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

Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.30 by root, Thu Jun 7 13:22:06 2012 UTC vs.
Revision 1.47 by root, Sun Jun 10 13:58:05 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	$EXPR = 'move -TX, -TY, load "argb.png"';
10	#$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 $HOME;
22	our ($bgdsl_self, $old, $new);	210	our ($self, $old, $new);
23	our ($x, $y, $w, $h);	211	our ($x, $y, $w, $h);
24		212
25	# enforce at least this interval between updates	213	# enforce at least this interval between updates
26	our $MIN_INTERVAL = 1/100;	214	our $MIN_INTERVAL = 6/59.951;
27		215
28	{	216	{
29	package urxvt::bgdsl; # background language	217	package urxvt::bgdsl; # background language
30		218
		219	use List::Util qw(min max sum shuffle);
		220
31	=head2 PROVIDERS/GENERATORS	221	=head2 PROVIDERS/GENERATORS
		222
		223	These functions provide an image, by loading it from disk, grabbing it
		224	from the root screen or by simply generating it. They are used as starting
		225	points to get an image you can play with.
32		226
33	=over 4	227	=over 4
34		228
35	=item load $path	229	=item load $path
36		230
37	Loads the image at the given C<$path>. The image is set to plane tiling	231	Loads the image at the given C<$path>. The image is set to plane tiling
38	mode.	232	mode.
39		233
40		234	Loaded images will be cached for one cycle.
41		235
42	=cut	236	=cut
43		237
44	sub load($) {	238	sub load($) {
45	my ($path) = @_;	239	my ($path) = @_;
46		240
47	$new->{load}{$path} = $old->{load}{$path} \|\| $bgdsl_self->new_img_from_file ($path);	241	$new->{load}{$path} = $old->{load}{$path} \|\| $self->new_img_from_file ($path);
48	}	242	}
		243
		244	=item root
		245
		246	Returns the root window pixmap, that is, hopefully, the background image
		247	of your screen. The image is set to extend mode.
		248
		249	This function makes your expression root sensitive, that means it will be
		250	reevaluated when the bg image changes.
		251
		252	=cut
49		253
50	sub root() {	254	sub root() {
51	$new->{rootpmap_sensitive} = 1;	255	$new->{rootpmap_sensitive} = 1;
52	die "root op not supported, exg, we need you";	256	die "root op not supported, exg, we need you";
53	}	257	}
54		258
		259	=item solid $colour
		260
		261	=item solid $width, $height, $colour
		262
		263	Creates a new image and completely fills it with the given colour. The
		264	image is set to tiling mode.
		265
		266	If C<$width> and C<$height> are omitted, it creates a 1x1 image, which is
		267	useful for solid backgrounds or for use in filtering effects.
		268
		269	=cut
		270
55	sub solid($;$$) {	271	sub solid($;$$) {
		272	my $colour = pop;
		273
56	my $img = $bgdsl_self->new_img (urxvt::PictStandardARGB32, $_[1] \|\| 1, $_[2] \|\| 1);	274	my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] \|\| 1, $_[1] \|\| 1);
57	$img->fill ($_[0]);	275	$img->fill ($colour);
58	$img	276	$img
59	}	277	}
60		278
		279	=item clone $img
		280
		281	Returns an exact copy of the image. This is useful if you want to have
		282	multiple copies of the same image to apply different effects to.
		283
		284	=cut
		285
		286	sub clone($) {
		287	$_[0]->clone
		288	}
		289
61	=back	290	=back
62		291
63	=head2 VARIABLES	292	=head2 TILING MODES
		293
		294	The following operators modify the tiling mode of an image, that is, the
		295	way that pixels outside the image area are painted when the image is used.
64		296
65	=over 4	297	=over 4
		298
		299	=item tile $img
		300
		301	Tiles the whole plane with the image and returns this new image - or in
		302	other words, it returns a copy of the image in plane tiling mode.
		303
		304	Example: load an image and tile it over the background, without
		305	resizing. The C<tile> call is superfluous because C<load> already defaults
		306	to tiling mode.
		307
		308	tile load "mybg.png"
		309
		310	=item mirror $img
		311
		312	Similar to tile, but reflects the image each time it uses a new copy, so
		313	that top edges always touch top edges, right edges always touch right
		314	edges and so on (with normal tiling, left edges always touch right edges
		315	and top always touch bottom edges).
		316
		317	Example: load an image and mirror it over the background, avoiding sharp
		318	edges at the image borders at the expense of mirroring the image itself
		319
		320	mirror load "mybg.png"
		321
		322	=item pad $img
		323
		324	Takes an image and modifies it so that all pixels outside the image area
		325	become transparent. This mode is most useful when you want to place an
		326	image over another image or the background colour while leaving all
		327	background pixels outside the image unchanged.
		328
		329	Example: load an image and display it in the upper left corner. The rest
		330	of the space is left "empty" (transparent or wahtever your compisotr does
		331	in alpha mode, else background colour).
		332
		333	pad load "mybg.png"
		334
		335	=item extend $img
		336
		337	Extends the image over the whole plane, using the closest pixel in the
		338	area outside the image. This mode is mostly useful when you more complex
		339	filtering operations and want the pixels outside the image to have the
		340	same values as the pixels near the edge.
		341
		342	Example: just for curiosity, how does this pixel extension stuff work?
		343
		344	extend move 50, 50, load "mybg.png"
		345
		346	=cut
		347
		348	sub pad($) {
		349	my $img = $_[0]->clone;
		350	$img->repeat_mode (urxvt::RepeatNone);
		351	$img
		352	}
		353
		354	sub tile($) {
		355	my $img = $_[0]->clone;
		356	$img->repeat_mode (urxvt::RepeatNormal);
		357	$img
		358	}
		359
		360	sub mirror($) {
		361	my $img = $_[0]->clone;
		362	$img->repeat_mode (urxvt::RepeatReflect);
		363	$img
		364	}
		365
		366	sub extend($) {
		367	my $img = $_[0]->clone;
		368	$img->repeat_mode (urxvt::RepeatPad);
		369	$img
		370	}
		371
		372	=back
		373
		374	=head2 VARIABLE VALUES
		375
		376	The following functions provide variable data such as the terminal window
		377	dimensions. They are not (Perl-) variables, they just return stuff that
		378	varies. Most of them make your expression sensitive to some events, for
		379	example using C<TW> (terminal width) means your expression is evaluated
		380	again when the terminal is resized.
		381
		382	=over 4
		383
		384	=item TX
		385
		386	=item TY
		387
		388	Return the X and Y coordinates of the terminal window (the terminal
		389	window is the full window by default, and the character area only when in
		390	border-respect mode).
		391
		392	Using these functions make your expression sensitive to window moves.
		393
		394	These functions are mainly useful to align images to the root window.
		395
		396	Example: load an image and align it so it looks as if anchored to the
		397	background.
		398
		399	move -TX, -TY, load "mybg.png"
		400
		401	=item TW
		402
		403	Return the width (C<TW>) and height (C<TH>) of the terminal window (the
		404	terminal window is the full window by default, and the character area only
		405	when in border-respect mode).
		406
		407	Using these functions make your expression sensitive to window resizes.
		408
		409	These functions are mainly useful to scale images, or to clip images to
		410	the window size to conserve memory.
		411
		412	Example: take the screen background, clip it to the window size, blur it a
		413	bit, align it to the window position and use it as background.
		414
		415	clip move -TX, -TY, blur 5, root
66		416
67	=cut	417	=cut
68		418
69	sub TX() { $new->{position_sensitive} = 1; $x }	419	sub TX() { $new->{position_sensitive} = 1; $x }
70	sub TY() { $new->{position_sensitive} = 1; $y }	420	sub TY() { $new->{position_sensitive} = 1; $y }
71	sub TW() { $new->{size_sensitive} = 1; $w }	421	sub TW() { $new->{size_sensitive} = 1; $w }
72	sub TH() { $new->{size_sensitive} = 1; $h }	422	sub TH() { $new->{size_sensitive} = 1; $h }
73		423
		424	=item now
		425
		426	Returns the current time as (fractional) seconds since the epoch.
		427
		428	Using this expression does I<not> make your expression sensitive to time,
		429	but the next two functions do.
		430
		431	=item again $seconds
		432
		433	When this function is used the expression will be reevaluated again in
		434	C<$seconds> seconds.
		435
		436	Example: load some image and rotate it according to the time of day (as if it were
		437	the hour pointer of a clock). Update this image every minute.
		438
		439	again 60; rotate TW, TH, 50, 50, (now % 86400) * -720 / 86400, scale load "myclock.png"
		440
		441	=item counter $seconds
		442
		443	Like C<again>, but also returns an increasing counter value, starting at
		444	0, which might be useful for some simple animation effects.
		445
		446	=cut
		447
74	sub now() { urxvt::NOW }	448	sub now() { urxvt::NOW }
75		449
76	sub again($) {	450	sub again($) {
77	$new->{again} = $_[0];	451	$new->{again} = $_[0];
78	}	452	}
79		453
80	sub counter($) {	454	sub counter($) {
81	$new->{again} = $_[0];	455	$new->{again} = $_[0];
82	$bgdsl_self->{counter} + 0	456	$self->{counter} + 0
83	}	457	}
84		458
85	=back	459	=back
86		460
87	=head2 TILING MODES	461	=head2 SHAPE CHANGING OPERATORS
88		462
89	The following operators modify the tiling mode of an image, that is, the	463	The following operators modify the shape, size or position of the image.
90	way that pixels outside the image area are painted when the image is used.
91		464
92	=over 4	465	=over 4
93
94	=item tile $img
95
96	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.
98
99	=item mirror $img
100
101	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
103	edges and so on (with normal tiling, left edges always touch right edges
104	and top always touch bottom edges).
105
106	=item pad $img
107
108	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
110	image over another image or the background colour while leaving all
111	background pixels outside the image unchanged.
112
113	=item extend $img
114
115	Extends the image over the whole plane, using the closest pixel in the
116	area outside the image. This mode is mostly useful when you more complex
117	filtering operations and want the pixels outside the image to have the
118	same values as the pixels near the edge.
119
120	=cut
121
122	sub pad($) {
123	my $img = $_[0]->clone;
124	$img->repeat_mode (urxvt::RepeatNone);
125	$img
126	}
127
128	sub tile($) {
129	my $img = $_[0]->clone;
130	$img->repeat_mode (urxvt::RepeatNormal);
131	$img
132	}
133
134	sub mirror($) {
135	my $img = $_[0]->clone;
136	$img->repeat_mode (urxvt::RepeatReflect);
137	$img
138	}
139
140	sub extend($) {
141	my $img = $_[0]->clone;
142	$img->repeat_mode (urxvt::RepeatPad);
143	$img
144	}
145
146	=back
147
148	=head2 PIXEL OPERATORS
149
150	The following operators modify the image pixels in various ways.
151
152	=over 4
153
154	=item clone $img
155
156	Returns an exact copy of the image.
157
158	=cut
159
160	sub clone($) {
161	$_[0]->clone
162	}
163		466
164	=item clip $img	467	=item clip $img
165		468
166	=item clip $width, $height, $img	469	=item clip $width, $height, $img
167		470
191	$img->sub_rect ($_[0], $_[1], $w, $h)	494	$img->sub_rect ($_[0], $_[1], $w, $h)
192	}	495	}
193		496
194	=item scale $img	497	=item scale $img
195		498
196	=item scale $size_percent, $img	499	=item scale $size_factor, $img
197		500
198	=item scale $width_percent, $height_percent, $img	501	=item scale $width_factor, $height_factor, $img
199		502
200	Scales the image by the given percentages in horizontal	503	Scales the image by the given factors in horizontal
201	(C<$width_percent>) and vertical (C<$height_percent>) direction.	504	(C<$width>) and vertical (C<$height>) direction.
202		505
203	If only one percentage is give, it is used for both directions.	506	If only one factor is give, it is used for both directions.
204		507
205	If no percentages are given, scales the image to the window size without	508	If no factors are given, scales the image to the window size without
206	keeping aspect.	509	keeping aspect.
207		510
208	=item resize $width, $height, $img	511	=item resize $width, $height, $img
209		512
210	Resizes the image to exactly C<$width> times C<$height> pixels.	513	Resizes the image to exactly C<$width> times C<$height> pixels.
211		514
212	=cut	515	=item fit $img
213		516
214	#TODO: maximise, maximise_fill?	517	=item fit $width, $height, $img
215		518
		519	Fits the image into the given C<$width> and C<$height> without changing
		520	aspect, or the terminal size. That means it will be shrunk or grown until
		521	the whole image fits into the given area, possibly leaving borders.
		522
		523	=item cover $img
		524
		525	=item cover $width, $height, $img
		526
		527	Similar to C<fit>, but shrinks or grows until all of the area is covered
		528	by the image, so instead of potentially leaving borders, it will cut off
		529	image data that doesn't fit.
		530
		531	=cut
		532
216	sub scale($$$) {	533	sub scale($;$;$) {
217	my $img = pop;	534	my $img = pop;
218		535
219	@_ == 2 ? $img->scale ($_[0] * $img->w * 0.01, $_[1] * $img->h * 0.01)	536	@_ == 2 ? $img->scale ($_[0] * $img->w, $_[1] * $img->h)
220	: @_ ? $img->scale ($_[0] * $img->w * 0.01, $_[0] * $img->h * 0.01)	537	: @_ ? $img->scale ($_[0] * $img->w, $_[0] * $img->h)
221	: $img->scale (TW, TH)	538	: $img->scale (TW, TH)
222	}	539	}
223		540
224	sub resize($$$) {	541	sub resize($$$) {
225	my $img = pop;	542	my $img = pop;
226	$img->scale ($_[0], $_[1])	543	$img->scale ($_[0], $_[1])
227	}	544	}
		545
		546	sub fit($;$$) {
		547	my $img = pop;
		548	my $w = ($_[0] \|\| TW) / $img->w;
		549	my $h = ($_[1] \|\| TH) / $img->h;
		550	scale +(min $w, $h), $img
		551	}
		552
		553	sub cover($;$$) {
		554	my $img = pop;
		555	my $w = ($_[0] \|\| TW) / $img->w;
		556	my $h = ($_[1] \|\| TH) / $img->h;
		557	scale +(max $w, $h), $img
		558	}
		559
		560	=item move $dx, $dy, $img
		561
		562	Moves the image by C<$dx> pixels in the horizontal, and C<$dy> pixels in
		563	the vertical.
		564
		565	Example: move the image right by 20 pixels and down by 30.
		566
		567	move 20, 30, ...
		568
		569	=item align $xalign, $yalign, $img
		570
		571	Aligns the image according to a factor - C<0> means the image is moved to
		572	the left or top edge (for C<$xalign> or C<$yalign>), C<0.5> means it is
		573	exactly centered and C<1> means it touches the right or bottom edge.
		574
		575	Example: remove any visible border around an image, center it vertically but move
		576	it to the right hand side.
		577
		578	align 1, 0.5, pad $img
		579
		580	=item center $img
		581
		582	=item center $width, $height, $img
		583
		584	Centers the image, i.e. the center of the image is moved to the center of
		585	the terminal window (or the box specified by C<$width> and C<$height> if
		586	given).
		587
		588	Example: load an image and center it.
		589
		590	center pad load "mybg.png"
		591
		592	=item rootalign $img
		593
		594	Moves the image so that it appears glued to the screen as opposed to the
		595	window. This gives the illusion of a larger area behind the window. It is
		596	exactly equivalent to C<move -TX, -TY>, that is, it moves the image to the
		597	top left of the screen.
		598
		599	Example: load a background image, put it in mirror mode and root align it.
		600
		601	rootalign mirror load "mybg.png"
		602
		603	Example: take the screen background and align it, giving the illusion of
		604	transparency as long as the window isn't in front of other windows.
		605
		606	rootalign root
		607
		608	=cut
228		609
229	sub move($$;$) {	610	sub move($$;$) {
230	my $img = pop->clone;	611	my $img = pop->clone;
231	$img->move ($_[0], $_[1]);	612	$img->move ($_[0], $_[1]);
232	$img	613	$img
233	}	614	}
234		615
		616	sub align($;$$) {
		617	my $img = pop;
		618
		619	move $_[0] * (TW - $img->w),
		620	$_[1] * (TH - $img->h),
		621	$img
		622	}
		623
		624	sub center($;$$) {
		625	my $img = pop;
		626	my $w = $_[0] \|\| TW;
		627	my $h = $_[1] \|\| TH;
		628
		629	move 0.5 * ($w - $img->w), 0.5 * ($h - $img->h), $img
		630	}
		631
		632	sub rootalign($) {
		633	move -TX, -TY, $_[0]
		634	}
		635
		636	=back
		637
		638	=head2 COLOUR MODIFICATIONS
		639
		640	The following operators change the pixels of the image.
		641
		642	=over 4
		643
		644	=item contrast $factor, $img
		645
		646	=item contrast $r, $g, $b, $img
		647
		648	=item contrast $r, $g, $b, $a, $img
		649
		650	Adjusts the I<contrast> of an image.
		651
		652	The first form applies a single C<$factor> to red, green and blue, the
		653	second form applies separate factors to each colour channel, and the last
		654	form includes the alpha channel.
		655
		656	Values from 0 to 1 lower the contrast, values higher than 1 increase the
		657	contrast.
		658
		659	Due to limitations in the underlying XRender extension, lowering contrast
		660	also reduces brightness, while increasing contrast currently also
		661	increases brightness.
		662
		663	=item brightness $bias, $img
		664
		665	=item brightness $r, $g, $b, $img
		666
		667	=item brightness $r, $g, $b, $a, $img
		668
		669	Adjusts the brightness of an image.
		670
		671	The first form applies a single C<$bias> to red, green and blue, the
		672	second form applies separate biases to each colour channel, and the last
		673	form includes the alpha channel.
		674
		675	Values less than 0 reduce brightness, while values larger than 0 increase
		676	it. Useful range is from -1 to 1 - the former results in a black, the
		677	latter in a white picture.
		678
		679	Due to idiosynchrasies in the underlying XRender extension, biases less
		680	than zero can be I<very> slow.
		681
		682	=cut
		683
		684	sub contrast($$;$$;$) {
		685	my $img = pop;
		686	my ($r, $g, $b, $a) = @_;
		687
		688	($g, $b) = ($r, $r) if @_ < 4;
		689	$a = 1 if @_ < 5;
		690
		691	$img = $img->clone;
		692	$img->contrast ($r, $g, $b, $a);
		693	$img
		694	}
		695
		696	sub brightness($$;$$;$) {
		697	my $img = pop;
		698	my ($r, $g, $b, $a) = @_;
		699
		700	($g, $b) = ($r, $r) if @_ < 4;
		701	$a = 1 if @_ < 5;
		702
		703	$img = $img->clone;
		704	$img->brightness ($r, $g, $b, $a);
		705	$img
		706	}
		707
		708	=item blur $radius, $img
		709
		710	=item blur $radius_horz, $radius_vert, $img
		711
		712	Gaussian-blurs the image with (roughly) C<$radius> pixel radius. The radii
		713	can also be specified separately.
		714
		715	Blurring is often I<very> slow, at least compared or other
		716	operators. Larger blur radii are slower than smaller ones, too, so if you
		717	don't want to freeze your screen for long times, start experimenting with
		718	low values for radius (<5).
		719
		720	=cut
		721
		722	sub blur($$;$) {
		723	my $img = pop;
		724	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
		725	}
		726
		727	=item rotate $new_width, $new_height, $center_x, $center_y, $degrees
		728
		729	Rotates the image by C<$degrees> degrees, counter-clockwise, around the
		730	pointer at C<$center_x> and C<$center_y> (specified as factor of image
		731	width/height), generating a new image with width C<$new_width> and height
		732	C<$new_height>.
		733
		734	#TODO# new width, height, maybe more operators?
		735
		736	Example: rotate the image by 90 degrees
		737
		738	=cut
		739
235	sub rotate($$$$$$) {	740	sub rotate($$$$$$) {
236	my $img = pop;	741	my $img = pop;
237	$img->rotate (	742	$img->rotate (
238	$_[0],	743	$_[0],
239	$_[1],	744	$_[1],
240	$_[2] * $img->w * .01,	745	$_[2] * $img->w,
241	$_[3] * $img->h * .01,	746	$_[3] * $img->h,
242	$_[4] * (3.14159265 / 180),	747	$_[4] * (3.14159265 / 180),
243	)	748	)
244	}
245
246	sub blur($$;$) {
247	my $img = pop;
248	$img->blur ($_[0], @_ >= 2 ? $_[1] : $_[0])
249	}
250
251	sub contrast($$;$$;$) {
252	my $img = pop;
253	my ($r, $g, $b, $a) = @_;
254
255	($g, $b) = ($r, $r) if @_ < 4;
256	$a = 1 if @_ < 5;
257
258	$img = $img->clone;
259	$img->contrast ($r, $g, $b, $a);
260	$img
261	}
262
263	sub brightness($$;$$;$) {
264	my $img = pop;
265	my ($r, $g, $b, $a) = @_;
266
267	($g, $b) = ($r, $r) if @_ < 4;
268	$a = 1 if @_ < 5;
269
270	$img = $img->clone;
271	$img->brightness ($r, $g, $b, $a);
272	$img
273	}	749	}
274		750
275	=back	751	=back
276		752
277	=cut	753	=cut
…		…
292	$self->recalculate;	768	$self->recalculate;
293	}	769	}
294		770
295	# evaluate the current bg expression	771	# evaluate the current bg expression
296	sub recalculate {	772	sub recalculate {
297	my ($self) = @_;	773	my ($arg_self) = @_;
298		774
299	# rate limit evaluation	775	# rate limit evaluation
300		776
301	if ($self->{next_refresh} > urxvt::NOW) {	777	if ($arg_self->{next_refresh} > urxvt::NOW) {
302	$self->{next_refresh_timer} = urxvt::timer->new->after ($self->{next_refresh} - urxvt::NOW)->cb (sub {	778	$arg_self->{next_refresh_timer} = urxvt::timer->new->after ($arg_self->{next_refresh} - urxvt::NOW)->cb (sub {
303	$self->recalculate;	779	$arg_self->recalculate;
304	});	780	});
305	return;	781	return;
306	}	782	}
307		783
308	$self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;	784	$arg_self->{next_refresh} = urxvt::NOW + $MIN_INTERVAL;
309		785
310	# set environment to evaluate user expression	786	# set environment to evaluate user expression
311		787
312	local $bgdsl_self = $self;	788	local $self = $arg_self;
313		789
		790	local $HOME = $ENV{HOME};
314	local $old = $self->{state};	791	local $old = $self->{state};
315	local $new = my $state = $self->{state} = {};	792	local $new = my $state = $self->{state} = {};
316		793
317	my $border = 0; #d#
318
319	($x, $y, $w, $h) =	794	($x, $y, $w, $h) =
320	$self->background_geometry ($border);	795	$self->background_geometry ($self->{border});
321		796
322	# evaluate user expression	797	# evaluate user expression
323		798
324	my $img = eval { $self->{expr}->() };	799	my $img = eval { $self->{expr}->() };
325	warn $@ if $@;#d#	800	warn $@ if $@;#d#
326	die if !UNIVERSAL::isa $img, "urxvt::img";	801	die if !UNIVERSAL::isa $img, "urxvt::img";
327		802
		803	$state->{size_sensitive} = 1
		804	if $img->repeat_mode != urxvt::RepeatNormal;
		805
328	# if the expression is sensitive to external events, prepare reevaluation then	806	# if the expression is sensitive to external events, prepare reevaluation then
329		807
330	my $repeat;	808	my $repeat;
331		809
332	if (my $again = $state->{again}) {	810	if (my $again = $state->{again}) {
333	$repeat = 1;	811	$repeat = 1;
		812	my $self = $self;
334	$state->{timer} = $again == $old->{again}	813	$state->{timer} = $again == $old->{again}
335	? $old->{timer}	814	? $old->{timer}
336	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {	815	: urxvt::timer->new->after ($again)->interval ($again)->cb (sub {
337	++$self->{counter};	816	++$self->{counter};
338	$self->recalculate	817	$self->recalculate
…		…
367	unless ($repeat) {	846	unless ($repeat) {
368	delete $self->{state};	847	delete $self->{state};
369	delete $self->{expr};	848	delete $self->{expr};
370	}	849	}
371		850
372	# prepare and set background pixmap	851	# set background pixmap
373		852
374	$img = $img->sub_rect (0, 0, $w, $h)
375	if $img->w != $w \|\| $img->h != $h;
376
377	$self->set_background ($img, $border);	853	$self->set_background ($img, $self->{border});
378	$self->scr_recolour (0);	854	$self->scr_recolour (0);
379	$self->want_refresh;	855	$self->want_refresh;
380	}	856	}
381		857
382	sub on_start {	858	sub on_start {
383	my ($self) = @_;	859	my ($self) = @_;
384		860
		861	my $expr = $self->x_resource ("%.expr")
		862	or return;
		863
385	$self->set_expr (parse_expr $EXPR);	864	$self->set_expr (parse_expr $expr);
		865	$self->{border} = $self->x_resource_boolean ("%.border");
		866
		867	$MIN_INTERVAL = $self->x_resource ("%.interval");
386		868
387	()	869	()
388	}	870	}
389		871

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Comparing rxvt-unicode/src/perl/background (file contents): Revision 1.30 by root, Thu Jun 7 13:22:06 2012 UTC vs. Revision 1.47 by root, Sun Jun 10 13:58:05 2012 UTC

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Comparing rxvt-unicode/src/perl/background (file contents):
Revision 1.30 by root, Thu Jun 7 13:22:06 2012 UTC vs.
Revision 1.47 by root, Sun Jun 10 13:58:05 2012 UTC