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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.29 by root, Thu Jun 7 13:12:08 2012 UTC vs.
Revision 1.49 by root, Sun Jun 10 15:29:18 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 $EXPR;	7	#TODO: once, rootalign
8	#$EXPR = 'move W * 0.1, -H * 0.1, resize W * 0.5, H * 0.5, repeat_none load "opensource.png"';
9	$EXPR = 'move -X, -Y, load "argb.png"';
10	#$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	=head1 NAME
21		10
		11	background - manage terminal background
		12
		13	=head1 SYNOPSIS
		14
		15	urxvt --background-expr 'background expression'
		16	--background-border
		17	--background-interval seconds
		18
		19	=head1 DESCRIPTION
		20
		21	This extension manages the terminal background by creating a picture that
		22	is behind the text, replacing the normal background colour.
		23
		24	It does so by evaluating a Perl expression that I<calculates> the image on
		25	the fly, for example, by grabbing the root background or loading a file.
		26
		27	While the full power of Perl is available, the operators have been design
		28	to be as simple as possible.
		29
		30	For example, to load an image and scale it to the window size, you would
		31	use:
		32
		33	urxvt --background-expr 'scale load "/path/to/mybg.png"'
		34
		35	Or specified as a X resource:
		36
		37	URxvt.background-expr: scale load "/path/to/mybg.png"
		38
		39	=head1 THEORY OF OPERATION
		40
		41	At startup, just before the window is mapped for the first time, the
		42	expression is evaluated and must yield an image. The image is then
		43	extended as necessary to cover the whole terminal window, and is set as a
		44	background pixmap.
		45
		46	If the image contains an alpha channel, then it will be used as-is in
		47	visuals that support alpha channels (for example, for a compositing
		48	manager). In other visuals, the terminal background colour will be used to
		49	replace any transparency.
		50
		51	When the expression relies, directly or indirectly, on the window size,
		52	position, the root pixmap, or a timer, then it will be remembered. If not,
		53	then it will be removed.
		54
		55	If any of the parameters that the expression relies on changes (when the
		56	window is moved or resized, its position or size changes; when the root
		57	pixmap is replaced by another one the root background changes; or when the
		58	timer elapses), then the expression will be evaluated again.
		59
		60	For example, an expression such as C<scale load "$HOME/mybg.png"> scales the
		61	image to the window size, so it relies on the window size and will
		62	be reevaluated each time it is changed, but not when it moves for
		63	example. That ensures that the picture always fills the terminal, even
		64	after it's size changes.
		65
		66	=head2 EXPRESSIONS
		67
		68	Expressions are normal Perl expressions, in fact, they are Perl blocks -
		69	which means you could use multiple lines and statements:
		70
		71	again 3600;
		72	if (localtime now)[6]) {
		73	return scale load "$HOME/weekday.png";
		74	} else {
		75	return scale load "$HOME/sunday.png";
		76	}
		77
		78	This expression gets evaluated once per hour. It will set F<sunday.png> as
		79	background on Sundays, and F<weekday.png> on all other days.
		80
		81	Fortunately, we expect that most expressions will be much simpler, with
		82	little Perl knowledge needed.
		83
		84	Basically, you always start with a function that "generates" an image
		85	object, such as C<load>, which loads an image from disk, or C<root>, which
		86	returns the root window background image:
		87
		88	load "$HOME/mypic.png"
		89
		90	The path is usually specified as a quoted string (the exact rules can be
		91	found in the L<perlop> manpage). The F<$HOME> at the beginning of the
		92	string is expanded to the home directory.
		93
		94	Then you prepend one or more modifiers or filtering expressions, such as
		95	C<scale>:
		96
		97	scale load "$HOME/mypic.png"
		98
		99	Just like a mathematical expression with functions, you should read these
		100	expressions from right to left, as the C<load> is evaluated first, and
		101	its result becomes the argument to the C<scale> function.
		102
		103	Many operators also allow some parameters preceding the input image
		104	that modify its behaviour. For example, C<scale> without any additional
		105	arguments scales the image to size of the terminal window. If you specify
		106	an additional argument, it uses it as a scale factor (multiply by 100 to
		107	get a percentage):
		108
		109	scale 2, load "$HOME/mypic.png"
		110
		111	This enlarges the image by a factor of 2 (200%). As you can see, C<scale>
		112	has now two arguments, the C<200> and the C<load> expression, while
		113	C<load> only has one argument. Arguments are separated from each other by
		114	commas.
		115
		116	Scale also accepts two arguments, which are then separate factors for both
		117	horizontal and vertical dimensions. For example, this halves the image
		118	width and doubles the image height:
		119
		120	scale 0.5, 2, load "$HOME/mypic.png"
		121
		122	Other effects than scalign are also readily available, for exmaple, you can
		123	tile the image to fill the whole window, instead of resizing it:
		124
		125	tile load "$HOME/mypic.png"
		126
		127	In fact, images returned by C<load> are in C<tile> mode by default, so the C<tile> operator
		128	is kind of superfluous.
		129
		130	Another common effect is to mirror the image, so that the same edges touch:
		131
		132	mirror load "$HOME/mypic.png"
		133
		134	This is also a typical background expression:
		135
		136	rootalign root
		137
		138	It first takes a snapshot of the screen background image, and then
		139	moves it to the upper left corner of the screen - the result is
		140	pseudo-transparency, as the image seems to be static while the window is
		141	moved around.
		142
		143	=head2 CYCLES AND CACHING
		144
		145	As has been mentioned before, the expression might be evaluated multiple
		146	times. Each time the expression is reevaluated, a new cycle is said to
		147	have begun. Many operators cache their results till the next cycle.
		148
		149	For example, the C<load> operator keeps a copy of the image. If it is
		150	asked to load the same image on the next cycle it will not load it again,
		151	but return the cached copy.
		152
		153	This only works for one cycle though, so as long as you load the same
		154	image every time, it will always be cached, but when you load a different
		155	image, it will forget about the first one.
		156
		157	This allows you to either speed things up by keeping multiple images in
		158	memory, or comserve memory by loading images more often.
		159
		160	For example, you can keep two images in memory and use a random one like
		161	this:
		162
		163	my $img1 = load "img1.png";
		164	my $img2 = load "img2.png";
		165	(0.5 > rand) ? $img1 : $img2
		166
		167	Since both images are "loaded" every time the expression is evaluated,
		168	they are always kept in memory. Contrast this version:
		169
		170	my $path1 = "img1.png";
		171	my $path2 = "img2.png";
		172	load ((0.5 > rand) ? $path1 : $path2)
		173
		174	Here, a path is selected randomly, and load is only called for one image,
		175	so keeps only one image in memory. If, on the next evaluation, luck
		176	decides to use the other path, then it will have to load that image again.
		177
		178	=head1 REFERENCE
		179
		180	=head2 COMMAND LINE SWITCHES
		181
		182	=over 4
		183
		184	=item --background-expr perl-expression
		185
		186	Specifies the Perl expression to evaluate.
		187
		188	=item --background-border
		189
		190	By default, the expression creates an image that fills the full window,
		191	overwriting borders and any other areas, such as the scrollbar.
		192
		193	Specifying this flag changes the behaviour, so that the image only
		194	replaces the background of the character area.
		195
		196	=item --background-interval seconds
		197
		198	Since some operations in the underlying XRender extension can effetively
		199	freeze your X-server for prolonged time, this extension enforces a minimum
		200	time between updates, which is normally about 0.1 seconds.
		201
		202	If you want to do updates more often, you can decrease this safety
		203	interval with this switch.
		204
		205	=back
		206
		207	=cut
		208
		209	our %_IMGCACHE;
		210	our $HOME;
22	our ($bgdsl_self, $old, $new);	211	our ($self, $old, $new);
23	our ($x, $y, $w, $h);	212	our ($x, $y, $w, $h);
24		213
25	# enforce at least this interval between updates	214	# enforce at least this interval between updates
26	our $MIN_INTERVAL = 1/100;	215	our $MIN_INTERVAL = 6/59.951;
27		216
28	{	217	{
29	package urxvt::bgdsl; # background language	218	package urxvt::bgdsl; # background language
30		219
		220	use List::Util qw(min max sum shuffle);
		221
31	=head2 PROVIDERS/GENERATORS	222	=head2 PROVIDERS/GENERATORS
		223
		224	These functions provide an image, by loading it from disk, grabbing it
		225	from the root screen or by simply generating it. They are used as starting
		226	points to get an image you can play with.
32		227
33	=over 4	228	=over 4
34		229
35	=item load $path	230	=item load $path
36		231
37	Loads the image at the given C<$path>. The image is set to plane tiling	232	Loads the image at the given C<$path>. The image is set to plane tiling
38	mode.	233	mode.
39		234
40		235	Loaded images will be cached for one cycle.
41		236
42	=cut	237	=cut
43		238
44	sub load($) {	239	sub load($) {
45	my ($path) = @_;	240	my ($path) = @_;
46		241
47	$new->{load}{$path} = $old->{load}{$path} \|\| $bgdsl_self->new_img_from_file ($path);	242	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);
48	}	243	}
		244
		245	=item root
		246
		247	Returns the root window pixmap, that is, hopefully, the background image
		248	of your screen. The image is set to extend mode.
		249
		250	This function makes your expression root sensitive, that means it will be
		251	reevaluated when the bg image changes.
		252
		253	=cut
49		254
50	sub root() {	255	sub root() {
51	$new->{rootpmap_sensitive} = 1;	256	$new->{rootpmap_sensitive} = 1;
52	die "root op not supported, exg, we need you";	257	die "root op not supported, exg, we need you";
53	}	258	}
54		259
		260	=item solid $colour
		261
		262	=item solid $width, $height, $colour
		263
		264	Creates a new image and completely fills it with the given colour. The
		265	image is set to tiling mode.
		266
		267	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
		268	useful for solid backgrounds or for use in filtering effects.
		269
		270	=cut
		271
55	sub solid($;$$) {	272	sub solid($;$$) {
		273	my $colour = pop;
		274
56	my $img = $bgdsl_self->new_img (urxvt::PictStandardARGB32, $_[1] \|\| 1, $_[2] \|\| 1);	275	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);
57	$img->fill ($_[0]);	276	$img->fill ($colour);
58	$img	277	$img
59	}	278	}
60		279
61	=back	280	=item clone $img
62		281
63	=head2 VARIABLES	282	Returns an exact copy of the image. This is useful if you want to have
		283	multiple copies of the same image to apply different effects to.
64		284
65	=over 4
66
67	=cut	285	=cut
68		286
69	sub X() { $new->{position_sensitive} = 1; $x }
70	sub Y() { $new->{position_sensitive} = 1; $y }
71	sub W() { $new->{size_sensitive} = 1; $w }
72	sub H() { $new->{size_sensitive} = 1; $h }
73
74	sub now() { urxvt::NOW }
75
76	sub again($) {
77	$new->{again} = $_[0];
78	}
79
80	sub counter($) {	287	sub clone($) {
81	$new->{again} = $_[0];	288	$_[0]->clone
82	$bgdsl_self->{counter} + 0
83	}	289	}
84		290
85	=back	291	=back
86		292
87	=head2 TILING MODES	293	=head2 TILING MODES
93		299
94	=item tile $img	300	=item tile $img
95		301
96	Tiles the whole plane with the image and returns this new image - or in	302	Tiles the whole plane with the image and returns this new image - or in
97	other words, it returns a copy of the image in plane tiling mode.	303	other words, it returns a copy of the image in plane tiling mode.
		304
		305	Example: load an image and tile it over the background, without
		306	resizing. The C<tile> call is superfluous because C<load> already defaults
		307	to tiling mode.
		308
		309	tile load "mybg.png"
98		310
99	=item mirror $img	311	=item mirror $img
100		312
101	Similar to tile, but reflects the image each time it uses a new copy, so	313	Similar to tile, but reflects the image each time it uses a new copy, so
102	that top edges always touch top edges, right edges always touch right	314	that top edges always touch top edges, right edges always touch right
103	edges and so on (with normal tiling, left edges always touch right edges	315	edges and so on (with normal tiling, left edges always touch right edges
104	and top always touch bottom edges).	316	and top always touch bottom edges).
105		317
		318	Example: load an image and mirror it over the background, avoiding sharp
		319	edges at the image borders at the expense of mirroring the image itself
		320
		321	mirror load "mybg.png"
		322
106	=item pad $img	323	=item pad $img
107		324
108	Takes an image and modifies it so that all pixels outside the image area	325	Takes an image and modifies it so that all pixels outside the image area
109	become transparent. This mode is most useful when you want to place an	326	become transparent. This mode is most useful when you want to place an
110	image over another image or the background colour while leaving all	327	image over another image or the background colour while leaving all
111	background pixels outside the image unchanged.	328	background pixels outside the image unchanged.
112		329
		330	Example: load an image and display it in the upper left corner. The rest
		331	of the space is left "empty" (transparent or wahtever your compisotr does
		332	in alpha mode, else background colour).
		333
		334	pad load "mybg.png"
		335
113	=item extend $img	336	=item extend $img
114		337
115	Extends the image over the whole plane, using the closest pixel in the	338	Extends the image over the whole plane, using the closest pixel in the
116	area outside the image. This mode is mostly useful when you more complex	339	area outside the image. This mode is mostly useful when you more complex
117	filtering operations and want the pixels outside the image to have the	340	filtering operations and want the pixels outside the image to have the
118	same values as the pixels near the edge.	341	same values as the pixels near the edge.
119		342
		343	Example: just for curiosity, how does this pixel extension stuff work?
		344
		345	extend move 50, 50, load "mybg.png"
		346
120	=cut	347	=cut
121		348
122	sub pad($) {	349	sub pad($) {
123	my $img = $_[0]->clone;	350	my $img = $_[0]->clone;
124	$img->repeat_mode (urxvt::RepeatNone);	351	$img->repeat_mode (urxvt::RepeatNone);
…		…
143	$img	370	$img
144	}	371	}
145		372
146	=back	373	=back
147		374
148	=head2 PIXEL OPERATORS	375	=head2 VARIABLE VALUES
149		376
150	The following operators modify the image pixels in various ways.	377	The following functions provide variable data such as the terminal window
		378	dimensions. They are not (Perl-) variables, they just return stuff that
		379	varies. Most of them make your expression sensitive to some events, for
		380	example using C<TW> (terminal width) means your expression is evaluated
		381	again when the terminal is resized.
151		382
152	=over 4	383	=over 4
153		384
154	=item clone $img	385	=item TX
155		386
156	Returns an exact copy of the image.	387	=item TY
157		388
158	=cut	389	Return the X and Y coordinates of the terminal window (the terminal
		390	window is the full window by default, and the character area only when in
		391	border-respect mode).
159		392
		393	Using these functions make your expression sensitive to window moves.
		394
		395	These functions are mainly useful to align images to the root window.
		396
		397	Example: load an image and align it so it looks as if anchored to the
		398	background.
		399
		400	move -TX, -TY, load "mybg.png"
		401
		402	=item TW
		403
		404	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		405	terminal window is the full window by default, and the character area only
		406	when in border-respect mode).
		407
		408	Using these functions make your expression sensitive to window resizes.
		409
		410	These functions are mainly useful to scale images, or to clip images to
		411	the window size to conserve memory.
		412
		413	Example: take the screen background, clip it to the window size, blur it a
		414	bit, align it to the window position and use it as background.
		415
		416	clip move -TX, -TY, blur 5, root
		417
		418	=cut
		419
		420	sub TX() { $new->{position_sensitive} = 1; $x }
		421	sub TY() { $new->{position_sensitive} = 1; $y }
		422	sub TW() { $new->{size_sensitive} = 1; $w }
		423	sub TH() { $new->{size_sensitive} = 1; $h }
		424
		425	=item now
		426
		427	Returns the current time as (fractional) seconds since the epoch.
		428
		429	Using this expression does I<not> make your expression sensitive to time,
		430	but the next two functions do.
		431
		432	=item again $seconds
		433
		434	When this function is used the expression will be reevaluated again in
		435	C<$seconds> seconds.
		436
		437	Example: load some image and rotate it according to the time of day (as if it were
		438	the hour pointer of a clock). Update this image every minute.
		439
		440	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
		441
		442	=item counter $seconds
		443
		444	Like C<again>, but also returns an increasing counter value, starting at
		445	0, which might be useful for some simple animation effects.
		446
		447	=cut
		448
		449	sub now() { urxvt::NOW }
		450
		451	sub again($) {
		452	$new->{again} = $_[0];
		453	}
		454
160	sub clone($) {	455	sub counter($) {
161	$_[0]->clone	456	$new->{again} = $_[0];
		457	$self->{counter} + 0
162	}	458	}
		459
		460	=back
		461
		462	=head2 SHAPE CHANGING OPERATORS
		463
		464	The following operators modify the shape, size or position of the image.
		465
		466	=over 4
163		467
164	=item clip $img	468	=item clip $img
165		469
166	=item clip $width, $height, $img	470	=item clip $width, $height, $img
167		471
…		…
184		488
185	=cut	489	=cut
186		490
187	sub clip($;$$;$$) {	491	sub clip($;$$;$$) {
188	my $img = pop;	492	my $img = pop;
189	my $h = pop \|\| H;	493	my $h = pop \|\| TH;
190	my $w = pop \|\| W;	494	my $w = pop \|\| TW;
191	$img->sub_rect ($_[0], $_[1], $w, $h)	495	$img->sub_rect ($_[0], $_[1], $w, $h)
192	}	496	}
193		497
194	=item scale $img	498	=item scale $img
195		499
196	=item scale $size_percent, $img	500	=item scale $size_factor, $img
197		501
198	=item scale $width_percent, $height_percent, $img	502	=item scale $width_factor, $height_factor, $img
199		503
200	Scales the image by the given percentages in horizontal	504	Scales the image by the given factors in horizontal
201	(C<$width_percent>) and vertical (C<$height_percent>) direction.	505	(C<$width>) and vertical (C<$height>) direction.
202		506
203	If only one percentage is give, it is used for both directions.	507	If only one factor is give, it is used for both directions.
204		508
205	If no percentages are given, scales the image to the window size without	509	If no factors are given, scales the image to the window size without
206	keeping aspect.	510	keeping aspect.
207		511
208	=item resize $width, $height, $img	512	=item resize $width, $height, $img
209		513
210	Resizes the image to exactly C<$width> times C<$height> pixels.	514	Resizes the image to exactly C<$width> times C<$height> pixels.
211		515
212	=cut	516	=item fit $img
213		517
214	#TODO: maximise, maximise_fill?	518	=item fit $width, $height, $img
215		519
		520	Fits the image into the given C<$width> and C<$height> without changing
		521	aspect, or the terminal size. That means it will be shrunk or grown until
		522	the whole image fits into the given area, possibly leaving borders.
		523
		524	=item cover $img
		525
		526	=item cover $width, $height, $img
		527
		528	Similar to C<fit>, but shrinks or grows until all of the area is covered
		529	by the image, so instead of potentially leaving borders, it will cut off
		530	image data that doesn't fit.
		531
		532	=cut
		533
216	sub scale($$$) {	534	sub scale($;$;$) {
217	my $img = pop;	535	my $img = pop;
218		536
219	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	537	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
220	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	538	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
221	: $img->scale (W, H)	539	: $img->scale (TW, TH)
222	}	540	}
223		541
224	sub resize($$$) {	542	sub resize($$$) {
225	my $img = pop;	543	my $img = pop;
226	$img->scale ($_[0], $_[1])	544	$img->scale ($_[0], $_[1])
227	}	545	}
228		546
229	# TODO: ugly	547	sub fit($;$$) {
		548	my $img = pop;
		549	my $w = ($_[0] \|\| TW) / $img->w;
		550	my $h = ($_[1] \|\| TH) / $img->h;
		551	scale +(min $w, $h), $img
		552	}
		553
		554	sub cover($;$$) {
		555	my $img = pop;
		556	my $w = ($_[0] \|\| TW) / $img->w;
		557	my $h = ($_[1] \|\| TH) / $img->h;
		558	scale +(max $w, $h), $img
		559	}
		560
		561	=item move $dx, $dy, $img
		562
		563	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
		564	the vertical.
		565
		566	Example: move the image right by 20 pixels and down by 30.
		567
		568	move 20, 30, ...
		569
		570	=item align $xalign, $yalign, $img
		571
		572	Aligns the image according to a factor - C<0> means the image is moved to
		573	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		574	exactly centered and C<1> means it touches the right or bottom edge.
		575
		576	Example: remove any visible border around an image, center it vertically but move
		577	it to the right hand side.
		578
		579	align 1, 0.5, pad $img
		580
		581	=item center $img
		582
		583	=item center $width, $height, $img
		584
		585	Centers the image, i.e. the center of the image is moved to the center of
		586	the terminal window (or the box specified by C<$width> and C<$height> if
		587	given).
		588
		589	Example: load an image and center it.
		590
		591	center pad load "mybg.png"
		592
		593	=item rootalign $img
		594
		595	Moves the image so that it appears glued to the screen as opposed to the
		596	window. This gives the illusion of a larger area behind the window. It is
		597	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
		598	top left of the screen.
		599
		600	Example: load a background image, put it in mirror mode and root align it.
		601
		602	rootalign mirror load "mybg.png"
		603
		604	Example: take the screen background and align it, giving the illusion of
		605	transparency as long as the window isn't in front of other windows.
		606
		607	rootalign root
		608
		609	=cut
		610
230	sub move($$;$) {	611	sub move($$;$) {
231	my $img = pop->clone;	612	my $img = pop->clone;
232	$img->move ($_[0], $_[1]);	613	$img->move ($_[0], $_[1]);
233	$img	614	$img
		615	}
		616
		617	sub align($;$$) {
234	# my $img = pop;	618	my $img = pop;
235	# $img->sub_rect (	619
236	# $_[0], $_[1],	620	move $_[0] * (TW - $img->w),
237	# $img->w, $img->h,	621	$_[1] * (TH - $img->h),
238	# $_[2],	622	$img
239	# )
240	}	623	}
		624
		625	sub center($;$$) {
		626	my $img = pop;
		627	my $w = $_[0] \|\| TW;
		628	my $h = $_[1] \|\| TH;
		629
		630	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		631	}
		632
		633	sub rootalign($) {
		634	move -TX, -TY, $_[0]
		635	}
		636
		637	=back
		638
		639	=head2 COLOUR MODIFICATIONS
		640
		641	The following operators change the pixels of the image.
		642
		643	=over 4
		644
		645	=item contrast $factor, $img
		646
		647	=item contrast $r, $g, $b, $img
		648
		649	=item contrast $r, $g, $b, $a, $img
		650
		651	Adjusts the I<contrast> of an image.
		652
		653	The first form applies a single C<$factor> to red, green and blue, the
		654	second form applies separate factors to each colour channel, and the last
		655	form includes the alpha channel.
		656
		657	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		658	contrast.
		659
		660	Due to limitations in the underlying XRender extension, lowering contrast
		661	also reduces brightness, while increasing contrast currently also
		662	increases brightness.
		663
		664	=item brightness $bias, $img
		665
		666	=item brightness $r, $g, $b, $img
		667
		668	=item brightness $r, $g, $b, $a, $img
		669
		670	Adjusts the brightness of an image.
		671
		672	The first form applies a single C<$bias> to red, green and blue, the
		673	second form applies separate biases to each colour channel, and the last
		674	form includes the alpha channel.
		675
		676	Values less than 0 reduce brightness, while values larger than 0 increase
		677	it. Useful range is from -1 to 1 - the former results in a black, the
		678	latter in a white picture.
		679
		680	Due to idiosynchrasies in the underlying XRender extension, biases less
		681	than zero can be I<very> slow.
		682
		683	=cut
		684
		685	sub contrast($$;$$;$) {
		686	my $img = pop;
		687	my ($r, $g, $b, $a) = @_;
		688
		689	($g, $b) = ($r, $r) if @_ < 3;
		690	$a = 1 if @_ < 4;
		691
		692	$img = $img->clone;
		693	$img->contrast ($r, $g, $b, $a);
		694	$img
		695	}
		696
		697	sub brightness($$;$$;$) {
		698	my $img = pop;
		699	my ($r, $g, $b, $a) = @_;
		700
		701	($g, $b) = ($r, $r) if @_ < 3;
		702	$a = 1 if @_ < 4;
		703
		704	$img = $img->clone;
		705	$img->brightness ($r, $g, $b, $a);
		706	$img
		707	}
		708
		709	=item blur $radius, $img
		710
		711	=item blur $radius_horz, $radius_vert, $img
		712
		713	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
		714	can also be specified separately.
		715
		716	Blurring is often I<very> slow, at least compared or other
		717	operators. Larger blur radii are slower than smaller ones, too, so if you
		718	don't want to freeze your screen for long times, start experimenting with
		719	low values for radius (<5).
		720
		721	=cut
		722
		723	sub blur($$;$) {
		724	my $img = pop;
		725	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
		726	}
		727
		728	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
		729
		730	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		731	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		732	width/height), generating a new image with width C<$new_width> and height
		733	C<$new_height>.
		734
		735	#TODO# new width, height, maybe more operators?
		736
		737	Example: rotate the image by 90 degrees
		738
		739	=cut
241		740
242	sub rotate($$$$$$) {	741	sub rotate($$$$$$) {
243	my $img = pop;	742	my $img = pop;
244	$img->rotate (	743	$img->rotate (
245	$_[0],	744	$_[0],
246	$_[1],	745	$_[1],
247	$_[2] * $img->w * .01,	746	$_[2] * $img->w,
248	$_[3] * $img->h * .01,	747	$_[3] * $img->h,
249	$_[4] * (3.14159265 / 180),	748	$_[4] * (3.14159265 / 180),
250	)	749	)
251	}
252
253	sub blur($$;$) {
254	my $img = pop;
255
256	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0]);
257	}
258
259	sub contrast($$;$$;$) {
260	my $img = pop;
261	my ($r, $g, $b, $a) = @_;
262
263	($g, $b) = ($r, $r) if @_ < 4;
264	$a = 1 if @_ < 5;
265
266	$img = $img->clone;
267	$img->contrast ($r, $g, $b, $a);
268	$img
269	}
270
271	sub brightness($$;$$;$) {
272	my $img = pop;
273	my ($r, $g, $b, $a) = @_;
274
275	($g, $b) = ($r, $r) if @_ < 4;
276	$a = 1 if @_ < 5;
277
278	$img = $img->clone;
279	$img->brightness ($r, $g, $b, $a);
280	$img
281	}	750	}
282		751
283	=back	752	=back
284		753
285	=cut	754	=cut
…		…
300	$self->recalculate;	769	$self->recalculate;
301	}	770	}
302		771
303	# evaluate the current bg expression	772	# evaluate the current bg expression
304	sub recalculate {	773	sub recalculate {
305	my ($self) = @_;	774	my ($arg_self) = @_;
306		775
307	# rate limit evaluation	776	# rate limit evaluation
308		777
309	if ($self->{next_refresh} > urxvt::NOW) {	778	if ($arg_self->{next_refresh} > urxvt::NOW) {
310	$self->{next_refresh_timer} = urxvt::timer->new->after ($self->{next_refresh} - urxvt::NOW)->cb (sub {	779	$arg_self->{next_refresh_timer} = urxvt::timer->new->after ($arg_self->{next_refresh} - urxvt::NOW)->cb (sub {
311	$self->recalculate;	780	$arg_self->recalculate;
312	});	781	});
313	return;	782	return;
314	}	783	}
315		784
316	$self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	785	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
317		786
318	# set environment to evaluate user expression	787	# set environment to evaluate user expression
319		788
320	local $bgdsl_self = $self;	789	local $self = $arg_self;
321		790
		791	local $HOME = $ENV{HOME};
322	local $old = $self->{state};	792	local $old = $self->{state};
323	local $new = my $state = $self->{state} = {};	793	local $new = my $state = $self->{state} = {};
324		794
325	my $border = 0; #d#
326
327	($x, $y, $w, $h) =	795	($x, $y, $w, $h) =
328	$self->background_geometry ($border);	796	$self->background_geometry ($self->{border});
329		797
330	# evaluate user expression	798	# evaluate user expression
331		799
332	my $img = eval { $self->{expr}->() };	800	my $img = eval { $self->{expr}->() };
333	warn $@ if $@;#d#	801	warn $@ if $@;#d#
334	die if !UNIVERSAL::isa $img, "urxvt::img";	802	die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
		803
		804	$state->{size_sensitive} = 1
		805	if $img->repeat_mode != urxvt::RepeatNormal;
335		806
336	# if the expression is sensitive to external events, prepare reevaluation then	807	# if the expression is sensitive to external events, prepare reevaluation then
337		808
338	my $repeat;	809	my $repeat;
339		810
340	if (my $again = $state->{again}) {	811	if (my $again = $state->{again}) {
341	$repeat = 1;	812	$repeat = 1;
		813	my $self = $self;
342	$state->{timer} = $again == $old->{again}	814	$state->{timer} = $again == $old->{again}
343	? $old->{timer}	815	? $old->{timer}
344	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {	816	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
345	++$self->{counter};	817	++$self->{counter};
346	$self->recalculate	818	$self->recalculate
…		…
375	unless ($repeat) {	847	unless ($repeat) {
376	delete $self->{state};	848	delete $self->{state};
377	delete $self->{expr};	849	delete $self->{expr};
378	}	850	}
379		851
380	# prepare and set background pixmap	852	# set background pixmap
381		853
382	$img = $img->sub_rect (0, 0, $w, $h)
383	if $img->w != $w \|\| $img->h != $h;
384
385	$self->set_background ($img, $border);	854	$self->set_background ($img, $self->{border});
386	$self->scr_recolour (0);	855	$self->scr_recolour (0);
387	$self->want_refresh;	856	$self->want_refresh;
388	}	857	}
389		858
390	sub on_start {	859	sub on_start {
391	my ($self) = @_;	860	my ($self) = @_;
392		861
		862	my $expr = $self->x_resource ("%.expr")
		863	or return;
		864
		865	$self->has_render
		866	or die "background extension needs RENDER extension 0.10 or higher, ignoring background-expr.\n";
		867
393	$self->set_expr (parse_expr $EXPR);	868	$self->set_expr (parse_expr $expr);
		869	$self->{border} = $self->x_resource_boolean ("%.border");
		870
		871	$MIN_INTERVAL = $self->x_resource ("%.interval");
394		872
395	()	873	()
396	}	874	}
397		875

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.29 by root, Thu Jun 7 13:12:08 2012 UTC vs. Revision 1.49 by root, Sun Jun 10 15:29:18 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.29 by root, Thu Jun 7 13:12:08 2012 UTC vs.
Revision 1.49 by root, Sun Jun 10 15:29:18 2012 UTC