes, it should only be used with
297	border in the background colour around it and behind the scrollbar.	822	images).
298		823
299	=cut	824	This can be extremely useful to avoid redoign the same slow operations
		825	again and again- for example, if your background expression takes the root
		826	background, blurs it and then root-aligns it it would have to blur the
		827	root background on every window move or resize.
300		828
301	sub border {	829	Putting the blur into a C<once> block will make sure the blur is only done
302	$border = @_ ? $_[0] : 1;	830	once:
		831
		832	rootlign once { blur 10, root }
		833
		834	This leaves the question of how to force reevaluation of the block, in
		835	case the root background changes: Right now, all once blocks forget that
		836	they ahve been executed before each time the root background changes (if
		837	the expression is sensitive to that) or when C<once_again> is called.
		838
		839	=item once_again
		840
		841	Resets all C<once> block as if they had never been called, i.e. on the
		842	next call they will be reevaluated again.
		843
		844	=cut
		845
		846	sub once(&) {
		847	my $once = $self->{once_cache}{$_[0]+0} \|\|= do {
		848	local $new->{again};
		849	my @res = $_[0]();
		850	[$new->{again}, \@res]
		851	};
		852
		853	$new->{again} = {
		854	%{ $new->{again} },
		855	%{ $once->[0] }
		856	};
		857
		858	# in scalar context we always return the first original result, which
		859	# is not quite how perl works.
		860	wantarray
		861	? @{ $once->[1] }
		862	: $once->[1][0]
		863	}
		864
		865	sub once_again() {
		866	delete $self->{once_cache};
303	}	867	}
304		868
305	=back	869	=back
306		870
307	=cut	871	=cut
…		…
322	$self->recalculate;	886	$self->recalculate;
323	}	887	}
324		888
325	# evaluate the current bg expression	889	# evaluate the current bg expression
326	sub recalculate {	890	sub recalculate {
327	my ($self) = @_;	891	my ($arg_self) = @_;
328		892
329	# rate limit evaluation	893	# rate limit evaluation
330		894
331	if ($self->{next_refresh} > urxvt::NOW) {	895	if ($arg_self->{next_refresh} > urxvt::NOW) {
332	$self->{next_refresh_timer} = urxvt::timer->new->after ($self->{next_refresh} - urxvt::NOW)->cb (sub {	896	$arg_self->{next_refresh_timer} = urxvt::timer->new->after ($arg_self->{next_refresh} - urxvt::NOW)->cb (sub {
333	$self->recalculate;	897	$arg_self->recalculate;
334	});	898	});
335	return;	899	return;
336	}	900	}
337		901
338	$self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	902	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
339		903
340	# set environment to evaluate user expression	904	# set environment to evaluate user expression
341		905
342	local $bgdsl_self = $self;	906	local $self = $arg_self;
343	local $border;
344		907
		908	local $HOME = $ENV{HOME};
345	local $old = $self->{state};	909	local $old = $self->{state};
346	local $new = my $state = $self->{state} = {};	910	local $new = my $state = $self->{state} = {};
347		911
348	($l, $t, $w, $h) =	912	($x, $y, $w, $h) =
349	$self->get_geometry;	913	$self->background_geometry ($self->{border});
350
351	warn "$l,$t,$w,$h\n";#d#
352		914
353	# evaluate user expression	915	# evaluate user expression
354		916
355	my $img = eval { $self->{expr}->() };	917	my $img = eval { urxvt::bgdsl::merge $self->{expr}->() };
356	warn $@ if $@;#d#	918	die $@ if $@;
357	die if !UNIVERSAL::isa $img, "urxvt::img";	919	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
358		920
359	# if the expression is sensitive to external events, prepare reevaluation then	921	# if the expression is sensitive to external events, prepare reevaluation then
360		922
361	my $repeat;
362
363	if (my $again = $state->{again}) {	923	my $again = delete $state->{again};
364	$repeat = 1;	924
		925	$again->{size} = 1
		926	if $img->repeat_mode != urxvt::RepeatNormal;
		927
		928	if (my $again = $again->{time}) {
		929	my $self = $self;
365	$state->{timer} = $again == $old->{again}	930	$state->{timer} = $again == $old->{again}
366	? $old->{timer}	931	? $old->{timer}
367	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {	932	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
368	++$self->{counter};	933	++$self->{counter};
369	$self->recalculate	934	$self->recalculate
370	});	935	});
371	}	936	}
372		937
373	if (delete $state->{position_sensitive}) {	938	if ($again->{position}) {
374	$repeat = 1;
375	$self->enable (position_change => sub { $_[0]->recalculate });	939	$self->enable (position_change => sub { $_[0]->recalculate });
376	} else {	940	} else {
377	$self->disable ("position_change");	941	$self->disable ("position_change");
378	}	942	}
379		943
380	if (delete $state->{size_sensitive}) {	944	if ($again->{size}) {
381	$repeat = 1;
382	$self->enable (size_change => sub { $_[0]->recalculate });	945	$self->enable (size_change => sub { $_[0]->recalculate });
383	} else {	946	} else {
384	$self->disable ("size_change");	947	$self->disable ("size_change");
385	}	948	}
386		949
387	if (delete $state->{rootpmap_sensitive}) {	950	if ($again->{rootpmap}) {
388	$repeat = 1;
389	$self->enable (rootpmap_change => sub { $_[0]->recalculate });	951	$self->enable (rootpmap_change => sub {
		952	delete $_[0]{once_cache}; # this will override once-block values from
		953	$_[0]->recalculate;
		954	});
390	} else {	955	} else {
391	$self->disable ("rootpmap_change");	956	$self->disable ("rootpmap_change");
392	}	957	}
393		958
394	# clear stuff we no longer need	959	# clear stuff we no longer need
395		960
396	%$old = ();	961	%$old = ();
397		962
398	unless ($repeat) {	963	unless (%$again) {
399	delete $self->{state};	964	delete $self->{state};
400	delete $self->{expr};	965	delete $self->{expr};
401	}	966	}
402		967
403	# prepare and set background pixmap	968	# set background pixmap
404		969
405	$img = $img->sub_rect (0, 0, $w, $h)
406	if $img->w != $w \|\| $img->h != $h;
407
408	$self->set_background ($img, $border);	970	$self->set_background ($img, $self->{border});
409	$self->scr_recolour (0);	971	$self->scr_recolour (0);
410	$self->want_refresh;	972	$self->want_refresh;
411	}	973	}
412		974
413	sub on_start {	975	sub on_start {
414	my ($self) = @_;	976	my ($self) = @_;
415		977
		978	my $expr = $self->x_resource ("%.expr")
		979	or return;
		980
		981	$self->has_render
		982	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		983
416	$self->set_expr (parse_expr $EXPR);	984	$self->set_expr (parse_expr $expr);
		985	$self->{border} = $self->x_resource_boolean ("%.border");
		986
		987	$MIN_INTERVAL = $self->x_resource ("%.interval");
417		988
418	()	989	()
419	}	990	}
420		991

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.28 by root, Thu Jun 7 12:56:27 2012 UTC vs. Revision 1.62 by root, Sun Jun 17 21:58:18 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.28 by root, Thu Jun 7 12:56:27 2012 UTC vs.
Revision 1.62 by root, Sun Jun 17 21:58:18 2012 UTC